Channel darter (Percina copelandi) COSEWIC assessment and status report: chapter 11

Technical Summary

Distribution

Extent of occurrence in Canada:

80 000 km²

Extent of occurrence in North America:

500 000 km²

Area of occupancy in Canada:

300 km²

Area of occupancy in North America:

unknown

Population information

Total number of individuals captured in Canada prior to 1993:

700+

Total number of individuals captured in Canada 1993 to 2001:

338+

Generation Time:

1-2 years

Population Trend:

The channel darter population is in decline. Fewer than 100 specimens of channel darter were captured in Ontario and 700+ specimens were captured in Quebec prior to 1993 (Goodchild 1994). Since this report, 184+ specimens have been captured in Ontario and 154+ specimens have been captured in Quebec. Channel darters are no longer found in 7 water bodies. Channel darters were captured in 10 new water bodies as a result of increased sampling, although fewer than ten specimens were captured at the majority of these new sites.

Number of sub-populations in Canada:

Specimens were captured at 55 separate locations in 23 water bodies

Is the population fragmented?

Yes

Number of individuals in each sub-population (range):

1-76 (number of specimens captured at a sampling site)

Number of extant sites in Canada:

specimens captured at 55 separate locations in 23 waterbodies

Number of historic sites from which species has been extirpated in Canada:

Does the species undergo fluctuations?

Yes. Channel darters are sensitive to habitat degradation. They live in dynamic environments in small streams and rivers likely to undergo changes in temperature and flow. This may result in variations in reproductive success from year to year.

Threats

Channel darters are threatened by the loss of suitable habitat because they are sensitive to sedimentation and decreased water quality. In Ontario, dams are also an important threat to this species. Other threats to the survival of Percina copelandi include the disruption of spawning activities. Any activity that impedes or slows water flow during spawning stops their spawning activities. Barriers blocking access to spawning areas also compromise the spawning success of this species. The introduced round goby Neogobius melanostomus may be a threat to the channel darter in Ontario. The round goby has become established in the Great Lakes area and likely competes with the channel darter for resources.

A tolerance for only a narrow range of habitat characteristics and a limited amount of suitable habitat restrict the population size and distribution of the channel darter. Percina copelandi is at the northern limit of its distribution in Canada with low species numbers and disjunct distributions. All of these factors threaten the continued survival of the channel darter in Canada.

Rescue potential

Does this species exist outside Canada?

Yes

Is immigration known or possible?:

Unlikely, although possible through the Great Lakes

Would individuals from the nearest foreign population be adapted to survive in Canada?

Yes

Would sufficient suitable habitat be available for immigrants?

Possibly. Current populations are threatened by habitat degradation due to agricultural activities and urban development. Goodchild (1994) suggested that channel darters may be able to repopulate areas when water quality improves.

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Date modified:: 2016-05-31

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