COSEWIC Assessment and Status Report on the Beluga Whale Delphinapterus leucas St. Lawrence Estuary population in Canada - 2014
Committee on the Status
of Endangered Wildlife
Comité sur la situation
des espèces en péril
COSEWIC status reports are working documents used in assigning the status of wildlife species suspected of being at risk. This report may be cited as follows:
COSEWIC. 2014. COSEWIC assessment and status report on the Beluga Whale Delphinapterus leucas, St. Lawrence Estuary population, in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xii + 64 pp.
COSEWIC. 2004. COSEWIC assessment and update status report on the beluga whale Delphinapterus leucas in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. ix + 70 pp.
Pippard, L. 1983. COSEWIC status report on the beluga whale Delphinapterus leucas (St. Lawrence River population) in Canada. Committee on the Status of Endangered Widlife in Canada. Ottawa. 46 pp.
Finley, K.J., J.P. Hickie and R.A. Davis. 1985. COSEWIC status report on the beluga whale Delphinapterus leucas (Beaufort Sea/Arctic Ocean population) in Canada. Committee on the Status of Endangered Widlife in Canada. Ottawa. 24 pp.
Reeves, R.R. and E. Mitchell. 1988. COSEWIC status report on the beluga whale Delphinapterus leucas (Eastern Hudson Bay population) in Canada. Committee on the Status of Endangered Widlife in Canada. Ottawa. 60 pp.
Reeves, R.R. and E. Mitchell. 1988. COSEWIC status report on the beluga whale Delphinapterus leucas (Ungava Bay population) in Canada. Committee on the Status of Endangered Widlife in Canada. Ottawa. 60 pp.
Richard, P.R. 1990. COSEWIC status report on the beluga whale Delphinapterus leucas (Southeast Baffin Island/Cumberland Sound population) in Canada. Committee on the Status of Endangered Widlife in Canada. Ottawa. 29 pp.
Doidge, D.W. and K.J. Finley. 1992. COSEWIC status report on the beluga whale Delphinapterus leucas (Eastern High Arctic/Baffin Bay population) in Canada. Committee on the Status of Endangered Widlife in Canada. Ottawa. 45 pp.
Richard, P. 1993. COSEWIC status report on the beluga whale Delphinapterus leucas (Western Hudson Bay population) in Canada. Committee on the Status of Endangered Widlife in Canada. Ottawa. 27 pp.
Lesage, V. and M.C.S. Kingsley. 1997. Update COSEWIC status report on the beluga whale Delphinapterus leucas (St. Lawrence River population) in Canada. Committee on the Status of Endangered Widlife in Canada. Ottawa. 31 pp.
COSEWIC acknowledges Véronique Lesage and Katherine Gavrilchuk for writing the status report on the Beluga Whale, Delphinapterus leucas, St. Lawrence Estuary population, in Canada, prepared with the financial support of the Department of Fisheries and Oceans. COSEWIC also acknowledges Randall R. Reeves for editing this status report. This report was overseen and edited by David Lee, Co-chair of the COSEWIC Marine Mammals Specialist Subcommittee.
For additional copies contact:
c/o Canadian Wildlife Service
Également disponible en français sous le titre Ếvaluation et Rapport de situation du COSEPAC sur le Béluga (Delphinapterus leucas), population de l’estuaire du Saint-Laurent, au Canada.
Beluga Whale - Photo by V. Lesage (Fisheries and Oceans Canada).
COSEWIC Assessment Summary
Assessment Summary – November 2014
- Common name
- Beluga Whale - St. Lawrence Estuary population
- Scientific name
- Delphinapterus leucas
- Reason for designation
- This population, endemic to Canada, is at the southernmost limit of the species’ distribution, and is reproductively and geographically isolated from other populations. This population of a long-lived, slowly reproducing species was severely reduced by hunting, which continued until 1979. Since population monitoring surveys began in the 1980s, the total population size has remained at around 1000 individuals -- less than 20% of the population size in the late 1800s or early 1900s. The major threats currently affecting this population include pathogens, toxic algal blooms, pollution, noise disturbance, and other human intrusions and disturbance. The impacts of these threats are likely amplified by the low number of mature individuals remaining in the population. Since the mid-2000s, the population has shown evidence of major demographic changes including increased neonate mortality and a decline in the proportion of young individuals in the population. These trends, together with past and ongoing habitat degradation, and projected increases in threats, suggest that the status of this population has worsened and is at considerably greater risk than when it was previously assessed by COSEWIC in 2004.
- Quebec, Atlantic Ocean
- Status history
- Designated Endangered in April 1983. Status re-examined and confirmed in April 1997. Status re-examined and designated Threatened in May 2004. Status re-examined and designated Endangered in November 2014.
COSEWIC Executive Summary
Beluga Whale (Delphinapterus leucas) St. Lawrence Estuary population
Wildlife Species Description and Significance
Beluga Whales (Delphinapterus leucas) are medium-sized toothed whales. They are born grey, and gradually become paler with maturity - adults are completely white. A primarily Arctic species, the Beluga is the only representative of its genus. The population in the St. Lawrence Estuary (SLE) is at the southernmost limit of the species’ global distribution.
In Canada, seven populations of Belugas have traditionally been recognized, based on disjunct summer distributions and genetic differences: 1) SLE, 2) Ungava Bay, 3) Eastern Hudson Bay, 4) Western Hudson Bay, 5) Eastern High Arctic–Baffin Bay, 6) Cumberland Sound, and 7) Eastern Beaufort Sea. Several of the Arctic populations mix during spring and autumn migrations and share common wintering areas.
SLE Belugas occur in the Estuary during the summer and shift eastward into the north-western Gulf of St. Lawrence during the fall and winter. Their winter distribution does not overlap that of any of the Arctic populations.
The timing and extent of seasonal movements are likely influenced primarily by sea ice, food availability, and predation risk. Spring is an important feeding period.
Spatial segregation by sex and age occurs, at least during the summer. Females accompanied by calves and juveniles aggregate mostly in the shallower, warmer, less saline, and more turbid waters of the Upper Estuary. Adult males concentrate in the deeper, colder, and more saline waters of the northern portion of the Lower Estuary.
Estuarine aggregation is typical of the species. The whales may depend on estuarine habitat for feeding, calving and nursing, skin moulting, and predator avoidance. The southern channel of the Upper Estuary resembles the shallow, relatively warm areas often associated with Beluga aggregations in other regions.
Habitat quality has declined over the past several decades, primarily as a result of the large volume of vessel traffic, chronic discharge of various chemical substances, fishing activities, changes in environmental conditions, and recurrent toxic algal blooms.
Belugas have mean life spans of 30–60 years (some individuals may live beyond age 70) and attain sexual maturity at 6–7 years. Most conceptions occur between April and June. Females give birth to one calf every 3 years on average. Reproductive output appears to have changed recently, with a decline in the proportion of immature individuals and other major changes in demography of the population since the late 1990s.
Belugas exhibit strong site fidelity to summering sites and estuaries, which render them vulnerable to site-specific anthropogenic threats. They occupy a relatively high trophic level and feed on a variety of fishes and invertebrates.
Population Size and Trends
The SLE Beluga population was reduced by intensive hunting. It probably numbered between 5,000 and 10,000 in the late 1800s but only approximately 1,000 in the 1980s when regular monitoring began. Numbers remained stable or increased slightly once the population was protected from hunting, but since the early 2000s it has declined slowly, with an estimated total population of 889 (95% Confidence interval (CI) 672-1167) in 2012. There was a model-estimated 10-year decline of 12.6% in the total population between 2002 and 2012. Reasons for this decline are not understood. The population model indicated 2293 mature individuals in 1934 (3 generations of 26 years) and 3168 in 1922 (3 generations of 30 years). This suggests that there was a 75% to 82% decline in mature individuals over the last 3 generations (78-90 years) with a model-derived estimate of 583 mature individuals in 2012.
Threats and Limiting Factors
SLE Belugas live downstream of a densely populated, highly industrialized part of North America. Chemical and biological contamination, as well as the loss and perturbation of habitat, are continuing threats. Toxic spills, harmful algal blooms, and epizootic diseases can lead to numerous deaths over short time scales (days or weeks).
SLE Belugas live in a much more temperate environment than those in the Arctic. As the climate changes, higher water temperatures and reduced ice cover may affect these animals indirectly in a number of ways (e.g., less shelter from storms during the winter, altered ecosystem structure leading to greater interspecific competition, novel pathogens, and more exposure to expanding human activities).
Protection, Status, and Ranks
SLE Belugas have been protected from hunting under the Marine Mammal Regulations of the Fisheries Act since 1979. The population was assessed by COSEWIC as Endangered in 1983 due to the decline in numbers caused by overhunting; COSEWIC confirmed this status in 1996. In 2004 COSEWIC assessed this designatable unit (DU) as Threatened and it was listed as such on Schedule 1 of the Canadian Species at Risk Act in May 2005, and under the Québec Loi sur les espèces menacées et vulnérables (Recueil des lois et des règlements du Québec [RLRQ], c E-12.01) (LEMV) (Act respecting threatened or vulnerable species) (Compilation of Québec Laws and Regulations [CQLR], c E-12.01) (Ministère des Ressources naturelles et de la Faune [MRNF] 2011), in March 2000. Most recently, COSEWIC assessed the status of the SLE Beluga Whale as Endangered in 2014. Globally, the Beluga (species level) is red-listed as Near Threatened. The general status of Belugas in Canada is secure according to Wild Species and NatureServe. The SLE Beluga population has a NatureServe status of Critically Imperilled, or at a high risk of extirpation. It currently receives special protection from harassment under regulations governing activities at sea in the Saguenay–St. Lawrence Marine Park, which is under both provincial and federal jurisdictions. Proposed critical habitat was finalized in 2012 and corresponds to the area occupied in summer by females accompanied by calves and juveniles. Legal protection of the critical habitat under Species at Risk Act (SARA) is pending.
- Scientific Name:
- Delphinapterus leucas
- English Name:
- Beluga Whale
- French Name:
- St. Lawrence Estuary population
Population de l’estuaire du Saint-Laurent
- Range of occurrence:
- Québec, Atlantic Ocean (Estuary and northwestern Gulf of St. Lawrence)
Generation time (usually average age of parents in the population; indicate if another method of estimating generation time indicated in the International Union for Conservation of Nature [IUCN] guidelines (2008) is being used).
Assumes 1 dentinal growth layer group per year (Stewart et al. 2006).
- 26-30 years
Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?
There is an inferred and projected continuing decline in number of mature individuals.
Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations] (52-60 years)
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations] (78-90 years)
A population model incorporating, among other things, data on catches of Belugas between 1913 and 1960, indicated that there were 2,293 mature individuals in 1934 (3 generations of 26 years = 78 years) and 3,168 in 1922 (3 generations of 30 years = 90 years); assuming 580 mature individuals in 2012 as estimated from the model, the number declined by 75% to 82% over the last 3 generations (78-90 years).
- 75% to 82%
[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations] (78-90 years).
A future decline is expected due to the recent high mortality rate of neonates. The threats calculator analysis produced an overall threat impact of “medium” to “very high”. “Very high” indicates that the population may experience a 50% to 100% (Median 75%) population reduction over the next 10 years.
[Observed, estimated, inferred or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.
A population model including, among other things, data on catches of Belugas between 1913 and 1960, indicated that there were 1440 mature individuals in 1937 (3 generations of 26 years) and 2163 mature individuals in 1925 (3 generations of 30 years). Assuming 583 mature individuals in 2012 and with a future decline expected, this means that a 60% to 82% decline in mature individuals can be inferred over a 3-generation time period (78-90 years) including both the past and the future.
- 60% to 82%
Are the causes of the decline clearly reversible and understood and ceased?
Some but not all major causes are understood; some apparently have not ceased and may not be reversible; multiple threats remain; new and emergent threats have been identified.
Are there extreme fluctuations in number of mature individuals?
Extent and Occupancy Information
Estimated extent of occurrence
Taken from COSEWIC (2004)
- ~36,000 km²
Index of area of occupancy (IAO, 2 x 2 km² grid values)
IAO: 20,628 km²
Summer IAO: 5,664 km²
- Summer critical habitat: 3,216 km²
Is the population severely fragmented?
Number of locations
Is there an observed continuing decline in extent of occurrence?
Is there an observed continuing decline in index of area of occupancy? (Current Area of Occupancy is 65% of historical; see Figure 4)
Is there an [observed, inferred, or projected] continuing decline in number of populations?
Is there an [observed, inferred, or projected] continuing decline in number of locations?
Is there an [observed, inferred, or projected] continuing decline in quality of habitat?
Habitat degradation through shoreline projects (e.g., construction of harbour infrastructure, hydroelectric development)
Contaminants from local and distant sources
Anthropogenic noise (e.g., marine traffic, underwater construction)
Are there extreme fluctuations in number of populations?
Are there extreme fluctuations in number of locations?
Are there extreme fluctuations in extent of occurrence?
Are there extreme fluctuations in index of area of occupancy?
Number of Mature Individuals
Total SLE Population:
583 is the number of mature individuals in 2012 representing 66% of the total population according to the Bayesian population model.
- 583 (95% C.I.: 444, 770)
Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years].
- Analysis not conducted
Threats (actual or imminent, to populations or habitats)
- Habitat loss and degradation affects the Beluga population both directly and indirectly. St. Lawrence Estuary Belugas are also threatened by chemical and biological contamination, anthropogenic noise and disturbance, climate variability and its effects on food availability, inbreeding, resource competition with commercial fisheries, fishing gear entanglement, strikes by small vessels, harmful algal blooms (sporadically), infections and parasitic diseases, and chronic contamination by toxic substances introduced by heavy marine traffic.
- Degradation and loss of critical habitat through coastal development and increased vessel traffic. Epizootic diseases represent a suspected threat or limiting factor.
Rescue Effect (immigration from outside Canada)
Status of outside population(s)?
- Status of Beluga DUs in eastern Canada varies from Endangered to Special Concern. The species is red-listed by IUCN as Near Threatened.
Is immigration known or possible?
Genetic analyses indicate that there is no mixing of this DU with other Canadian Beluga DUs.
Would immigrants be adapted to survive in the SLE?
Is there sufficient habitat for immigrants in the SLE?
Current decline may be associated with a decrease in quantity or quality of available habitat.
Is rescue from outside populations likely?
- Is this a data-sensitive species?
- COSEWIC: Designated Endangered in April 1983. Status re-examined and confirmed in April 1997. Status re-examined and designated Threatened in May 2004. Status re-examined and designated Endangered in November 2014.
Status and Reasons for Designation:
- Alpha-numeric code:
- A2abce+4abce; C2a(ii)
- Reasons for designation:
- This population, endemic to Canada, is at the southernmost limit of the species’ distribution, and is reproductively and geographically isolated from other populations. This population of a long-lived, slowly reproducing species was severely reduced by hunting, which continued until 1979. Since population monitoring surveys began in the 1980s, the total population size has remained at around 1000 individuals--less than 20% of the population size in the late 1800s or early 1900s. The major threats currently affecting this population include pathogens, toxic algal blooms, pollution, noise disturbance, and other human intrusions and disturbance. The impacts of these threats are likely amplified by the low number of mature individuals remaining in the population. Since the mid-2000s, the population has shown evidence of major demographic changes including increased neonate mortality and a decline in the proportion of young individuals in the population. These trends, together with past and ongoing habitat degradation, and projected increases in threats, suggest that the status of this population has worsened and is at considerably greater risk than when it was previously assessed by COSEWIC in 2004.
Applicability of Criteria
- Criterion A (Decline in Total Number of Mature Individuals):
- Meets Endangered A2abce, with an estimated decline in mature individuals of 75% or 82% over the past 3 generations (78 and 90 years, respectively) based on direct observation of the disappearance of Belugas from a formerly important part of their habitat (Manicouagan Bank (a), an index of historical vs. current abundance (Bayesian model-derived) (subcriterion b), a documented reduction in IAO and quality of habitat (subcriterion c), and effects of pathogens and pollutants (subcriterion e). Causes of the reduction may not have ceased, are not understood, and may not be reversible. Also meets A4abce.
- Criterion B (Small Distribution Range and Decline or Fluctuation):
- Not applicable. Extent of occurrence and area of occupancy exceed thresholds.
- Criterion C (Small and Declining Number of Mature Individuals):
- Meets Endangered C2a(ii) with< 2500 mature individuals, continuing decline in number of mature individuals is inferred based on increased numbers of beach-cast calves, documented decline in young individuals as a proportion of the population and consequent expected decline in recruitment, and all mature individuals are in a single population. Threats assessment provides an overall threat impact in a range from medium to very high. This suggests a potential decline up to 75% of the population in the next 10 years.
- Criterion D (Very Small or Restricted Population):
- Meets Threatened D1, with an estimated 583 (95% CI: 444, 770) mature individuals.
- Criterion E(Quantitative Analysis):
- No applicable analyses conducted.
The St. Lawrence Estuary (SLE) Beluga Whale was assessed by COSEWIC as Threatened in 2004. At that time, abundance estimates (corrected for bias) indicated a larger population than previously thought (Kingsley 2002). An updated Recovery Strategy was published in 2012, identifying this population’s critical habitat, specifying the most serious threats to the population, and presenting a schedule of mitigation actions to achieve objectives related to population size and distribution (DFO 2012).
Despite the implementation of several programs to protect habitat and reduce anthropogenic impacts in its core distribution area, the SLE Beluga population has not increased since the last assessment (DFO 2014a). In fact, recent analyses indicate that the population has declined over the past 10 years, and has experienced changes in vital rates and age structure. The population appears to have moved from a relatively stable to an unstable period characterized by an apparent shift from a 3-year calving cycle to a 2-year cycle, increased variability in neonate mortality and pregnancy rates, and a decline in the proportion of immature individuals and newborns in the population.
The documented changes in population dynamics and demographic characteristics occurred during a period of changing environmental conditions in the Gulf of St. Lawrence, concomitant with high levels of some contaminants in Beluga tissues, chronic and increasing exposure to noise and recreational activities, and sporadic toxic algal blooms in the SLE.
There has been an important change in scientific understanding of Belugas since the last COSEWIC assessment. The previous scientific consensus was that Belugas are exceptional among the toothed cetaceans in that they form two rather than one dentinal growth layers in their teeth annually. These layers (referred to as Growth Layer Groups, or (GLGs); Perrin and Myrick 1980) are used for age estimation and their interpretation has a major influence on estimates of life history parameters including generation time. After a period of controversy (e.g., see Sergeant 1959; Brodie 1969; Goren et al. 1987; Brodie et al. 1990, 2013; Heide-Jørgensen et al. 1994; Stewart et al. 2006; Lockyer et al. 2007), it has now been generally accepted that only one GLG is formed annually (North Atlantic Marine Mammal Commission [NAMMCO] 2012). This has the effect of doubling the generation time from 13-15 years (average of 14 years; COSEWIC 2004) to 26-30 years in this report.
The Marine Mammals Subcommittee has commissioned a separate report on Beluga designatable units (DUs) but that report is not expected to be available in completed form until at least the fall of 2015 (possibly later), after which the species (all DUs) throughout Canada will be reassessed. However, an unsolicited status report on the SLE DU was received in May, 2014, leading the Subcommittee to proceed with reassessment of this DU in 2014.
The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.
The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.
COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non-government science members and the co-chairs of the species specialist subcommittees and the Aboriginal Traditional Knowledge subcommittee. The Committee meets to consider status reports on candidate species.
- Wildlife Species
- A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.
- Extinct (X)
- A wildlife species that no longer exists.
- Extirpated (XT)
- A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.
- Endangered (E)
- A wildlife species facing imminent extirpation or extinction.
- Threatened (T)
- A wildlife species likely to become endangered if limiting factors are not reversed.
- Special Concern (SC)
(Note: Formerly described as “Vulnerable” from 1990 to 1999, or “Rare” prior to 1990.)
- A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.
- Not at Risk (NAR)
(Note: Formerly described as “Not In Any Category”, or “No Designation Required.”)
- A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.
- Data Deficient (DD)
(Note: Formerly described as “Indeterminate” from 1994 to 1999 or “ISIBD” [insufficient scientific information on which to base a designation] prior to 1994. Definition of the [DD] category revised in 2006.)
- A category that applies when the available information is insufficient (a) to resolve a species’ eligibility for assessment or (b) to permit an assessment of the species’ risk of extinction.
The Canadian Wildlife Service, Environment Canada, provides full administrative and financial support to the COSEWIC Secretariat.
Wildlife Species Description and Significance
Name and Classification
The Beluga Whale, Delphinapterus leucas (Pallas, 1776) (Figure 1), derives its English common name from belukha in Russian meaning white. Delphinus is Latin for dolphin and pteron (Ancient Greek) means fin or wing, thus apteron refers to the lack of a dorsal fin. The other often-used English vernacular name is white whale. Béluga is the common name in French although marsouin blanc or baleine blanche have also been used. The Beluga is the only species in its genus; it and the Narwhal, Monodon monoceros, comprise the family Monodontidae (Rice 1998).
Belugas are toothed whales with a rounded head, broad flippers, and no dorsal fin. They are the only cetacean with unfused cervical vertebrae, allowing unusual flexibility of the neck and head (Stewart and Stewart 1989).
Newborn Belugas are dark grey or brown and become lighter with age. Transition to uniformly white occurs at 10-20 years of age, assuming one growth layer group (GLG) per year is deposited in tooth dentine (Stewart et al. 2006). This transition does not always coincide with sexual maturity.
Belugas are about 1.5 m long at birth (48% the length of their mothers), and adult lengths range from 2.6 to 4.5 m depending on the population, with adult females being approximately 80% the length of adult males (reviewed in Lesage et al. 2014b). SLE Belugas are of medium size compared to other populations in Canada (Sergeant and Brodie 1969), with average adult lengths of 3.6 m for females and 4.2 m for males, which are reached approximately 5 years later in males than females (Lesage et al. 2014b).
Population Spatial Structure and Variability
When last assessed by COSEWIC in 2004, seven populations were recognized as DUs (Figure 2): (1) St. Lawrence Estuary (SLE), (2) Ungava Bay, (3) Eastern Hudson Bay, (4) Western Hudson Bay, (5) Eastern High Arctic–Baffin Bay, (6) Cumberland Sound, and (7) Eastern Beaufort Sea. Recent studies indicate that there may be more population structure than currently recognized, although these studies would not alter previous conclusions regarding SLE Belugas (Richard 2010; Postma et al. 2012).
Beluga population spatial structure in Canada has been defined primarily according to the location of summer aggregations, but also according to behavioural, morphometric and genetic characteristics (COSEWIC 2004). Spatial structure has also been examined by reference to the timing and routes of migration of satellite-tracked whales (Martin et al. 1993; Smith et al. 2007; Bailleul et al. 2012), traditional knowledge obtained from Inuit communities (Hammill and Lesage 2009; Lewis et al. 2009), contaminant levels (Innes et al. 2002b), and a combination of isotopic signatures and trace elements (Rioux et al. 2012).
Mitochondrial DNA (mtDNA) analyses revealed two assemblages of Belugas in North America that are geographically disjunct, one in the SLE and eastern Hudson Bay and the other consisting of the rest of the summering populations (Brennin et al. 1997; Brown Gladden et al. 1997; Postma et al. 2012). Taking account of populations in Svalbard and Russia (O’Corry-Crowe et al. 2010), Belugas appear to have undertaken a postglacial recolonization from two different refugia, followed by isolation and limited dispersal over evolutionary timescales.
Behavioural and molecular genetic studies indicate a high degree of philopatry to summer aggregation areas (Caron and Smith 1990; Smith et al. 1994; Colbeck et al. 2013). Fall, winter, and spring distributions are contiguous or overlapping for some of the populations in the Arctic (Brown Gladden et al. 1999a; de March et al. 2002; de March and Postma 2003; COSEWIC 2004) but there is no evidence to suggest that the distribution of SLE Belugas significantly overlaps that of any other population at any season.
The previous status report on Belugas in Canada divided the species into seven designatable units (DUs) (COSEWIC 2004). There is compelling evidence for considering the SLE population to be discrete and evolutionarily significant. Also, this population exists in an ecological setting that is unusual, if not unique, for the species, and local adaptations are likely, although not defined with certainty. It therefore qualifies as a DU.
Fossil remains suggest that Belugas became established in the St. Lawrence area during the Wisconsin glaciation, about 10,000 years ago (Harington 1977, 2008). Molecular genetic studies indicate that the population most closely related to SLE Belugas is in eastern Hudson Bay, and the two populations have been isolated from the others over evolutionary timescales (Brennin et al. 1997; Brown Gladden et al. 1997; O’Corry-Crowe et al. 2010; de March and Postma 2003; Postma et al. 2012). SLE Belugas are differentiated from all other Canadian Beluga populations by both mtDNA haplotypes and microsatellites (Brown Gladden et al. 1997, 1999a; de March and Postma 2003). The St. Lawrence Beluga is the most genetically divergent population of Belugas in Canada based on both nuclear and mitochondrial markers, with average pairwise nuclear and mitochondrial differentiation (FST) of 0.083 and 0.41, respectively (de March and Postma 2003). Two of the three mtDNA haplotypes found in SLE Belugas are unique to their population (Brown Gladden et al. 1997). A very low level of genetic exchange is thought to be sufficient to increase genetic variability in the absence of strong selection (Crow and Kimura 1970). The low nuclear genetic diversity observed in SLE Belugas is similar to that observed in other isolated, insular populations of mammals (de March and Postma 2003; Patenaude et al. 1994), and suggests that contributions from neighbouring populations are insignificant.
SLE Belugas undertake seasonal movements, as do most other Beluga populations, but the extent of such movements appears to be limited to the northwestern Gulf of St. Lawrence (Mosnier et al. 2010). The winter distribution of eastern Hudson Bay Belugas extends into the Labrador Sea, but only to several hundreds of kilometres north of the Gulf of St. Lawrence (Bailleul et al. 2012). Small numbers of Belugas have been observed along the north shore of the St. Lawrence and south coast of Labrador and off Newfoundland (Vladykov 1944; Reeves and Katona 1980; Reeves and Mitchell 1984; Pippard 1985b; Sergeant 1986; Michaud and Chadenet 1990; Curren and Lien 1998; Kingsley and Reeves 1998; Benjamins and Ledwell 2009). However, significant ongoing immigration is considered unlikely given that the nearest populations in Ungava Bay, Hudson Bay, and West Greenland are depleted (Smith and Hammill 1986; Reeves and Mitchell 1989; Richard 1991, 1993; Hammill et al. 2009). The low genetic diversity observed in the SLE Belugas further suggests that immigration from neighbouring populations is unlikely.
A recent study analyzing genetic variation at 13 microsatellite loci indicates that Belugas maintain associations with close relatives during migration, a behaviour which could facilitate learning of migration routes (Colbeck et al. 2013). This cultural conservatism may impede recolonization of extirpated summering areas and limit dispersal between stocks that use different migration routes (Colbeck et al. 2013). Evidence for this scenario comes from, among other places, the Mucalic River (Ungava Bay), Great Whale River and Nowliapik River (eastern Hudson Bay) and probably Manicouagan Bank, which Belugas appear to have abandoned in the wake of extensive hunting and hydroelectric development in north shore rivers flowing into the SLE (Sergeant and Brodie 1975; Reeves and Mitchell 1987; Sergeant and Hoek 1988; Hammill et al. 2004).
Aboriginal traditional knowledge regarding Belugas in the St. Lawrence estuary is limited. There is some archaeological evidence of Beluga harvest by Iroquois hunters, and an account of hunters travelling with Jacques Cartier, who mentioned that they hunted Belugas in the river (Tremblay 1993). The available Aboriginal traditional knowledge appears to support other sources of information that the SLE Beluga population is distinct from other populations.
The Beluga is the only species of its genus and is one of only two species in the family Monodontidae, the other being the Narwhal. Belugas are found only in Arctic and sub-Arctic latitudes of the northern hemisphere (Stewart and Stewart 1989). The SLE Beluga population lives at the southernmost limit of the species’ northern circumpolar distribution. This population and the population in Cook Inlet, Alaska, are more exposed than others to chronic anthropogenic stressors such as chemical and biological contaminants, noise, algal toxins, and infectious and parasitic diseases (Martineau 2012). As such, their study may advance understanding of the effects of marine development in more pristine Arctic areas (Fox 2001).
The SLE Beluga population has social and economic importance primarily in the form of whale-watching tourism, as it is the only population of this species in North America that is easily accessible to the public. In Québec, SLE Belugas are, along with the Peregrine Falcon (Falco peregrinus), the icon for the conservation of species at risk, protection of the St. Lawrence and biodiversity. Concerns over the future of SLE Belugas were a determining factor leading to the establishment, in 1998, of the Saguenay-St. Lawrence Marine Park, jointly managed by the federal and provincial governments.
Belugas have a discontinuous circumpolar distribution, inhabiting Arctic and sub-Arctic waters of North America and Eurasia (Figure 3) (Stewart and Stewart 1989; Reeves 1990). Their range extends south to 60°N in the Pacific and 47°N in the Atlantic, including the SLE (Sergeant 1962; Ivashin and Mineev 1981; Laidre et al. 2000).
The International Whaling Commission’s (IWC) Scientific Committee has divided the global Beluga population into 29 putative stocks, or provisional management units (IWC 2000), totalling well over 150,000 animals (Jefferson et al. 2012). Some of these management units are of unknown size. Several of them have distinct geographical ranges during the summer months but mix during spring and autumn migrations and share common wintering areas.
Belugas are distributed in the western Arctic (Beaufort Sea), high Arctic (Lancaster Sound, Baffin Bay), eastern Arctic (Cumberland Sound and elsewhere off southeastern Baffin Island), Hudson Bay, James Bay, Ungava Bay, and the SLE (COSEWIC 2004). The SLE and Cumberland Sound populations appear to have a smaller seasonal range than other Canadian populations, with distribution shifting only tens to a few hundred kilometres from their summer range (Richard 2010).
Beluga summer distribution in the SLE is centred at the outflow of the Saguenay River, between Battures aux Loups Marins and Rivière Portneuf on the north shore of the SLE, Rimouski on the south shore of the SLE, and to Baie-Sainte-Marguerite in the Saguenay River (Figure 4). The distribution range of Beluga varies seasonally but seldom extends west of Battures aux Loups Marins, or east of Sept-Îles (north shore of the SLE) or Cloridorme (on the Gaspé Peninsula). Occasional observations occur in Baie-des-Chaleurs, and up to Saint-Fulgence in the Saguenay River (Mosnier et al. 2010).
Extent of Occurrence and Area of Occupancy
The extent of occurrence is ~36,000 km² (COSEWIC 2004).
The index area of occupancy (IAO; using 2 x 2 km grid values) is estimated at 20,628 km² (Figure 4 upper panel). The summer IAO is estimated at 5,664 km². When considering the most limiting or vulnerable life history stage, i.e., calving females, the IAO would be reduced to 3,216 km², which corresponds to the critical habitat of the population (Figure 5), or the area occupied by females accompanied by calves and juveniles during summer (June-October) (DFO 2012).
The current area of occupancy of SLE Belugas (i.e., 20,628 km²) is a fraction (ca. 65%) of their historical area of occupancy using 1938 as the reference year. Whether this range contraction has resulted from reduced population size, habitat loss or both is unknown. A similar range contraction, thought to be associated with population decline, has been observed in the small, isolated Beluga population of Cook Inlet, Alaska over the past 30 years (Rugh et al. 2010). Habitat alteration resulting from the damming of the Manicouagan and Outardes Rivers in the 1960s, in combination with over-hunting in this area, may be responsible for the disappearance of Belugas from that part of their historical range (Vladykov 1944; Pippard and Malcolm 1978; Sergeant and Brodie 1975; Laurin 1982; Reeves and Mitchell 1984; Pippard 1985a; Michaud et al. 1990).
Recent observations suggest a possible range expansion of Belugas to the east of what has come to be viewed as their regular summer distribution, notably between Rimouski and Pointe-des-Monts (Michaud 1993; Kingsley 1996; Kingsley and Reeves 1998; Lawson and Gosselin 2009). Vladykov (1944) had recognized this as an area of Beluga summer occurrence during the 1930s. There has been negligible survey effort in summer between Rimouski and Pointe-des-Monts to investigate whether the whales are expanding their range into this formerly significant area (Mosnier et al. 2010).
Since 1973, there has been considerable effort to estimate abundance and characterize the distribution of SLE Belugas. Thirty-six systematic aerial surveys conducted in summer between 1988 and 2009 are in the process of being summarized by DFO researchers (A. Mosnier and J.-F. Gosselin).
The vast majority of the studies of SLE Beluga distribution and abundance have been conducted in the summer (Pippard and Malcolm 1978; Pippard 1985a; Sergeant 1986; Béland et al. 1987; Sergeant and Hoek 1988; Kingsley and Hammill 1991; Kingsley 1993, 1996, 1998, 1999; Michaud 1993; Gosselin et al. 2007, 2014). Several survey techniques and platforms have been employed, including systematic and non-systematic designs using marine vessels, helicopters, and airplanes. Since 1988, systematic strip transect aerial photographic surveys have been used as the standard method to investigate abundance (Kingsley 2002). Starting in 2003, multiple replicate visual aerial surveys following a line-transect design were also flown annually in an attempt to reduce survey costs and uncertainty around abundance estimates. These surveys covered the entire known summer distribution, and were conducted at the same period each year (late August to early September), providing continuous and comparable data on Beluga summer distribution and estimates of population size (see Population Sizes and Trends section).
Information on Beluga distribution outside the summer period is based on a limited number of studies and surveys, several of which followed a non-systematic design. Fall distribution was assessed with two visual aerial surveys conducted in mid-October and November 1989 covering the entire SLE (Boivin and INESL 1990). Winter distribution is based on 12 visual aerial surveys or patrols with variable coverage, conducted from December to March (Sears and Williamson 1982; Boivin and INESL 1990). Four of these
surveys followed a systematic transect design and covered the entire SLE (Boivin and INESL 1990; Michaud et al. 1990). The only data on Beluga spring distribution comes from anecdotal reports and two visual aerial surveys conducted over the SLE in late April and early June 1990 (Michaud and Chadenet 1990).
The earlier surveys in the St. Lawrence were part of a process to refine search techniques for better population estimates. Consequently, there is ambiguity in how some of the estimates from the early years (pre-1988) were obtained as well as differences in methodology, which limits their value in the analysis of population trends (Michaud and Béland 2001).
Most of the effort to estimate Beluga abundance and characterize their distribution in the SLE has been restricted to the summer season, and to areas of known and regular occurrence. While survey lines were added over the years at the eastern and western extremities of the summer range, few studies have extended much beyond these limits. The two most systematic efforts, which covered the entire SLE and a large part of the Gulf of St. Lawrence, confirmed that the population is generally restricted to the zone frequently surveyed in the summer. However, 17 sightings totalling 27 Belugas downstream of the assumed summer distribution in July 2007 (i.e., one month earlier than the regular surveys (Lawson and Gosselin 2009)), raised questions as to the current limits of the distribution. Since then, summer surveys have included an additional set of transects to the east, but no Belugas were seen in this zone during the 2009 survey (Gosselin et al. 2014).
The type of habitat used by Belugas varies seasonally, and can range from ice-free and estuarine to coastal and offshore ice-covered marine environments (Moore et al. 2000; Barber et al. 2001; Suydam et al. 2001; Lydersen et al. 2002). During summer, they tend to concentrate in shallow estuaries (Vladykov 1944; Sergeant 1973; Smith and Martin 1994; Moore et al. 2000) or in other relatively warm environments where surface water temperatures can reach 15–17°C (St. Aubin et al. 1990; Smith and Martin 1994; Boily 1995), but they can also occur offshore and in waters several hundreds of metres deep (Martin and Smith 1992; Heide-Jørgensen et al. 1998; Kingsley et al. 2001; Boltunov and Belikov 2002; Innes et al. 2002a; Lewis et al. 2009). Life processes associated with estuary occupancy may include calving and nursing, breeding, feeding, skin moulting, and predator avoidance (Tomilin 1967; Kleinenberg et al. 1969; Fraker et al. 1979; Finley 1982; Doidge 1990; Frost and Lowry 1990; St. Aubin et al. 1990; Watts et al. 1991; Boily 1995; Richard et al. 2001).
Habitat requirements also vary according to age, sex, size and reproductive status and may be modulated by energy requirements and survival strategies (Michaud 2005; Loseto et al. 2006). Spatial segregation of age- and sex-classes is typical for Belugas during the summer (Michaud 1993; Smith et al. 1994; Smith and Martin 1994; Heide-Jørgensen and Lockyer 2001; Michaud 2005; Loseto et al. 2006, 2008). Generally, small-sized individuals, including females nursing calves, tend to remain closer to shore or in shallower waters, while large individuals tend to remain in deeper or more offshore waters (Vladykov 1944; Smith and Martin 1994; Richard et al. 1997). Whether spatial segregation by sex- and age-class is maintained outside the summer season is unclear, although there is some evidence, from Belugas harvested in the same location and on the same day, to indicate that social groups composed of females and their relatives (i.e., related genetically) stay together during the spring and fall migrations (Colbeck et al. 2013).
In the St. Lawrence ecosystem, sub-Arctic conditions (cold, productive waters and seasonal ice cover), and substantial freshwater input from several sources, notably the Saguenay, aux Outardes, and Manicouagan Rivers, have favoured the continued presence of Belugas at these low latitudes (El-Sabh and Silverberg 1990).
The summer distribution of Belugas in these waters varies with age and sex: 1) females accompanied by calves and juveniles aggregate in the Upper Estuary, between the Battures aux Loups Marins and the Saguenay River, in relatively shallow, warm, turbid, and brackish waters; 2) large white adults, presumably males, aggregate in the deeper, colder and more saline waters of the Laurentian Channel in the northern Lower Estuary, where females with calves and juveniles are seldom observed during summer; and 3) mixed herds, composed of white adults, adults with calves and juveniles, or both, gather in an intermediate sector encompassing the Saguenay River, the head of the Laurentian channel and the southern section of the Lower Estuary east almost to St-Fabien (Michaud 1993).
The critical habitat of SLE Belugas for the period of June to October has been defined based on areas of high usage or concentration (Figure 5) (Pippard and Malcolm 1978; Michaud 1993; Lemieux et al. 2012), and corresponds to the concentration areas of females, calves and juveniles (Figure 6). Data are currently too scarce to define critical habitat for other seasons. Habitat features considered essential for Beluga vital functions include food availability, the oceanographic processes leading to the upwelling of cold mineral-rich and productive waters, a suitable acoustic environment, and shallow waters (DFO 2012).
Beluga individual home ranges and site fidelity in the SLE are not well understood, thus the degree of connectivity among areas of high residency as well as the degree of habitat fragmentation, must be resolved. Belugas have been observed crossing large parts of their summer range several times per day, suggesting various sites are visited sequentially by individuals, possibly using specific travel routes (Pippard and Malcolm 1978; Pippard 1985a; Michaud 1992; Chadenet 1997; Lemieux Lefebvre et al. 2012).
The St. Lawrence River and Estuary comprise a major commercial seaway to interior North America, with over 7400 transits by large merchant ships a year, twice as many whale-watching transits over the summer period, variable activity by a few thousand pleasure boats, and tens of thousands of transits each year by ferries providing daily service crossing the SLE and the mouth of the Saguenay River (Ménard et al. 2014; Som 2007). Maritime shipping routes along the North Shore, as well as the vast majority of the whale-watching activity, currently overlap the Belugas’ summer distribution and part of their critical habitat (Figure 7) (Lesage et al. 2014a; Ménard et al. 2014). The at-sea whale-watching industry nearly tripled its activity between 1993 and 2003 (Ménard et al. 2014). An increase in certain types of navigational activities was also documented in specific portions of the SLE Beluga critical habitat between 2003 and 2012 (Ménard et al. 2014). While commercial shipping and ferry activities have been relatively constant over the past decade, an increasing interest in developing Québec’s natural resources or exporting Canadian products may lead, in the short to medium term, to increased maritime traffic in the St. Lawrence Seaway. All of these ongoing and future activities, in combination, can be expected to contribute to acoustic habitat degradation for SLE Belugas (Clark et al. 2009; Jensen et al. 2009; Gervaise et al. 2012).
Chronic discharge of a variety of chemical and biological contaminants over the past several decades has also contributed to the degradation of SLE habitat quality. Despite regulation or a complete ban on discharge, persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) are still present in the Beluga environment, and remain stable or are decreasing only at a slow rate in Belugas (Lebeuf et al. 2007; Lebeuf et al. 2014a). Other toxic chemicals such as polybrominated diphenyl ethers (PBDEs) increased exponentially in Belugas and their environment in the 1990s (De Wit 2002; Lebeuf et al. 2004). In addition, new persistent compounds have been recently discovered in the St. Lawrence food chain (e.g., organochlorinated compounds such as tris (4-chlorophenyls)), and are accumulating in Beluga tissues (Lebeuf et al. 2001; Lebeuf et al. 2007; Lebeuf et al. 2014a). Other contaminants of a biological nature such as viruses, bacteria and parasites are also discharged into the St. Lawrence ecosystem from point sources such as municipal sewage, waste water from maritime vessels (cargo ships, recreational boats) and coastal runoff.
Other trends in habitat quality over the past few decades have been linked to Beluga trophic ecology, prey quality and abundance, and environmental conditions in the St. Lawrence (Lesage 2014; Plourde et al. 2014), and may have some relevance to the observed changes in Beluga population dynamics over the same time period. The assessment of Beluga diet from 1988 to 2012 has revealed a decline over the period of 2003–2012 of approximately 1 part per mil in a tracer of carbon sources (13C/12C ratio), which corresponds to a drop in nearly one trophic level (Lesage 2014). The food sources and/or environmental factors responsible for this decrease are not known at this time. Changes in carbon isotope ratios can result from either a change in diet or a change in the carbon isotope ratios of preferred prey. For example, in Cook Inlet, Alaska, researchers found shifts of more than one trophic level from one year to the next in some salmonids, albeit based on a very limited sample (Hobbs pers. comm. 2014). A time-series analysis of 28 indices representing ecosystem variability and habitat quality in the Gulf of St. Lawrence identified changes in conditions since 1971, some of which occurred in the period when isotopic tracers in Beluga tissues shifted (Figure 8) (Plourde et al. 2014). Some of the changes in the environment also corresponded to when Beluga population dynamics became unstable and when calf productivity and mortality increased, suggesting a decline in habitat quality in recent years (Plourde et al. 2014). Specifically, environmental conditions shifted from a period of above to below long-term averages in the late 1990s, with the most extreme conditions occurring between 2010 and 2012. The period of below long-term average environmental conditions was when Gulf of St. Lawrence stocks of large demersal fish (e.g., Atlantic Cod (Gadus morhua) and Atlantic Herring (Clupea harengus); Northwest Atlantic Fisheries Organization (NAFO) Division 4T) had collapsed, and were at their lowest biomass, and when ice conditions were below average and water temperatures above average (Figure 8).
The SLE Beluga population also may be affected by recurrent toxic algal bloom events, or red tides, caused by the dinoflagellate Alexandrium tamarense. The phycotoxin released by this organism is responsible for outbreaks of paralytic shellfish poisoning and poses serious health risks for marine organisms and humans. In the St. Lawrence, three major red tides have occurred over the past two decades (1996, 1998 and 2008), one of which (2008) was well-documented and coincided with unusually high mortality of a variety of marine organisms, including Belugas, over a short period of time (Truchon et al. 2013; Scarratt et al. 2014). In the context of climate and oceanographic changes, toxic algal blooms may become more frequent (Anderson et al. 2012; Scarratt et al. 2014).
Additional factors to consider (e.g., novel or introduced species, species with expanding ranges) are discussed under Threats and Limiting Factors (below).
The following section presents life history parameters assuming 1 ‘growth layer group’ (GLG) in Beluga teeth corresponds to one year of growth (NAMMCO 2012).
Life Cycle, Demographic Parameters and Reproduction
Age of Belugas is determined by reading layers in the dentine (sometimes in the cementum) of the teeth. Double lines, common in Belugas, cause overestimation; wear, loss, or interrupted growth of teeth prevents estimation or produces underestimates (Sergeant 1973). SLE Belugas with 17 GLGs can, and with 20 or more commonly do, have worn teeth; the oldest individual with unworn teeth had 32 GLGs (Lesage et al. 2014b).
A longevity for the species has been (probably under-) estimated at 114 GLGs (Harwood et al. 2002); for the SLE at 72 GLGs (Lesage et al. 2014b). Life expectancy at birth in different populations ranges from 30 to 60 GLGs; in the SLE it is estimated at 34 GLGs (Lesage et al. 2014b).
Sexual maturity (evidence of ovarian activity in females, and mature testes in males) occurs at an earlier age in females than males, i.e., 6–14 GLGs in females vs. 16–22 GLGs in males (Brodie 1971; Sergeant 1973; Ognetev 1981; Finley et al. 1982; Burns and Seaman 1985; Heide-Jørgensen and Teilmann 1994; Robeck et al. 2005; Suydam 2010). In SLE Belugas, the youngest female found dead and carrying a fetus had 7 GLGs (Lair et al. 2014), but it is unknown what proportion of females at this age conceive, carry to term or wean a calf. Generation time (see Stewart et al. 2006 for calculation), which was estimated at 13–15 years under the 2 GLGs deposition rate assumption (Braham 1984; Burns and Seaman 1985; Lesage and Kingsley 1995), roughly doubles when using 1 GLG per year (Stewart et al. 2006) at 26–30 years.
The timing of mating and calving varies between Beluga populations, although in general mating takes place in the spring (Doan and Douglas 1953; Boltunov and Belikov 2002)--between April and June in SLE Belugas (Vladykov 1944). Females give birth to one calf, very rarely two, in July-August following a 14 to 15-month gestation period (Kleinenberg et al. 1969; Brodie 1971; Sergeant 1973; Doidge 1990; Heide-Jørgensen and Teilmann 1994). Complete senescence has not been confirmed, but there are indications that fecundity may decline in older females (Burns and Seaman 1985; Lair et al. 2014). Lactation may last from 20 months (Brodie 1971; Sergeant 1973; Burns and Seaman 1985; Heide-Jørgensen and Teilmann 1994) to 32 months (Doidge 1990), although ingestion of solid food supplements the diet in the second year of life (Vladykov 1944; Brodie 1971; Sergeant 1973). Lactation may overlap with the following gestation, suggesting a 3-year reproductive cycle (Vladykov 1944; Brodie 1971; Sergeant 1973; Burns and Seaman 1985; Doidge 1990; Heide-Jørgensen and Teilmann 1994). This is supported in SLE Belugas by a long-term study, where peaks in indices of calf production were observed every three to four years (Michaud 2014).
Survivorship in Belugas is generally estimated from age-specific frequencies in harvests (COSEWIC 2004). Due to the absence of a hunt for SLE Belugas, mortality rates, along with other demographic parameters, were estimated from an age-structured hierarchical model fitted using Markov chain Monte Carlo methods within a Bayesian framework. The state process of the model described the true, but unknown, population dynamics of SLE Belugas, including the size of the population and values of demographic parameters at different times, whereas the observational process linked these parameters to data from three input sources: 1) the number and age (newborn vs older Beluga) of individuals reported dead between 1983 and 2012 through a carcass monitoring program, 2) population size estimates from seven photographic surveys flown between 1990 and 2009, and 3) percentage of< 2 years old individuals (i.e., calves and yearlings) observed on aerial photographs from these surveys (Mosnier et al. 2014). The dynamics of the population were modelled by considering 11 age-classes grouped into four stages [newborn, yearling, immature (2 to 7 GLGs), mature (8+ GLGs)], each characterized by specific mortality and fecundity rates. Prior distributions describing the range of plausible values of stage-specific mortality and pregnancy rates were derived from the literature (details in Mosnier et al. 2014). The model made a number of assumptions based on prior knowledge of Beluga biology, including that if a female caring for a newborn or yearling died during a given year, the latter also died during the same year, and that if a newborn died, the mother became available to reproduce in the following year, i.e., one year earlier than normal.
The model incorporated two periods. The 1913-1982 period used fixed mortality and pregnancy rates and incorporated 1913-1960 hunting catches (Laurin 1982 in Reeves and Mitchell 1984). The aim of this part was to minimize sensitivity to the initial age-structure imposed in the starting year of the model (i.e. 1912) by allowing the population to evolve over a period of nearly 70 years. For the period 1983-2012, data from the aerial surveys and the carcass monitoring program were used to inform the model. During this period, mortality and pregnancy rates were random variables that could vary each year, as would be expected in a wild population.
Raw data from the carcass monitoring program indicated year-to-year variation, but no trend in the number of carcasses of mature Belugas reported (male and female) over the period 1983–2012, and unusually high numbers of newborn calf deaths in 2008, 2010 and 2012 with 8, 8 and 16 carcasses respectively, compared to the period 1983-2007 when the number of neonate carcasses varied between 0 and 3 per year (Figure 9) (Lesage et al. 2014b). Using carcasses as a sample is not free of bias, as found carcasses may underrepresent deaths in some age classes, such as young juveniles (Béland et al. 1988; Lesage et al. 2014b; Mosnier et al. 2014). Moreover, it cannot be assumed that the numbers of carcasses reflect only mortality rates (a peak of newborn carcasses, for instance, may be the consequence of a peak in birth rates). For this reason, the state process of the population model calculates the number of dead calves by estimating several parameters: the number of females available for reproduction in a given year, their pregnancy rates, birth rates the following year, and both adult and newborn mortality. The resulting number of dead adults and calves is then fitted to the carcass recovery data, while the estimated abundance and proportion of young are fitted simultaneously to aerial survey data. By incorporating all these data, the model estimated mortality rates of approximately 6.1% for adults (8+ GLGs), with interannual variability of 4.0 to 8.7% (Mosnier et al. 2014). The 6% annual mortality rate for adult SLE Belugas falls within the 3–8% range of adult mortality rates estimated for five Canadian Arctic Beluga populations (Luque and Ferguson 2010). These Arctic populations are subject to hunting, unlike the SLE population, which has been protected from hunting since 1979. Thus, the adult mortality rate estimated by the model for SLE Belugas appears high, and may imply lower life expectancy than is usually assumed for the species. However, there are no data from the live population to assess life expectancy in SLE Belugas. For newborn calves, mortality rates estimated by the model varied between years, from 8 to 69% (Mosnier et al. 2014).
Reproductive output may have changed in SLE Belugas over the past 15 years. Photogrammetric studies using aerial survey data indicate that the proportion of calves and yearlings in the population fell from 15–18% in the 1990s to 3–8% in the 2000s. These estimates were free of bias from reader differences because all the films were re-examined by the same person (Gosselin et al. 2014). The model fitted to the above data, and the other two data sources (carcasses and abundance estimates), revealed a decline of newborns in the population and other major changes in demography since the late 1990s. According to the model, the population appears to have moved from a relatively stable to an unstable period characterized by a shift from a 3-year to a 2-year calving cycle, combined with an increased variability in annual mortality of newborns (8 to 69%), and female pregnancy rates (14.5% to more than 50%), and with a decline in the proportion of immature individuals (Mosnier et al. 2014).
Specifically, the model indicated that in the period 1984–1998 the mortality rate of newborns was relatively stable (median values: 14–27% with peaks every 3 to 4 years), as was the pregnancy rate (~30% with small peaks every 3 years). Population age structure was also stable during this period, with a mature:immature ratio of around 59:41, with 7.5% of the population being newborn calves. In contrast, the period from 1999 to 2012 was characterized by demographic instability and major changes in population parameters and age structure: the year 1999 had abnormally high newborn mortality (~40%) and was followed by high pregnancy rates >50%) in 2000, presumably because more females were available for reproduction after losing their calves in 1999. Since then, there have been spikes in newborn mortality interspersed with spikes in high pregnancy rates, the latter separated by periods of below-average fecundity (~15% in 2001–2002) (Mosnier et al. 2014). A pattern also emerged over the last 6 years of the model, with female reproduction apparently shifting from a 3-year cycle, with a third of mature females pregnant each year, to a 2-year cycle, with around half of the females pregnant. This coincided with an increase in newborn mortality. These changes had strong effects on the population age structure. The estimated proportion of newborns in the population deviated from its 3-year cycle and started to fluctuate strongly in the early 2000s, while also decreasing from 6–8% prior to 1999 to 4–6% following 2007. During this same period, the estimated proportion of immatures in the population decreased, resulting in a proportional increase in mature Belugas even though their absolute numbers remained constant (Figure 10).
The demographic parameters outlined above are based on a model and therefore are sensitive to input data. For instance, the abundance estimates had a large influence on the estimated population trend and the proportion of young seen on the aerial photographic surveys informed the model that the age structure was changing (fewer calves and yearlings being observed), but neither could inform the model on year-to-year variability in demographic parameters. Only the carcass data contained information on yearly variation in the number of dead calves and adults, and therefore these data were the main driver of year-to-year variation in the final model outputs. However, several independent observations increased confidence in model conclusions. A long-term photo-identification program of live SLE Belugas (1989–2012) indicated changes in age structure and calf production that are in agreement with those suggested by the model. In particular, years of high pregnancy rates predicted by the model for the period 2004–2012 were corroborated by observations of high calf production in the field the following year. The photo-identification program also indicated a slight increase in the proportion of grey individuals (juveniles and young adults) from 1989 to the mid-2000s, with a recent transition to a negative trend shown in the model as a reduction in the proportion of immature individuals (Michaud 2014).
Physiology and Adaptability
The Beluga lacks a dorsal fin and has a relatively thick dermis (5-12 mm), which makes the species well adapted to survive in ice-laden waters (Stewart and Stewart 1989). Their hypodermis, a layer of fatty and fibrous connective tissue below the skin, constitutes their main energy reserve and 40% of the body weight (Sergeant and Brodie 1969). The extent of their reliance on blubber fat for withstanding periods of lower food intake is undocumented. However, Belugas appear to feed throughout the year (e.g., Hobbs et al. 2008), take two years to wean their calf and thus probably have more in common with income than true capital breeders (Houston et al. 2007).
Belugas occupy a variety of polar and temperate habitats which differ considerably in water temperature, salinity, and depth. They can dive to depths of over 800 m (Richard et al. 2001) and have been observed in depths as shallow as 4 m in the wild (Martin et al. 2001). They can remain submerged for at least 15 min (Martin and Smith 1992; Martin et al. 1993; Martin and Smith 1999) and perhaps longer, given that the theoretical aerobic dive limit exceeds this threshold for toothed whales larger than 750 kg such as the Beluga (Schreer and Kovacs 1997). Belugas do not regularly occur at latitudes below 47°N, which suggests they are intolerant of prolonged periods in warm waters. Water temperatures can reach over 12°C in some parts of their range in the SLE during the summer (Plourde et al. 2002).
Belugas appear to be highly philopatric to summering sites and estuaries, which may render them vulnerable to a variety of anthropogenic threats. Site fidelity is supported by significant differentiation in mtDNA but not nuclear DNA among Beluga stocks (de March and Postma 2003; Turgeon et al. 2012). Site fidelity has also been proposed based on repeated observations of the same individuals over more than a season (Caron and Smith 1990), but was not supported by recent genetic analysis investigating relatedness among
Belugas hunted in the same estuaries, a finding interpreted as a fidelity to general summering areas rather than to specific estuaries (Colbeck et al. 2013). Site fidelity might hamper recolonization of abandoned sites, or dispersion to new areas more suitable for Beluga survival (Mosnier et al. 2010; Colbeck et al. 2013). This was put forward as an explanation hypothesis for the complete or near disappearance of Belugas in some estuaries following extensive hunting (e.g., the Mucalic River in Ungava Bay, Great Whale and Nowliapic rivers in eastern Hudson Bay, and probably the Manicouagan Bank in the SLE (Reeves and Mitchell 1987; Sergeant and Hoek 1988; Hammill et al. 2004) although in the case of Manicouagan Bank, it is important to recognize that a series of dams constructed in the Manicouagan and Outardes rivers in the early 1960s caused major hydrological changes that in turn could have made the bank less suitable as Beluga habitat (Sergeant and Brodie 1975). Fidelity (high philopatry) to specific sectors of the estuarine system presumably makes SLE Belugas particularly vulnerable to the impacts of disruptive human activities (e.g., port development and marine hydrocarbon exploration and exploitation) that take place where and when they congregate.
Dispersal and Migration
SLE Belugas appear to undertake only limited seasonal movements (Vladykov 1944; Mosnier et al. 2010; Gosselin et al. 2014; Michaud 2014). Dispersal is more likely to occur outside the summer period when their distribution extends to the east and into the northwestern Gulf of St. Lawrence (Mosnier et al. 2010; Gosselin et al. 2014).
During winter, Belugas are found either in the Lower Estuary or the northwestern Gulf of St. Lawrence, which remain partially ice-free throughout winter (Figure 11) (Sears and Williamson 1982; Boivin and INESL 1990; Michaud et al. 1990; Lesage et al. 2007).
Small numbers of solitary Belugas, likely young individuals, are occasionally reported in nearshore waters of Newfoundland and Labrador in Atlantic Canada. Over the past decade, extralimital reports totalling more than ten have been documented throughout Newfoundland and Labrador (Curren and Lien 1998; Benjamins and Ledwell 2009). Population identity of these lone Belugas is uncertain, although analyses of chemical substances or trace elements suggest an Arctic origin for at least some of the individuals that have been sampled in those areas (Béland et al. 1992; Muir et al. 1996; Brown Gladden et al. 1999b). A group of a few hundred Belugas, containing both adults and juveniles, was sighted and photographed along the west coast of Newfoundland in April 2009 (Lawson pers. comm. 2009). Animals from northern stocks would not be expected to reach such low latitudes based on satellite telemetry data (Bailleul et al. 2012). If this sighting involved SLE Belugas, it would indicate that winter movements extend over much larger distances than generally believed.
Predation by Killer Whales (Orcinus orca) is at least an occasional cause of Beluga mortality in the Arctic (Mitchell and Reeves 1981; Reeves and Mitchell 1988; Shelden et al. 2003; Higdon and Ferguson 2009) and avoidance of mammal-eating Killer Whales has been suggested as one reason for the intensive use of very shallow estuarine waters by Belugas during summer, on the assumption that Killer Whales are unable to navigate such areas as efficiently or safely (Sergeant and Brodie 1969). In the SLE, Killer Whale predation might have played a role in habitat selection by Belugas in the past, when these predators were fairly common there, and some attacks were reported during the early 1900s (Vladykov 1944; Michaud 2005). Killer Whales are now rarely observed in the SLE, and no attacks on Belugas have been reported recently. Greenland Sharks (Somniosus microcephalus) are possible Beluga predators (Beck and Mansfield 1969; MacNeil et al. 2012); however, there is no evidence of such predation in the SLE.
As for several other marine mammals, Belugas feed at a relatively high trophic level in the estuarine food web of the St. Lawrence ecosystem, and males at a higher trophic level than females (Lesage et al. 2001; Lesage 2014). Similar to Belugas elsewhere, SLE Belugas feed on a variety of species, with a diet dominated by fish prey (Vladykov 1946; Lesage 2014). While recent diet data are fragmentary for SLE Belugas (Lesage 2014), a study conducted in the 1930s suggested that pelagic species such as Capelin (Mallotus villosus) and herring, sandlance (Ammodytes sp.), and large demersal species such as cod (Gadus morhua and G. ogac) and redfish (Sebastes sp.) may be seasonally important in SLE Beluga diet (Vladykov 1946). Several of these stocks have collapsed since the 1990s, and there are currently concerns that Belugas may be competing with fisheries for some of these resources (DFO 2014a; Plourde et al. 2014).
The SLE Belugas might also be competing for food resources with other marine mammals, although the extent of this potential interaction remains to be documented. Based on stable isotope ratios, adult female Belugas occupy trophic positions similar to those occupied by Harp Seals, whereas adult male Belugas have a trophic position similar to that of Grey Seals (Halichoerus grypus), juvenile Harbour Seals (Phoca vitulina) and female Hooded Seals (Cystophora cristata) (Lesage et al. 2001). Baleen whales occupy slightly lower trophic positions, but with prey items shared with Belugas (Gavrilchuk et al. 2014). Several of these marine mammal populations are currently increasing, and it is expected that increased numbers of certain species such as the Harp Seal and the Grey Seal, which enter the SLE mainly to feed, add to the competition pressure for food resources.
Ice cover determines the winter distribution of marine mammal species in the SLE and is predicted to decrease gradually in coming years with climate variability and associated warming temperatures (Bourque and Simonet 2008). Thus, climate change could lead to a lengthening of the ice-free season and may affect SLE Belugas through changes in food resources and increases in interspecific competition as other species expand their range or extend their stay due to loss of ice cover (Kingsley 2002; Measures 2004).
Population Sizes and Trends
Sampling Effort and Methods
There was an attempt in the late 1990s to standardize the earlier data and examine long-term population trends (Kingsley 1999). However, the method was criticized and it was argued that only the systematic strip transect photographic aerial surveys conducted since 1988 were comparable and could be used to reliably estimate population trends (Michaud and Béland 2001). A second series of replicate aerial surveys following a line-transect design was initiated in 2003, and is also currently used to examine population size and trends (Gosselin et al. 2014) (see Figure 12 for the basic survey design).
SLE Belugas occupy a relatively small area during the summer, making the population relatively easy to survey in that season. Each replicate of summer surveys was completed in a single day. Photographic surveys have generally covered around 50% of the total Beluga distribution, whereas slightly lower coverage has been achieved with visual surveys (Gosselin et al. 2014). Although survey design was similar between years for the photographic surveys, coverage progressively increased over time to account for a possible expansion of Beluga distribution (Gosselin et al. 2014).
Eight photographic aerial surveys were flown between 1988 and 2009, and 28 visual line transect surveys were conducted between 2001 and 2009 (Table 1) (Gosselin et al. 2014). In some years, both visual and photographic surveys were flown to assess some of the variability observed between surveys, as well as to compare visual versus photographic abundance estimates. The Saguenay River was surveyed visually by helicopter while photographic/visual surveys were being conducted in the SLE.
|Year||Method||No. of surveys||Estuary estimate||Saguenay count||Corrected abundance index||95% CI|
Despite standardization of survey methods, there is considerable variability between abundance indices, even within a given year (Gosselin et al. 2007). In surveys conducted from 1992 to 2003, 50% of the Belugas detected were on only 10–14 out of approximately 1,000 photo frames. The clumped nature of Beluga distribution and consequent detection or failure to detect large groups can have a substantial effect on the indices.
A correction factor of 2.09 (SE = 0.16) for availability, which was specifically developed for photographic surveys of SLE Belugas (Kingsley and Gauthier 2002), was applied to the density in the SLE, before adding the Saguenay count to provide the abundance indices (Gosselin et al. 2014). This correction adjusts for Belugas under the surface and not photographed as the plane passes over. The separation width of aerial survey transect lines and the addition of transect lines over time were accounted for in abundance estimates.
The most recent abundance estimates for SLE Belugas were obtained in 2009, using six replicate visual line-transect surveys and one photographic strip transect survey (Table 1). The 2009 estimates were the lowest of the two time series, at 676 individuals (95% CI: 490–906) for the photographic survey, and 979 individuals (95% CI: 750–1277) for the combined visual surveys. The age-structured population model (see section on Life Cycle, Demographic Parameters and Reproduction), which incorporates these abundance estimates in addition to other population parameters, estimated a total population of 889 individuals (95% CI: 672–1167) in 2012, of which 583 were mature (8+ GLGs) (Mosnier et al. 2014)
Survey estimates for SLE Belugas are associated with relatively wide confidence intervals (15–25% Coefficient of variation [CV]) relative to the expected percent change in population size. This uncertainty and that associated with the estimate itself are mainly attributable to the aggregated distribution of Belugas.
Fluctuations and Trends
During the late 1920s/early 1930s, the Québec government subsidized bombing of Belugas in the SLE due to their alleged damage to the cod fishing industry (Reeves and Mitchell 1984). Beginning in 1932, a bounty was offered by Québec for each Beluga killed in the St. Lawrence and a total of 2233 bounties were paid from 1932-1938, with the bounty program ending in 1939 (Vladykov 1944; Reeves and Mitchell 1984). Population size was estimated at 5,000–10,000 individuals in the 1800s and less than 1,000 in the late 1970s when hunting was officially banned (Reeves and Mitchell 1984; Pippard 1985a; Hammill et al. 2007; Mosnier et al. 2014).
The age-structured hierarchical model described above (under Life Cycle, Demographic Parameters and Reproduction), which incorporated historical catch data and recent field survey and carcass report data, suggested that the total population numbered approximately 1017 individuals in 1988, and remained stable or showed a slight increase (growth rate ~0.13% per year) from the end of commercial hunting in the 1960s to the early 2000s (Mosnier et al. 2014). The model then predicted a decrease in abundance (-1.13% per year) to 889 individuals (95% CI: 672–1167) in 2012 (Figure 13), equivalent to a 12.6% decline in total population since 1988, or over the last 10 years of modelling, (i.e., between 2002 and 2012), if one assumes a stationary population since 1988. The rate of population decline was affected by the choice of input data, the steepest decline being achieved when fitting only to survey abundance estimates. However, all versions of the model suggested a relatively stable population after hunting ceased, and a decreasing population size since the early 2000s (Mosnier et al. 2014). The model specifically indicated that there were 2293 mature individuals in 1934 (3 generations of 26 years = 78 years ago) and 3168 in 1922 (3 generations of 30 years = 90 years ago); assuming 580 mature individuals in 2012 as indicated by the model, the number of mature individuals declined by 75% to 82% over the last 3 generations (78-90 years).
Trends in SLE Beluga abundance and dynamics may be affected by biases in the time series, such as: 1) inconsistencies with photograph frame overlap over the years, which may have led to over- or underestimated counts in certain years; 2) difficulty in detecting all animals on the photographs because grey or dark-colored individuals do not stand out (would negatively bias abundance estimation and calf/juvenile proportions); 3) variability associated with the correction factor applied to account for detectability (animals not seen at the surface) (could cause negative or positive bias); 4) not correcting visual abundance estimates for perception bias (observer error) (would negatively bias abundance estimation from visual surveys but not photographic surveys) (Gosselin et al. 2014). It is not possible to make a meaningful assessment of the net effect of these potential biases, but a precautionary interpretation is that SLE Beluga numbers have been declining slowly in recent years and are likely to continue doing so.
Immigrating Belugas from Arctic populations presumably would not be adapted to conditions in the St. Lawrence system, although it is impossible to predict whether they would or would not be capable of adapting over time. Cultural knowledge held by individuals in the existing population may be key to its persistence in the SLE habitat, but such knowledge may not be available to immigrants and therefore would not be available at all if the present population were to become extinct.
The likelihood that dispersal from a different population has contributed significantly to, or would repopulate, the SLE Beluga population is considered low (Pippard 1985a; Sergeant and Hoek 1988; Lesage and Kingsley 1998). Significant contributions from other populations would be more likely if they were in closer proximity and not depleted (which most of them are).
Based on what is known concerning migration distances exhibited by other populations of this species (Richard et al. 2001; Smith et al. 2007; Bailleul et al. 2012), Belugas would be capable of moving into and out of the Gulf of St. Lawrence. In some years, small numbers of Belugas have been observed well outside their normal range, with reports from as far south as New Jersey, U.S.A. (Reeves and Katona 1980; Curren and Lien 1998). The proportion of these animals that belong to the SLE population and whether they eventually return to the SLE is largely unknown (Kingsley 2002).
Immigration and a rescue effect would be possible only if suitable habitat was available. The SLE Beluga population currently occupies only a fraction of its historical range (Mosnier et al. 2010), has grown at a lower than expected rate since the end of the hunting period, and is currently in decline. Whether the decrease in its occupied range and its limited population growth indicate a reduced carrying capacity, and thus a shortage of suitable habitat for immigrants, is unknown.
Threats and Limiting Factors
A threats assessment for this population produced an overall threat impact score ranging from “medium” to “very high”. A “medium” overall threat impact indicates an estimated population reduction of 3-30% (median = 15%). A “very high” score indicates an estimated population reduction of 50-100% (median = 75%). Low- to medium-level threats included human intrusions and disturbance from recreational activities. Low- to high-level threats included ecosystem modifications such as those caused by fisheries, invasive and other problematic species, pollution by industrial effluents, air-borne pollutants, excess energy (e.g. anthropogenic noise), and climate change (e.g., severe weather events, and temperature extremes).
Principal causes of death of 222 SLE Belugas that were subjected to complete necropsies since 1983 were infectious disease (32% of the cases), malignant neoplasia (tumours; 14%) and dystocia or post-partum complications in mature females (15%), with additional deaths from vessel strikes (4%), primary starvation (2%), fishing gear entanglement (1%), and intoxication (one case) (Table 2) (Lair et al. 2014). Two cases of intersex have been documented in SLE Belugas (one case of true hermaphroditism (De Guise et al. 1994) and one pseudohermaphroditic male). These are the only documented cases in cetaceans worldwide (Lair et al. 2014). No cases of neoplasia have been documented in SLE Belugas estimated to have been born after 1971 (Lair et al. 2014). Immunosuppression increases susceptibility to infectious disease, the leading cause of death in SLE Belugas, and immunosuppression may be associated with social or reproductive stress (Schuurs and Verheul 1989), malnutrition, infectious and non-infectious agents, and chemical contaminants within the system such as PCBs (Hall et al. 2006; Lebeuf et al. 2007; Selgrade 2007).
|Primary causes of death||Age groups|
[n (% in age group)]
[n (% in age group)]
(< 8 GLGs)
[n (% in age group)]
(8 to 19 GLGs)
[n (% in age group)]
(> 19 GLGs)
|Infectious diseases||-||18 (72%)||8 (36%)||46 (29%)||72 (32%)|
|Malignant neoplasia||-||-||-||31 (20%)||31 (14%)|
|Dystocia / post-partum complication||-||-||6 (40%)Note a of Table 2||12 (15%)Note a of Table 2||18 (15%)Note a of Table 2|
|Neonatal mortality||18 (95%)||-||-||-||18 (8%)|
|Ship/Boat strike||-||1 (4%)||-||7 (4%)||8 (4%)|
|Primary starvation||-||-||-||5 (3%)||5 (2%)|
|Fishing gear entanglement||1 (5%)||-||-||1||2 (1%)|
|Other non-infectious causes||-||2 (8%)||3 (14%)||7 (5%)||12 (5%)|
|Undetermined||-||4 (16%)||5 (23%)||46 (29%)||55 (25%)|
Notes of Table 2
- Note a of Table 2
Percentage of females.
Sporadic threats which have the potential to cause multiple deaths in a short time include spills of toxic substances, harmful algal blooms, and epizootic diseases (epidemic in an animal population). Many ships travelling through the St. Lawrence transport petroleum products and other toxic substances, and the number of laden tankers moving through the Seaway began to increase in 2014 with oil from Alberta being offloaded in Sorel from the railway system using existing facilities. Such traffic is expected to increase in the near- and medium-term future.
Human intrusions and disturbance
SLE Belugas are chronically exposed to high volumes of marine traffic including both large and small vessels (Chion et al. 2009; Ménard et al. 2014; Som 2007). They are considered to be at only low risk of being struck by large commercial ships given the generally slow speed and predictable trajectory of these vessels, and their own manoeuvrability and acute hearing (Johnson et al. 1989; Erbe 2008; Mooney et al. 2008). However, the whales could be at a relatively high risk of being struck by small or fast-moving vessels or other motorized vehicles, as indicated by a handful of cases documented since 1983 (Lair et al. 2014).
Vessel traffic and recreational activities involving motorized or non-motorized vehicles (e.g., kayaks) may interfere with the birth process if direct approaches to calving females are attempted. Vessel traffic related to tourism and recreation peaks in July-August when SLE Belugas give birth, and the volume of this traffic increased in areas used by females, juveniles and calves between 2003 and 2012 (Ménard et al. 2014). Disturbance during calving, which may take many hours (e.g., Robeck et al. 2005), could be an aggravating factor, especially if the animals are weakened by dystocia, health problems due to contaminants, infections, or other illnesses (Ménard et al. 2014). The years 2010 and 2012 were particularly favourable for navigation in the St. Lawrence and they were also years when high numbers of dead calves were reported (Ménard et al. 2014). Whether Belugas were exposed to more anthropogenic disturbance in those years than in years with summers of average meteorological conditions is unknown.
Aircraft flying at low latitude may also cause short-term negative behavioural responses (Richardson et al. 1995). While flights at altitudes less than 1000 feet (305 m) are prohibited within the limits of the Saguenay-St. Lawrence Marine Park, there is no such regulation in other parts of SLE Beluga habitat.
Natural System Modifications
Fisheries can cause decreased abundance, quality and availability of Beluga prey as well as ecosystem-wide changes. In recent decades, several fish populations in the SLE and the Gulf of St. Lawrence (e.g., American Eel (Anguilla rostrata), and Atlantic Cod) have declined significantly, likely as a result of overfishing, but also at least partially due to habitat degradation and barriers to migration (COSEWIC 2006; DFO 2009). The coincidence of changes in the population dynamics of SLE Belugas with the collapse of some overexploited fish stocks supports the hypothesis that there is a relationship between Beluga population growth and the consequences of fishery activities for prey on which these whales depend (e.g., Atlantic Herring) (Plourde et al. 2014).
Invasive and Other Problematic Species and Genes
As in many other temperate coastal areas, blooms of the dinoflagellate Alexandrium tamarense, a producer of paralytic shellfish toxins which include saxitoxin (STX) and its derivatives, occur on a regular basis in the SLE, and have been associated with mortality of Belugas and other marine species (Scarratt et al. 2014). The strain of A. tamarense native to the SLE is noted for being extremely noxious, and there are indications of chronic sub-lethal exposure in SLE Belugas in recent years, which may render the animals more vulnerable to other stressors and accidents (Scarratt et al. 2014). Eutrophication, climatic variability, and changes in rainfall patterns may lead to higher frequency and severity of toxic algal blooms caused by A. tamarense and other toxic algae species occurring in the SLE (Van Dolah 2000; Anderson et al. 2012). The risk may be particularly acute in small, isolated populations such as the SLE Beluga, which could be significantly affected by a single intoxication event (Scarratt et al. 2014).
Epizootic diseases are caused primarily by viruses such as papillomavirus and herpesvirus, which have been reported in SLE Belugas (De Guise et al. 1994; Lair et al. 2014). Other pathogens such as the Brucella bacterium and the protozoan Toxoplasma gondii can cause infectious diseases leading to reproductive disorders (Mikaelian et al. 2000; Nielsen et al. 2001). Cetacean distemper virus or cetacean morbillivirus (CeMV) poses a high risk to SLE Belugas because they apparently have not been exposed previously (Mikaelian et al. 1999; Nielsen et al. 2000). CeMV has caused hundreds of deaths of cetaceans elsewhere in the world (Taubenberger et al. 1996) and a related virus, phocine distemper virus (PDV), has caused thousands of deaths of pinnipeds (Osterhaus and Vedder 1988; Jensen et al. 2002), including recently in New England (Earle et al. 2011). From 2013 to 2014 more than 1,200 cetaceans reportedly died from an epizootic of CeMV off the east coast of the U.S.A. (NOAA 2014). Morbilliviruses cause broncho-pneumonia, encephalitis, immune suppression and death and can quickly become epizootic due to their highly contagious nature and ease of transmission among social animals (Kennedy 1998; Di Guardo et al. 2005). Belugas are at risk of becoming infected with morbilliviruses through contact with terrestrial or marine mammal carriers (Barrett 1999; Philippa et al. 2004).
Several factors render SLE Belugas vulnerable to epizootics: small population size, gregariousness, limited distribution, isolation from neighbouring populations, a potentially weakened immune system from chronic exposure to contaminants, and low Major histocompatibility complex (MHC) haplotype diversity, which is essential in antigen-specific immune responses (Murray et al. 1999; Nielsen et al. 2000; DFO 2012). A global warming trend could favour pathogen survival and transmission, or expansion of the range of exotic infected marine mammal species into the SLE and Gulf of St. Lawrence, which would expose SLE Belugas to exotic pathogens to which they may have no immune resistance (DFO 2002; Measures 2004, 2008; Burek et al. 2008). Biological contaminants from municipal sewage, waste and ballast water from maritime vessels, and coastal runoff discharged into the St. Lawrence ecosystem may also infect SLE Belugas causing morbidity and death. These may include coliform bacteria, human enteric viruses, protozoan parasites such as Cryptosporidium and Toxoplasma gondii, as well as antibiotic-resistant bacteria (Measures and Olson 1999; Higgins 2000; Mikaelian et al. 2000; Payment et al. 2000, 2001; Miller et al. 2002; Measures 2004).
Microorganisms such as viruses, bacteria, parasites and toxic algae may affect the longevity or reproductive success of Belugas. Infectious diseases were the cause of death in 32% of Belugas examined by necropsy between 1983 and 2012, and diseases were particularly prevalent in young Belugas (Lair et al. 2014). These included bacterial infections (11%), verminous pneumonia (11%), verminous gastro-enteritis/peritonitis (4%), toxoplasmosis (2%), protozoal pneumonia (2%) and herpesviral infections (1%). Only one case of saxitoxin intoxication, caused by the dinoflagellate Alexandrium tamarense, was documented in 2008, although this organism was suspected to have been responsible for several additional deaths during the massive bloom event documented that year in the SLE (Scarratt et al. 2014; Starr unpubl. data). Non-fatal infections by different species of parasitic worms were documented in some Beluga carcasses (Lair et al. 2014). Such infections are believed to weaken the immune system or decrease the fitness of heavily infected individuals.
The strong tides and currents, seasonal ice cover, and frequent fog characteristics of the SLE and Gulf of St. Lawrence increase the risk of toxic spills. So far, there have been very few major spills in the St. Lawrence, and most have occurred in ports (Villeneuve and Quilliam 1999). Nevertheless, a major toxic spill can have widespread effects as pollutants spread rapidly (Kingston 2005). Because the area occupied by SLE Belugas is limited, and considering the proposed petroleum port within their critical habitat, a large oil spill could affect a significant number of individuals and have long-term consequences in a large proportion of their range (Peterson et al. 2003). International statistics on small < 7 tonnes), medium (between 7 and 700 tonnes), and large spills (> 700 tonnes) from oil tankers indicated a consistent decline both in the spill volume and number of incidents over the period 1970 to 2013. Small and medium-sized spills accounted for 95% of the incidents recorded worldwide during this period, with 40% of small spills and 29% of medium-sized spills occurring during loading and discharging operations, which normally take place in ports and oil terminals (ITOPF 2013). A recent study examining current oil spill risk in Canadian waters, based on the most recent 10 years of vessel traffic and oil volumes combined with current environmental information, identified the St. Lawrence River and Gulf of St. Lawrence as being among the zones with the highest probability of a large spill occurring (WSP Canada Inc. 2014). In Canada, 30 water pollution incidents involving spills of oil, chemicals or other pollutants were reported between 2007 and 2009 at oil handling facilities (i.e., average of 10 per year). Volumes of spills were not available (Office of Auditor General of Canada 2010).
SLE Belugas live downstream of the Great Lakes and the St. Lawrence River, a densely populated and highly industrialized region of Canada and the United States. Consequently, the SLE Belugas are among the most contaminated marine mammals (DFO 2012). Chemical and biological contaminants in the St. Lawrence ecosystem come from a variety of sources (agricultural, industrial and municipal waste, maritime shipping, dredging operations, and others) and are of concern for the recovery of the SLE Beluga population. Although actions have been taken to ban or reduce toxic chemical discharges (e.g., the International Joint Commission of Canada and the United States’ Great Lakes Water Quality Agreement of 1978), some contaminants will persist in the ecosystem and Beluga tissues for decades (Lebeuf et al. 2007, 2014a). Persistent organic pollutants are transferred, some with high efficiency, from one generation to another (Desforges et al. 2012; Lebeuf et al. 2014a). New contaminants such as toxic flame retardants (polybrominated diphenyl ethers or PBDEs), accumulated at an exponential rate in Belugas until their regulation in the late 1990s, but are still at their maxima in adult and newborn Beluga tissues (De Wit 2002; Lebeuf et al. 2004, 2014a, 2014b). Others continue to appear in the environment, as those recently reported in American Eel from eastern Canada, a potential prey of SLE Belugas (Byer et al. 2014). Some pathologies associated with chronic exposure to chemical contaminants may take many years to develop (15–25 years), suggesting that past pollution may still compromise the health of the current population. In addition, effluents from municipal sewage treatment plants contain residues of detergents, pharmaceutical products, and various other contaminants with hormone-disrupting chemicals. The effect of these contaminants on Belugas is unknown, although they have the potential to accumulate in the food chain (see references in DFO 2012).
Chemical contamination may be contributing to the abnormally high rates of cancer and other diseases observed in SLE Belugas (Lair 2007; Lair et al. 2014), as well as to changes in the reproductive system, although a cause and effect relationship has not been established, and may never be, in SLE Belugas (Béland et al. 1992; De Guise et al. 1996; Martineau et al. 2003; Lebeuf et al. 2010, 2014b; Lair et al. 2014). For a summary of the main types of chemical contaminants present in the St. Lawrence ecosystem, see Appendix 2 of the Beluga Recovery Strategy (DFO 2012). The hypothesis proposed to explain the high level of cancer in SLE Belugas is exposure to carcinogenic chemicals such as polyaromatic hydrocarbons (PAHs) (Martineau et al. 1994; De Guise et al. 1995; Martineau et al. 1995, 1998, 2002). The occurrence of gastro-intestinal adenocarcinomas in SLE Belugas (extremely rare in cetaceans) suggests a relationship between cancer and PAHs. It was speculated that Belugas may ingest carcinogenic sediment (Martel et al. 1986) during suction feeding on benthic prey (Pelletier et al. 2009), which could lead to development of cancers of the digestive tract (Martineau et al. 1995). However, this hypothesis has been the subject of debate (Dillberger 1995; Theriault et al. 2002; Hammill et al. 2003). The absence of cases of neoplasia in Belugas born after 1971, i.e., after direct discharges of PAHs from aluminum smelters ceased, tends to support the hypothesis of a relationship between intestinal adenocarcinoma and PAHs (Lair et al. 2014). Other pathologies suspected of being caused by chemical contamination have since been associated with advanced age (Measures 2008; Lair et al. 2014).
While SLE Belugas appear more tolerant of vessel traffic (Blane and Jackson 1994; Lesage et al. 1999) than Belugas in the Arctic, where shipping is (or was until recently) nearly non-existent (Finley 1990), they are not immune to disturbance. Physiological and vocal responses to noise have been documented in SLE Belugas (Lesage et al. 1999; Scheifele et al. 2005), and their abandonment of sectors such as Tadoussac Bay following the construction of a marina is suspected to be related to increased vessel traffic (Pippard 1985a). There is growing recognition that exposure to ship noise and other chronic, low-intensity noise might affect cetaceans and other aquatic organisms, and be of great significance in affecting individual fitness and population status (Wright 2009; Tyack 2008; Hatch and Fristrup 2009; Clark et al. 2009). Noise can mask important signals, reduce “acoustic space,” divert attention and disrupt natural behaviour, lead to habituation or ‘learned deafness’, and cause chronic stress (Rolland et al. 2012; Hatch and Fristrup 2009; Clark et al. 2009). Noise exposure may compromise physiological functions by reducing the energy and time allocated to critical activities (e.g., foraging) or by impairing social interactions (e.g., acoustic connections as calves venture away from their mother for longer periods during weaning (Smolker et al. 1993; Taber and Thomas 1982; Tyack and Clark 2000). At the Saguenay River mouth, the potential communication space for Belugas is reduced by vessel traffic to less than 30% of its expected level under natural noise conditions for half of the time, and to less than 15% for one quarter of the time, regardless of call frequency (McQuinn et al. 2011, Gervaise et al. 2012). Depending on source levels and transit directions, merchant ships travelling through the SLE expose up to 15-48% of the Beluga population to noise levels in excess of 120 dB re 1 µPa RMS approximately 18 times per day (Lesage et al. 2014b). Such levels may make the environment unsuitable for Belugas to carry out vital functions (DFO 2012).
Climate Change and Severe Weather
Climate models are forecasting that the Gulf of St. Lawrence will be ice-free within 50 years (Dufour and Ouellet 2007). The Beluga is an ice-adapted species and its capacity to survive in an environment where ice may be reduced or absent, and mean water temperatures increased, is unknown. Increased water temperature and reduced ice-cover may affect Belugas directly by reducing shelter from storms during winter (Barber et al. 2001), or could alter ecosystem structure, affect food availability and increase interspecific competition as other species expand their ranges due to a loss of ice cover (Moore and Huntington 2008; Heide-Jørgensen et al. 2010). Many fish species are sensitive to water temperature, which affects survival, spawning, growth and migration period and routes (Gilbert and Couillard 1995; Minns et al. 1995; Narayana et al. 1995; Gilbert 1996; Gilbert and Pettigrew 1996). In addition, biodiversity and productivity in the SLE and Gulf of St. Lawrence is burdened by hypoxia, or oxygen deprivation (Diaz 2001), conditions that might further affect prey availability to SLE Belugas.
Commercial Development, Transportation and Service Corridors
Industrial activities related to coastal development may reduce habitat quality for SLE Belugas. Construction and operation of a proposed petroleum terminal at Cacouna, in one of the few areas where females, juveniles and calves congregate and where they have been only lightly exposed to ship noise (DFO 2014b), would likely reduce the quality and quantity of critical habitat, and therefore must be seen as a potential threat to SLE Beluga recovery.
Blane and Jackson (1994) observed that Belugas showed ship avoidance behaviour by prolonging the intervals between surface breathing, increasing swimming speed, and forming tighter groups. As mentioned earlier, Belugas may have abandoned the Bay of Tadoussac and altered their movements at the mouth of the Saguenay River as a result of increased marine traffic in that area (Pippard, 1985a; Caron and Sergeant, 1988). The St. Lawrence Estuary is used by an increasing variety of vessels, and the threat of ship strikes to belugas is correspondingly increasing. Dredging (for maintenance, Rivière-du-Loup) outside shipping lanes and port maintenance operations which occur on a regular basis in various parts of the critical habitat, even though in a restricted area, temporarily affect the habitat of a small proportion of the population. The impact of such disturbance is unknown.
The Beluga has a relatively long life expectancy, late sexual maturity, and low reproductive rate (Ray 1981), all factors that could limit recovery. In the event of mass mortality, the SLE Beluga population would take many years to return to its current population size (DFO 2012). Further, in small isolated Beluga populations such as that in the SLE, the likelihood of inbreeding and inbreeding depression is relatively high. Inbreeding depression and lowered heterozygosity can reduce metabolic efficiency, growth rate, and reproductive rate, as well as affect immune system function and disease resistance (Gilpin and Soule 1986; O’Brien and Evermann 1988; Knapp et al. 1996; Keller and Waller 2002). The SLE Belugas have low genetic diversity (de March et al. 2002), but the degree to which this might affect their reproduction or general health is uncertain.
Number of Locations
The threats assessment revealed one location in which a single threatening event could rapidly affect all individuals of the taxon present.
Protection, Status and Ranks
Legal Protection and Status
Hunting of Belugas in the SLE was prohibited in 1979 by the Beluga Protection Regulations under the Fisheries Act, which was replaced by the Marine Mammal Regulations in 1993. The currently applicable regulations are being revised, but it is likely to remain unlawful to disturb a marine mammal except with exemptions under permit.
In 1983 COSEWIC designated the SLE Beluga population as Endangered (Pippard 1985a), and this designation was reaffirmed in 1996 (Lesage and Kingsley 1998). The population’s status was changed to Threatened in 2004 (COSEWIC 2004). SLE Belugas have been listed as Threatened under the Québec Act respecting threatened or vulnerable species (CQLR, c E-12.01) or ‘Loi sur les espèces menacées et vulnérables’ (RLRQ, c E-12.01) since March 2000. Most recently, COSEWIC assessed the status of the SLE Beluga Whale population as Endangered in 2014.
The SLE Beluga population was listed as Threatened on Schedule 1 of the Canadian Species at Risk Act (SARA) in May 2005. The Act prohibits the killing, harming, harassment, capture, or take of any individual of this species (DU), or damage to the residence of one or more individuals. The Act also prohibits the destruction of any part of the critical habitat of the species, and requires that a Recovery Strategy be prepared and critical habitat be identified. An initial Recovery Strategy for SLE Belugas was developed prior to their listing under SARA (DFO and WWF 1998). A second Recovery Strategy, including formal identification of critical habitat, was published in 2012 (DFO 2012). Critical habitat of SLE Belugas corresponds to the area occupied in summer by females accompanied by calves and juveniles (Figure 6).
An Action Plan to implement the Recovery Strategy for SLE Belugas is expected to be available by 2016 (DFO 2012). In 2012, recovery of the SLE Beluga population was deemed feasible, with the long-term goal of achieving a population of 7,070 individuals, or 70% of its estimated historical size. At a population growth rate of 4%, this level of abundance would have been achievable by the 2050s. However, at a rate of 1% (Hammill et al. 2007), which was the assumed growth rate for the population at the time the Recovery Strategy was written, this goal would not be reached for another 90 years. Thus, an intermediate objective of 1,000 mature individuals was proposed (DFO 2012). It is unlikely that original recovery targets and time frames for reaching them will be met.
Belugas are also protected under the Marine Activities in the Saguenay-St. Lawrence Marine Park Regulations (2002) adopted under of the Saguenay-St. Lawrence Marine Park Act. The Saguenay-St. Lawrence Marine Park, one of Canada’s first marine protected areas, was established to favour the recovery of the Beluga population in 1998. The park is managed by Parks Canada, and permits are required to operate a marine tour business or shuttle service, to conduct scientific research or to hold a special activity in the park. These regulations prohibit the killing, injury or disturbance of any marine mammal, and require that a minimum distance of 400 m be maintained between a vessel and a species or population that is listed as endangered or threatened under SARA, which includes SLE Belugas.
The Beluga is also protected under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). CITES monitors international trade in products derived from protected flora and fauna to ensure the survival of these species. In Canada, CITES is administered and enforced under the Wild Animal and Plant Protection and Regulation of International and Interprovincial Trade Act. The SLE Beluga population is listed in Schedule II under CITES, which stipulates that a permit is required to import or export Beluga samples.
Non-Legal Status and Ranks
The Beluga is red-listed as Near-Threatened by the IUCN. NatureServe has assigned it a global status of G4T3QFootnote 1 (last reviewed in 24 Oct 2000), which indicates that the species is ‘apparently secure’. The ‘T-rank’ following the species’ global rank specifies that SLE Belugas qualify for an ‘Infraspecific Taxon Conservation Status Rank’ of 3, or vulnerable: “At moderate risk of extinction or elimination due to a fairly restricted range, relatively few populations or occurrences, recent and widespread declines, threats, or other factors.” The qualifier ‘Q’ used after the T-rank denotes the informal nature of the population intraspecific taxonomic status. Nationally, SLE Belugas have a status of N2 (15 Nov 2011) and thus are considered “Imperilled - at high risk of extirpation.” (NatureServe 2014). At the provincial level, V. Lesage, DFO, has provided the rank assessment for the SLE Beluga population as S1: “Critically imperiled - at very high risk of extirpation in the jurisdiction.” The proposed change in status from S2 to S1 was accepted by the Québec government, and will be updated on the NatureServe website in the spring of 2015 (Gauthier pers. comm. 2014).
According to Wild Species, the most current (2010) general status for the Beluga is Secure at the Canada level, and At Risk in the Atlantic, where the SLE population is the only one of this species (Wild Species 2010).
Habitat Protection and Ownership
Until recently, the Canadian Fisheries Act prohibited any activity that could alter, disrupt, or destroy fish habitat, which, as defined by the Act, included marine mammal habitat. The Fisheries Act was amended in 2012 to afford protection to the habitat of fish against serious harm. However, this protection extends only to fish that are part of or supporting a commercial, recreational or Aboriginal (CRA) fishery (DFO 2013). SLE Belugas are not fished (or hunted), and do not support a CRA fishery; consequently, their habitat is no longer legally and directly protected under the amended Act. However, because SLE Belugas coexist with fish species that are considered to be part of or that support a CRA fishery, some features of the Belugas’ habitat may be afforded protection indirectly by the Fisheries Act prohibition against serious harm to fish habitat.
The Fisheries Act also regulates the introduction of toxic substances into fish habitat. Further federal regulatory or legislative measures exist to control activities liable to affect the SLE Beluga population and its habitat, such as the Canada Shipping Act (2001), the Canadian Environmental Assessment Act (1992), and the Canadian Environmental Protection Act (1999) (DFO 2012).
A significant piece of legislation for habitat protection is SARA, which requires that the critical habitat of all listed species be legally protected within six months once identified in a finalized SARA Recovery Strategy or Action Plan. However, legal protection of the SLE Beluga critical habitat, which was, according to SARA requirements, due in September 2012, was still pending as of September 2014.
At the provincial level, the SLE Belugas and their habitat are protected directly or indirectly under various other laws and policies: the Loi sur les espèces menacées ou vulnérables (RLRQ, c E-12.01) (LEMV) (Act respecting threatened or vulnerable species) (CQLR, c E-12.01), the Loi sur la qualité de l’environnement (RLRQ, c. Q-2) (Environment Quality Act) (CQLR, c. Q-2), and the Loi affirmant le caractère collectif des ressources en eau et visant à renforcer leur protection (chapitre C 6.2) (Act to affirm the collective nature of water resources and provide for increased water resource protection) (chapter C-6.2). SLE Belugas and their habitat are also afforded protection under the Loi sur la conservation et la mise en valeur de la faune (RLRQ, c. C- 61.1) (LCMVF) (Act respecting the conservation and development of wildlife) (CQLR, c. C-61.1). Under article 26 of the LCMVF, it is illegal to disturb, destroy, or damage the eggs or nest of an animal. It is also prohibited to capture, hunt, and/or keep in captivity any species / animals that are native to Québec.
In 1998, the Saguenay-St. Lawrence Marine Park (SSLMP) covering 1,245 km² was established in the SLE as a measure to protect the Beluga population, as well as provide refuge for other transient marine mammal species including rorquals. One of the protections for habitat that are listed in the Saguenay-St. Lawrence Marine Park Act is the prohibition of seismic surveys and oil and gas development within the limits of the Park.
Acknowledgements and Authorities Contacted
For help in preparing this report, the writers are grateful to Thomas Doniol-Valcroze, Michel Lebeuf, Michael Scarratt, Lena Measures, Christine Abraham, Christie Whelan, Arnaud Mosnier, Jean-François Gosselin, Ian McQuinn, and Ashley Kling from DFO; Nadia Ménard from Parks Canada (Saguenay-St. Lawrence Marine Park); Isabelle Gauthier from the Ministère des Forêts, de la Faune et des Parcs; and Randall R. Reeves.
Anderson, D.M., A.D. Cembella, and G.M. Hallegraeff. 2012. Progress in understanding harmful algal blooms: paradigm shifts and new technologies for research, monitoring, and management. Annual Review of Marine Science 4:143-176.
Bailleul, F., V. Lesage, M. Power, D.W. Doidge, and M.O. Hammill. 2012. Differences in diving and movement patterns of two groups of beluga whales in a changing Arctic environment reveal discrete populations. Endangered Species Research 17:27-41.
Barber, D.G., E. Saczuk, and P.R. Richard. 2001. Examination of beluga-habitat relationships through the use of telemetry and a Geographic Information System. Arctic 54:305-316.
Barrett, T. 1999. Morbillivirus infections, with special emphasis on morbillivirus of carnivores. Veterinary Microbiology 69:3-13.
Beck, B., and A.W. Mansfield. 1969. Observations on the Greenland Shark, Somniosus microcephalus, in Northern Baffin Island. Journal of the Fisheries Research Board of Canada 26:143-145.
Béland, P., R. Michaud, and D. Martineau. 1987. Recensements de la population de bélugas (Delphinapterus leucas) du Saint-Laurent par embarcations en 1985. Rapports techniques canadiens des sciences halieutiques et aquatiques 1545. 21 pp.
Béland, P., A. Vézina, and D. Martineau. 1988. Potential for growth of the St. Lawrence (Québec, Canada) beluga whale (Delphinapterus leucas) population based on modeling. Ices Journal of Marine Science 45:22-32.
Béland, P., S. Deguise and R. Plante. 1992. Toxicology and pathology of St. Lawrence marine mammals. Final report for the World Wildlife Fund’s Wildlife Toxicology Fund: 95 pp.
Benjamins, S., and W. Ledwell. 2009. Vagrant sociable Monodontids in Newfoundland and Labrador, Canada. ECS Special Publication Series No. 52. 28-31 pp. European Cetacean Society Workshop on Solitary Cetaceans, The Netherlands.
Blane, J., and R. Jaakson. 1994. The impact of ecotourism boats on the St. Lawrence beluga whales. Environmental Conservation 21:267-269.
Boily, P. 1995. Theoretical heat flux in water and habitat selection of phocid seals and beluga whales during the annual molt. Journal of Theoretical Biology 172:235-244.
Boivin, Y., and INESL. 1990. Survols aériens pour l’estimation de la distribution saisonnière et des déplacements des bélugas, INESL. Available at: Institut National d'Écotoxicologie du Saint-Laurent, 5040 Mentana, Montréal, QC, CAN. H2J 3C3. 91 pp.
Boltunov, A.N., and S.E. Belikov. 2002. Belugas (Delphinapterus leucas) of the Barents, Kara and Laptev seas. NAMMCO Scientific Publications 4:149-168.
Braham, H.W. 1984. Review of reproduction in the white whale, Delphinapterus leucas, narwhal, Monodon monoceros, and Irrawaddy dolphin, Orcaella brevirostris, with comments on stock assessment. Report of the International Whaling Commission Special Issue 6:81-89.
Brennin, R., B.W. Murray, M.K. Friesen, D. Maiers, J.W. Clayton, and B.N. White. 1997. Population genetic structure of beluga whales (Delphinapterus leucas): mitochondrial DNA sequence variation within and among North American populations. Canadian Journal of Zoology 75:795-802.
Brodie, P.F. 1969. Mandibular layering in the Delphinapterus leucas and age determination. Nature 221:956–958.
Brodie, P.F. 1971. A reconsideration of aspects of growth, reproduction, and behavior of the white whale (Delphinapterus leucas), with reference to the Cumberland Sound, Baffin Island, population. Journal of the Fisheries Research Board of Canada 28:1309-1318.
Brodie, P.F., J.W. Geraci, and D.J. St. Aubin. 1990. Dynamics of tooth growth in beluga whales, Delphinapterus leucas, and effectiveness of tetracycline as a marker for age determination. Advances in Research on the Beluga Whale, Delphinapterus leucas. Canadian Bulletin of Fisheries and Aquatic Sciences 224. T.G. Smith, D.J. St. Aubin and J.R. Geraci. Department of Fisheries and Oceans, Ottawa, ON. 141-148 pp.
Brodie, P.F., K. Ramirez, and M. Haulena. 2013. Growth and maturity of belugas (Delphinapterus leucas) in Cumberland Sound, Canada, and in captivity: evidence for two growth layer groups (GLGs) per year in teeth. Journal of Cetacean Research and Management 13:1-18.
Brown Gladden, J.G., M.M. Ferguson, and J.W. Clayton. 1997. Matriarchal genetic population structure of North American beluga whales, Delphinapterus leucas, (Cetacea: Monodontidae). Molecular Ecology 6:1033-1046.
Brown Gladden, J.G., M.M. Ferguson, M.K. Friesen, and J.W. Clayton. 1999a. Population structure of North American beluga whales (Delphinapterus leucas) based on nuclear DNA microsatellite variation and contrasted with the population structure revealed by mitochondrial DNA variation. Molecular Ecology 8:347-363.
Brown Gladden, J.G., P.F. Brodie, and J.W. Clayton. 1999b. Mitochondrial DNA used to identify an extralimital beluga whale (Delphinapterus leucas) from Nova Scotia as originating from the St. Lawrence population. Marine Mammal Science 15:556-558.
Burek, K.A., F.M.D. Gulland, and T.M. O'Hara. 2008. Effects of climate change on Arctic marine mammal health. Ecological Applications 18:S126-S134.
Burns, J.J., and G.A. Seaman. 1985. Investigations of beluga whales in coastal waters of western and northern Alaska. II. Biology and ecology. Alaska Department of Fisheries and Game NA 81 RAC 00049. 129 pp.
Byer, J.D., G. Pacepavicius, M. Lebeuf, R.S. Brown, S. Backus, P.V. Hodson, and M. Alaee. 2014. Qualitative analysis of halogenated organic contaminants in American eel by gas chromatography/time-of-flight mass spectrometry. Chemosphere DOI: 10.1016/j.chemosphere.2014.02.032:116, pages 98-103.
Caron, L., and T.G. Smith. 1990. Philopatry and site tenacity of belugas, Delphinapterus leucas, hunted by the Inuit at the Nastapoka estuary, eastern Hudson Bay. Canadian Bulletin of the Fisheries and Aquatic Sciences 224:69-79.
Chion, C., S. Turgeon, R. Michaud, J.-A. Landry, et L. Parrott. 2009. Portrait de la navigation dans le parc du Saguenay-Saint-Laurent. Caractérisation des activités sans prélèvement de ressources entre le 1er mai et le 31octobre 2007. Présenté à Parcs Canada. 86 p.
Clark, C.W., W.T. Ellison, B.L. Southall, L. Hatch, S.M. Van Parijs, A. Frankel, and D. Ponirakis. 2009. Acoustic masking in marine ecosystem: intuitions, analysis, and implication. Marine Ecology Progress Series 395:201-222.
Colbeck, G.J., P. Duchesne, L.D. Postma, V. Lesage, M.O. Hammill, and J. Turgeon. 2013. Groups of related belugas (Delphinapterus leucas) travel together during their seasonal migrations in and around Hudson Bay. Proceedings of the Royal Society B: Biological Sciences 280:no. 1752 20122552.
COSEWIC. 2004. COSEWIC assessment and update status report on the beluga whale Delphinapterus leucas in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. ix + 70 pp.
COSEWIC. 2006. COSEWIC assessment and status report on the American eel Anguilla rostrata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 71 pp.
Crow, J.F., and M. Kimura. 1970. An introduction to population genetic theory. Harper and 1701 Rowe. New York.
Curren, K., and J. Lien. 1998. Observations of white whales, Delphinapterus leucas, in waters off Newfoundland and Labrador and the Gulf of St. Lawrence, 1979-1991. Canadian Field Naturalist 11:28-31.
De Guise, S., A. Lagace, and P. Béland. 1994. True hermaphroditism in a St. Lawrence beluga whale (Delphinapterus leucas). Journal of Wildlife Diseases 30:287-290.
De Guise, S., D. Martineau, P. Béland, and M. Fournier. 1995. Possible mechanisms of action of environmental contaminants on St. Lawrence beluga whales (Delphinapterus leucas). Environmental Health Perspectives 103:73-77.
De Guise, S., J. Bernier, D. Martineau, P. Béland, and M. Fournier. 1996. Effects of in vitro exposure of beluga whale splenocytes and thymocytes to heavy metals. Environmental Toxicology and Chemistry 15:1357-1364.
de March, B.G.E., L.D. Maiers, and M.K. Friesen. 2002. An overview of genetic relationships of Canadian and adjacent populations of belugas (Delphinapterus leucas) with emphasis on Baffin Bay and Canadian eastern Arctic populations. NAMMCO Scientific Publications 4:17-38.
de March, B.G.E., and L.D. Postma. 2003. Molecular genetic stock discrimination of belugas (Delphinapterus leucas) hunted in Eastern Hudson Bay, Northern Québec, Hudson Strait, and Sanikiluaq (Belcher Islands), Canada, and comparisons to adjacent populations. Arctic 56:111-124.
De Wit, C.A. 2002. An overview of brominated flame retardants in the environment. Chemosphere 46:583-624.
Desforges, J.-P.W., P.S. Ross, and L.L. Loseto. 2012. Transplacental transfer of polychlorinated biphenyls and polybrominated diphenyl ethers in Arctic beluga whales (Delphinapterus leucas). Environmental Toxicology and Chemistry 31:296-300.
DFO, and World Wildlife Fund (WWF). 1998. Implementation of the St. Lawrence beluga recovery plan. Department of Fisheries and Oceans and World Wildlife Fund. Prepared by the beluga recovery team. 102 pp.
DFO. 2002. Atelier scientifique sur les mammifères marins, leurs habitats et leurs ressources alimentaires dans le cadre de l’élaboration du projet de zone de protection marine de l’estuaire du Saint-Laurent du 3 au 7 avril, 2000. Maurice-Lamontagne Institute, Mont-Joli, QC. Proceedings. 344 pp.
DFO. 2007. Stock assessment of Atlantic halibut of the Gulf of St. Lawrence (NAFO Divisions 4RST) in 2006. DFO Canadian Scientific Advisory Secretariat, Science Advisory Report 2007/007. 13 pp.
DFO. 2009. Assessment of cod stock in the northern Gulf of St. Lawrence (3Pn, 4RS) in 2008. DFO Canadian Scientific Advisory Secretariat, Science Advisory Report 2009/010. 15 pp.
DFO. 2010. Advice relevant to the identification of critical habitat for St. Lawrence beluga (Delphinapterus leucas). DFO Canadian Science Advisory Secretariat, Science Advisory Report 2009/070: 8 pp.
DFO. 2012. Recovery Strategy for the beluga whale (Delphinapterus leucas) St. Lawrence Estuary population in Canada. Species at Risk Act Recovery Strategy Series. Fisheries and Oceans Canada, Ottawa. x + 87 pp.
DFO. 2013. Fisheries Protection Policy Statement. Ottawa. October 2013. 22 pp.
DFO. 2014a. Status of beluga (Delphinapterus leucas) in the St. Lawrence River estuary. DFO Canadian Science Advisory Secretariat, Research Document 2013/076. 17 pp.
DFO. 2014b. Impacts of geophysical surveys at the Cacouna harbour on the St. Lawrence beluga. DFO Canadian Science Advisory Secretariat, Research Document 2014/020. 19 pp.
Di Guardo, G., G. Marruchella, U. Agrimi, and S. Kennedy. 2005. Morbillivirus infections in aquatic mammals: A brief overview. Journal of Veterinary Medicine Series A: Physiology Pathology Clinical Medicine 52:88-93.
Diaz, R.J. 2001. Overview of hypoxia around the world. Journal of Environmental Quality 30:275-281.
Dillberger, J. 1995. Tumors in St. Lawrence beluga whales (Delphinapterus leucas). Veterinary Pathology 32:211-212.
Doan, K.H., and C.W. Douglas. 1953. Beluga of the Churchill region in Hudson Bay. Bulletin of the Fisheries Research Board of Canada 98:1-27.
Dufour, R., and P. Ouellet. 2007. Rapport d'aperçu et d'évaluation de l'écosystème marin de l'estuaire et du golfe du Saint-Laurent. Rapports techniques canadien des sciences halieutiques et aquatiques 2744F. 123 pp.
Earle, J.A.P., M.M. Melia, N.V. Doherty, O. Nielsen, and S.L. Cosby. 2011. Phocine distemper virus in seals, East Coast, United States, 2006. Emerging Infectious Diseases 17:215-220.
El-Sabh, M.I., and N. Silverberg. 1990. Oceanography of a large-scale estuarine system: the St. Lawrence. Coastal Estuarine Studies No. 39. 434 pp.
Erbe, C. 2008. Critical ratios of beluga whales (Delphinapterus leucas) and masked signal duration. Journal of Acoustical Society of America 124: 2216-2223.
Finley, K.J. 1982. The estuarine habit of the beluga or white whale Delphinapterus leucas. Cetus 4:4-5.
Finley, K.J. 1990. The impacts of vessel traffic on the behaviour of belugas. Pour l'avenir du béluga. Compte rendu du Forum international pour l'avenir du béluga. J. Prescott and M. Gauquelin. Sillery, QC, Presses de l'Universtié du Québec.
Finley, K.J., G.W. Miller, M. Allard, R.A. Davis, and C.R. Evans. 1982. The belugas (Delphinapterus leucas) of northern Québec: distribution, abundance, stock identity, catch history and management. Canadian Technical Report of Fisheries and Aquatic Sciences 1123. 57 pp.
Fox, G.A. 2001. Wildlife as sentinels of human health effects in the Great Lakes-St. Lawrence basin. Environmental Health Perspectives 109:853-861.
Fraker, M.A., C.D. Gordon, J. McDonald, J. Ford, and G. Cambers. 1979. The distribution of white whales in the Mackenzie estuary in relation to physical and chemical factors. Canadian Fisheries Maritime Service Technical Reports 863. 56 pp.
Frost, K.J., and L.F. Lowry. 1990. Distribution, abundance, and movements of beluga whales, Delphinapterus leucas, in coastal waters of western Alaska. . Advances in research on the beluga whale, Delphinapterus leucas. Canadian Bulletin of Fisheries and Aquatic Sciences. T.G. Smith, D.J. St. Aubin and J.R. Geraci. 224: 39-57.
Gauthier, I., pers comm. 2014. Email correspondence to V. Lesage followed by a phone conversation on 23 September 2014. Biologiste, Coordonnatrice provinciale, espèces fauniques menacées et vulnérables, Ministère des Forêts de la Faune, et des Parcs.
Gavrilchuk, K., V. Lesage, C. Ramp, R. Sears, M. Bérubé, S. Bearhop, and G. Beauplet. 2014. Trophic niche partitioning among sympatric baleen whale species following the collapse of groundfish stocks in the Northwest Atlantic. Marine Ecology Progress Series 497:285-301.
Gervaise, C., Y. Simard, N. Roy, B. Kinda, and N. Ménard. 2012. Shipping noise in whale habitat: Characteristics, sources, budget, and impact on belugas in Saguenay–St. Lawrence Marine Park hub. The Journal of the Acoustical Society of America 132:76-89.
Gilbert, M., and C.M. Couillard. 1995. Observations de mortalités de sébastes (Sebastes sp.) dans la région de la baie des Ha! Ha!, fjord du Saguenay: examen des causes possibles. Canadian Bulletin of the Fisheries and Aquatic Sciences 2278. 15 pp.
Gilbert, M. 1996. Mortalités de sébastes dans la région de la baie des Ha! Ha!, fjord du Saguenay: choc thermique. Le Naturaliste canadien 120:61-63.
Gilbert, M., and B. Pettigrew. 1996. Variation de la couche froide intermédiaire du golfe du Saint-Laurent de 1984 à 1995. Le Naturaliste canadien 120:69-71.
Gilpin, M.E., and M.E. Soule. 1986. Minimum viable populations: processes of species extinctions. Conservation Biology: The Science of Scarcity and Diversity. M. E. Soule. Sunderland, Massachusetts, Sinauer Associates: 19-34.
Goren, A.D., P.F. Brodie, S. Spotte, G.C. Ray, H.W. Kaufman, A.J. Gwinnett, J.J. Sciubba, and J.D. Buck. 1987. Growth layer groups (GLGs) in the teeth of an adult belukha whale (Delphinapterus leucas) of known age: evidence for two annual layers. Marine Mammal Science 3:14-21.
Gosselin, J.-F., M.O. Hammill, and V. Lesage. 2007. Comparison of photographic and visual abundance indices of belugas in the St. Lawrence Estuary in 2003 and 2005. Canadian Science Advisory Secretariat, Research Document 2007/025. ii + 27 pp.
Gosselin, J.-F., M.O. Hammill, and A. Mosnier. 2014. Summer abundance indices of St. Lawrence Estuary beluga (Delphinapterus leucas) from a photographic survey in 2009 and 28 line transect surveys from 2001 to 2009. DFO Canadian Scientific Advisory Secretariat, Research Document 2014/021. iv + 51 pp.
Gosselin, J.-F., V. Lesage, and A. Robillard. 2001. Population index estimate for the beluga of the St. Lawrence River Estuary in 2000. DFO Canadian Science Advisory Secretariat, Science Advisory Report 2001/049. 21 pp.
Hall, A. J., K. Hugunin, R. Deaville, R. J. Law, C. R. Allchin, and P. D. Jepson. 2006. The risk of infection from polychlorinated biphenyl exposure in the harbor porpoise (Phocoena phocoena): a case-control approach. Environmental Health Perspectives 114:704-711.
Hammill, M. O., V. Lesage, and M.C.S. Kingsley. 2003. Cancer in beluga from the St. Lawrence estuary. Environmental Health Perspectives 111:A77-A78.
Hammill, M. O., V. Lesage, J.-F. Gosselin, H. Bourdages, B.G.E. de March, and M.C.S. Kingsley. 2004. Evidence for a decline in Northern Québec (Nunavik) belugas. Arctic 57:183-195.
Hammill, M.O., L.N. Measures, J.-F. Gosselin, and V. Lesage. 2007. Lack of recovery in St. Lawrence estuary beluga. DFO Canadian Science Advisory Secretariat, Research Document 2007/026. 19 pp.
Hammill, M.O., and V. Lesage. 2009. Seasonal movements and abundance of beluga in Northern Québec (Nunavik) based on weekly sightings information. DFO Canadian Science Advisory Secretariat, Research Document 2009/010. iv + 14 pp.
Hammill, M.O., M.C.S. Kingsley, V. Lesage, and J.-F. Gosselin. 2009. Abundance of Eastern Hudson Bay belugas. DFO Canadian Science Advisory Secretariat, Science Advisory Report 2009/09: iv + 22 p.
Harington, C.R. 1977. Marine mammals in the Champlain Sea and the Great Lakes. Annals of the New York Academy of Sciences 288:508-537.
Harington, C.R. 2008. The evolution of Arctic marine mammals. Ecological Applications 18:S23-S40.
Harwood, L.A., P. Norton, B. Day, and P.A. Hall. 2002. The harvest of beluga whales in Canada's Western Arctic: Hunter-based monitoring of the size and composition of the catch. Arctic 55:10-20.
Hatch, L.T., and K.M. Fristrup. 2009. No barrier at the boundaries: implementing regional frameworks for noise management in protected natural areas. Marine Ecology Progress Series 395:223-244.
Heide-Jørgensen, M.-P., and C. Lockyer. 2001. Age and sex distributions in the catches of belugas, Delphinapterus leucas, in West Greenland and in western Russia. Mammalian Biology 66:215-227.
Heide-Jørgensen, M.-P., J. Jensen, A.H. Larsen, J. Teilmann, and B. Neurohr. 1994. Age estimation of white whales (Delphinapterus leucas) from Greenland. Meddelelser om Grøenland Bioscience 39:187-193.
Heide-Jørgensen, M.-P., and J. Teilmann. 1994. Growth, reproduction, age structure and feeding habits of white whales (Delphinapterus leucas) in West Greenland waters. Meddelelser om Grøenland Bioscience 39:195-212.
Heide-Jørgensen, M.-P., P.R. Richard, and A. Rosingasvid. 1998. Dive patterns of belugas (Delphinapterus leucas) in waters near eastern Devon Island. Arctic 51:17–26.
Heide-Jørgensen, M.P., K.L. Laidre, D. Borchers, T.A. Marques, H. Stern, and M. Simon. 2010. The effect of sea-ice loss on beluga whales (Delphinapterus leucas) in West Greenland. Polar Research 29:198-208.
Higdon, J.W., and S.H. Ferguson. 2009. Loss of Arctic sea ice causing punctuated change in sightings of killer whales (Orcinus orca) over the past century. Ecological Applications 19:1365-1375.
Higgins, R. 2000. Bacteria and fungi of marine mammals: a review. Canadian Veterinary Journal 41:105-116.
Hobbs, R., pers comm. 2014. Email correspondence to D. Lee. 15 September 2014. Research Analyst, National Oceanic and Atmospheric Administration.
Houston, A.I., P.A. Stephens, I.L. Boyd, K.C. Harding, and J.M. McNamara. 2007. Capital or income breeding? A theoretical model of female reproductive strategies. Behavioral Ecology 18:241-250.
Innes, S., R.E.A. Stewart, M.P. Heide-Jørgensen, and R. Dietz. 2002a. Stock identity of belugas (Delphinapterus leucas) in Eastern Canada and Western Greenland based on organochlorine contaminants in the blubber. NAMMCO Scientific Publications 4:51-68.
Innes, S., M.-P. Heide-Jørgensen, J.L. Laake, K.L. Laidre, H.J. Cleator, P. Richard, and R.E.A. Stewart. 2002b. Surveys of belugas and narwhals in the Canadian High Arctic in 1996. NAMMCO Scientific Publications 4:169-190.
ITOPF. 2013. Oil tanker spill statistics 2013 (en anglais seulement). The International Tanker Owners Pollution Federation Limited.
Ivashin, M.V., and V.M. Mineev. 1981. Notes on the distribution and whaling for white whales (Delphinapterus leucas Pallas, 1776). Report of the International Whaling Commission 31:589-590.
IWC. 2000. International Whaling Commission Report of the Sub-Committee on small cetaceans. Journal of Cetacean Research and Management 2:235-264.
Jefferson, T.A., Karkzmarski, L., Laidre, K., O’Corry-Crowe, G., Reeves, R., Rojas-Bracho, L., Secchi, E., Slooten, E., Smith, B.D., Wang, J.Y.& Zhou, K. 2012. Delphinapterus leucas. The IUCN Red List of Threatened Species. Version 2014.3. [accessed December 31, 2014]
Jensen, F.H., L. Bejder, M. Wahlberg, N. Aguilar De Soto, M.P. Johnson, and P.T. Madsen. 2009. Vessel noise effects on delphinid communication. Marine Ecology Progress Series 395:161-175.
Jensen, T., M. van de Bildt, H.H. Dietz, T.H. Andersen, A.S. Hammer, T. Kuiken, and A. Osterhaus. 2002. Another phocine distemper outbreak in Europe. Science 297:209.
Johnson, C.S., M.W. McManus, and D. Skaar. 1989. Masked tonal hearing thresholds in the beluga whale. Journal of Acoustical Society of America 85: 2651-2654.
Keller, L.F., and D.M. Waller. 2002. Inbreeding effects in wild populations. Trends in Ecology& Evolution 17:230-241.
Kennedy, S. 1998. Morbillivirus infections in aquatic mammals. Journal of Comparative Pathology 119:201-225.
Kingsley, M.C.S., and M.O. Hammill. 1991. Photographic census surveys of the St. Lawrence beluga population, 1988 and 1990. Canadian Technical Report of Fisheries and Aquatic Sciences 1776. 19 pp.
Kingsley, M.C.S. 1993. Census, trend, and status of the St. Lawrence beluga population in 1992. Canadian Technical Report of Fisheries and Aquatic Sciences 1938. 17 pp.
Kingsley, M.C.S. 1996. Population index estimate for the belugas of the St. Lawrence in 1996. Canadian Technical Report of Fisheries and Aquatic Sciences 2117. 38 pp.
Kingsley, M.C.S. 1998. Population index estimates for the St. Lawrence belugas, 1973-1995. Marine Mammal Science 14:508-529.
Kingsley, M.C.S., and R.R. Reeves. 1998. Aerial surveys of cetaceans in the Gulf of St. Lawrence in 1995 and 1996. Canadian Journal of Zoology 76:1529-1550.
Kingsley, M.C.S. 1999. Population indices and estimates for the belugas of the St. Lawrence Estuary. Canadian Technical Report of Fisheries and Aquatic Sciences 2266. 27 pp.
Kingsley, M.C.S., S. Gosselin, and G.A. Sleno. 2001. Movements and dive behaviour of belugas in Northern Québec. Arctic 54:262-275.
Kingsley, M.C.S. 2002. Status of the belugas of the St. Lawrence estuary, Canada. NAMMCO Scientific Publications 4:239-257.
Kingsley, M.C.S., and I. Gauthier. 2002. Visibility of St. Lawrence belugas to aerial photography, estimated by direct observation. NAMMCO Scientific Publications 4:259-270.
Kingston, P. 2005. Recovery of the marine environment following the Braer spill, Shetland. International Oil Spill Conference, IOSC 2005. 6797-6815.
Kleinenberg, S.E., A. Yablokov, B.M. Belkovich, and M.N. Tarasevich. 1969. Beluga (Delphinapterus leucas): investigation of the species. Israel Program for Scientific Translations, Jerusalem, No. TT-67-51345 (original publication in Russian, Moscow, 1964). 376 pp.
Knapp, L.A., J.C. Ha, and G.P. Sackett. 1996. Parental MHC antigen sharing and pregnancy wastage in captive pigtailed macaques. Journal of Reproductive Immunology 32:73-88.
Laidre, K.L., K.E.W. Shelden, D.J. Rugh, and B.A. Mahoney. 2000. Beluga, Delphinapterus leucas, distribution and survey effort in the Gulf of Alaska. Marine Fisheries Review 62:27-36.
Lair, S. 2007. Programme de nécropsie - suivi de la santé de la population de béluga de l'estuaire du Saint-Laurent à l'aide de l'examen post-mortem des carcasses échouées. Compte-rendu de l'atelier sur le béluga de l'estuaire du Saint-Laurent - revue du programme des carcasses. Pêches et Océans Canada (MPO) Secrétariat Canadien de Consultation Scientifique, Compte-rendu 2007/005: 11-14.
Lair, S., D. Martineau, and L.N. Measures. 2014. Causes of mortality in St. Lawrence Estuary beluga (Delphinapterus leucas) from 1983 to 2012. DFO Canadian Scientific Advisory Secretariat, Research Document 2013/119. iv + 37 pp.
Laurin, J. 1982. Étude écologique et éthologique de la population de bélugas, Delphinapterus leucas, du fjord du Saguenay, Québec. M.Sc Thesis., Université de Montréal, Montréal, QC, CAN: 145 pp.
Lawson, J.W., pers comm. 2009. Email correspondence to V. Lesage. 26 April 2009. Research Scientist, Fisheries and Oceans Canada.
Lawson, J.W., and J.-F. Gosselin. 2009. Distribution and preliminary abundance estimates for cetaceans seen during Canada’s marine megafauna survey - A component of the 2007 Trans North Atlantic Sightings Survey (TNASS). DFO Canadian Science Advisory Secretariat, Research Document. 2009/031. vi + 28 pp.
Lebeuf, M., K.E. Bernt, S. Trottier, M. Noël, M.O. Hammill, and L. Measures. 2001. Tris (4-chlorophenyl) methane and tris (4-chlorophenyl) methanol in marine mammals from the Estuary and Gulf of St. Lawrence. Environmental Pollution 111:29-43.
Lebeuf, M., B. Gouteux, L. Measures, and S. Trottier. 2004. Levels and temporal trends (1988−1999) of polybrominated diphenyl ethers in beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary, Canada. Environmental Science and Technology 38:2971-2977.
Lebeuf, M., M. Noël, S. Trottier, and L. Measures. 2007. Temporal trends (1987-2002) of persistent, bioaccumulative and toxic (PBT) chemicals in beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary, Canada. Science of the Total Environment 383:216-231.
Lebeuf, M., S. Trottier, M. Noël, M. Raach, and L. Measures. 2010. A twenty year (1987-2007) trend of PBDEs in beluga from the St. Lawrence Estuary, Canada. Organohalogen Compounds 71:372-376.
Lebeuf, M., L. Measures, M. Noël, M. Raach, and S. Trottier. 2014a. A twenty-one year temporal trend of persistent organic pollutants in St. Lawrence Estuary beluga, Canada. Science of the Total Environment 485:377-386.
Lebeuf, M., M. Raach, L. Measures, N. Ménard, and M. Hammill. 2014b. Temporal trends of PBDEs in adult and newborn beluga (Delphinapterus leucas) from the St. Lawrence Estuary. DFO Canadian Science Advisory Secretariat, Research Document 2013/120. v + 11 pp.
Lemieux Lefebvre, S., R. Michaud, V. Lesage, and D. Berteaux. 2012. Identifying high residency areas of the threatened St. Lawrence beluga whale from fine-scale movements of individuals and coarse-scale movements of herds. Marine Ecology Progress Series 450:243-257.
Lesage, V., and M.C.S. Kingsley. 1995. Bilan des connaissances de la population de bélugas (Delphinapterus leucas) du Saint-Laurent. Rapport technique canadien des sciences halieutiques et aquatiques 2041. vii + 44 pp.
Lesage, V., and M.C.S. Kingsley. 1998. Updated status of the St. Lawrence River population of the beluga, Delphinapterus leucas. Canadian Field Naturalist 112:98-114.
Lesage, V., C. Barrette, M.C.S. Kingsley, and B. Sjare. 1999. The effect of vessel noise on the vocal behavior of belugas in the St. Lawrence River estuary, Canada. Marine Mammal Science 15:65-84.
Lesage, V., M.O. Hammill, and K.M. Kovacs. 2001. Marine mammals and the community structure of the Estuary and Gulf of St Lawrence, Canada: evidence from stable isotope analysis. Marine Ecology Progress Series 210:203-221.
Lesage, V., J.-F. Gosselin, M.O. Hammill, M.C.S. Kingsley, and J.W. Lawson. 2007. Ecologically and Biologically Significant Areas (EBSAs) in the Estuary and Gulf of St. Lawrence – A marine mammal perspective. Canadian Science Advisory Secretariat(CSAS) Research Document 2007/046. iii + 92 pp.
Lesage, V. 2014. Trends in the trophic ecology of St. Lawrence beluga (Delphinapterus leucas) over the period 1988-2012, based on stable isotope analysis. DFO Canadian Science Advisory Secretariat, Research Document 2013/126. iv + 25 pp.
Lesage, V., L. Measures, A. Mosnier, S. Lair, and P. Béland. 2014a. Mortality patterns in St. Lawrence Estuary beluga (Delphinapterus leucas), inferred from the carcass recovery data, 1983-2012. DFO Canadian Science Advisory Secretariat, Research Document 2013/118. iv + 23 pp.
Lesage, V., I.H. McQuinn, D. Carrier, J.-F. Gosselin, and A. Mosnier. 2014b. Exposure of the beluga (Delphinapterus leucas) to marine traffic under various scenarios of transit route diversion in the St. Lawrence Estuary. DFO Canadian Science Advisory Secretariat, Research Document 2013/125. iv + 28 pp.
Lewis, A.E., M.O. Hammill, M. Power, D.W. Doidge, and V. Lesage. 2009. Movement and aggregation of Eastern Hudson Bay beluga whales (Delphinapterus leucas): a comparison of patterns found through satellite telemetry and Nunavik traditional ecological knowledge. Arctic 62:13-24.
Lockyer, C., A.A. Hohn, W.D. Doidge, M.P. Heide-Jørgensen, and R. Suydam. 2007. Age determination in belugas (Delphinapterus leucas): a quest for validation of dentinal layering. Aquatic Mammals 33:293-304.
Loseto, L.L., P. Richard, G.A. Stern, J. Orr, and S.H. Ferguson. 2006. Segregation of Beaufort Sea beluga whales during the open-water season. Canadian Journal of Zoology 84:1743-1751.
Loseto, L.L., G.A. Stern, and S.H. Ferguson. 2008. Size and biomagnifications: how habitat selection explains beluga mercury levels. Environmental Science and Technology 42:3982-3988.
Luque, S.P., and S.H. Ferguson. 2010. Age structure, growth, mortality, and density of belugas (Delphinapterus leucas) in the Canadian Arctic: responses to environment? Polar Biology 33:163-178.
Lydersen, C., O.A. Nøst, P. Lovell, B.J. McConnell, T. Gammelsrød, C. Hunter, M.A. Fedak, and K.M. Kovacs. 2002. Salinity and temperature structure of a freezing Arctic fjord - monitored by white whales (Delphinapterus leucas). Geophysical Research Letters 29:2119-2122.
MacNeil, M.A., B.C. McMeans, N.E. Hussey, P. Vecsei, J. Svavarsson, K.M. Kovacs, C. Lydersen, M.A. Treble, G.B. Skomal, M. Ramsey, and A.T. Fisk. 2012. Biology of the Greenland shark Somniosus microcephalus. Journal of Fish Biology 80:991-1018.
Martel, L., M.J. Gagnon, R. Masse, A. Leclerc, and L. Tremblay. 1986. Polycyclic aromatic hydrocarbons in sediments from the Saguenay Fjord, Canada. Bulletin of Environmental Contamination and Toxicology 37:133-140.
Martin, A.R., and T.G. Smith. 1992. Deep diving in wild, free-ranging beluga whales, Delphinapterus leucas. Canadian Journal of Fisheries and Aquatic Sciences 49:462-466.
Martin, A.R., T.G. Smith, and O.P. Cox. 1993. Studying the behaviour and movements of High Arctic belugas with satellite telemetry. Symposia of the Zoological Society London 66:195-210.
Martin, A.R., and T.G. Smith. 1999. Strategy and capability of wild belugas, Delphinapterus leucas, during deep, benthic diving. Canadian Journal of Zoology 77:1783-1793.
Martin, A.R., P. Hall, and P.R. Richard. 2001. Dive behaviour of belugas (Delphinapterus leucas) in the shallow waters of western Hudson Bay. Arctic 54:276-283.
Martineau, D. 2012. Contaminants and health of beluga whales of the Saint Lawrence Estuary. Ecosystem Health and Sustainable Agriculture: Ecology and Animal health. L. Norrgren and J. M. Levengood. The Baltic University Programme, Uppsala University: 139-148.
Martineau, D., S. De Guise, M. Fournier, L. Shugart, C. Girard, A. Lagacé, and P. Béland. 1994. Pathology and toxicology of beluga whales from the St. Lawrence Estuary, Québec, Canada. Past, present and future. Science of the Total Environment 154:201-215.
Martineau, D., S. Lair, S. De Guise, and P. Béland. 1995. Intestinal adenocarcinomas in two beluga whales (Delphinapterus leucas) from the estuary of the St. Lawrence River. Canadian Veterinary Journal 36:563-565.
Martineau, D., A. Lagacé, P. Béland, R. Higgins, D. Armstrong, and L. R. Shugart. 1988. Pathology of stranded beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary, Québec, Canada. Journal of Comparative Pathology 98(3): 287-310.
Martineau, D., K. Lemberger, A. Dallaire, P. Labelle, T.P. Lipscomb, P. Michel, and I. Mikaelian. 2002. Cancer in wildlife, a case study: beluga from the St. Lawrence Estuary, Québec, Canada. Environmental Health Perspectives 110:285-292.
Martineau, D., K. Lemberger, A. Dallaire, P. Michel, P. Béland, P. Labelle, and T.P. Lipscomb. 2003. Cancer in the beluga: response. Environmental Health Perspectives 111: A78-A79.
McQuinn, I. H., V. Lesage, D. Carrier, G. Larrivée, Y. Samson, S. Chartrand, R. Michaud and J. Theriault. 2011. A threatened beluga (Delphinapterus leucas) population in the traffic lane: vessel-generated noise characteristics of the Saguenay-St. Lawrence Marine Park, Canada. The Journal of the Acoustical Society of America 130(6): 3661-3673.
Measures, L. 2004. Marine mammals and “wildlife rehabilitation” programs. DFO Canadian Scientific Advisory Secretariat, Research Document 2004/122. 39 pp.
Measures, L. 2008. Les causes de mortalité du béluga du Saint-Laurent. Naturaliste canadien 132:75-79.
Measures, L.N., and M. Olson. 1999. Giardiasis in pinnipeds from eastern Canada. Journal of Wildlife Diseases 35:779-782.
Ménard, N., R. Michaud, C. Chion, and S. Turgeon. 2014. Documentation of maritime traffic and navigational interactions with St. Lawrence Estuary beluga (Delphinapterus leucas) in calving areas between 2003 and 2012. DFO Canadian Science Advisory Secretariat, Research Document 2013/003. v + 24 pp.
Michaud, R. 1992. Fréquentation de la Baie Sainte-Marguerite par le béluga du Saint-Laurent (Delphinapterus leucas). INESL, Rimouski (Qc) pour le Ministère des Pêches et des Océans, Mont-Joli (Qc). Contrat # FP 707 1 5171. Available at: Maurice Lamontagne Institute, P.O. Box 1000, 850 Route de la mer, Mont-Joli, QC, CAN, G5H 3Z4. 34 pp.
Michaud, R. 1993. Distribution estivale du béluga du Saint-Laurent; synthèse 1986 à 1992. Rapport technique canadien des sciences halieutiques et aquatiques 1906. vi + 28 pp.
Michaud, R. 2005. Sociality and ecology of the odontocetes. Sexual segregation in vertebrates: ecology of the two sexes. K. E. Ruckstuhl and P. Neuhaus. AU, Cambridge University Press: p. 303-326.
Michaud, R. 2014. St. Lawrence Estuary beluga (Delphinapterus leucas) population parameters based photo-identification surveys, 1989-2012. DFO Canadian Science Advisory Secretariat, Research Document 2013/130. iv + 27 pp
Michaud, R., and P. Béland. 2001. Looking for trends in the endangered St. Lawrence Beluga population [A critique of Kingsley, M.C.S 1998. Population index estimates for the St. Lawrence Belugas, 1973-1995. Marine Mammal Science. 14: 508-530]. Marine Mammal Science 17:206-212.
Michaud, R., and V. Chadenet. 1990. Survols aériens pour l'estimation de la distribution printanière et des déplacements des bélugas du Saint-Laurent. Préparé par l'Institut National d'Écotoxicologie du Saint-Laurent, pour Pêches et Océans Canada. Available at: Maurice Lamontagne Institute, P.O. Box 1000, 850 Route de la mer, Mont-Joli, QC, CAN, G5H 3Z4. 36 pp.
Michaud, R., A. Vézina, N. Rondeau, and Y. Vigneault. 1990. Annual distribution and preliminary characterization of beluga (Delphinapterus leucas) habitats in the St. Lawrence. Canadian Journal of Fisheries and Aquatic Sciences 1757. 37 pp.
Mikaelian, I., M.-P. Tremblay, C. Montpetit, S.V. Tessaro, H.J. Cho, C. House, L. Measures, and D. Martineau. 1999. Seroprevalence of selected viral infections in a population of beluga whales (Delphinapterus leucas) in Canada. The Veterinary Record 144:50-51.
Mikaelian, I., J. Boisclair, J.P. Dubey, S. Kennedy, and D. Martineau. 2000. Toxoplasmosis in beluga whales (Delphinapterus leucas) from the St Lawrence Estuary: two case reports and a serological survey. Journal of Comparative Pathology 122:73-76.
Miller, M.A., I.A. Gardner, C. Kreuder, D.M. Paradies, K.R. Worchester, D.A. Jessup, E. Dodd, M.D. Harris, J.A. Ames, A.E. Packham, and P.A. Conrad. 2002. Coastal freshwater runoff is a risk factor for Toxoplasma gondii infection of southern sea otters (Enhydra lutris nereis). International Journal for Parasitology 32:997-1006.
Minns, C. K., R. G. Rendall, E. M. P. Chadwick, J. E. Moore and R. Green. 1995. Potential impact of climate change on the habitat and population dynamics of juvenile Atlantic Salmon (Salmo salar) in Eastern Canada. Climate Change and Northern Fish Populations. Canadian Special Publication of Fisheries and Aquatic Sciences 121. R. J. Beamish: p. 699-708.
Mitchell, E., and R.R. Reeves. 1981. Catch history and cumulative catch estimates of initial population size of cetaceans in the eastern Canadian Arctic. Reports of the International Whaling Commission 31:645-682.
Mooney, A.T., P.E. Nachtigall, M. Castellote, K.A. Taylor, A.F. Pacini, and J.-A. Esteban. 2008. Hearing pathways and directional sensitivity of the beluga whale, Delphinapterus leucas. Journal of Experimental Marine Biology and Ecology 362: 108-116.
Moore, S.E., K.E.W. Shelden, L.K. Litzky, B.A. Mahoney, and D.J. Rugh. 2000. Beluga, Delphinapterus leucas, habitat associations in Cook Inlet, Alaska. Marine Fisheries Review 62:60–80.
Moore, S.E., and H.P. Huntington. 2008. Arctic marine mammals and climate change: impacts and resilience. Ecological Applications 18:S157-S165.
Mosnier, A., V. Lesage, J.-F. Gosselin, S. Lemieux Lefebvre, M.O. Hammill, and T. Doniol-Valcroze. 2010. Information relevant to the documentation of habitat use by St. Lawrence beluga (Delphinapterus leucas), and quantification of habitat quality. DFO Canadian Science Advisory Secretariat Research Document 2009/098. iv + 35 pp.
Mosnier, A., T. Doniol-Valcroze, J.-F. Gosselin, V. Lesage, L. Measures, and M.O. Hammill. 2014. An age structured Bayesian population model for St. Lawrence Estuary beluga (Delphinapterus leucas). DFO Canadian Science Advisory Secretariat, Research Document 2013/127. v + 39 pp.
Muir, D.C.G., C.A. Ford, B. Rosenberg, R.J. Norstrom, M. Simon, and P. Béland. 1996. Persistent organochlorines in beluga whales (Delphinapterus leucas) from the St Lawrence River estuary-I. Concentrations and patterns of specific PCBs, chlorinated pesticides and polychlorinated dibenzo-p-dioxins and dibenzofurans. Environmental Pollution 93:219-234.
Murray, B.W., Michaud, R. and B.N. White 1999. Allelic and haplotype variation of Major Histocompatibility Complex class II DRB1 and DQB loci in the St Lawrence beluga (Delphinapterus leucas). Molecular Ecology 8: 1127-1159.
NAMMCO. 2012. NAMMCO Annual Report. North Atlantic Marine Mammal Commission. Tromsø, Norway. 642 pp.
NatureServe. 2014. NatureServe Status. [accessed February 5, 2014]
Narayana, S., J. Carscadden, J. B. Dempsin, M. F. O'Connell, S. Prinsenberg, D. G. Reddin, and N. Shackell. 1995. Marine climate off Newfoundland and its influence on salmon (Salmo salar) and capelin (Mallotus villosus). Climate Change and Northern Fish Populations. Canadian Special Publication of Fisheries and Aquatic Sciences 121. R. J. Beamish: p. 461-474.
Nielsen, O., R.E.A. Stewart, L. Measures, P. Duignan, and C. House. 2000. A morbillivirus antibody survey of Atlantic walrus, narwhal and beluga in Canada. Journal of Wildlife Diseases 36:508-517.
Nielsen, O., R.E.A. Stewart, K. Nielsen, L. Measures, and P. Duignan. 2001. Serologic survey of Brucella spp. antibodies in some marine mammals of North America. Journal of Wildlife Diseases 37:89-100.
National Oceanic and Atmospheric Administration (NOAA). 2014. 2013-2014 Bottlenose Dolphin Unusual Mortality Event in the Mid-Atlantic. [accessed September 24, 2014]
O'Brien, S.J., and J.F. Evermann. 1988. Interactive influence of infectious disease and genetic diversity in natural populations. Trends in Ecology & Evolution 3:254-259.
O'Corry-Crowe, G.O., C. Lydersen, M.P. Heide-Jørgensen, L. Hansen, L.M. Mukhametov, O. Dove, and K.M. Kovacs. 2010. Population genetic structure and evolutionary history of North Atlantic beluga whales (Delphinapterus leucas) from West Greenland, Svalbard and the White Sea. Polar Biology 33:1179-1194.
Office of Auditor General of Canada. 2010. Report of the Commissioner of the Environment and Sustainable Development to the House of Commons. Chapter 1. Oil Spills from Ships.
Ognetev, G.N. 1981. Studies on the ecology and taxonomy of the white whale (Delphinapterus leucas Pallas 1776) inhabiting the Soviet Arctic. Report of the International Whaling Commission 31:515-520.
Osterhaus, A.D.M.E., and E.J. Vedder. 1988. Identification of a virus causing recent distemper deaths. Nature 335:20.
Patenaude, N. J., J. S. Quinn, P. Beland, M. Kingsley and B. N. White. 1994. Genetic 2239 variation of the St. Lawrence beluga whale population assessed by DNA 2240 fingerprinting. Molecular Ecology 3(4): 375-381.
Payment, P., A. Berte, M. Prévost, B. Ménard, and B. Barbeau. 2000. Occurrence of pathogenic microorganisms in the Saint Lawrence River (Canada) and comparison of health risks for populations using it as their source of drinking water. Canadian Journal of Microbiology 46:565–576.
Payment, P., R. Plante, and P. Cejka. 2001. Removal of indicator bacteria, human enteric viruses, Giardia cysts, and Cryptosporidium oocysts at a large wastewater primary treatment facility. Canadian Journal of Microbiology 47:188-193.
Pelletier, É., I. Desbiens, P. Sargian, N. Côté, A. Curtosi, and R. St-Louis. 2009. Présence des hydrocarbures aromatiques polycycliques (HAP) dans les compartiments biotiques et abiotiques de la rivière et du fjord du Saguenay. Revue des Sciences de l'eau 22:235-251.
Perrin, W.F., and A.C. Myrick Jr. (Editors). 1980. Age determination of toothed whales and sirenians. Rep. Int. Whaling Comm., Spec. Issue 3, 229 p.
Peterson, C.H., S.D. Rice, J.W. Short, D. Esler, J.L. Bodkin, B.E. Ballachey, and D.B. Irons. 2003. Long-term ecosystem response to the Exxon Valdez oil spill. Science 302:2082-2086.
Philippa, J.D.W., F.A. Leighton, P.Y. Daoust, O. Nielsen, M. Pagliarulo, H. Schwantje, T. Shury, R. Van Herwunen, B.E.E. Martina, T. Kuiken, M.W.G. Van De Bildt, and A.D.M.E. Osterhaus. 2004. Antibodies to selected pathogens in free-ranging terrestrial carnivores and marine mammals in Canada. Veterinary Record 155:135-140.
Pippard, L., and H. Malcolm. 1978. White whales (Delphinapterus leucas). Observations on their distribution, population and critical habitats in the St. Lawrence and Saguenay rivers. Unpublished report prepared for Department of Indian and Northern Affairs, Parks Canada, Ottawa. 161 pp.
Pippard, L. 1985a. Patterns of movements of the St. Lawrence white whales. Canadian Wildlife Service & Parks Canada. Available at: Maurice Lamontagne Institute, P.O. Box 1000, 850 Route de la mer, Mont-Joli, QC, CAN, G5H 3Z4. 309 pp.
Pippard, L. 1985b. Status of the St. Lawrence River population of beluga, Delphinapterus leucas. Canadian Field Naturalist 99:438-450.
Plourde, S., J.J. Dodson, J.A. Runge, and J.C. Therriault. 2002. Spatial and temporal variations in copepod community structure in the lower St. Lawrence Estuary, Canada. Marine Ecology Progress Series 230:211-224.
Plourde, S., P. Galbraith, V. Lesage, F. Grégoire, H. Bourdage, J.-F. Gosselin, I. McQuinn, and M. Scarratt. 2014. Ecosystem perspective on changes and anomalies in the Gulf of St. Lawrence: a context in support to the management of the St. Lawrence beluga whale population. DFO Canadian Scientific Advisory Secretariat. Research Document 2013/129. v + 29 pp.
Postma, L.D., S.D. Petersen, J. Turgeon, M.O. Hammill, V. Lesage, and T. Doniol-Valcroze. 2012. Beluga whales in James Bay: a separate entity from Eastern Hudson Bay belugas? DFO Canadian Science Advisory Secretariat, Research Document 2012/074. iii + 23 pp.
Ray, G. C. 1981. The role of large organisms. Analysis of Marine Ecosystems. A. R. Longhurst, Academic Press, London, UK: p. 397-413.
Reeves, R.R. 1990. An overview of the distribution, exploitation and conservation status of belugas, worldwide. Pour l'avenir du béluga: Compte rendu du forum international. J. Prescott and M. Gauquelin. Québec, Les Presses de l'Université du Québec: p. 47-58.
Reeves, R.R., and S.K. Katona. 1980. Extralimital records of white whales (Delphinapterus leucas) in eastern North American waters. Canadian Field Naturalist 94:239-247.
Reeves, R.R., and E. Mitchell. 1984. Catch history and initial population of white whales (Delphinapterus leucas) in the river and Gulf of St. Lawrence, eastern Canada. Canadian Field Naturalist 111:63-121.
Reeves, R.R., and E. Mitchell. 1987. Catch history, former abundance, and distribution of white whales in Hudson Strait and Ungava Bay. Naturaliste canadien 114:1-65.
Reeves, R.R., and E. Mitchell. 1988. Distribution and seasonality of killer whales in the eastern Canadian Arctic. Rit Fiskideildar 11:136-160.
Reeves, R. R. and E. Mitchell. 1989. Status of white whales, Delphinapterus leucas, in Ungava Bay and Eastern Hudson Bay. Canadian Field Naturalist 103: 220–239.
Richard, P.R., A.R. Martin, and J.R. Orr. 1997. Study of summer and fall movements and dive behaviour of Beaufort Sea belugas, using satellite telemetry: 1992-1995. Environmental Studies Research Fund Reports 134. 26 pp + Appendices.
Richard, P.R., M.-P. Heide-Jørgensen, J.R. Orr, R. Dietz, and T.G. Smith. 2001. Summer and autumn movements and habitat use by belugas in the Canadian High Arctic and adjacent areas. Arctic 54:207–222.
Richard, P.R. 2010. Stock definition of belugas and narwhals in Nunavut. DFO Canadian Science Advisory Secretariat, Research Document 2010/022. iv + 14 pp.
Richard, P.R. 1991. Status of the belugas, Delphinapterus leucas, of southeast Baffin 2291 Island, Northwest Territories. Canadian Field Naturalist 105: 206-214. 2292.
Richard, P.R. 1993. Stocks of beluga, Delphinapterus leucas, in western and southern 2293 Hudson Bay. Canadian Field Naturalist 107: 524-532.
Richardson, W. J., D. Thomson, C. Greene Jr, and C. Malme. 1995. Marine Mammals and Noise. Vol., Academic Press, San Diego, CA
Rioux, È., V. Lesage, L.D. Postma, É. Pelletier, J. Turgeon, R.E.A. Stewart, G. Stern, and M.O. Hammill. 2012. Use of stable isotopes and trace elements to determine harvest composition and wintering assemblages of belugas at a contemporary ecological scale. Endangered Species Research 18:179-191.
Robeck, T.R., S.L. Monfort, P.P. Calle, J.L. Dunn, E. Jensen, J.R. Boehm, S. Young, and S.T. Clark. 2005. Reproduction, growth and development in captive beluga (Delphinapterus leucas). Zoo Biology 24:29-49.
Rolland, R.M., S.E. Parks, K.E. Hunt, M. Castellote, P.J. Corkeron, D.P. Nowacek, S.K. Wasser, and S.D. Kraus. 2012. Evidence that ship noise increases stress in right whales. Proceedings of the Royal Society B: Biological Sciences 279:2363-2368.
Rugh, D.J., K.E.W. Shelden, and R.C. Hobbs. 2010. Range contraction in a beluga whale population. Endangered Species Research 12:69-75.
Sears, R. and J. M. Williamson. 1982. A preliminary aerial survey of marine mammals for the Gulf of St. Lawrence to determine their distribution and relative abundance. Mingan Island Cetacean Study-Station de Recherche des Îles Mingan (MICS), Falmouth, Mass. and Sept-Îles (Québec).
Scarratt, M., S. Michaud, L. Measures, and M. Starr. 2014. Phytotoxin analyses in St. Lawrence Estuary beluga. DFO Canadian Science Advisory Secretariat, Research Document 2013/124 v + 16 pp.
Scheifele, P.M., S. Andrew, R.A. Cooper, M. Darre, F.E. Musiek, and L. Max. 2005. Indication of a Lombard vocal response in the St. Lawrence River beluga. Journal of Acoustical Society of America 117:1486-1492.
Schreer, J.F., and K.M. Kovacs. 1997. Allometry of diving capacity in air-breathing vertebrates. Canadian Journal of Zoology 75:339-358.
Schuurs, A.H., and H.A. Verheul. 1989. Effect of gender and steroids on the immune response. Journal of Steroid Biochemistry 35:157-172.
Selgrade, M.K. 2007. Immunotoxicity: the risk is real. Toxicology Sciences 100:328-332.
Sergeant, D.E. 1959. Age determination of odontocete whales from dentinal growth layers. Norsk Hvalfangsttid 48:273-288.
Sergeant, D.E. 1962. The biology and hunting of beluga or white whales in the Canadian Arctic. Fisheries Research Board of Canada, Arctic Unit 8:1-13.
Sergeant, D.E., and P.F. Brodie. 1969. Body size in white whales, Delphinapterus leucas. Journal of the Fisheries Research Board of Canada 26:2561-2580.
Sergeant, D.E. and P.F. Brodie. 1975. Identity, abundance, and present status of populations of white whales, (Delphinapterus leucas) in North America. Journal of the Fisheries Research Board of Canada 32: 1047-1054.
Sergeant, D.E. 1973. Biology of white whales (Delphinapterus leucas) in western Hudson Bay. Journal of the Fisheries Research Board of Canada 30:1065-1090.
Sergeant, D.E. 1986. Present status of white whales Delphinapterus leucas in the St. Lawrence Estuary. Naturaliste canadien 113:61-81.
Sergeant, D.E., and W. Hoek. 1988. An update of the status of white whales Delphinapterus leucas in the St. Lawrence Estuary, Canada. Biological Conservation 45:287-302.
Shelden, K.E.W., J.R. David, B.A. Mahoney, and M.I. Dalheim. 2003. Killer whale predation on belugas in Cook inlet, Alaska - Implications for a depleted population. Marine Mammal Science 19:529-544.
Smith, T.G. and M.O. Hammill. 1986. Population estimates of white whale, Delphinapterus leucas, in James Bay, Eastern Hudson bay, and Ungava Bay. 2364 Canadian Journal of Fisheries and Aquatic Sciences 43(10): 1982-1987
Smith, A., P. Richard, J. Orr, and S. Ferguson. 2007. Study of the use of the Nelson Estuary and adjacent waters by beluga whales equipped with satellite-linked radio transmitters: 2002-2005. June 2007 Final Report to Manitoba Hydro. 45 pp.
Smith, T.G., M.O. Hammill, and A.R. Martin. 1994. Herd composition and behaviour of belugas, Delphinapterus leucas, in two Canadian Arctic estuaries. Meddelelser om Grøenland Bioscience 39:175-184.
Smith, T.G., and A.R. Martin. 1994. Distribution and movements of belugas, Delphinapterus leucas, in the Canadian High Arctic. Canadian Journal of Fisheries and Aquatic Sciences 51:1653-1663.
Smolker, R.A., J. Mann, and B.B. Smuts. 1993. Use of signature whistles during separations and reunions by wild bottlenose dolphin mothers and infants. Behavioral Ecology and Sociobiology 33:393-402.
SOM. 2007. Étude auprès des plaisanciers navigants dans le parc marin Saguenay-Saint‐Laurent, Rapport final présenté à Parcs Canada, Service de la recherche en sciences sociales, Centre de services du Québec. 63p.
St. Aubin, D.J., T.G. Smith, and J.R. Geraci. 1990. Seasonal epidermal molt in beluga, Delphinapterus leucas. Canadian Journal of Zoology 68:359-367.
Stewart, B.E., and R.E. Stewart. 1989. Delphinapterus leucas. Mammalian Species 336:1-8.
Stewart, R.E.A., S.E. Campana, C.M. Jones, and B.E. Stewart. 2006. Bomb radiocarbon dating calibrates beluga (Delphinapterus leucas) age estimates. Canadian Journal of Zoology 84:1840-1852.
Suydam, R.S. 2010. Age, growth, reproduction and movements of beluga whales (Delphinapterus leucas) from the eastern Chukchi Sea, University of Washington. Ph.D. thesis.
Suydam, R.S., L.F. Lowry, K.J. Frost, G.M. O’Corry-Crowe and D. Pikok, Jr. 2001. Satellite tracking of eastern Chukchi Sea beluga whales into the Arctic Ocean. Arctic 54: 237–243.
Taber, S., and P. Thomas. 1982. Calf development and mother-calf spatial relationships in southern right whales. Animal Behaviour 30:1072-1083.
Taubenberger, J.K., M. Tsai, A.E. Kraft, J.H. Lichy, A.H. Reid, R.Y. Shulman, and T.P. Lipscomb. 1996. Two morbilliviruses implicated in bottlenose dolphin epizootics. Emerging Infectious Diseases 2:213-216.
Theriault, G., G. Gibbs, and C. Tremblay. 2002. Cancer in belugas from the St. Lawrence estuary. Environmental Health Perspectives 110:A562.
Tomilin, A.G. 1967. Mammals of the U.S.S.R. and adjacent countries. Volume IX, Cetacea. Izdatel'stvo Akademi Nauk SSSR, Moscow. Translated from Russian. Israël Program for Scientific. Translation, Jerusalem, 1967. Available at: Maurice Lamontagne Institute, P.O. Box 1000, 850 Route de la mer, Mont-Joli, QC, CAN, G5H 3Z4. 717 pp.
Tremblay, R. 1993. Iroquoian Beluga Hunting on île Verte. pp. 121-137. In J.F. Pendergast and C. Chapdelaine (eds.) Essays in St. Lawrence Iroquoian Archaeology. Occasional Papers in Northeastern Archaeology 8. Copetown Press, Dundas, Ontario. 161 pp.
Truchon, M.-H., L. Measures, V. L’Hérault, J.-C. Brêthes, P.S. Galbraith, M. Harvey, S. Lessard, M. Starr, and N. Lecomte. 2013. Marine mammal strandings and environmental changes: a 15-year study in the St. Lawrence ecosystem. Public Library Of Science (PLoS) ONE 8:e59311.
Turgeon, J., P. Duchesne, G.J. Colbeck, L.D. Postma, and M.O. Hammill. 2012. Spatiotemporal segregation among summer stocks of beluga (Delphinapterus leucas) despite nuclear gene flow: implication for the endangered belugas in eastern Hudson Bay (Canada). Conservation Genetics 13:419-433.
Tyack, P.L., and C.W. Clark. 2000. Communication and acoustic behavior of dolphins and whales. pp. 156-224. in W.W.L Au and R.R Fay (eds.). Hearing by whales and dolphins, Springer, New York.
Tyack, P.L. 2008. Implications for marine mammals of large-scale changes in the marine acoustic environment. Journal of Mammalogy 89:549-558.
Van Dolah, F.M. 2000. Marine algal toxins: Origins, health effects, and their increased occurrence. Environmental Health Perspectives 108:133-141.
Villeneuve, S., and L. Quilliam. 1999. Les risques et les conséquences environnementales de la navigation sur le Saint-Laurent. Rapport scientifique et technique ST-188. Centre Saint-Laurent. Montréal, QC. 160 pp.
Vladykov, V.D. 1944. Études sur les mammifères aquatiques. III. Chasse, biologie et valeur économique du marsouin blanc ou béluga (Delphinapterus leucas) du fleuve et du golfe du Saint-Laurent. Département des Pêcheries, Province de Québec. 194 pp.
Vladykov, V.D. 1946. Études sur les mammifères aquatiques. IV. Nourriture du marsouin blanc (Delphinapterus leucas) du fleuve Saint-Laurent. Département des Pêcheries, Province de Québec Numéro 17. 119 pp.
Watts, P.D., B.A. Draper, and J. Henrico. 1991. Preferential use of warm water habitat by adult beluga whales. Journal of Thermal Biology 16:57-60.
Wild Species. 2010. Wild Species General Status. Web Site: www.wildspecies.ca [accessed April 14, 2014]
Wright, A.J. 2009. Report of the workshop on assessing the cumulative impacts of underwater noise with other anthropogenic stressors on marine mammals: From ideas to action. Okeanos-Foundation for the Sea 26-29.
Risk assessment for marine spills in Canadian waters. Phase 1: Oil spills South of 60th Parallel. Prepared for Transport Canada. Report number 131-17593-00.
Biographical Summary of Report Writers
Katy Gavrilchuk is a biologist under contract to the Marine Mammal Research group of Fisheries and Oceans Canada. She recently completed her Master’s research at Université Laval in Québec on trophic niche partitioning of four species of rorquals in the Gulf of St. Lawrence following the collapse of groundfish stocks. She has worked as a field biologist for the Mingan Island Cetacean Study, a non-profit organization in Québec, since 2007.
Véronique Lesage has worked for Fisheries and Oceans Canada, Maurice Lamontagne Institute, Québec, for 14 years as scientist in charge of Cetacean Ecology Research, with a special focus on species at risk. She has been studying Belugas and other marine mammals over the past 25 years. Dr. Lesage has been a member of the Board of Scientific Advisors for the Society for Marine Mammalogy from 2008 to 2014 and a member of Arcticnet and Québec Ocean. She holds adjunct professor status at Université Laval and Université du Québec à Rimouski (UQAR). Much of her research involves population, ecology and behaviour studies of Belugas and baleen whales. Her past and current research on St. Lawrence Belugas has focused on examining effects of anthropogenic noise on Beluga communication, exposure to noise in their preferred habitat, trophic ecology, habitat use, and population dynamics. She is the lead author of three reviews on the status and biology of SLE Belugas, including one prepared for COSEWIC in 1998, as well as the most recent one conducted by DFO in 2013. She has published over 30 papers in the primary scientific literature on many aspects of arctic and temperate-region seal and whale research, and nearly 50 reports and advisory documents for DFO, of which half dealt specifically with Belugas in the Arctic or the St. Lawrence Estuary.
- Footnote 1
This status is expected to be changed to G4T1Q to follow the recent change in S-rank from S2 to S1 (Gauthier pers. comm. 2014).
- Date Modified: