River darter (Percina shumardi), various populations, COSEWIC assessment and status report 2016: chapter 2
Appendix 1. Threats assessment calculator DU1.
Threats assessment worksheet
- Species or Ecosystem Scientific Name:
- River Darter - DU1: Saskatchewan - Nelson River population
- Date:
- 26 Feb 2015
- Assessor(s):
- Nicholas Mandrak, Thomas Pratt, Dwayne Lepitzki, Scott Reid, Margaret Docker, Angele Cyr, John Post and Douglas Watkinson
- References:
- Teleconf on 26 Feb 2015
Threat Impact | Threat Impact (descriptions) | Level 1 Threat Impact Counts: high range |
Level 1 Threat Impact Counts: low range |
---|---|---|---|
A | Very High | 0 | 0 |
B | High | 0 | 0 |
C | Medium | 0 | 0 |
D | Low | 2 | 2 |
- | Calculated Overall Threat Impact: | Low | Low |
# | Threat | Impact (calculated |
Impact (description) |
Scope (next 10 Yrs) |
Severity (10 Yrs or 3 Gen.) |
Timing | Comments |
---|---|---|---|---|---|---|---|
1 | Residential and commercial development | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | housing development on rivers unlikely, |
1.1 | Housing and urban areas | - | - | - | - | - | unlikely development on habitat in the next 10 yrs |
1.2 | Commercial and industrial areas | - | - | - | - | - | not applicable |
1.3 | Tourism and recreation areas | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | - |
2 | Agriculture and aquaculture | - | - | - | - | - | - |
2.1 | Annual and perennial non-timber crops | - | - | - | - | - | Row crop occuring but not directly in rivers. siltation occuring but accounted for under 9.3. not as intensly coupled with agriculture. Not found in drains. habitat modifcation dealt with under threat 9.3 |
2.2 | Wood and pulp plantations | - | - | - | - | - | not applicable |
2.3 | Livestock farming and ranching | - | - | - | - | - | not applicable |
2.4 | Marine and freshwater aquaculture | - | - | - | - | - | not applicable |
3 | Energy production and mining | - | - | - | - | - | - |
3.1 | Oil and gas drilling | - | - | - | - | - | not applicable |
3.2 | Mining and quarrying | - | - | - | - | - | not applicable |
3.3 | Renewable energy | - | - | - | - | - | not applicable |
4 | Transportation and service corridors | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | - |
4.1 | Roads and railroads | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | east side road planned in Winnipeg right over River Darter habitat. |
4.2 | Utility and service lines | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | pipe lines and electrical transmission lines planned for this DU range |
4.3 | Shipping lanes | - | - | - | - | - | not applicable |
4.4 | Flight paths | - | - | - | - | - | not applicable |
5 | Biological resource use | - | - | - | - | - | - |
5.1 | Hunting and collecting terrestrial animals | - | - | - | - | - | not applicable |
5.2 | Gathering terrestrial plants | - | - | - | - | - | not applicable |
5.3 | Logging and wood harvesting | - | - | - | - | - | not applicable |
5.4 | Fishing and harvesting aquatic resources | - | - | - | - | - | bait fishery bycatch? Not applicable. Forzen bait catch in this DU but encounters with Darters are very uncommon and arent present in bait fish by catch. |
6 | Human intrusions and disturbance | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | - |
6.1 | Recreational activities | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | ATV's arent running through river darter habitat. |
6.2 | War, civil unrest and military exercises | - | - | - | - | - | Some DND activities in darter range but not aquatic. |
6.3 | Work and other activities | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | collection occuring but very low, negligible. |
7 | Natural system modifications | D | Low | Restricted (11-30%) | Slight (1-10%) | High (Continuing) | - |
7.1 | Fire and fire suppression | - | - | - | - | - | not applicable. |
7.2 | Dams and water management/use | D | Low | Restricted (11-30%) | Slight (1-10%) | High (Continuing) | A lot of areas will have impact of dams in this DU but a lot of range will not be affected. Flow management practices are peaking but not severe though. |
7.3 | Other ecosystem modifications | - | Unknown | Small (1-10%) | Unknown | High (Continuing) | Zebra Mussels affecting the water clarity (detrimental in the DU - increase in water clarity and a decrease in phosphorus) and Round Goby compete with Darters (detrimental). Overall decline from this threat but unknown severity. some evidence to suggest that there are only Goby's left in benthic habitats. considering effects of Goby only under 7.3 for all effects (including competition, space and resources). impact is somewhat unknown since Goby feeds on other eggs and Darter tends to burry eggs. |
8 | Invasive and other problematic species and genes | - | - | - | - | - | - |
8.1 | Invasive non-native/alien species | - | - | - | - | - | not applicable. zebra mussels accounted for under 7.3 Smallmouth Bass is likely present and preys on Darters. Unknown impact. |
8.2 | Problematic native species | - | - | - | - | - | not applicable. round goby accounted for under 7.3 |
8.3 | Introduced genetic material | - | - | - | - | - | not applicable. |
9 | Pollution | D | Low | Restricted (11-30%) | Moderate (11-30%) | High (Continuing) | - |
9.1 | Household sewage and urban waste water | D | Low | Restricted (11-30%) | Slight (1-10%) | High (Continuing) | household sewage and urban waste water treated by municipal treatment plant. |
9.2 | Industrial and military effluents | - | Negligible | Negligible (<1%) | Serious - Slight (1-70%) | High (Continuing) | most industrial and military effluents present in this DU but treated by municipal treatment. Spills plausible. |
9.3 | Agricultural and forestry effluents | D | Low | Restricted (11-30%) | Moderate (11-30%) | High (Continuing) | slaughter houses, pulp and paper mills applicable. |
9.4 | Garbage and solid waste | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | garbage and spills present but negligible impact. |
9.5 | Air-borne pollutants | - | - | - | - | - | not applicable. |
9.6 | Excess energy | - | - | - | - | - | not applicable. |
10 | Geological events | - | - | - | - | - | - |
10.1 | Volcanoes | - | - | - | - | - | not applicable. |
10.2 | Earthquakes/ tsunamis | - | - | - | - | - | not applicable. |
10.3 | Avalanches/landslides | - | - | - | - | - | not applicable. |
11 | Climate change and severe weather | - | Unknown | Pervasive (71-100%) | Unknown | High (Continuing) | - |
11.1 | Habitat shifting and alteration | - | - | - | - | - | not applicable. |
11.2 | Droughts | - | Unknown | Pervasive (71-100%) | Unknown | High (Continuing) | drought occuring but impact unknown. Sometimes drought occuring yearly. |
11.3 | Temperature extremes | - | Unknown | Pervasive (71-100%) | Unknown | High (Continuing) | |
11.4 | Storms and flooding | - | Unknown | Pervasive (71-100%) | Unknown | High (Continuing) | not applicable. Flooding is beneficial to Darters since it increases habitat but not occuring in this part of range due to water management flow controlled by dams. |
Glossary
- Impact
- The degree to which a species is observed, inferred, or suspected to be directly or indirectly threatened in the area of interest. The impact of each threat is based on Severity and Scope rating and considers only present and future threats. Threat impact reflects a reduction of a species population or decline/degradation of the area of an ecosystem. The median rate of population reduction or area decline for each combination of scope and severity corresponds to the following classes of threat impact: Very High (75% declines), High (40%), Medium (15%), and Low (3%). Unknown: used when impact cannot be determined (e.g., if values for either scope or severity are unknown); Not Calculated: impact not calculated as threat is outside the assessment timeframe (e.g., timing is insignificant/negligible or low as threat is only considered to be in the past); Negligible: when scope or severity is negligible; Not a Threat: when severity is scored as neutral or potential benefit.
- Scope
- Proportion of the species that can reasonably be expected to be affected by the threat within 10 years. Usually measured as a proportion of the species' population in the area of interest. (Pervasive = 71-100%; Large = 31-70%; Restricted = 11-30%; Small = 1-10%; Negligible < 1%).
- Severity
- Within the scope, the level of damage to the species from the threat that can reasonably be expected to be affected by the threat within a 10-year or three-generation timeframe. Usually measured as the degree of reduction of the species' population. (Extreme = 71-100%; Serious = 31-70%; Moderate = 11-30%; Slight = 1-10%; Negligible < 1%; Neutral or Potential Benefit > 0%).
- Timing
- High = continuing; Moderate = only in the future (could happen in the short term [< 10 years or 3 generations]) or now suspended (could come back in the short term); Low = only in the future (could happen in the long term) or now suspended (could come back in the long term); Insignificant/Negligible = only in the past and unlikely to return, or no direct effect but limiting.
Appendix 2. Threats Assessment Calculator DU2.
Threats assessment worksheet
- Species or Ecosystem Scientific Name:
- River Darter - DU2: Southern Hudson Bay - James Bay population
- Date:
- 26 Feb 2015
- Assessor(s):
- Nicholas Mandrak, Thomas Pratt, Dwayne Lepitzki, Scott Reid, Margaret Docker, Angele Cyr, John Post and Douglas Watkinson
- References:
- Teleconf on 26 Feb 2015
Threat Impact | Threat Impact (descriptions) | Level 1 Threat Impact Counts: high range |
Level 1 Threat Impact Counts: low range |
---|---|---|---|
A | Very High | 0 | 0 |
B | High | 0 | 0 |
C | Medium | 0 | 0 |
D | Low | 1 | 1 |
- | Calculated Overall Threat Impact: | Low | Low |
# | Threat | Impact (calculated |
Impact (description) |
Scope (next 10 Yrs) |
Severity (10 Yrs or 3 Gen.) |
Timing | Comments |
---|---|---|---|---|---|---|---|
1 | Residential and commercial development | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | - |
1.1 | Housing and urban areas | - | - | - | - | - | some housing development planned on habitat in the next 10 yrs |
1.2 | Commercial and industrial areas | - | - | - | - | - | not applicable |
1.3 | Tourism and recreation areas | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | - |
2 | Agriculture and aquaculture | - | - | - | - | - | - |
2.1 | Annual and perennial non-timber crops | - | - | - | - | - | Row crop occuring but not directly in rivers. siltation occuring but accounted for under 9.3. not as intensly coupled with agriculture. Not found in drains. habitat modifcation dealt with under threat 9.3 |
2.2 | Wood and pulp plantations | - | - | - | - | - | quite a bit of logging that occurs but impact is unknown. Could be accounted for under 7.3 as it relates to result of turbidity from loss of trees? |
2.3 | Livestock farming and ranching | - | - | - | - | - | not applicable |
2.4 | Marine and freshwater aquaculture | - | - | - | - | - | not applicable |
3 | Energy production and mining | - | Unknown | Unknown | Unknown | Moderate - Low | |
3.1 | Oil and gas drilling | - | - | - | - | - | potential for great deal of development. unknown. |
3.2 | Mining and quarrying | - | Unknown | Unknown | Unknown | Moderate - Low | new mining plausible (or) but unknown. Spatial component in terms of mining claims. Some mining is right on fish habitat. One in Manitoba is beneath lake. |
3.3 | Renewable energy | - | - | - | - | - | potential for great deal of development in the next 10 yrs but unknown. |
4 | Transportation and service corridors | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | - |
4.1 | Roads and railroads | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | some road development planned over darter habitat in this DU |
4.2 | Utility and service lines | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | fair number of hydro electric lines planned for development within this DU range. Oil |
4.3 | Shipping lanes | - | - | - | - | - | not applicable |
4.4 | Flight paths | - | - | - | - | - | not applicable |
5 | Biological resource use | - | - | - | - | - | - |
5.1 | Hunting and collecting terrestrial animals | - | - | - | - | - | not applicable |
5.2 | Gathering terrestrial plants | - | - | - | - | - | not applicable |
5.3 | Logging and wood harvesting | - | - | - | - | - | not applicable |
5.4 | Fishing and harvesting aquatic resources | - | - | - | - | - | not applicable |
6 | Human intrusions and disturbance | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | - |
6.1 | Recreational activities | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | ATV's likely running through rivers but whether theyre driving through darter habitat is unlikely. |
6.2 | War, civil unrest and military exercises | - | - | - | - | - | not applicable. Some DND activities in darter range but not aquatic. |
6.3 | Work and other activities | - | Negligible | Negligible (<1%) | Negligible (<1%) | Moderate (Possibly in the short term, < 10 yrs) | collection occuring but very low, negligible. |
7 | Natural system modifications | D | Low | Small (1-10%) | Slight (1-10%) | High (Continuing) | - |
7.1 | Fire and fire suppression | - | - | - | - | - | not applicable. |
7.2 | Dams and water management/use | D | Low | Small (1-10%) | Slight (1-10%) | High (Continuing) | Impoundments. Dam present at lake St-Joseph which is a diversion dam. Dam developments planned within the next 10 yrs. Albany river has a few generation dams present and no new developments planned. Dams are downstream from River Darter habitat except for the Lake St-Joseph diversion (which affect much of the habitat downstream). |
7.3 | Other ecosystem modifications | - | - | - | - | - | not applicable. zebra mussels arent present yet in this DU nor Goby. |
8 | Invasive and other problematic species and genes | - | - | - | - | - | - |
8.1 | Invasive non-native/alien species | - | - | - | - | - | not applicable. zebra mussels accounted for under 7.3. Small Mouth Bass is likely present and preys on Darters. Unknown impact. |
8.2 | Problematic native species | - | - | - | - | - | not applicable. round goby accounted for under 7.3. |
8.3 | Introduced genetic material | - | - | - | - | - | not applicable. |
9 | Pollution | - | Negligible | Negligible (<1%) | Serious - Slight (1-70%) | High (Continuing) | - |
9.1 | Household sewage and urban waste water | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | area is quite rural |
9.2 | Industrial and military effluents | - | Negligible | Negligible (<1%) | Serious - Slight (1-70%) | High (Continuing) | |
9.3 | Agricultural and forestry effluents | - | Negligible | Negligible (<1%) | Moderate (11-30%) | High (Continuing) | forestry effluent very likely as well as pulp and paper mill effluent (eastward - Hearst) plausible but unknown. Sedimentation from forestry is considered. |
9.4 | Garbage and solid waste | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | garbage present (such as drink cans, etc) but negligible impact. |
9.5 | Air-borne pollutants | - | - | - | - | - | not applicable. |
9.6 | Excess energy | - | - | - | - | - | not applicable. |
10 | Geological events | - | - | - | - | - | - |
10.1 | Volcanoes | - | - | - | - | - | not applicable. |
10.2 | Earthquakes/ tsunamis | - | - | - | - | - | not applicable. |
10.3 | Avalanches/landslides | - | - | - | - | - | not applicable. |
11 | Climate change and severe weather | - | Unknown | Pervasive (71-100%) | Unknown | High (Continuing) | - |
11.1 | Habitat shifting and alteration | - | - | - | - | - | not applicable. |
11.2 | Droughts | - | Unknown | Pervasive (71-100%) | Unknown | High (Continuing) | drought occuring but impact unknown. Waterbody is more intact for these areas and therefore less succeptible to the effects of droughts. Water system is less managed and therefore more natural. |
11.3 | Temperature extremes | - | Unknown | Pervasive (71-100%) | Unknown | High (Continuing) | |
11.4 | Storms and flooding | - | Unknown | Pervasive (71-100%) | Unknown | High (Continuing) | not applicable. Flooding is beneficial to Darters since it increases habitat but not occuring in this part of range. |
Glossary
- Impact
- The degree to which a species is observed, inferred, or suspected to be directly or indirectly threatened in the area of interest. The impact of each threat is based on Severity and Scope rating and considers only present and future threats. Threat impact reflects a reduction of a species population or decline/degradation of the area of an ecosystem. The median rate of population reduction or area decline for each combination of scope and severity corresponds to the following classes of threat impact: Very High (75% declines), High (40%), Medium (15%), and Low (3%). Unknown: used when impact cannot be determined (e.g., if values for either scope or severity are unknown); Not Calculated: impact not calculated as threat is outside the assessment timeframe (e.g., timing is insignificant/negligible or low as threat is only considered to be in the past); Negligible: when scope or severity is negligible; Not a Threat: when severity is scored as neutral or potential benefit.
- Scope
- Proportion of the species that can reasonably be expected to be affected by the threat within 10 years. Usually measured as a proportion of the species' population in the area of interest. (Pervasive = 71–100%; Large = 31–70%; Restricted = 11–30%; Small = 1–10%; Negligible < 1%).
- Severity
- Within the scope, the level of damage to the species from the threat that can reasonably be expected to be affected by the threat within a 10-year or three-generation timeframe. Usually measured as the degree of reduction of the species' population. (Extreme = 71–100%; Serious = 31–70%; Moderate = 11–30%; Slight = 1–10%; Negligible < 1%; Neutral or Potential Benefit > 0%).
- Timing
- High = continuing; Moderate = only in the future (could happen in the short term [< 10 years or 3 generations]) or now suspended (could come back in the short term); Low = only in the future (could happen in the long term) or now suspended (could come back in the long term); Insignificant/Negligible = only in the past and unlikely to return, or no direct effect but limiting.
Appendix 3. Threats Assessment Calculator DU3.
Threats assessment worksheet
- Species or Ecosystem Scientific Name:
- River Darter - DU3: Great Lakes - Upper St. Lawrence population
- Date:
- 26 Feb 2015
- Assessor(s):
- Nicholas Mandrak, Thomas Pratt, Dwayne Lepitzki, Scott Reid, Margaret Docker, Angele Cyr, John Post and Douglas Watkinson
- References:
- Teleconf on 26 Feb 2015
Threat Impact | Threat Impact (descriptions) | Level 1 Threat Impact Counts: high range |
Level 1 Threat Impact Counts: low range |
---|---|---|---|
A | Very High | 0 | 0 |
B | High | 1 | 0 |
C | Medium | 1 | 1 |
D | Low | 1 | 2 |
- | Calculated Overall Threat Impact: | High | Medium |
# | Threat | Impact (calculated |
Impact (description) |
Scope (next 10 Yrs) |
Severity (10 Yrs or 3 Gen.) |
Timing | Comments |
---|---|---|---|---|---|---|---|
1 | Residential and commercial development | - | - | - | - | - | - |
1.1 | Housing and urban areas | - | - | - | - | - | unlikely development on habitat in the next 10 yrs |
1.2 | Commercial and industrial areas | - | - | - | - | - | not applicable |
1.3 | Tourism and recreation areas | - | - | - | - | - | not applicable |
2 | Agriculture and aquaculture | - | - | - | - | - | - |
2.1 | Annual and perennial non-timber crops | - | - | - | - | - | not as intensly coupled with agriculture. Not found in drains. siltation dealt with under 9.3. habitat modifcation dealt with under threat? |
2.2 | Wood and pulp plantations | - | - | - | - | - | not applicable |
2.3 | Livestock farming and ranching | - | - | - | - | - | not applicable |
2.4 | Marine and freshwater aquaculture | - | - | - | - | - | not applicable |
3 | Energy production and mining | - | - | - | - | - | - |
3.1 | Oil and gas drilling | - | - | - | - | - | not applicable |
3.2 | Mining and quarrying | - | - | - | - | - | mining of the gravel in the darter beds unknown? Province isnt permitted regardless. |
3.3 | Renewable energy | - | - | - | - | - | footprint of wind mills does not extend into aquatic habitat. Draining has already occurred. |
4 | Transportation and service corridors | D | Low | Small (1-10%) | Serious - Moderate (11-70%) | High (Continuing) | - |
4.1 | Roads and railroads | - | - | - | - | - | not applicable |
4.2 | Utility and service lines | - | - | - | - | - | not applicable |
4.3 | Shipping lanes | D | Low | Small (1-10%) | Serious - Moderate (11-70%) | High (Continuing) | dredging sites have an overall decrease in population size for darter. More expected over the next 10 years but not at a higher intensity than current. Lake St.Clair marina projects have access plans that imply dredging. Nothing planned for thames, maybe something in lower sydenham. unlikely areas that darter would occupy though. however darters arent restricted to riverine habitat so plausible effect from dredging planned in the next 10yrs. |
4.4 | Flight paths | - | - | - | - | - | not applicable |
5 | Biological resource use | - | - | - | - | - | - |
5.1 | Hunting and collecting terrestrial animals | - | - | - | - | - | not applicable |
5.2 | Gathering terrestrial plants | - | - | - | - | - | not applicable |
5.3 | Logging and wood harvesting | - | - | - | - | - | not applicable |
5.4 | Fishing and harvesting aquatic resources | - | - | - | - | - | bait fishery bycatch? Not applicable. Encounters with Darters are very uncommon and arent present in bait fishery by catch areas. |
6 | Human intrusions and disturbance | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | - |
6.1 | Recreational activities | - | - | - | - | - | not applicable. ATV's arent running through river darter habitat. |
6.2 | War, civil unrest and military exercises | - | - | - | - | - | not applicable. |
6.3 | Work and other activities | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | Collection for scientific research is occuring and catches are kept and killed summing to 4 individuals over the past 15 yrs. Therefore negligible. Occurs in specific areas. |
7 | Natural system modifications | BD | High - Low | Pervasive (71-100%) | Serious - Slight (1-70%) | High (Continuing) | - |
7.1 | Fire and fire suppression | - | - | - | - | - | not applicable. |
7.2 | Dams and water management/use | D | Low | Large (31-70%) | Slight (1-10%) | High (Continuing) | new dams and/or effects of current dams. No new dams proposed for this species nor are they subject to the effects of current dams. Water management use for municipal use or agricultural use is accounted for under 7.3. water flow regime altered upstream but arent from large reservoirs so effect is negligible. Dams built by conservation authorities reduce risk of flood in the spring and in summer reduce the risk of drought. This species actually does not benefit from dams regulating water levels since Darters benefit from flooding events where habitat is increased. not creating large impoundments nor are they greatly affecting flow regimes. |
7.3 | Other ecosystem modifications | BD | High - Low | Pervasive (71-100%) | Serious - Slight (1-70%) | High (Continuing) | rip rap (detrimental effect) along shoreline and other ecosystem modifications such as zebra mussels affecting the water clarity (might be beneficial) and Round Goby compete with Darters (detrimental). Round Goby is present in Lake St. Clair, lower parts of Sydenham and throughout the Thames. Overall decline from this threat. some evidence to suggest that there are only Goby's left in benthic habitats. considering effects of Goby only under 7.3 for all effects (including competition, space and resources). impact is somewhat unknown since Goby feeds on other eggs and Darter tends to bury eggs. |
8 | Invasive and other problematic species and genes | - | - | - | - | - | - |
8.1 | Invasive non-native/alien species | - | - | - | - | - | Zebra mussels may actually be beneficial to Darters since it is thought to feed on Zebra Mussels. But this has not been confirmed. Likely reported benefit is related to water clarity and this is accounted for in 7.3. Zebra mussels may also be detrimental in terms of water quality (again accounted for under 7.3) since they reduce turbidity and increased water clarity could reduce available oxygen. round goby accounted for under 7.3 |
8.2 | Problematic native species | - | - | - | - | - | |
8.3 | Introduced genetic material | - | - | - | - | - | not applicable. |
9 | Pollution | C | Medium | Pervasive (71-100%) | Moderate (11-30%) | High (Continuing) | - |
9.1 | Household sewage and urban waste water | D | Low | Large (31-70%) | Slight (1-10%) | High (Continuing) | effluents and some waste water present via urban activitities, particulary in the London area but ecological footprint unlikely to extend into darter range for this DU. |
9.2 | Industrial and military effluents | CD | Medium - Low | Restricted - Small (1-30%) | Serious - Slight (1-70%) | High (Continuing) | Industrial activities downstream of Sarnia? There are occurences of spills such as Gas or industrial spills, even manure spills mainly in specific areas where Darter is present. |
9.3 | Agricultural and forestry effluents | C | Medium | Pervasive (71-100%) | Moderate (11-30%) | High (Continuing) | agricultural effluents present over part of its range for this DU |
9.4 | Garbage and solid waste | - | Negligible | Negligible (<1%) | Negligible (<1%) | High (Continuing) | some manure spills occur over Darter habitat. Impact of spills is greater than other threats in the category. Spills cause entire population mortality in the area of occurrence. This species can tolerate turbidity but rather the nutrient loading from a manure spill is lethal. |
9.5 | Air-borne pollutants | - | - | - | - | - | not applicable. |
9.6 | Excess energy | - | - | - | - | - | not applicable. |
10 | Geological events | - | - | - | - | - | - |
10.1 | Volcanoes | - | - | - | - | - | not applicable. |
10.2 | Earthquakes/ tsunamis | - | - | - | - | - | not applicable. |
10.3 | Avalanches/landslides | - | - | - | - | - | not applicable. |
11 | Climate change and severe weather | - | Unknown | Pervasive (71-100%) | Unknown | High (Continuing) | - |
11.1 | Habitat shifting and alteration | - | - | - | - | - | not applicable according to guidelines. Climate change may be applicable but unknown. |
11.2 | Droughts | - | Unknown | Pervasive (71-100%) | Unknown | Moderate (Possibly in the short term, < 10 yrs) | drought occuring but randomly one year and not the other. |
11.3 | Temperature extremes | - | Unknown | Pervasive (71-100%) | Unknown | High (Continuing) | not applicable. While warmer temperature could be detrimental, the range for this DU already has very warm temperatures for rivers and impact is negligible. |
11.4 | Storms and flooding | - | Unknown | Pervasive (71-100%) | Unknown | High (Continuing) | not applicable. Flooding is beneficial to Darters since it increases habitat but not occuring in this part of range due to water management flow controlled by dams. |
Glossary
- Impact
- The degree to which a species is observed, inferred, or suspected to be directly or indirectly threatened in the area of interest. The impact of each threat is based on Severity and Scope rating and considers only present and future threats. Threat impact reflects a reduction of a species population or decline/degradation of the area of an ecosystem. The median rate of population reduction or area decline for each combination of scope and severity corresponds to the following classes of threat impact: Very High (75% declines), High (40%), Medium (15%), and Low (3%). Unknown: used when impact cannot be determined (e.g., if values for either scope or severity are unknown); Not Calculated: impact not calculated as threat is outside the assessment timeframe (e.g., timing is insignificant/negligible or low as threat is only considered to be in the past); Negligible: when scope or severity is negligible; Not a Threat: when severity is scored as neutral or potential benefit.
- Scope
- Proportion of the species that can reasonably be expected to be affected by the threat within 10 years. Usually measured as a proportion of the species' population in the area of interest. (Pervasive = 71–100%; Large = 31–70%; Restricted = 11–30%; Small = 1–10%; Negligible < 1%).
- Severity
- Within the scope, the level of damage to the species from the threat that can reasonably be expected to be affected by the threat within a 10-year or three-generation timeframe. Usually measured as the degree of reduction of the species' population. (Extreme = 71–100%; Serious = 31–70%; Moderate = 11–30%; Slight = 1–10%; Negligible < 1%; Neutral or Potential Benefit > 0%).
- Timing
- High = continuing; Moderate = only in the future (could happen in the short term [< 10 years or 3 generations]) or now suspended (could come back in the short term); Low = only in the future (could happen in the long term) or now suspended (could come back in the long term); Insignificant/Negligible = only in the past and unlikely to return, or no direct effect but limiting.
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