Northern brook lamprey (Ichthyomyzon fossor) COSEWIC assessment and status report: chapter 11

Technical Summary: Great Lakes – Upper St. Lawrence Biogeographic Area

Ichthyomyzon fossor

Northern brook lamprey – Lamproie du nord

Range of Occurrence in Canada:

Ontario, Quebec (Great Lakes - Upper St. Lawrence Biogeographic Area)

Extent and Area Information

Extent of occurrence (EO) (km²) – based on Figure 2

280,000km²

Specify trend in EO

Stable

Are there extreme fluctuations in EO?

No

Area of occupancy (AO) (km²) – based on Table 1 (sum of stream widths × occupied lengths)

>26 <31 km²

Specify trend in AO

Declining

Are there extreme fluctuations in AO?

No

Number of known or inferred current locations

36 streams

Specify trend in #

Declining (11 streams no longer occupied since 1960-1989 time period, seven new streams documented since 1990; three in Ontario and four in Quebec)

Are there extreme fluctuations in number of locations?

No

Specify trend in area, extent or quality of habitat

Now stable

Population Information

Generation time (average age of parents in the population)

6 years

Number of mature individuals

Unknown

Total population trend:

Declining

% decline over the last/next 10 years or 3 generations.

Unknown

Are there extreme fluctuations in number of mature individuals?

No

Is the total population severely fragmented?

No

Specify trend in number of populations

3 of 9 streams not documented in Lake Superior basin in the last 15 years (roughly three generations)

Are there extreme fluctuations in number of populations?

List populations with number of mature individuals in each:

Threats (actual or imminent threats to populations or habitats)

Lampricide treatments of populations co-existing with sea lamprey larvae, stream barriers impeding gene flow, sedimentation.

Rescue Effect (immigration from an outside source)

Status of outside population(s)?

USA: Stable [other jurisdictions or agencies]

Is immigration known or possible?

Possible, but unlikely due to non-migratory behaviour

Would immigrants be adapted to survive in Canada?

Yes

Is there sufficient habitat for immigrants in Canada?

Yes

Is rescue from outside populations likely?

No

Other Status

COSEWIC: Special Concern (1991)
Classified as S2 (imperiled) in Manitoba, S3 (vulnerable) in Ontario and Quebec.

Status: Special Concern

Alpha numeric Code: not applicable

Reason for Designation: This nonparasitic lamprey is distributed in streams throughout the Great Lakes basin (except Lake Ontario) and in southwestern Quebec. In the Great Lakes basin, which comprises most of its range, about 50% of the streams it is known to inhabit are subjected to ongoing chemical treatment for sea lamprey control which causes mortality to its larval stage. However, in untreated streams, the species is still abundant.

Applicability of Criteria

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2018-01-02