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COSEWIC Assessment and Update Status Report on the Deepwater Sculpin (Western and Great Lakes-Western St. Lawrence Populations) in Canada

Technical Summary

Myoxocephalus thompsonii

Deepwater Sculpin, Great Lakes – Western St. Lawrence populations
Chabot de profondeur, populations des Grands Lacs - Ouest du Saint-Laurent

Range of occurrence by province and territory: ON, QC

COSEWIC Aquatic Ecozones represented in the species’ range:
 - Ecozone 10: Great Lakes – Western St. Lawrence


Extent and Area Information

extent of occurrence (EO) (from Figure 4 using a best fit polygon)
~ 850 000 km2


trend in EO

Stable

are there extreme fluctuations in EO (> 1 order of magnitude)?

No


area of occupancy (AO) many locations, not calculated, but considerably less than EO

< 800 000 km2



trend in AO

Unknown

are there extreme fluctuations in AO (> 1 order magnitude)?

No


number of extant locations

10 lakes

trend in # locations

Decline (3 apparently extirpated 2 in QC and 1 in ON), Lake Huron - decline

are there extreme fluctuations in # locations (>1 order of magnitude)?

No


habitat trend

Some decline


Population Information

generation time (average age of parents in the population)
4-5 years


number of mature individuals (capable of reproduction) in the Canadian population)

Unknown



Total population trend:

Decline

if decline, % decline over the last/next 10 years or 3 generations, whichever is greater

Unknown



are there extreme fluctuations in number of mature individuals (> 1 order of magnitude)?

Unknown



is the total population severely fragmented?

Yes


list each population and the number of mature individuals in each

ON - Lakes Superior, Huron, Erie, Ontario, Fairbank, and Nipigon
QC - Lakes Roddick, des Iles, Thirty-one-Mile, and Heney

Unknown in all







specify trend in number of populations (decline, stable, increasing, unknown)

Decline- 2 locations extirpated in QC, 1 in ON

are there extreme fluctuations in number of populations (>1 order of magnitude)?

No



Threats (actual or imminent threats to populations or habitats)

Competition and predation with invasive species; pollution; eutrophication


Rescue Effect (immigration from an outside source)

does species exist elsewhere (in Canada or outside)?
Yes in U.S. and Ecozone 4


status of the outside population(s)?
Ecozone 4 – DD
Secure except for NY – S!

is immigration known or possible?

Possible only in Gt. Lakes

would immigrants be adapted to survive here?

Unknown


is there sufficient habitat for immigrants here?

Yes


Quantitative Analysis

Not Applicable


Existing Status

Nature Conservancy Ranks (NatureServe 2005)

Global– G5

National
 US – N5
 Canada N4

Regional
 US:
IN – S4, MI – S5, MN – SSNR, NY – S1, OH – SNR, PA – SX, WI – S4
 Canada: AB – S1, MB – S2S3, NT – SNR, ON – S4, QC – S1S2, SK – S5

Wild Species 2000 (Canadian Endangered Species Council 2001)
 Canada - NA
 Provinces – AB – 5, MB – 2*, ON – 4, QC – 2, NT – 3, SK – 5
 *Duncan indicates that this should be 3 or 4 (J. Duncan, Biodiversity Conservation Section, Manitoba Conservation, Winnipeg, Manitoba; rank comments in relation to the data output for the Wild Species web site for freshwater fish species).

COSEWIC
- Threatened 1987 (Great Lakes populations only);
- Special Concern 2006 (Great Lakes – Western St. Lawrence populations.


Status and Reasons for Designation

Status: Special Concern
Alpha-numeric code: not applicable

Reasons for Designation: This species occurs in the deeper parts of 10 coldwater lakes, including lakes Superior, Huron and Ontario, in Ontario and Quebec. Previously thought to be exterminated in Lake Ontario, it now appears to be reestablished in that lake, albeit in small numbers. Populations have been exterminated in 2 lakes in Quebec due to eutrophication of these lakes, and may be in decline in Lake Huron, possibly in relation to the introduction of zebra mussel.


Applicability of Criteria

Criterion A (Declining Total Population):
Not Applicable – no evidence to establish decline.

Criterion B (Small Distribution, and Decline or Fluctuation):
Not Applicable – Wide distribution – population abundance and trend information not available.

Criterion C (Small Total Population Size and Decline):
Not Applicable – population abundance and trend information not available.

Criterion D (Very Small Population or Restricted Distribution):
Not Applicable. Widespread distribution.

Criterion E (Quantitative Analysis):
Not Applicable – no data.

 

Myoxocephalus thompsonii

Deepwater Sculpin, Western populations
Chabot de profondeur, populations de l’Ouest

Range of occurrence by province and territory: NWT, AB, SK, MB, ON, QC

COSEWIC Aquatic Ecozones represented in the species’ range:
 - Ecozone 13: Western Arctic (corresponds to the portion of the species’ range in the Northwest Territories and Northern Saskatchewan)
 - Ecozone 5: Western Hudson Bay (corresponds to the portion of the species’ range in Northeastern Saskatchewan)
 - Ecozone 4: Saskatchewan/Nelson (corresponds to the portion of the species’ range in Alberta, Central Saskatchewan, Manitoba, and Northwestern Ontario)


Extent and Area Information

extent of occurrence (EO) (from Figure 4 using a best fit polygon)
~ 100 000 000 km2


trend in EO

Unknown

are there extreme fluctuations in EO (> 1 order of magnitude)?

No


area of occupancy (AO) many locations, not calculated, but considerably less than EO

< 1 000 000 km2



trend in AO

Unknown

are there extreme fluctuations in AO (> 1 order magnitude)?

No


number of extant locations

52 lakes in 3 ecozones

trend in # locations

Unknown - 4 apparently extirpated, but found at 4 new locations

are there extreme fluctuations in # locations (>1 order of magnitude)?

No


habitat trend

Some decline


Population Information

generation time (average age of parents in the population)
4-5 years


number of mature individuals (capable of reproduction) in the Canadian population)

Unknown



Total population trend:

Unknown

if decline, % decline over the last/next 10 years or 3 generations, whichever is greater

Unknown



are there extreme fluctuations in number of mature individuals (> 1 order of magnitude)?

Unknown



is the total population severely fragmented?

Yes


list each population and the number of mature individuals in each

Unknown in all


Ecozone 7 – Waterton Lake

Ecozone 13 NT – Gt. Slave, La Marte, Keller, GT
Bear and Alexie lakes
 SK – Reindeer, Wollaston, Athabasca, Black, Riou, Beaverlodge, Canoe, East, Hatchet, Laonil, Milliken, Waterbury, Yalowega, C1 lakes

Ecozone 4 SK – La Ronge, La Plonge, Mirond, MacKay, McLenna
 MB – Athapapuskow, Cranberry Lakes Westhawk, George and Clearwater lakes
 ON – Lake 259, Teggau, Lake 310, Lake 258, High, William, Horseshoe, Dicker, Passover, Burton, Trout, Eagle, Cedar, Raven , Burchell, Saganaga, Squeers, Huston, Notellum, Manitou and Teggau lakes

specify trend in number of populations (decline, stable, increasing, unknown)

Unknown


are there extreme fluctuations in number of populations (>1 order of magnitude)?

No



Threats (actual or imminent threats to populations or habitats)

Competition and predation with invasive species; pollution; eutrophication


Rescue Effect (immigration from an outside source)

does species exist elsewhere (in Canada or outside)?
Yes in U.S. and Ecozone 3


status of the outside population(s)?
No neighbouring U.S. Population

is immigration known or possible?

Not Possible

would immigrants be adapted to survive here?

Unknown


is there sufficient habitat for immigrants here?

Yes


Quantitative Analysis

Not Applicable


Existing Status

Nature Conservancy Ranks (NatureServe 2005)

Global– G5

National
 US – N5
 Canada N4

Regional
 US:
IN – S4, MI – S5, MN – SSNR, NY – S1, OH – SNR, PA – SX, WI – S4
 Canada: AB – S1, MB – S2S3, NT – SNR, ON – S4, QC – S1S2, SK – S5

Wild Species 2000 (Canadian Endangered Species Council 2001)
 Canada - NA
 Provinces – AB – 5, MB – 2*, ON – 4, QC – 2, NT – 3, SK – 5
 *Duncan indicates that this should be 3 or 4 (J. Duncan, Biodiversity Conservation Section, Manitoba Conservation, Winnipeg, Manitoba; rank comments in relation to the data output for the Wild Species web site for freshwater fish species).

COSEWIC
- Western populations first assessed as NAR in 2006.


Status and Reasons for Designation

Status: Not At Risk
Alpha-numeric code: not applicable

Reasons for Designation: This species is widely distributed in western Canada where it is found in the deepest parts of at least 52 coldwater lakes in northwestern Ontario, Manitoba, Saskatchewan, Alberta and the Northwest Territories. There is no evidence to indicate population declines, or of any threats that would convey a degree of risk to these populations.


Applicability of Criteria

Criterion A (Declining Total Population):
Not Applicable – no evidence to establish decline.

Criterion B (Small Distribution, and Decline or Fluctuation):
Not Applicable – Wide distribution – population abundance and trend information not available.

Criterion C (Small Total Population Size and Decline):
Not Applicable – population abundance and trend information not available.

Criterion D (Very Small Population or Restricted Distribution):
Not Applicable. Widespread distribution.

Criterion E (Quantitative Analysis):
Not Applicable – no data.