Salish sucker (Catostomus sp.) proposed recovery strategy: chapter 3
3. Critical habitat
3.1 Identification of critical habitat
Critical habitat is defined in the Species at Risk Act (2002) section 2(1) as:
“…the habitat that is necessary for the survival or recovery of a listed wildlife species and that is identified as the species’ critical habitat in a recovery strategy or in an action plan for the species.” [s. 2(1)]
Species at Risk Act (SARA) defines habitat for aquatic species at risk as:
“… spawning grounds and nursery, rearing, food supply, migration and any other areas on which aquatic species depend directly or indirectly in order to carry out their life processes, or areas where aquatic species formerly occurred and have the potential to be reintroduced.” [s. 2(1)]
For the Salish Sucker, critical habitat is identified to the extent possible, using the best information currently available. The critical habitat identified in this recovery strategy describes the geospatial area that contains the biophysical features, functions and attributes necessary for the survival or recovery of the species. The identified critical habitat includes all habitats within occupied watersheds considered to be high quality or potentially high quality for the Salish Sucker, and constitutes the habitat deemed to be necessary to achieve the population and distribution objectives.
The current area identified may not be sufficient to achieve the population and distribution objectives for the species and its description will need to be further refined. The schedule of studies outlines the activities required to identify additional critical habitat or refine the description of the existing critical habitat in order to support its protection.
3.1.1 Information and methods used to identify critical habitat
Critical habitat for the Salish Sucker was defined using in-stream habitat characteristics at the scale of the reach, a natural unit of stream habitat that ranges from hundreds to thousands of metres in length (Frissell et al. 1986). There are three reasons for adopting this scale. First, the reach scale corresponds to the distribution of subpopulations within watersheds and usually contains all habitat types used during the life cycle (Pearson 2004a). Second, the ‘channel units’ of critical habitat (riffles and pools) are dynamic and frequently move during flood events in these streams. Effective protection and management of critical habitat in these circumstances must allow for normal channel processes and must, therefore, occur at a spatial scale larger than the channel unit. The reach scale is the next largest in accepted stream habitat classifications (Frissell et al. 1986; Imhof et al. 1996) and by definition represents relatively homogenous segments of stream demarcated by distinct geomorphic or land use transitions. Third, the reach scale corresponds most closely to that of land ownership in these watersheds and, consequently, to most recovery actions.
The protocol used for identifying Salish Sucker critical habitat was consistent with guidelines for documenting habitat quality and use by species at risk (Rosenfeld & Hatfield 2006; Fisheries and Oceans Canada 2007) and the approach and results have been reviewed and approved by the Pacific Science Advise Review Committee (Pearson 2008). Specifically, area of deep pool habitat in each reach (a key habitat feature) was used to quantify carrying capacity and the degree of hypoxia was identified as the key variable in determining its quality. Its spatial configuration was mapped and a rough estimate was provided of the present amount that is of sufficient quality to support Salish Suckers. The supply of habitat was equated with population and distribution objectives and advice was provided on the feasibility of restoring additional habitat. All identified critical habitat is believed to be required to meet the population and distribution objectives. Advice was provided on the extent to which threats can lower the quality and quantity of critical habitat.
Defining width of riparian reserve strips
Riparian reserve strips are included in critical habitat for Salish Sucker. The required widths of riparian reserve strips vary among sites and should be defined in reach scale assessments. Riparian reserve strips must be sufficient to control sediment entry to the stream from overland flow, to prevent excessive bank erosion and to buffer stream temperatures. Reserve areas will also remove significant amounts of nitrate and phosphorous from groundwater, although their efficacy depends strongly on hydrogeologic conditions (Martin et al. 1999; Wigington et al. 2003; Puckett 2004;). The effectiveness of a riparian reserve in preventing materials (sediment, nutrients, toxins, etc.) from entering a stream depends strongly on its longitudinal continuity and its lateral width (Weller et al. 1998). Consequently, riparian reserves in critical habitat reaches should be continuous and sufficiently wide. In open landscapes, such as agricultural fields, vegetation from reserve areas will collect windblown insects (Whitaker et al. 2000). Such insects, falling from riparian vegetation into the water constitute an important food source for drift-feeding fishes in headwater streams (Schlosser 1991; Allan et al. 2003;). More than 30 m of riparian vegetation may be required for full mitigation of warming (Brown & Krygier 1970; Lynch et al. 1984; Castelle et al. 1994;), and siltation (Moring 1982; Davies & Nelson 1994; Kiffney et al. 2003), and for long-term maintenance of channel morphology (Murphy et al. 1986; Murphy & Koski 1989). At least 10 m are required to maintain levels of terrestrial carbon (i.e., leaf) and food (invertebrate) inputs similar to those of forested landscapes (Culp & Davies 1983). Reserves as narrow as 5 m provide significant protection from bank erosion and sediment deposition from overland flow (Lee et al. 2003; McKergow et al. 2003).
Failure to maintain an adequate riparian reserve as part of critical habitat is likely to cause population-level impacts. In habitats lacking sufficient flow or groundwater, absence of shade may increase water temperatures to harmful levels. Increased erosion due to poorer bank stability will cause sediment deposition in riffles, and impair spawning and incubation. Nutrient loading will be higher in reaches without adequate riparian vegetation (Martin et al. 1999; Dhondt et al. 2002; Lee et al. 2003) and is likely to contribute to hypoxia through eutrophication. Solar radiation in nutrient rich reaches lacking adequate riparian shading (Kiffney et al. 2003) will also contribute to eutrophication and hypoxia.
Specific research on the widths of riparian reserves required to protect key habitat attributes for Salish Sucker in particular has not been done, although this relationship has been investigated for other fish species. Mature Salish Suckers are benthic feeders (Scott & Crossman 1973) indicating that they are less dependant on insects of terrestrial origin than drift-feeding fishes like salmonids. They also appear tolerant of slightly higher water temperatures than salmonids (Wehrly et al. 2003), suggesting a reduced need for shading, but this may not be true under future climate warming scenarios. However, Salish Suckers are likely to be as vulnerable as salmonids to habitat degradation caused by sedimentation, loss of scope for natural channel movement, reduction in large woody debris supply, and invasive plant overgrowth of riffles fuelled by nutrient loading and riparian loss. Benthic insectivores, like Salish Suckers, are among the most sensitive fish species to loss of wooded riparian areas (Stauffer et al. 2000), probably due to the impacts of siltation and alterations to macroinvertebrate community structure (Kiffney et al. 2003; Allan 2004). Overall, there is little reason to believe that Salish Suckers require narrower or wider buffers than salmonids.
It should be noted that unidirectional transport of sediment in flowing waters means that riparian reserve strips upstream of critical habitat reaches are important in minimizing sedimentation and other impacts within instream critical habitat. For this reason stewardship programs should promote the establishment of continuous riparian reserve strips of native vegetation throughout the watershed, not just along critical habitat reaches.
Widths of riparian reserve strips included in critical habitat for Salish Sucker were assessed using Geographic Information Systems (GIS)-based methodology adapted directly from and consistent with the British Columbia Riparian Areas Regulation (RAR, Reg. 837 under the Fish Protection Act [S.B.C. 1997, c. 21], Province of British Columbia 2006). The B.C. Ministry of Environment (B.C. MoE) and Fisheries and Oceans Canada (DFO) developed and implemented this methodology for determining riparian reserve widths required to maintain riparian function and protect fish habitat. The Riparian Areas Regulation (RAR) was developed under the provincial Fish Protection Act to protect “salmonids, game fish, and regionally significant fish” from the impacts of land development. In the absence of definitive data for a SARA-listed species, this is a reasonable standard to apply in the identification of critical habitat because it represents a benchmark and standard methodology to which both federal and provincial agencies responsible for management of species at risk have already agreed, and it forms the basis of the methodology employed. Further details of methods and an assessment of existing riparian vegetation in these areas can be found in Pearson (2008).
3.1.2 Identification of critical habitat: Geospatial
Critical habitat for the Salish Sucker consists of relatively homogenous segments of stream demarcated by distinct geomorphic or land use transitions, or otherwise known as reaches, within the Salmon River, Bertrand Creek, Pepin Brook, Fishtrap Creek, Salwein Creek/Hopedale Slough, Atchelitz/Chilliwack/ Semmihault Creeks, Elk Creek/Hope Slough, Mountain Slough, Agassiz Slough and Miami River watersheds. Only those reaches that include more than 50 m of continuous pool with a water depth exceeding 70 cm under summer low flow conditions constitute critical habitat. Critical habitat within these reaches includes all the aquatic habitat features and attributes identified in section 3.1.3 and riparian reserve strips of native vegetation on both banks for the entire length of the reach. Riparian reserve strips are continuous and extend laterally (inland) from the top of bank to varying widths identified for each reach in Appendix 2. The width of the riparian reserve strip for each reach is equal to the widest zone of sensitivity (ZOS) calculated for each of five riparian features, functions and conditions: large woody debris supply for fish habitat and maintenance of channel morphology, localized bank stability, channel movement, shade, and insect and debris fall. The ZOS values are calculated using methods consistent with those used under the British Columbia Riparian Areas Regulation (Reg. 837) under the Fish Protection Act (S.B.C. 1997, c. 21).
The combined length of critical habitat identified for the Salish Sucker in this recovery strategy is 145.74 km (of 329.1 km of surveyed stream channel). Maps showing the location of critical habitat and the width of riparian reserve strips for identified reaches are provided in Appendix 2.
The areas identified as critical habitat are those considered necessary to support the species survival and recovery and to reach the population and distribution objectives for Salish Sucker. Additional areas may be identified as critical habitat in subsequent action plans if new information determines that they are necessary to the survival and recovery of Salish Sucker.
3.1.3 Identification of Critical Habitat: Biophysical Functions Features and Their Attributes
Within the identified geographic boundaries, the critical habitat supports the following biophysical functions, features and attributes:
Deep pool habitat
Deep pool habitat is the biophysical feature that supports the life cycle functions of feeding and rearing for adult and juvenile Salish Suckers. Adults and larger juveniles (>70 mm) are concentrated in reaches containing long stretches of pool habitat that exceed 70 cm in depth at low flow (Pearson 2004a). As the primary habitat used for the majority of the life cycle, this feature is comprised of all deep pool habitats in reaches that contain more than 50 m of continuous channel and that have a depth exceeding 70 cm. The 50 m threshold was chosen because it is the minimum length of all reaches known to contain moderate or high densities of Salish Suckers (catch per unit effort > 1.8 individual per trapFootnote 2, Pearson, unpublished data). It also includes reaches that contain excellent physical habitat (i.e., meet the 50 m length threshold and 70 cm minimum depth), but where severe hypoxia appears to currently limit Salish Sucker numbers (i.e., this is habitat critical to recovery).
Essential attributes:
- A minimum depth of 70 cm is an essential attribute of deep pool habitat features.
- Dissolved oxygen levels of ≥ 4 mg/L
- Water temperatures between 6 and 23ºC
- Adequate quantity and quality of food supply (terrestrial and aquatic insects)
- Little or no additional sediment
- Few or no additional nutrients
- Few or no additional toxins
Riffle Habitat
Riffle habitats are an essential feature of critical habitat used by Salish Suckers for spawning and incubation. Riffles tend to be rare (and potentially limiting) in the reaches occupied by high densities of Salish Suckers, which consist predominantly of headwater ponds and marshes (Pearson 2004a). Consequently, all riffle habitats within reaches containing more than 50 m of habitat with water depths exceeding 70 cm are identified as critical. In some reaches fish leave their ‘home’ reach to spawn (Pearson & Healey 2003). The riffles where this is known to occur are within identified critical habitat reaches, but other undocumented spawning sites outside identified critical habitat may exist.
Essential Attributes:
- Cobble or gravel substrate
- Dissolved oxygen levels of ≥ 4 mg/L
- Water temperatures between 6 and 23ºC
- Sufficient water flow to support riffles
- Adequate quantity and quality of food supply (terrestrial and aquatic insects)
- Little or no additional sediment
- Few or no additional nutrients
- Few or no additional toxins
Shallow pool and glide habitats
Shallow pools and glides less than 40 cm in depth are an essential feature of critical habitat that are used by young-of-the-year Salish Suckers (<70 mm fork length) as a nursery habitat for feeding and rearing, although they are occasionally captured in deeper water (Pearson 2004a). All shallow pool and glide habitats within reaches that contain more than 50 m of continuous habitat and water depths exceeding 70 cm are designated as critical as it is potentially limiting as nursery habitat.
Essential Attributes:
- A minimum depth of 40 cm is an essential attribute of deep pool habitat features.
- Dissolved oxygen levels of ≥ 4 mg/L
- Water temperatures between 6 and 23ºC
- Adequate quantity and quality of food supply (terrestrial and aquatic insects)
- Little or no additional sediment
- Few or no additional nutrients
- Few or no additional toxins
Riparian Habitats
Riparian habitats with native vegetation are an essential feature of critical habitat that maintain the instream habitat attributes necessary to support Salish Suckers’ use of these areas for biological functions of feeding, rearing and spawning. Native riparian vegetation is an essential attribute of riparian habitat features. Loss of riparian vegetation contributes to bank erosion, siltation, water temperature elevation, and nutrient inputs, all of which directly degrade instream critical habitat.
Failure to maintain an adequate riparian reserve as part of critical habitat is likely to cause population-level impacts. In habitats lacking sufficient flow or groundwater, absence of shade may increase water temperatures to harmful levels. Increased erosion due to poorer bank stability will cause sediment deposition in riffles, and impair spawning and incubation. Nutrient loading will be higher in reaches without adequate riparian vegetation (Martin et al. 1999; Dhondt et al. 2002; Lee et al. 2003) and is likely to contribute to hypoxia through eutrophication. Solar radiation in nutrient rich reaches lacking adequate riparian shading (Kiffney et al. 2003) will also contribute to eutrophication and hypoxia.
Essential Attributes:
- Native riparian vegetation
- Continuous for the entire length of the reach
- Extends laterally (inland) from the top of the bank to a widthFootnote 3 equal to the widest zone of sensitivity, or ZOS (calculated using methods consistent with those used under the BC Riparian Areas Regulation), in order to ensure the following functions:
- Protects the integrity of other aquatic features such as riffle and shallow pool habitat.
- Provides large and small woody debris
- Provides localized bank stability
- Provides shade to buffer instream temperatures
- Provides terrestrial insect input
- Limits entry of added nutrients
- Maintains natural channel morphology
Summary of critical habitat features functions and attributes
Table 4 summarizes the essential functions, features and attributes of the Salish Sucker critical habitat identified in this recovery strategy:
| Geospatial location | Life Stage | Function | Feature (s) | Attribute(s) |
|---|---|---|---|---|
| Reaches within Salmon River, Bertrand Creek, Pepin Brook, Fishtrap Creek, Salwein Creek/Hopedale Slough, Atchelitz/Chilliwack/ Semmihault Creeks, Elk Creek/Hope Slough, Mountain Slough, Agassiz Slough and Miami River watersheds | Adults and Juveniles (> 70 mm fork length) |
Feeding and Rearing | Deep Pool Habitat |
|
| Reaches within Salmon River, Bertrand Creek, Pepin Brook, Fishtrap Creek, Salwein Creek/Hopedale Slough, Atchelitz/Chilliwack/ Semmihault Creeks, Elk Creek/Hope Slough, Mountain Slough, Agassiz Slough and Miami River watersheds | Juveniles (<70 mm fork length) |
Feeding and Rearing | Shallow Pool and Glide Habitat |
|
| Reaches within Salmon River, Bertrand Creek, Pepin Brook, Fishtrap Creek, Salwein Creek/Hopedale Slough, Atchelitz/Chilliwack/ Semmihault Creeks, Elk Creek/Hope Slough, Mountain Slough, Agassiz Slough and Miami River watersheds | Adult | Spawning and incubation | Riffle Habitat |
|
| Reaches within Salmon River, Bertrand Creek, Pepin Brook, Fishtrap Creek, Salwein Creek/Hopedale Slough, Atchelitz/Chilliwack/Semmihault Creeks, Elk Creek/Hope Slough, Mountain Slough, Agassiz Slough and Miami River watersheds | Adult and juveniles | Spawning, incubation, feeding and rearing | Riparian habitat |
|
3.2 Activities likely to result in destruction of critical habitat
The definition of destruction is interpreted as:
Destruction of critical habitat would result if any part of the critical habitat were degraded, either permanently or temporarily, such that it would not serve its function when needed by the species. Destruction may result from single or multiple activities at one point in time or from cumulative effects of one or more activities over time.
Under SARA, critical habitat must be legally protected from destruction once it is identified. This will be accomplished through a s.58 Order, which will prohibit the destruction of the identified critical habitat unless permitted by the Minister of Fisheries and Oceans Canada pursuant to the conditions of SARA.
The Minister of Fisheries and Oceans invites all interested Canadians to submit comments on the potential use of a s.58 Order to protect the critical habitat of the Salish Sucker as soon as possible. Please note that, pursuant to s.58, any such Order must be operational within 180 days of the posting of the final version of the Recovery Strategy, or Action Plan, that identifies critical habitat.
The activities described in this table are neither exhaustive nor exclusive and have been guided by the Threats described in section 2.1 of the recovery strategy for the species. The absence of a specific human activity does not preclude, or fetter the department’s ability to regulate it pursuant to SARA. Furthermore, the inclusion of an activity does not result in its automatic prohibition as it is destruction of critical habitat that is prohibited. Since habitat use is often temporal in nature, every activity is assessed on a case-by-case basis and site-specific mitigation is applied where it is reliable and available. In every case, where information is available, thresholds and limits are associated with attributes to better inform management and regulatory decision-making. However, in many cases the knowledge of a species and its critical habitat may be lacking and in particular, information associated with a species or habitats thresholds of tolerance to disturbance from human activities, is lacking and must be acquired.
Gaps in our understanding of the attributes of critical habitat features and the activities that could affect them will be a focus for research in one or more action plans.
| Activity (Related Threat) |
Affect – Pathway | Function Affected | Feature Affected | Attribute Affected |
|---|---|---|---|---|
Over-application of Fertilizer (Hypoxia) |
Nutrient loading in streams through excessive application of manure is the most common cause of the chronic late summer hypoxia that affects many reaches inhabited by Salish Suckers (Schreier et al. 2003). | Feeding, Rearing, Spawning and Incubation | Deep Pools Shallow Pools and Glides Riffles |
Oxygen levels Nutrient levels |
Drainage projects (Physical destruction of habitat and sediment deposition) |
Dredging, dyking, and channelization directly destroy habitat, cause sediment deposition in riffles, and reduce base flow. | Feeding, Rearing, Spawning and incubation | Deep Pools Shallow Pools and Glides Riffles |
Sediment levels Water flow Water levels Riffle structure |
Urban storm drainage (Toxicity, sediment deposition and seasonal lack of water) |
Storm drain systems that discharge directly to creeks are major sources of toxic contamination and sediment. They also reduce base flow by inhibiting groundwater recharge. | Feeding, Rearing, Spawning and Incubation | Deep Pools Shallow Pools and Glides Riffles |
Sediment levels Toxicity levels Water flow Water levels |
Riparian vegetation removal (Hypoxia and Sediment Deposition) |
Loss of riparian vegetation causes increased erosion and sediment deposition, elevated water temperatures that can contribute to eutrophication and hypoxia, reduced supplies of terrestrially derived food, and increased nutrient loading. | Feeding, Rearing, Spawning and Incubation | Riparian Habitat | Native riparian vegetation Bank stability Supply of woody debris Channel movement Shade Quantity and quality of terrestrial insects |
Riparian vegetation removal (Hypoxia and Sediment Deposition) |
Loss of riparian vegetation causes increased erosion and sediment deposition, elevated water temperatures that can contribute to eutrophication and hypoxia, reduced supplies of terrestrially derived food, and increased nutrient loading. | Feeding, Rearing, Spawning and Incubation | Deep Pools Shallow Pools and Glides Riffles |
Water temperature Sediment levels Nutrient levels Oxygen levels Supply of terrestrial insects |
Mowing native vegetation (hypoxia and sediment deposition) |
Mowing or removal of native vegetation in the riparian portion of critical habitat prevents the establishment of mature riparian vegetation and causes elevated erosion and sediment deposition, elevated water temperatures, reduced supplies of terrestrially derived food, and increased nutrient loading. | Feeding, Rearing, Spawning and Incubation | Riparian Habitat | Native riparian vegetation Bank stability Supply of woody debris Channel movement Shade Quantity and quality of terrestrial insects |
Mowing native vegetation (hypoxia and sediment deposition) |
Mowing or removal of native vegetation in the riparian portion of critical habitat prevents the establishment of mature riparian vegetation and causes elevated erosion and sediment deposition, elevated water temperatures, reduced supplies of terrestrially derived food, and increased nutrient loading. | Feeding, Rearing, Spawning and Incubation | Deep Pools Shallow Pools and Glides Riffles |
Water temperature Sediment levels Nutrient levels Oxygen levels Supply of terrestrial insects |
Livestock access to creeks (Hypoxia and sediment deposition) |
Livestock damage habitat by trampling or causing erosion that clogs riffles with sediment. Access also contributes to nutrient loading. | Spawning and Incubation | Riffles | Sediment levels Nutrient levels Oxygen levels |
Livestock access to creeks (Hypoxia and sediment deposition) |
Livestock damage habitat by trampling or causing erosion that clogs riffles with sediment. Access also contributes to nutrient loading. | Feeding Rearing |
Deep Pools Shallow Pools and Glides |
Nutrient levels Oxygen levels |
Excessive water withdrawal (Seasonal lack of water and hypoxia) |
Water extraction (surface or ground), especially during dry periods, reduces flows and can contribute to hypoxia and drying of riffles needed for spawning. | Feeding Rearing Spawning and Incubation |
Deep Pools Shallow Pools and Glides Riffles |
Water levels Water flow Oxygen levels Water temperature Riffle structure |
| Excessive sediment releases (Sediment deposition) |
Sediment deposition in spawning substrate and inhibition of the flow of oxygen-rich water to eggs and larvae during incubation. | Spawning and Incubation | Riffles | Sediment levels Water flow Oxygen levels |
| Activity | Bert | Pep | Fish | Salm | Salw | Chill | Miam | Moun | Agas | Hope | L.Cam |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Over application of fertilizer | major concern | moderate concern | major concern | major concern | moderate concern | major concern | major concern | major concern | moderate concern | major concern | major concern |
| Drainage projects | moderate concern | minor concern | major concern | moderate concern | moderate concern | major concern | major concern | major concern | minor concern | major concern | moderate concern |
| Urban storm drainage | major concern | no concern | major concern | no concern | no concern | major concern | moderate concern | no concern | major concern | moderate concern | minor concern |
| Riparian vegetation removal | moderate concern | minor concern | major concern | moderate concern | major concern | major concern | major concern | major concern | moderate concern | major concern | moderate concern |
| Livestock access to creeks | minor concern | minor concern | minor concern | moderate concern | moderate concern | moderate concern | moderate concern | moderate concern | minor concern | moderate concern | moderate concern |
| Excessive water withdrawal | major concern | minor concern | moderate concern | major concern | minor concern | moderate concern | moderate concern | moderate concern | moderate concern | moderate concern | moderate concern |
| Excessive sediment releases | minor concern | major concern | moderate concern | minor concern | minor concern | moderate concern | minor concern | major concern | minor concern | moderate concern | minor concern |
Bert=Bertrand Creek; Pep=Pepin Brook; Fish=Fishtrap Creek; Salm=Salmon River; Salw=Salwein Creek/Hopedale Slough; Chill=Atchelitz/Little Chilliwack/Semmihault/Luckacuck Creeks; Miam=Miami River; Moun= Mountain Slough; Agas=Agassiz Slough; Hope = Elk Creek/Hope Slough; L.Cam=Little Campbell River
3.3 Schedule of studies to identify critical habitat
This recovery strategy includes an identification of critical habitat to the extent possible, based on the best available information. Critical habitat areas and attributes that support life functions during the adult and spawning life stages have been identified. Further research is required to determine if all critical habitat has been identified and to refine our understanding of spawning areas as well as habitats used by juveniles, as per Table 7 below. At present, Salish Suckers are known to occur in 10 watersheds. Critical habitat areas, features and attributes that support functions required by adult and spawning life stages have been identified for these populations. Further research is required to locate and confirm additional spawning areas and critical habitat for juveniles.
| Study | Description | Timeframe |
|---|---|---|
| Surveys of additional areas for critical habitat features | Approximately 60 km of channel in watersheds containing populations needs to be surveyed to determine if critical habitat features (eg. deep pools) are present | 2011-2014 |
| Improve information used to identify juvenile critical habitat | Intensive trapping/seining in habitats near known spawning sites to gather more information on juvenile habitat use. | 2012-2016 |
| Identify spawning sites for all populations | Visual identification of spawning site use. | 2011-2016 |
3.4 Knowledge gaps in Salish sucker biology
Additional studies should address the following data needs related to specific threats to the Salish Sucker. This information will contribute to the protection of Salish Sucker populations and their critical habitats.
| Study | Description |
|---|---|
| Surveys for the presence/ absence of Salish Sucker in other area watersheds | Several of the currently known populations of Salish Sucker have been found since 2000. Surveys in other areas watersheds could reveal additional populations. |
| Characterize long-term population dynamics | Measure changes in abundance at the reach scale in watersheds where Salish Sucker are present. |
| Characterize impacts of introduced predators on mortality and habitat use by different life stages. | A variety of experimental and correlational approaches could be used to study the impacts of introduced predators. Those involving young-of-the-year and yearling Salish Suckers are of highest priority. |
| Potential connections among watersheds. | Assess the possibility and ecological consequences of connections among watersheds via Fraser River mainstem or during occasional floods. |
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