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COSEWIC Assessment and Status Report on the Pygmy Whitefish Prosopium coulterii in Canada 2016

COSEWIC Assessment and Status Report on the Pygmy Whitefish Prosopium coulterii in Canada 2016

Photo of Pygmy Whitefish
Photo: © Dr. G. Court

Southwestern Yukon Beringian populations - Data deficient
Yukon River populations - Data deficient
Pacific populations - Not at risk
Western Arctic populations - Not at risk
Great Lakes – Upper St. Lawrence populations - Threatened
Waterton Lake populations - Special concern
Saskatchewan - Nelson Rivers populations - Data deficient
2016

Table of contents

List of figures

  • Figure 1. Pygmy Whitefish from a) Nelson and Paetz (1992) and b) Scott and Crossman (1973).
  • Figure 2. Anatomical features distinguishing Pygmy Whitefish from other coregonines: a) single nasal flap between nostrils of Prosopium spp. (left) and two nasal flaps present on other coregonines (from McPhail and Lindsey 1970); b) ventral notch in adipose eyelid of Prosopium spp. (from McPhail and Lindsey 1970); c) profile of head of a Mountain Whitefish (left) and Pygmy Whitefish (right) (from Nelson and Paetz 1992).
  • Figure 3. Global distribution of Pygmy Whitefish. Glacial refugia from which Pygmy Whitefish populations likely originated are shown: red = Bering Refuge (B); blue = Pacific Refuge and/or Mississippi Refuge (P/M), green = Mississippi Refuge (M). Figure modified from Blanchfield et al. (2014).
  • Figure 4. Plot of high and low raker forms of Pygmy Whitefish. H = high-raker form; L = low-raker form; AR= Athabasca River, AB; C = Copper River, AK; WL = Waterton Lake AB; EL = Elliot Lake, YT; LS = Lake Superior, MI; BL – Bull Lake, MT; LM = Lake McDonald, MT; SI = Snake Indian River, AB. Reproduced from Mayhood (1992).
  • Figure 5. Distribution of Pygmy Whitefish designatable units in Canada in relation to national freshwater biogeographic zones. More detailed maps are provided for DU1 (Figure 6), DU2 (Figure 7), DU3 (Figure 8), and DU7 (Figure 9).
  • Figure 6. Extent of Occurrence and Area of Occupancy for Pygmy Whitefish in DU1 - Southwestern Yukon Beringian populations.
  • Figure 7. Extent of Occurrence and Area of Occupancy for Pygmy Whitefish in DU2 – Yukon River populations.
  • Figure 8. Extent of Occurrence and Area of Occupancy for Pygmy Whitefish in DU3 – Pacific populations.
  • Figure 9. Extent of Occurrence and Area of Occupancy for Pygmy Whitefish in DU7 – Saskatchewan-Nelson Rivers populations.
  • Figure 10. Location of trawl surveys in Lake Superior that have captured Pygmy Whitefish since the 1960s. Trawls were conducted by the USGS in Lake Superior with expansion to more sites in Canada beginning in 1989. Data courtesy of Mark Vinson (USGS).
  • Figure 11. Annual Pygmy Whitefish density (fish per surveyed hectare) in Lake Superior as determined by nearshore trawl surveys completed by the USGS, indicating a 48% decline for the last three generations of Pygmy Whitefish, 2000-2016. Data courtesy of Mark Vinson (USGS).

List of tables

  • Table 1. Historical search effort for Pygmy Whitefish. Waterbody, year sampled, number captured, catch-per-unit-effort (CUPE), if Pygmy Whitefish were the target species (Y/N), and the number of mature individuals are listed.

List of appendices


Document information

COSEWIC
Committee on the Status
of Endangered Wildlife
in Canada

COSEWIC logo

COSEPAC
Comité sur la situation
des espèces en péril
au Canada

COSEWIC status reports are working documents used in assigning the status of wildlife species suspected of being at risk. This report may be cited as follows:

COSEWIC. 2016. COSEWIC assessment and status report on the Pygmy Whitefish Prosopium coulterii, Southwestern Yukon Beringian populations, Yukon River populations, Pacific populations, Western Arctic populations, Great Lakes – Upper St. Lawrence populations, Waterton Lake populations and Saskatchewan - Nelson Rivers populationsin Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xxxvi + 69 pp. (Species at Risk Public Registry website).

Production note:

COSEWIC would like to acknowledge Jeff Sereda for writing the status report on Pygmy Whitefish, Prosopium coulterii in Canada, prepared under contract with Environment and Climate Change Canada. This report was overseen and edited by Eric Taylor, former Co-chair and Nick Mandrak, Co-chair of the COSEWIC Freshwater Fishes Specialist Subcommittee.

For additional copies contact:

COSEWIC Secretariat
c/o Canadian Wildlife Service
Environment and Climate Change Canada
Ottawa, ON
K1A 0H3

Tel.: 819-938-4125
Fax: 819-938-3984
E-mail: COSEWIC E-mail
Website: COSEWIC

Également disponible en français sous le titre Ếvaluation et Rapport de situation du COSEPAC sur la Corégone pygmée (Prosopium coulterii), populations béringiennes du sud–ouest du Yukon, populations du fleuve Yukon, populations du Pacifique, populations de l'ouest de l'Arctique, populations des Grands Lacs et du haut Saint–Laurent, population du lac Waterton et populations de la rivière Saskatchewan et du fleuve Nelson au Canada.

Cover illustration/photo:

Cover image of Pygmy whitefish of approximately 12 cm total length (Dr. G. Court; used with permission).


COSEWIC assessment summary

Assessment summary – November 2016

Common name:
Pygmy Whitefish - Southwestern Yukon Beringian populations
Scientific name:
Prosopium coulterii
Status:
Data Deficient
Reason for designation:
This freshwater fish is known from seven lakes in British Columbia and Yukon Territory, but may exist in others. Quantitative data on population sizes, geographic range, and known threats are too limited to determine status.
Occurrence:
Yukon, British Columbia
Status history:
Species considered in November 2016 and placed in the Data Deficient category.

Assessment summary – November 2016

Common name:
Pygmy Whitefish - Yukon River populations
Scientific name:
Prosopium coulterii
Status:
Data Deficient
Reason for designation:
This freshwater fish is known from three lakes in Yukon Territory, but may exist in others. Quantitative data on population sizes, geographic range, and known threats are too limited to determine status.
Occurrence:
Yukon
Status history:
Species considered in November 2016 and placed in the Data Deficient category.

Assessment summary – November 2016

Common name:
Pygmy Whitefish - Pacific populations
Scientific name:
Prosopium coulterii
Status:
Not at Risk
Reason for designation:
This small-bodied freshwater fish is relatively broadly distributed across many lakes and some rivers. Most lakes and rivers are relatively isolated from human impacts, and there are no known imminent threats to any population.
Occurrence:
Yukon, British Columbia
Status history:
Designated Not at Risk in November 2016.

Assessment summary – November 2016

Common name:
Pygmy Whitefish - Western Arctic populations
Scientific name:
Prosopium coulterii
Status:
Not at Risk
Reason for designation:
This small-bodied freshwater fish is relatively broadly distributed across many lakes and some rivers. Most lakes and rivers are relatively isolated from human impacts, and there are very few known imminent threats to any population.
Occurrence:
Northwest Territories, British Columbia, Alberta
Status history:
Designated Not at Risk in November 2016.

Assessment summary – November 2016

Common name:
Pygmy Whitefish - Great Lakes – Upper St. Lawrence populations
Scientific name:
Prosopium coulterii
Status:
Threatened
Reason for designation:
This small-bodied freshwater fish has experienced dramatic declines in abundance over the last several decades, with an overall estimated decline of 48% since 2000. The continued presence of invasive fishes and recovery of native predatory fishes may threaten or limit recovery, respectively.
Occurrence:
Ontario
Status history:
Designated Threatened in November 2016.

Assessment summary – November 2016

Common name:
Pygmy Whitefish - Waterton Lake populations
Scientific name:
Prosopium coulterii
Status:
Special Concern
Reason for designation:
This small-bodied freshwater fish is known from a single lake in southwestern Alberta. The population size is relatively small and a change in water quality or habitat induced by local pollution or climate change could put the population at risk.
Occurrence:
Alberta
Status history:
Designated Special Concern in November 2016.

Assessment summary – November 2016

Common name:
Pygmy Whitefish - Saskatchewan - Nelson Rivers populations
Scientific name:
Prosopium coulterii
Status:
Data Deficient
Reason for designation:
This freshwater fish has only recently been documented in four lakes in northwestern Ontario, but may exist in others. Quantitative data on population sizes, geographic range, and known threats are too limited to determine status.
Occurrence:
Ontario
Status history:
Species considered in November 2016 and placed in the Data Deficient category.

COSEWIC executive summary

Pygmy Whitefish
Prosopium coulterii

Southwestern Yukon Beringian populations
Yukon River populations
Pacific populations
Western Arctic populations
Great Lakes – Upper St. Lawrence populations
Waterton Lake populations
Saskatchewan - Nelson Rivers populations

Wildlife species description and significance

The Pygmy Whitefish (Prosopium coulterii) is the smallest species within the whitefishes with a maximum size of approximately 150 mm total length (TL) for the “regular” form and up to 260 mm TL for the “giant” form. It is typically brownish green along the back with silvery sides and a white belly. In cross-section the depth of the body is less than twice its width, and the eye is relatively large; its diameter is larger than the snout length. Except in the largest individuals, there are 7 to 14 dark patches along their side and 12 to 14 along their back. The Pygmy Whitefish is a glacial relict with genetically distinct populations originating from different refugia (DU1, Beringia refugium, and DUs 2-7, Pacific and Mississippi refugia).

Distribution

The Pygmy Whitefish may have the most discontinuous range of any freshwater fish in North America (~2,200 km from Yukon to Lake Superior). Populations exist within: portions of the Columbia River system in British Columbia, Washington, Montana, and Idaho; Fraser, Skeena, Peace, Alsek, and Yukon River systems in British Columbia and Yukon; Chignik and Ugashik river systems in southwestern Alaska; Lake Athabasca in Alberta and Saskatchewan; Upper Waterton Lake and portions of the Athabasca River in Alberta; Great Bear and Bluefish lakes in the Northwest Territories; Lake Superior in Michigan, Wisconsin, Minnesota and Ontario; and four lakes in northwestern Ontario. In addition to its vast North American range, the species is found across a small area outside North America in the Amguen River system in the Chukotsk Peninsula, Siberia.

Habitat

Pygmy Whitefish typically inhabits cold, deep, boreal and montane lakes of low productivity. It is usually found at depths greater than 30 m, but has been located at depths <5 m and as great as 168 m. Pygmy Whitefish is most often encountered at water temperatures below 10°C and oxygen concentrations above 5 mg/l. Pygmy Whitefish is also recorded from moderate to fast-moving, clear or silted, montane rivers where it occupies depths of 0.5 to 1 m in nearshore eddies along the edge of faster mainstream flow.

Biology

Pygmy Whitefish tends to be relatively short-lived with life expectancies ranging between 3 and 10 years (median 7 years). It generally matures at a young age and small size. Males mature at 1 to 3 years of age and 58 to 130 mm total length (TL), whereas females mature at 2 to 4 years of age and 61 to 228 mm TL. Spawning occurs annually between September and December, but can occur as late as January when water temperatures are between 2 and 5°C. Eggs are broadcast over coarse gravel in shallow water in rivers or along lake shorelines at night. Egg production scales with body size; individual females may produce between about 100 to 1,000 eggs. Pygmy Whitefish is a generalist carnivore typically feeding on a variety of benthic invertebrates. In some populations, Pygmy Whitefish may forage on zooplankton in the pelagic zone.

Population size and trends

The small size of the Pygmy Whitefish and the great depths at which it is found often makes its capture through conventional fishing methods difficult. Consequently, little information exists on its population size or trends across the range and population estimates typically do not exist. Nonetheless, it has been estimated that about 2,000 individuals reside within Alberta (range in estimate, 700 to 3,000). Annual trawl surveys conducted in Lake Superior indicate that Pygmy Whitefish densities have ranged from 1.5 to 135 fish per surveyed hectare since 1963. Systematic trawling surveys suggest that the Lake Superior population has declined over the past three generations (16 yrs).

Threats and limiting factors

The Pygmy Whitefish is a cold-water stenotherm, typically preferring water temperatures < 10 °C and dissolved oxygen levels > 5 mg/l; therefore, the distribution of this species is likely limited, in part, by a general lack of tolerance to conditions where these parameters are exceeded. Degradation of habitat including water quality associated with forestry, hydroelectric, oil, gas and mining development, agriculture, and urbanization pose the greatest potential anthropogenic threats to Pygmy Whitefish, although few specific threats have been identified. Stocking with non-native fishes negatively affects Pygmy Whitefish populations, particularly in smaller closed-basin lakes where refugia from predation may be limited. Fishes with limited dispersal ability and stenothermic tolerances, such as Pygmy Whitefish, could be at the greatest risk of extinction following the loss of coldwater habitats from global warming.

Protection, status, and ranks

The Pygmy Whitefish may receive protection under the federal Fisheries Act because although it is unlikely to be considered to be of direct significance to Commercial, Recreational, or Aboriginal fisheries, its status as a forage fish means it likely supports such fisheries. Currently, Pygmy Whitefish are ranked as secure, G5 and N5 for global and national populations, respectively. Regionally, Pygmy Whitefish is ranked S1 in Alberta, S4 in British Columbia and the Yukon, and SU in Ontario and the Northwest Territories. Pygmy Whitefish is considered a non-game fish throughout Canada and, therefore, anglers generally have no restriction on the number of Pygmy Whitefish that they may keep, except in British Columbia where there is a maximum daily limit of 15. Only five populations of Pygmy Whitefish (in Jasper, Waterton, Yoho, and Kluane national parks) are protected from overexploitation. Under the National Park Sport Fishing Regulations, Pygmy Whitefish is not specifically listed in the catch-and-possession limits and, therefore, falls into the category of “other species” that have no limit on retention. Habitat is protected by the National Parks Act where it occurs in a national park or national park reserve.


Technical summary: DU 1

Scientific name:
Prosopium coulterii
English name:
Pygmy Whitefish
Southwestern Yukon Beringian populations
French name:
Corégone pygmée
Populations béringiennes sud-ouest du Yukon
Range of occurrence in Canada (province/territory/ocean):
Yukon, British Columbia

Demographic information

Demographic information of the species
Summary itemsInformation

Generation time (usually average age of parents in the population; indicate if another method of estimating generation time indicated in the IUCN guidelines(2011) is being used)

Based on Alberta populations

5.5 yrs

Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?

No compelling reasons to suspect declines from historical levels

Unknown, but unlikely
Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations].Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations].Unknown
[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations].Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.Unknown
Are the causes of the decline a. clearly reversible and b. understood and c. ceased?
  1. not applicable
  2. not applicable
  3. not applicable
Are there extreme fluctuations in number of mature individuals?Unknown, but likely not

Extent and occupancy information

Extent and occupancy information of the species
Summary itemsinformation
Estimated extent of occurrence51,747 km2

Index of area of occupancy (IAO)

(Always report 2x2 grid value).

28 km2 (discrete)

2,624 km2 (continuous)

Is the population “severely fragmented” i.e. is >50% of its total area of occupancy is in habitat patches that are (a) smaller than would be required to support a viable population, and (b) separated from other habitat patches by a distance larger than the species can be expected to disperse?
  1. No
  2. Yes

Number of “locations”i (use plausible range to reflect uncertainty if appropriate)

Known from seven lakes, YT and BC, but search effort has been very low and there are no known threats to these populations.

Unknown, but at least 7 (could be 10 or more)
Is there an [observed, inferred, or projected] decline in extent of occurrence?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in index of area of occupancy?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in number of subpopulations?Unknown, but likely not

Is there an [observed, inferred, or projected] decline in number of “locations”i?

Suspected to increase with greater survey effort (underway)

Unknown, but likely not
Is there an [observed, inferred, or projected] decline in [area, extent and/or quality] of habitat?Unknown, but likely not
Are there extreme fluctuations in number of subpopulations?Unknown, but likely not
Are there extreme fluctuations in number of “locations”i?Unknown, but likely not
Are there extreme fluctuations in extent of occurrence?Unknown, but likely not
Are there extreme fluctuations in index of area of occupancy?Unknown, but likely not

i See Definitions and abbreviations on COSEWIC website and IUCN (Feb 2014) for more information on this term.

Number of mature individuals (in each subpopulation)

Number of mature individuals of the species
Subpopulations (give plausible ranges)N Mature Individuals
Aishihik LakeUnknown
Atlin LakeUnknown
Bates LakeUnknown
Kathleen LakeUnknown
Little Salmon LakeUnknown
Mush LakeUnknown
Tagish LakeUnknown
TotalUnknown

Quantitative analysis

Quantitative analysis of the species
Summary itemsInformation
Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years].Unknown

Threats (actual or imminent, to populations or habitats, from highest impact to least)

Overall threat impact was unknown and all threat categories were unknown.

Was a threats calculator completed for this species and if so, by whom? Yes; Jeff Sereda, Bruce Bennett, Tom Jung, Randy Zemlak, Olive Barker, Bill Tonn, Dwayne Lepitzki (moderator), Angèle Cyr (recorder)

Rescue effect (immigration from outside Canada)

Rescue effect of the species
Summary itemsInformation

Status of outside population(s) most likely to provide immigrants to Canada.

The only other known Beringian clade Pygmy Whitefish are found in southwestern Alaska, which are isolated by major watershed divides

Idaho (SNR), Montana (S3), Washington (S1S2)
Is immigration known or possible?Possible through the Okanagan and Kootenay Rivers, but improbable given the distance of travel required
Would immigrants be adapted to survive in Canada?Yes
Is there sufficient habitat for immigrants in Canada?Yes
Are conditions deteriorating in Canada?iiNo
Are conditions for the source population deteriorating?iiNo
Is the Canadian population considered to be a sink?iiNo
Is rescue from outside populations likely?iiNo

ii See Table 3 (Guidelines for modifying status assessment based on rescue effect)

Data-sensitive species

Data-sensitive information of the species
Summary itemsInformation
Is this a data sensitive species?No

Status history

Status history
Summary itemsInformation
COSEWIC Status History:Designated Not at Risk in November 2016.

Status and reasons for designation:

Status and reasons for designation
Summary itemsInformation
Status:Not at Risk
Alpha-numeric code:Not applicable
Reasons for designation:This small-bodied freshwater fish is relatively broadly distributed across many lakes and some rivers. Most lakes and rivers are relatively isolated from human impacts and there are no known imminent threats to any population.

Applicability of criteria:

Applicability of criteria
Summary itemsInformation
Criterion A
(Decline in Total Number of Mature Individuals):
Not applicable. No data to detect declines or their magnitude.
Criterion B
(Small distribution range and decline or fluctuation):
Not applicable. Although IAO is below the threshold for Endangered, thresholds for all other criteria are exceeded.
Criterion C
(Small and declining number of mature individuals):
Not applicable. Population sizes unknown, but likely exceed criteria and no evidence of continuing declines.
Criterion D
(Very small or restricted population):
Not applicable. All criteria exceeded.
Criterion E
(Quantitative analysis):
Not performed. Data not available to conduct analysis.

Technical summary: DU 2

Scientific name:
Prosopium coulterii
English name:
Pygmy Whitefish
Yukon River populations
French name:
Corégone pygmée
Populations de la rivière Yukon
Range of occurrence in Canada (province/territory/ocean):
Yukon

Demographic information

Demographic information of the species
Summary itemsInformation

Generation time (usually average age of parents in the population; indicate if another method of estimating generation time indicated in the IUCN guidelines (2011) is being used)

Based on estimates from Alberta populations

5.5 yrs
Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?Unknown, but likely not
Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations].Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations].Unknown
[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations].Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.Unknown
Are the causes of the decline a. clearly reversible and b. understood and c. ceased?
  1. not applicable
  2. not applicable
  3. not applicable
Are there extreme fluctuations in number of mature individuals?Unknown, but likely not

Extent and occupancy information

Extent and occupancy information of the species
Summary itemsinformation
Estimated extent of occurrence28,151 km2
Index of area of occupancy (IAO)
(Always report 2x2 grid value).

12 km2 (discrete)

892 km2 (continuous)

Is the population “severely fragmented” i.e. is >50% of its total area of occupancy is in habitat patches that are (a) smaller than would be required to support a viable population, and (b) separated from other habitat patches by a distance larger than the species can be expected to disperse?
  1. No
  2. Yes

Number of “locations”iii (use plausible range to reflect uncertainty if appropriate)

Known from three lakes, YT, but search effort has been very low and there are no known threats to these populations.

Unknown, but at least 3 (could be 10 or more)
Is there an [observed, inferred, or projected] decline in extent of occurrence?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in index of area of occupancy?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in number of subpopulations?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in number of “locations”iii?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in [area, extent and/or quality] of habitat?Unknown, but likely not
Are there extreme fluctuations in number of subpopulations?Unknown, but likely not
Are there extreme fluctuations in number of “locations”iii?Unknown, but likely not
Are there extreme fluctuations in extent of occurrence?Unknown, but likely not
Are there extreme fluctuations in index of area of occupancy?Unknown, but likely not

iii See Definitions and abbreviations on COSEWIC website and IUCN (Feb 2014) for more information on this term.

Number of mature individuals (in each subpopulation)

Number of mature individuals of the species
PopulationN clones (index of mature individuals)
Marsh LakeUnknown
Mayo LakeUnknown
Teslin LakeUnknown
TotalUnknown

Quantitative analysis

Quantitative analysis of the species
Summary itemsInformation
Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years].Unknown

Threats (actual or imminent, to populations or habitats, from highest impact to least)

Overall threat impact was unknown and all threat categories were unknown.

Was a threats calculator completed for this species and if so, by whom? Yes; Jeff Sereda, Bruce Bennett, Tom Jung, Randy Zemlak, Olive Barker, Bill Tonn, Dwayne Lepitzki (moderator), Angèle Cyr (recorder)

Rescue effect (immigration from outside Canada)

Rescue effect of the species
Summary itemsInformation

Status of outside population(s) most likely to provide immigrants to Canada.

Populations are isolated from other DUs and non-Canadian populations by the watershed divides.

Not applicable
Is immigration known or possible?Not possible
Would immigrants be adapted to survive in Canada?Yes
Is there sufficient habitat for immigrants in Canada?Yes
Are conditions deteriorating in Canada?ivNo
Are conditions for the source population deteriorating?ivNo
Is the Canadian population considered to be a sink?No
Is rescue from outside populations likely?No

iv See Table 3 (Guidelines for modifying status assessment based on rescue effect)

Data-sensitive species

Data-sensitive information of the species
Summary itemsInformation
Is this a data sensitive species?No

Status history

Status history
Summary itemsInformation
COSEWIC:Species considered in November 2016 and placed in the Data Deficient category.

Status and reasons for designation:

Status and reasons for designation
Summary itemsInformation
Status:Data Deficient
Alpha-numeric code:Not applicable
Reasons for designation:This freshwater fish is known from three lakes in Yukon Territory, but may exist in others. Quantitative data on population sizes, geographic range, and known threats are too limited to determine status.

Applicability of criteria:

Applicability of criteria
Summary itemsInformation
Criterion A
(Decline in total number of mature individuals):
Not applicable. Data are insufficient to determine.
Criterion B
(Small distribution range and decline or fluctuation):
Not applicable. Although IAO from known populations are below thresholds for Endangered, the geographic range may be more extensive and there are an unknown number of locations and no evidence of extreme fluctuations or decline in habitat quality, quantity, or adult population sizes.
Criterion C
(Small and declining number of mature individuals):
Not applicable. Insufficient data to assess thresholds.
Criterion D
(Very small or restricted population):
Not applicable. Exceeds IAO threshold and number of locations is highly uncertain.
Criterion E
(Quantitative analysis):
Not performed. No data to conduct quantitative analysis.

Technical summary: DU 3

Scientific name:
Prosopium coulterii
English name:
Pygmy Whitefish
Pacific populations
French name:
Corégone pygmée
Populations du Pacifique
Range of occurrence in Canada (province/territory/ocean):
British Columbia, Yukon.

Demographic information

Demographic information of the species
Summary itemsInformation

Generation time (usually average age of parents in the population; indicate if another method of estimating generation time indicated in the IUCN guidelines(2011) is being used)

Based on estimates from Alberta populations

5.5 yrs
Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?Unknown, but likely not
Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations].Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations].Unknown
[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations].Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.Unknown
Are the causes of the decline a. clearly reversible and b. understood and c. ceased?
  1. not applicable
  2. not applicable
  3. not applicable
Are there extreme fluctuations in number of mature individuals?Unknown, but likely not

Extent and occupancy information

Extent and occupancy information of the species
Summary itemsinformation
Estimated extent of occurrence206,839 km2
Index of area of occupancy (IAO)
(Always report 2x2 grid value).

52 km2 (discrete)

1,092 km2 (continuous)

Is the population “severely fragmented” i.e. is >50% of its total area of occupancy is in habitat patches that are (a) smaller than would be required to support a viable population, and (b) separated from other habitat patches by a distance larger than the species can be expected to disperse?
  1. No
  2. Yes
Number of “locations”v (use plausible range to reflect uncertainty if appropriate)12
Is there an [observed, inferred, or projected] decline in extent of occurrence?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in index of area of occupancy?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in number of subpopulations?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in number of “locations”v?Unknown, but likely not

Is there an [observed, inferred, or projected] decline in [area, extent and/or quality] of habitat?

Some lakes may have experienced habitat degradation in past (e.g., Okanagan Lake, Kootenay Lake, Arrow Lakes), but, overall, habitat is likely stable.

Unknown, but likely not
Are there extreme fluctuations in number of subpopulations?Unknown, but likely not
Are there extreme fluctuations in number of “locations”v?Unknown, but likely not
Are there extreme fluctuations in extent of occurrence?Unknown, but likely not
Are there extreme fluctuations in index of area of occupancy?Unknown, but likely not

v See Definitions and abbreviations on COSEWIC website and IUCN (Feb 2014) for more information on this term.

Number of mature individuals (in each subpopulation)

Number of mature individuals of the species
Subpopulations (give plausible ranges)N Mature Individuals
Upper and Lower Arrow Lake, BCUnknown
Chapman Lake, BCUnknown
Cluculz Lake, BCUnknown
Jack of Clubs Lake, BCUnknown
Kicking Horse River, BCUnknown
Kootenay Lake, BCUnknown
McLeese Lake, BCUnknown
Moose Lake, BCUnknown
Okanagan Lake, BCunknown
Owen Lake, BCunknown
Tyhee Lake, BCunknown
Yellowhead Lake, BCunknown
Totalunknown

Quantitative analysis

Quantitative analysis of the species
Summary itemsInformation
Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years].Unknown

Threats (actual or imminent, to populations or habitats, from highest impact to least)

Overall threat impact was unknown and all threat categories were either negligible or unknown.

Was a threats calculator completed for this species and if so, by whom? Yes; Jeff Sereda, Bruce Bennett, Tom Jung, Randy Zemlak, Olive Barker, Bill Tonn, Dwayne Lepitzki (moderator), Angèle Cyr (recorder)

Rescue effect (immigration from outside Canada)

Rescue effect of the species
Summary itemsInformation

Status of outside population(s) most likely to provide immigrants to Canada.

Populations are isolated from other DUs and non-Canadian populations by the watershed divides.

Idaho (SNR), Montana (S3), Washington (S1S2)
Is immigration known or possible?Possible through the Okanagan and Kootenay Rivers, but improbable given the distance of travel required
Would immigrants be adapted to survive in Canada?Yes
Is there sufficient habitat for immigrants in Canada?Yes
Are conditions deteriorating in Canada?viNo
Are conditions for the source population deteriorating?viNo
Is the Canadian population considered to be a sink?No
Is rescue from outside populations likely?No

vi See Table 3 (Guidelines for modifying status assessment based on rescue effect)

Data-sensitive species

Data-sensitive information of the species
Summary itemsInformation
Is this a data sensitive species?No

Status history

Status history
Summary itemsInformation
COSEWIC Status History:Designated Not at Risk in November 2016.

Status and reasons for designation:

Status and reasons for designation
Summary itemsInformation
Status:Not at Risk
Alpha-numeric code:Not applicable
Reasons for designation:This small-bodied freshwater fish is relatively broadly distributed across many lakes and some rivers. Most lakes and rivers are relatively isolated from human impacts and there are no known imminent threats to any population.

Applicability of criteria:

Applicability of criteria
Summary itemsInformation
Criterion A
(Decline in total number of mature individuals):
Not applicable. No data to detect declines or their magnitude.
Criterion B
(Small distribution range and decline or fluctuation):
Not applicable. Although IAO is below the threshold for Endangered, thresholds for all other criteria are exceeded.
Criterion C
(Small and declining number of mature individuals):
Not applicable. Population sizes unknown, but likely exceed criteria and no evidence of continuing declines.
Criterion D
(Very small or restricted population):
Not applicable. All criteria exceeded.
Criterion E
(Quantitative analysis):
Not performed. Data not available to conduct analysis.

Technical summary: DU 4

Scientific name:
Prosopium coulterii
English name:
Pygmy Whitefish
Western Arctic populations
French name:
Corégone pygmée
Populations de l’ouest de l’Arctique
Range of occurrence in Canada (province/territory/ocean):
Alberta, British Columbia, Northwest Territories

Demographic information

Demographic information of the species
Summary itemsInformation

Generation time (usually average age of parents in the population; indicate if another method of estimating generation time indicated in the IUCN guidelines (2011) is being used)

Based on information from Dina Lake #1 population

Males 2+, Females 3+

Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?

Potential for some declines in heavily impacted areas such as upper Athabasca River watershed.

Unknown, but likely not
Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations].Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations].Unknown
[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations].Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.Unknown
Are the causes of the decline a. clearly reversible and b. understood and c. ceased?
  1. not applicable
  2. not applicable
  3. not applicable
Are there extreme fluctuations in number of mature individuals?Unknown, but likely not

Extent and occupancy information

Extent and occupancy information of the species
Summary itemsinformation
Estimated extent of occurrence1,394,815 km2
Index of area of occupancy (IAO)
(Always report 2x2 grid value).
<2,000 km2
Is the population “severely fragmented” i.e. is >50% of its total area of occupancy is in habitat patches that are (a) smaller than would be required to support a viable population, and (b) separated from other habitat patches by a distance larger than the species can be expected to disperse?
  1. No
  2. Yes
Number of “locations”vii (use plausible range to reflect uncertainty if appropriate)22
Is there an [observed, inferred, or projected] decline in extent of occurrence?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in index of area of occupancy?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in number of subpopulations?Unknown, but likely not

Is there an [observed, inferred, or projected] decline in number of “locations”vii?

Possibly Dina Lake #1 has experienced a decline following heavy stocking of predatory Rainbow Trout

Unknown, but likely not

Is there an [observed, inferred, or projected] decline in [area, extent and/or quality] of habitat?

Probably not for most areas, but notable exceptions (e.g., Athabasca River) exist

Probably not
Are there extreme fluctuations in number of subpopulations?Unknown, but likely not
Are there extreme fluctuations in number of “locations”vii?Unknown, but likely not
Are there extreme fluctuations in extent of occurrence?Unknown, but likely not
Are there extreme fluctuations in index of area of occupancy?Unknown, but likely not

vii See Definitions and abbreviations on COSEWIC website and IUCN (Feb 2014) for more information on this term.

Number of mature individuals (in each subpopulation)

Number of mature individuals of the species
Subpopulations (give plausible ranges)N Mature Individuals
Athabasca River, AB (one 46 km section)267 (95% C.I = 50 - 450)
Aiken Lake, BCUnknown
Arctic Lake, BCUnknown
Bluefish Lake, NWTUnknown
Chuchi Lake, BCUnknown
Dina lake #1, BCUnknown
Elliot Lake, BCUnknown
Great Bear Lake, NWTUnknown
Kwadacha River, BCunknown
Lake Athabasca, AB/SKunknown
Lower Mason Lake, BCunknown
Lower Tacheeda Lake, BCunknown
Monkman Lake, BCunknown
Quentin Lake, BCUnknown
Thutade Lake, BCUnknown
Tutizzi Lake, BCUnknown
Upper Liard River, BC/YTUnknown
Upper Mason Lake, BCUnknown
Upper Tacheeda Lake, BCUnknown
Uslika Lake, BCUnknown
Weissener Lake, BCUnknown
Williston Reservoir, BCUnknown
TotalUnknown

Quantitative analysis

Quantitative analysis of the species
Summary itemsInformation
Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years].Unknown

Threats (actual or imminent, to populations or habitats, from highest impact to least)

Overall threat impact was unknown and all threat categories were either negligible or unknown.

Was a threats calculator completed for this species and if so, by whom? Yes; Jeff Sereda, Bruce Bennett, Tom Jung, Randy Zemlak, Olive Barker, Bill Tonn, Dwayne Lepitzki (moderator), Angèle Cyr (recorder)

Rescue effect (immigration from outside Canada)

Rescue effect of the species
Summary itemsInformation

Status of outside population(s) most likely to provide immigrants to Canada.

Populations are isolated from other DUs and non-Canadian populations by watershed divides.

Not applicable
Is immigration known or possible?Not possible
Would immigrants be adapted to survive in Canada?Yes
Is there sufficient habitat for immigrants in Canada?Yes
Are conditions deteriorating in Canada?viiiNo
Are conditions for the source population deteriorating?viiiNo
Is the Canadian population considered to be a sink?viiiNo
Is rescue from outside populations likely?No

viii See Table 3 (Guidelines for modifying status assessment based on rescue effect)

Data-sensitive species

Data-sensitive information of the species
Summary itemsInformation
Is this a data sensitive species?No

Status history

Status history
Summary itemsInformation
COSEWIC Status History:Designated Not at Risk in November 2016.

Status and reasons for designation:

Status and reasons for designation
Summary itemsInformation
Status:Not at Risk
Alpha-numeric code:Not applicable
Reasons for designation:This small-bodied freshwater fish is relatively broadly distributed across many lakes and some rivers. Most lakes and rivers are relatively isolated from human impacts, and there are very few known imminent threats to any population.

Applicability of criteria:

Applicability of criteria
Summary itemsInformation
Criterion A
(Decline in total number of mature individuals):
Not applicable. No data to detect declines or their magnitude.
Criterion B
(Small distribution range and decline or fluctuation):
Not applicable. Although IAO is below the threshold for Endangered, thresholds for all other criteria are exceeded.
Criterion C
(Small and declining number of mature individuals):
Not applicable. Populations sizes unknown, but likely exceed criteria, and there is no evidence of continuing declines.
Criterion D
(Very small or restricted population):
Not applicable. All criteria exceeded.
Criterion E
(Quantitative analysis):
Not performed. Data not available to conduct analysis.

Technical summary: DU 5

Scientific name:
Prosopium coulterii
English name:
Pygmy Whitefish
Great Lakes – Upper St. Lawrence populations
French name:
Corégone pygmée
Populations des Grands Lacs et du haut Saint-Laurent
Range of occurrence in Canada (province/territory/ocean):
Ontario (Lake Superior)

Demographic information

Demographic information of the species
Summary itemsInformation

Generation time (usually average age of parents in the population; indicate if another method of estimating generation time indicated in the IUCN guidelines(2011) is being used)

Based on information from Alberta populations

5.5 yrs

Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?

Trawl surveys suggest decline over last three generations over all age classes

Yes
Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]Unknown

Suspected percent reduction in total number of mature individuals over the last [10 years, or 3 generations].

Possible decline of 48% in all age classes collected by trawl surveys

48%
[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations].Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.Unknown
Are the causes of the decline a. clearly reversible and b. understood and c. ceased?
  1. No
  2. No
  3. No
Are there extreme fluctuations in number of mature individuals?Unknown, but likely not

Extent and occupancy information

Extent and occupancy information of the species
Summary itemsinformation
Estimated extent of occurrence39,407 km2
Index of area of occupancy (IAO)
(Always report 2x2 grid value).
>2,000 km2
Is the population “severely fragmented” i.e. is >50% of its total area of occupancy is in habitat patches that are (a) smaller than would be required to support a viable population, and (b) separated from other habitat patches by a distance larger than the species can be expected to disperse?
  1. No
  2. No

Number of “locations”ix (use plausible range to reflect uncertainty if appropriate)

Population structure within Lake Superior is poorly known and this vast lake could contain several isolated spawning subpopulations. Locations could be as few as one if invasive species are the principal threat to several if threats act independently at different spawning areas.

1
Is there an [observed, inferred, or projected] decline in extent of occurrence?No
Is there an [observed, inferred, or projected] decline in index of area of occupancy?Unknown, but likely not

Is there an [observed, inferred, or projected] decline in number of subpopulations?

Population substructure is unknown

Unknown, but likely not
Is there an [observed, inferred, or projected] decline in number of “locations”ix?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in [area, extent and/or quality] of habitat?No
Are there extreme fluctuations in number of subpopulations?Unknown, but likely not
Are there extreme fluctuations in number of “locations”ix?No
Are there extreme fluctuations in extent of occurrence?No
Are there extreme fluctuations in index of area of occupancy?Unknown, but likely not

ix See Definitions and abbreviations on COSEWIC website and IUCN (Feb 2014) for more information on this term.

Number of mature individuals (in each subpopulation)

Number of mature individuals of the species
Subpopulations (give plausible ranges)N Mature Individuals
Lake SuperiorUnknown
TotalUnknown

Quantitative analysis

Quantitative analysis of the species
Summary itemsInformation
Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years].Unknown

Threats (actual or imminent, to populations or habitats, from highest impact to least)

Overall threat impact was unknown and all threat categories were either negligible or unknown.

Was a threats calculator completed for this species and if so, by whom? Yes Bill Tonn, Dwayne Lepitzki (moderator) and Angèle Cyr (recorder)

Rescue effect (immigration from outside Canada)

Rescue effect of the species
Summary itemsInformation
Status of outside population(s) most likely to provide immigrants to Canada.Wisconsin S2
Minnesota SNR
Michigan S4
Is immigration known or possible?Possible (likely)
Would immigrants be adapted to survive in Canada?Yes
Is there sufficient habitat for immigrants in Canada?Yes
Are conditions deteriorating in Canada?xNo
Are conditions for the source population deteriorating?xNo
Is the Canadian population considered to be a sink?xNo

Is rescue from outside populations likely?

Canadian population is probably continuous with fish from US side of Lake Superior, but US populations suffering similar trend of decline in trawl catches

Probably

x See Table 3 (Guidelines for modifying status assessment based on rescue effect)

Data-sensitive species

Data-sensitive information of the species
Summary itemsInformation
Is this a data sensitive species?No

Status history

Status history
Summary itemsInformation
COSEWIC Status History:Designated Threatened in November 2016.

Status and reasons for designation:

Status and reasons for designation
Summary itemsInformation
Status:Threatened
Alpha-numeric code:A2be+4be
Reasons for designation:This small-bodied freshwater fish has experienced dramatic declines in abundance over the last several decades, with an overall estimated decline of 48% since 2000. The continued presence of invasive fishes and recovery of native predatory fishes may threaten or limit recovery, respectively.

Applicability of criteria:

Applicability of criteria
Summary itemsInformation
Criterion A
(Decline in total number of mature individuals):
Meets Threatened, A2be+4be, because the index of abundance has declined by 48% over the past three generations.
Criterion B
(Small distribution range and decline or fluctuation):
Not applicable. EOO and IAO exceed criteria and the number of locations is unknown. There is no evidence of significant declines in habitat quality.
Criterion C
(Small and declining number of mature individuals):
Not applicable. Population sizes unknown, but likely exceed criteria.
Criterion D
(Very small or restricted population):
Not applicable. Exceeds criteria.
Criterion E
(Quantitative analysis):
Not performed. Data not available to conduct analysis.

Technical summary: DU 6

Scientific name:
Prosopium coulterii
English name:
Pygmy Whitefish
Waterton Lake populations
French name:
Corégone pygmée
Populations du lac Waterton
Range of occurrence in Canada (province/territory/ocean):
Alberta

Demographic information

Demographic information of the species
Summary itemsInformation

Generation time (usually average age of parents in the population; indicate if another method of estimating generation time indicated in the IUCN guidelines (2011) is being used)

Based on information from Alberta populations

5.5 yrs
Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?Unknown, but likely not
Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations].Unknown
[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations].Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.Unknown
Are the causes of the decline a. clearly reversible and b. understood and c. ceased?
  1. not applicable
  2. not applicable
  3. not applicable
Are there extreme fluctuations in number of mature individuals?Unknown, but likely not

Extent and occupancy information

Extent and occupancy information of the species
Summary itemsinformation
Estimated extent of occurrence44 km2
Index of area of occupancy (IAO)
(Always report 2x2 grid value).
44 km2
Is the population “severely fragmented” i.e. is >50% of its total area of occupancy is in habitat patches that are (a) smaller than would be required to support a viable population, and (b) separated from other habitat patches by a distance larger than the species can be expected to disperse?
  1. No
  2. Yes
Number of “locations”xi (use plausible range to reflect uncertainty if appropriate)1
Is there an [observed, inferred, or projected] decline in extent of occurrence?No
Is there an [observed, inferred, or projected] decline in index of area of occupancy?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in number of subpopulations?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in number of “locations”xi?No
Is there an [observed, inferred, or projected] decline in [area, extent and/or quality] of habitat?Unknown, but likely not
Are there extreme fluctuations in number of subpopulations?Unknown, but likely not
Are there extreme fluctuations in number of “locations”xi?No
Are there extreme fluctuations in extent of occurrence?No
Are there extreme fluctuations in index of area of occupancy?Unknown, but likely not

xi See Definitions and abbreviations on COSEWIC website and IUCN (Feb 2014) for more information on this term.

Number of mature individuals (in each subpopulation)

Number of mature individuals of the species
Subpopulations (give plausible ranges)N Mature Individuals
Waterton Lake, AB1,800 (750-3,300 95% C.I.)
TotalUnknown

Quantitative analysis

Quantitative analysis of the species
Summary itemsInformation
Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years].Unknown

Threats (actual or imminent, to populations or habitats, from highest impact to least)

Overall threat impact was unknown and all threat categories were unknown.

Was a threats calculator completed for this species and if so, by whom? Yes; Jeff Sereda, Bruce Bennett, Tom Jung, Randy Zemlak, Olive Barker, Bill Tonn, Dwayne Lepitzki (moderator), Angèle Cyr (recorder)

Rescue effect (immigration from outside Canada)

Rescue effect of the species
Summary itemsInformation

Status of outside population(s) most likely to provide immigrants to Canada.

Populations are isolated from other DUs and non-Canadian populations by watershed divides.

Not applicable
Is immigration known or possible?Not applicable
Would immigrants be adapted to survive in Canada?Yes
Is there sufficient habitat for immigrants in Canada?Yes
Are conditions deteriorating in Canada?xiiNo
Are conditions for the source population deteriorating?xiiNo
Is the Canadian population considered to be a sink?xiiNo
Is rescue from outside populations likely?No

xii See Table 3 (Guidelines for modifying status assessment based on rescue effect)

Data-sensitive species

Data-sensitive information of the species
Summary itemsInformation
Is this a data sensitive species?No

Status history

Status history
Summary itemsInformation
COSEWIC Status History:Designated Special Concern in November 2016.

Status and reasons for designation:

Status and reasons for designation
Summary itemsInformation
Status:Special Concern
Alpha-numeric code:Not applicable
Reasons for designation:This small-bodied freshwater fish is known from a single lake in southwestern Alberta. The population size is relatively small and a change in water quality or habitat induced by local pollution or climate change could put the population at risk.

Applicability of criteria:

Applicability of criteria
Summary itemsInformation
Criterion A
(Decline in total number of mature individuals):
Not applicable. Data are insufficient to determine.
Criterion B
(Small distribution range and decline or fluctuation):
Not applicable. Although comes close to qualifying for Endangered, because the EOO and IAO (both 44 km2) are below thresholds and population exists at a single location, no subcriteria are met.
Criterion C
(Small and declining number of mature individuals):
Not applicable. Although there is evidence that the population has fewer than 10,000 mature individuals and may be lower than 2,500, there is no evidence of continuing declines in abundance.
Criterion D
(Very small or restricted population):
Not applicable. Although comes close to qualifying for Threatened, D2, the population is not at risk of extinction in a short period of time.
Criterion E
(Quantitative analysis):
Not performed. Data not available to conduct analysis.

Technical summary: DU 7

Scientific name:
Prosopium coulterii
English name:
Pygmy Whitefish
Saskatchewan - Nelson Rivers populations
French name:
Corégone pygmée
Populations de la rivière Saskatchewan et du fleuve Nelson
Range of occurrence in Canada (province/territory/ocean):
Ontario

Demographic information

Demographic information of the species
Summary itemsInformation

Generation time (usually average age of parents in the population; indicate if another method of estimating generation time indicated in the IUCN guidelines (2011) is being used)

Based on information from Alberta populations

5.5 yrs
Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?Unknown, but likely not
Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations].Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations].Unknown
[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations].Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.Unknown
Are the causes of the decline a. clearly reversible and b. understood and c. ceased?
  1. not applicable
  2. not applicable
  3. not applicable
Are there extreme fluctuations in number of mature individuals?Unknown, but likely not

Extent and occupancy information

Extent and occupancy information of the species
Summary itemsinformation
Estimated extent of occurrence4,843 km2
Index of area of occupancy (IAO)
(Always report 2x2 grid value).
16 km2 (discrete) 324 km2 (continuous)
Is the population “severely fragmented” i.e. is >50% of its total area of occupancy is in habitat patches that are (a) smaller than would be required to support a viable population, and (b) separated from other habitat patches by a distance larger than the species can be expected to disperse?
  1. No
  2. Yes

Number of “locations”xiii (use plausible range to reflect uncertainty if appropriate)

May increase with increased survey efforts; known locations discovered only within last 10 years

Unknown (at least 4)
Is there an [observed, inferred, or projected] decline in extent of occurrence?Unknown, but likely not

Is there an [observed, inferred, or projected] decline in index of area of occupancy?

Has increased with recent discoveries

Unknown, but likely not
Is there an [observed, inferred, or projected] decline in number of subpopulations?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in number of “locations”xiii?Unknown, but likely not
Is there an [observed, inferred, or projected] decline in [area, extent and/or quality] of habitat?Unknown, but likely not
Are there extreme fluctuations in number of subpopulations?Unknown, but likely not
Are there extreme fluctuations in number of “locations”xiii?Unknown, but likely not

Are there extreme fluctuations in extent of occurrence?

Known distribution only recently resolved

No
Are there extreme fluctuations in index of area of occupancy?No

xiii See Definitions and abbreviations on COSEWIC website and IUCN (Feb 2014) for more information on this term.

Number of mature individuals (in each subpopulation)

Number of mature individuals of the species
Subpopulations (give plausible ranges)N Mature Individuals
Delaney Lake, ONUnknown
Mameigwess Lake, ONUnknown
Silver Lake, ONUnknown
Winnange Lake, ONUnknown
TotalUnknown

Quantitative analysis

Quantitative analysis of the species
Summary itemsInformation
Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years].Unknown

Threats (actual or imminent, to populations or habitats, from highest impact to least)

Overall threat impact was unknown and all threat categories were unknown.

Was a threats calculator completed for this species and if so, by whom? Yes; Bill Tonn, Dwayne Lepitzki (moderator) and Angele Cyr (recorder)

Rescue effect (immigration from outside Canada)

Rescue effect of the species
Summary itemsInformation

Status of outside population(s) most likely to provide immigrants to Canada.

Populations are isolated from other DUs and non-Canadian populations by watershed divides.

Not applicable
Is immigration known or possible?Not possible
Would immigrants be adapted to survive in Canada?Yes
Is there sufficient habitat for immigrants in Canada?Yes
Are conditions deteriorating in Canada?xivNo
Are conditions for the source population deteriorating?xivNo
Is the Canadian population considered to be a sink?xivNo
Is rescue from outside populations likely?No

xiv See Table 3 (Guidelines for modifying status assessment based on rescue effect)

Data-sensitive species

Data-sensitive information of the species
Summary itemsInformation
Is this a data sensitive species?No

Status history

Status history
Summary itemsInformation
COSEWIC Status History:Species considered in November 2016 and placed in the Data Deficient category.

Status and reasons for designation:

Status and reasons for designation
Summary itemsInformation
Status:Data Deficient
Alpha-numeric code:Not applicable
Reasons for designation:This freshwater fish has only recently been documented in four lakes in northwestern Ontario, but may exist in several others. Quantitative data on population sizes, geographic range, and known threats are too limited to determine status.

Applicability of criteria:

Applicability of criteria
Summary itemsInformation
Criterion A
(Decline in total number of mature individuals):
Not applicable. Data are insufficient to determine.
Criterion B
(Small distribution range and decline or fluctuation):
Not applicable. Although EOO and IAO from known populations are below thresholds for Endangered, the geographic range may be more extensive and there are an unknown number of locations and no evidence of extreme fluctuations or decline in habitat quality, quantity, or adult population sizes.
Criterion C
(Small and declining number of mature individuals):
Not applicable. Insufficient data to assess thresholds.
Criterion D
(Very small or restricted population):
Not applicable. Exceeds IAO threshold and number of locations is highly uncertain.
Criterion E
(Quantitative analysis):
Not performed. No data to conduct quantitative analysis.

COSEWIC history

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.

COSEWIC mandate

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.

COSEWIC membership

COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non-government science members and the co-chairs of the species specialist subcommittees and the Aboriginal Traditional Knowledge subcommittee. The Committee meets to consider status reports on candidate species.

Definitions (2016)

Wildlife species
A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.
Extinct (X)
A wildlife species that no longer exists.
Extirpated (XT)
A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.
Endangered (E)
A wildlife species facing imminent extirpation or extinction.
Threatened (T)
A wildlife species likely to become endangered if limiting factors are not reversed.
Special concern (SC)
(Note: Formerly described as “Vulnerable” from 1990 to 1999, or “Rare” prior to 1990.)
A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.
Not at risk (NAR)
(Note: Formerly described as “Not In Any Category”, or “No Designation Required.”)
A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.
Data deficient (DD)
(Note: Formerly described as “Indeterminate” from 1994 to 1999 or “ISIBD” [insufficient scientific information on which to base a designation] prior to 1994. Definition of the [DD] category revised in 2006.)
A category that applies when the available information is insufficient (a) to resolve a species’ eligibility for assessment or (b) to permit an assessment of the species’ risk of extinction.

The Canadian Wildlife Service, Environment and Climate Change Canada, provides full administrative and financial support to the COSEWIC Secretariat.


Wildlife species description and significance

Name and classification

Phylum:
Chordata
Class:
Actinopterygii
Order:
Salmoniformes
Family:
Salmonidae
Genus:
Prosopium
Species:
Prosopium coulterii, Eigenmann and Eigenmann, 1892
English common name:
Pygmy Whitefish
French common name:
Corégone pygmée

Morphological description

The Pygmy Whitefish is the smallest of all the species within the subfamily Coregoninae (whitefishes) with a maximum size of approximately 150 mm TL for the “regular” form, but adults can be as large as 260 mm TL for the “giant” form (see below). Its back is typically brownish green and it has silvery sides and a white belly. In cross-section, the depth of its body is less than twice its width (Scott and Crossman 1973). Its head length is greater than the body depth and the diameter of the eye is larger than the snout length (Scott and Crossman 1973) (Figure 1). Eye position is slightly upward or slightly on top of head. Pygmy Whitefish has 50 to 70 scales along its lateral line and 13 to 33 pyloric caeca. Individuals typically exhibit 7 to 14 parr marks along their sides and 12 to 14 along their back (Sullivan 2011). Both sexes develop orange ventral fins (Heard and Hartman 1965) and breeding tubercles on the head, back, sides and pectoral fins (Weisel and Dillon 1954) during breeding season. Prosopium species are distinguished from other coregonines by a single flap between the nostrils and a ventral notch in the adipose eyelid (Figure 2) (Sullivan 2011). Pygmy Whitefish can be distinguished from Mountain Whitefish (Prosopium williamsoni) by having six rows of scales above the lateral line rather than 11, and from the Round Whitefish (P. cylindraceum) by its more elongate head, large eye, blunt snout, and relatively small adipose fin.

Figure 1. Pygmy Whitefish from a) Nelson and Paetz (1992) and b) Scott and Crossman (1973).
Illistration of Pygmy Whitefish (see long description below)
Long description for figure 1

Two line drawings of the Pygmy Whitefish; one is from Nelson and Paetz (1992) and the other is from Scott and Crossman (1973). In the Pygmy Whitefish, the head length is greater than the body depth and the diameter of the eye is larger than the snout length. Eye position is slightly upward or slightly on top of head. Individuals typically exhibit 7 to 14 parr marks along their sides and 12 to 14 along their backs.

Figure 2. Anatomical features distinguishing Pygmy Whitefish from other coregonines: a) single nasal flap between nostrils of Prosopium spp. (left) and two nasal flaps present on other coregonines (from McPhail and Lindsey 1970); b) ventral notch in adipose eyelid of Prosopium spp. (from McPhail and Lindsey 1970); c) profile of head of a Mountain Whitefish (left) and Pygmy Whitefish (right) (from Nelson and Paetz 1992).
Illustration of Pygmy Whitefish feautures (see long description below)
Long description for figure 2

Five line drawings illustrating anatomical features that distinguish the Pygmy Whitefish from other coregonines. The top two images show the single nasal flap between nostrils of Prosopium species and the two nasal flaps present on other coregonines. The middle image shows the ventral notch in the adipose eyelid of Prosopium species. The bottom two images show the head profiles of a Mountain Whitefish and a Pygmy Whitefish.

Population spatial structure and variability

Pygmy Whitefish has arguably the greatest discontinuous range of any freshwater fish in North America (Eschmeyer and Bailey 1955). Populations appear to be highly isolated from each other through residency in remote, deep, lakes and, as a result, have diverged morphologically and genetically (McCart 1970; Taylor et al. 2011; Witt et al. 2011). The current diversity of Pygmy Whitefish likely results from isolation in, and postglacial dispersal from, three glacial refugia: Beringian, Pacific, and Mississippi refugia (Figure 3; Table A1).

Figure 3. Global distribution of Pygmy Whitefish. Glacial refugia from which Pygmy Whitefish populations likely originated are shown: red = Bering Refuge (B); blue = Pacific Refuge and/or Mississippi Refuge (P/M), green = Mississippi Refuge (M). Figure modified from Blanchfield et al. (2014).
Image of map (see long description below)
Long description for figure 3

Map of the global distribution of the Pygmy Whitefish, outlining the glacial refugia from which Pygmy Whitefish populations likely originated. The Pygmy Whitefish has a disjunct distribution across North America and is also found in a small portion of the Amguen River system in the Chukotsk Peninsula, Siberia, in northeastern Russia.

Two morphological forms (the “high-raker” and “low-raker”) of Pygmy Whitefish have been identified based on a combination of the numbers of gill rakers, caudal peduncle scales, and dorsal fin rays (McCart 1970; Figure 4). High-raker and low-raker forms were thought to represent populations isolated within different refugia, the Beringian and the Pacific, respectively (McCart 1970). The continental distribution of high-raker and low-raker forms, as well as their coexistence in an Alaskan lake originating from a single refuge (see below) brought the separate refugium hypothesis for the origin of gill-raker morphs into question (Gowell et al. 2012). Two major clades have since been identified through mitochondrial and nuclear DNA sequence analysis: one derived from populations in southwestern Alaska (Clade 1); and another derived from populations in Cascadia, Peace River drainage, Lake Superior, and northwestern Ontario (Clade 2) (Table A1; Witt et al. 2011; Blanchfield et al. 2014). Additionally, it has been proposed that morphological differences may result from niche partitioning. Specifically, differences in diet between gill-raker forms have been identified, with benthivorous and planktivorous whitefish being low-raker and high-raker forms, respectively (Gowell et al. 2012).

Figure 4. Plot of high- and low-raker forms of Pygmy Whitefish. H = high-raker form; L = low-raker form; AR= Athabasca River, AB; C = Copper River, AK; WL = Waterton Lake AB; EL = Elliot Lake, YT; LS = Lake Superior, MI; BL – Bull Lake, MT; LM = Lake McDonald, MT; SI = Snake Indian River, AB. Reproduced from Mayhood (1992).
Graph (see long description below)
Long description for figure 4

Scatterplot of high and low gill raker forms of Pygmy Whitefish. Y axis is ratio of gillrakers to caudal penduncle scales and x axis is number of dorsal fin rays. 

Designatable units

Seven designatable units (DU) are recognized in Pygmy Whitefish based on the discrete and significance criteria (COSEWIC 2014). First, the two major clades differ from each other by more than 3% mtDNA sequence divergence and also form distinct nDNA clades, which strongly suggests that they are pre-glacial in origin (i.e., at least several hundreds of thousands of years old), Witt et al. 2011). Consequently, they have likely resulted from isolation, divergence, and dispersal from distinct glacial refugia (Figure 3). The fact that the discreteness of these clades represents relatively ancient divergences, and is thus of phylogeographic significance, supports the recognition of a distinct DU (DU 1), particularly because many lakes in southern and eastern portions of the Pygmy Whitefish’s distribution have been examined and found not to contain this divergent clade (Taylor et al. 2011; Witt et al. 2011; E.B. Taylor, Dept. of Zoology, University of British Columbia, Vancouver, unpubl. data). All other occurrences of Pygmy Whitefish apparently contain only fish characterized as belonging to Clade 2, but can be further subdivided by their occurrence in five National Freshwater Biogeographic Zones (NFBZ; Figures 5-9: Pacific, Western Arctic, Yukon, Saskatchewan - Nelson, and Great Lakes - Upper St. Lawrence (COSEWIC 2014). Each of the NFBZ has been defined based on their discrete drainage patterns and their distinctive freshwater fish faunas that are the product of historical isolation and recolonization during and following the Pleistocene glaciations (Scott and Crossman 1973; COSEWIC 2014). The discrete distribution of Pygmy Whitefish within these NFBZ is associated with distinctive abiotic and biotic characteristics and biogeographic histories. For example, the Western Arctic NFBZ (DU4) encompasses numerous lakes with a distinctive zoogeographic assemblage of fishes (being a variable mix of largely Bering and Great Plains species). The Great Lakes - Upper St. Lawrence populations (DU5) represents the only known occurrence of Pygmy Whitefish within the Atlantic basin. Furthermore, the isolation of Pygmy Whitefish in distinct biogeographic zones has likely resulted in the evolution of potentially adaptive traits (e.g., the “giant” Pygmy Whitefish, fish of exceptionally large body size, found in some lakes within DU3, e.g., McCart 1965) a common characteristic of salmonid fishes (see Taylor 1991; Fraser et al. 2011). Finally, the Saskatchewan-Nelson NFBZ contains Pygmy Whitefish that consist of two components (one within one lake, the other found in two lakes) that are separated by a natural range disjunction of over 1,400 km (Figure 5) and that exist in very different ecological conditions (e.g., elevation differences of > 1,000 m; sub-alpine lake versus boreal forest, lowland lakes). Consequently, the Waterton Lake populations (DU6) and the Nelson River populations (DU7), although both part of the Saskatchewan-Nelson Rivers Watershed NFBZ, have been placed in separate DUs. In summary, seven designatable units are recognized: Southwestern Yukon Beringian (DU1), Yukon River (DU2), Pacific (DU3), Western Arctic (DU4), Great Lakes - Upper St Lawrence (DU5), Waterton Lake (DU6), and Saskatchewan - Nelson Rivers (DU7) (Figures 5-9).

Figure 5. Distribution of Pygmy Whitefish designatable units in Canada in relation to national freshwater biogeographic zones. More detailed maps are provided for DU1 (Figure 6), DU2 (Figure 7), DU3 (Figure 8), and DU7 (Figure 9).
Image of map (see long description below)
Long description for figure 5

Map of the distribution of Pygmy Whitefish designatable units in Canada in relation to national freshwater biogeographic zones.

Special significance

Pygmy Whitefish is a glacial relict with one of the greatest discontinuous ranges of any freshwater fish in North America (Eschmeyer and Bailey 1955) with genetically unique populations stemming from different refugial origins: DU1, the Beringia refugium, DUs 2-4 (Pacific refugium), and DUs 5-7 (Mississippi refugium). Like many small-bodied fishes, the Pygmy Whitefish plays a role as a forage fish for larger-bodied predatory fishes (Dryer et al. 1965; Fraley and Shepard 1989).


Distribution

Global range

The Pygmy Whitefish has a disjunct global distribution across North America (~2,200 km) and is also found in a small portion of the Amguen River system in the Chukotsk Peninsula, Siberia, in northeastern Russia (Chereshnev and Skopets 1992).

Canadian range

The Pygmy Whitefish has a scattered and disjunct distribution within Canada. Known populations exist within some central British Columbia lakes; portions of the Columbia, Fraser, Upper Peace, Liard, Skeena, Alsek, and Yukon river systems in British Columbia and Yukon (Pacific and Yukon NFBZ); Upper Waterton Lakes and a portion of the Athabasca River between Snaring River and Solomon Creek in Alberta (Western Arctic and Saskatchewan-Nelson NFBZ); the Saskatchewan portion of Lake Athabasca (Western Arctic NFBZ); Bluefish and Great Bear lakes in the Northwest Territories (Western Arctic NFBZ); Lake Superior in Ontario (Great Lakes-Upper St. Lawrence NFBZ; and, four lakes in northwestern Ontario (Saskatchewan-Nelson NFBZ) (McPhail 2007; Witt et al. 2011; Blanchfield et al. 2014). The distribution of Pygmy Whitefish continues to be better understood as lakes containing extant populations have been recently identified through incidental capture (e.g., Winnange and Mameigwess lakes in Ontario and Bluefish Lake, NWT, see Blanchfield et al. 2014 and Vecsei and Panayi 2015). Approximately 90% of the global range of Pygmy Whitefish lies within Canada.

Extent of occurrence and area of occupancy in Canada

The EOO and IAO were estimated for each DU according to the COSEWIC guidelines (i.e., using the minimum convex polygon method for EO, and using an overlaid grid of cells 2 km x 2 km for IAO). All IAO calculations are minimum estimates based on confirmed Pygmy Whitefish observations.

The Southwestern Yukon Beringian DUincludes seven lakes in the southwestern Yukon and northern British Columbia. Its EOO has been estimated as 51,747 km2 and the IAO is 28 km2 (discrete) and 2,624 km2 (continuous) (Figure 6). This DU includes ~2% of the lakes known to contain Pygmy Whitefish.

The Yukon River DU contains about ~7% of the lakes known to contain Pygmy Whitefish: Marsh, Mayo, and Teslin lakes. In this DU, the EOO has been estimated as 28,151 km2 and the IAO is 12 km2 (discrete) and 892 km2 (continuous) (Figure 7).

The Pacific DU encompasses about ~34% of the lakes known to contain Pygmy Whitefish which are found in lakes within the Columbia, Fraser, and Skeena River drainages in British Columbia. The EOO of this DU has been estimated as 206,839 km2 and the IAO is 52 km2 (discrete) and 1,092 km2 (continuous) (Figure 8).

The Western Arctic DU includes numerous lakes within the Williston Reservoir Watershed (upper Peace River) of British Columbia, Lake Athabasca and Athabasca River in Alberta, Bluefish and Great Bear lakes in the Northwest Territories, and Elliot Lake in the Yukon. The EOO of this DU has been estimated as 1,394,815 km2 and the IAO is in excess of 2,000 km2. This DU includes ~50% of the lakes known to contain Pygmy Whitefish.

The Great Lakes - Upper St. Lawrence DU represents the only known population in the Laurentian Great Lakes in Lake Superior. This DU comprises ~2% of the lakes known to contain Pygmy Whitefish. Its EOO has been estimated as 39,407 km2 and the IAO is in excess of 2,000 km2.

The Waterton Lake DU comprises ~2% of the lakes known to contain Pygmy Whitefish. Its EOO and IAO have been estimated as 44 km2.

The Saskatchewan - Nelson River DU includes four lakes in northwestern Ontario. Its EOO has been estimated at 4,843 km2 and the IAO is 16 km2 (discrete) and 324 km2 (continuous). This DU contains ~5% of the lakes known to contain Pygmy Whitefish (Figure 9).

Figure 6. Extent of occurrence and area of occupancy for Pygmy Whitefish in DU1 - Southwestern Yukon Beringian populations.
Image of map (see long description below)
Long description for figure 6

Map illustrating extent of occurrence (polygon) and area of occupancy (grid cells) for Pygmy Whitefish in designatable unit 1 – Southwestern Yukon Beringian.

Figure 7. Extent of Occurrence and Area of Occupancy for Pygmy Whitefish in DU2 – Yukon River populations.
Image of map (see long description below)
Long description for figure 7

Map illustrating extent of occurrence (polygon) and area of occupancy (grid cells) for Pygmy Whitefish in designatable unit 2 – Yukon River.

Figure 8. Extent of occurrence and area of occupancy for Pygmy Whitefish in DU3 – Pacific populations.
Image of map (see long description below)
Long description for figure 8

Map illustrating extent of occurrence (polygon) and area of occupancy (grid cells) for Pygmy Whitefish in designatable unit 3 – Pacific.

Figure 9. Extent of occurrence and area of occupancy for Pygmy Whitefish in DU7 – Saskatchewan - Nelson Rivers populations.
Image of map (see long description below)
Long description for figure 9

Map illustrating extent of occurrence (polygon) and area of occupancy (grid cells) for Pygmy Whitefish in designatable unit 7 – Saskatchewan - Nelson Rivers.

Figure 10. Location of trawl surveys in Lake Superior that have captured Pygmy Whitefish since the 1960s. Trawls were conducted by the USGS in Lake Superior with expansion to more sites in Canada beginning in 1989. Data courtesy of Mark Vinson (USGS).
Image of map (see long description below)
Long description for figure 10

Map indicating the locations of trawl surveys in Lake Superior that have captured Pygmy Whitefish since the 1960s.

Figure 11. Annual Pygmy Whitefish density (fish per surveyed hectare) in Lake Superior as determined by nearshore trawl surveys completed by the USGS, indicating a 48% decline for the last three generations of Pygmy Whitefish, 2000-2016. Data courtesy of Mark Vinson (USGS).
Image of map (see long description below)
Long description for figure 11

Annual Pygmy Whitefish density (fish per surveyed hectare) in Lake Superior as determined by nearshore trawl surveys completed by the USGS, indicating a 48% decline for the last three generations of Pygmy Whitefish, 2000-2016. Data courtesy of Mark Vinson (USGS).

Search effort

In general, and with only a few exceptions, search effort for Pygmy Whitefish has been very low across its range (Table 1). The low search effort results from a combination of its lack of importance as a commercial or recreational fishery species and its occurrence in often remote or very deep lakes. Typically, when search efforts have been made in suitable habitats, more populations of Pygmy Whitefish have been discovered (e.g., Zemlak and McPhail 2006; Blanchfield et al. 2014; Vecsei and Panayi 2014).

Historical search effort for Pygmy Whitefish. Waterbody, year sampled, number captured, catch-per-unit-effort (CUPE), if Pygmy Whitefish were the target species (Y/N), and the number of mature individuals are listed. a
ReferenceWaterbodyYear sampledFishing methodaNumber capturedCPUETargeted Y/NNo. of mature individuals
Government of Alberta status report, 2011Athabasca River, AB20081150.17
fish/100m of river
Y267
(50-450 95% C.L.)
Government of Alberta status report, 2011Upper Waterton Lakes, AB2009242N/AY1800
(750-3300 95% C.L.)
Zemlak and Cowie, 2013Dina Lake #1, BC2000/2001 (combined data)3a74218.5 fish/ 100 m of netY129
Zemlak and Cowie, 2013Dina Lake #1, BC20013b22140.17 fish/ per net/hrY56
Zemlak and Cowie, 2013Dina Lake #1, BC20043a39N/AYN/A
Zemlak and Cowie, 2013Dina Lake #1, BC20063a70N/AY18
Zemlak and Cowie, 2013Quentin Lake. BCblank 3a59N/AYN/A
Zemlak and Cowie, 2013Weissener Lake20033a37N/AYN/A
Zemlak and Cowie, 2013Thutade Lake20033a00YN/A
Zemlak and Cowie, 2013Peace Reach – Williston Reservoir, BC20043a90N/AYN/A
Zemlak and Cowie, 2013Tacheeda Lake North, BC20043a25N/AYN/A
Zemlak and Cowie, 2013Tacheeda Lake North, BC20053a130N/AYN/A
Zemlak and Cowie, 2013Tacheeda Lake South, BC20043a39N/AYN/A
Zemlak and Cowie, 2013Tacheeda Lake South, BC20053a55N/AYN/A
Zemlak and Cowie, 2013Aiken Lake, BC20053a59N/AYN/A
Zemlak and Cowie, 2013Tutizzi Lake, BC20053a67N/AYN/A
Zemlak and Cowie, 2013Manson Lakes (Upper), BC20053a65N/AYN/A
Zemlak and Cowie, 2013Manson Lakes (Lower), BC20053a71N/AYN/A
Zemlak and Cowie, 2013Uslika Lake, BC200645911.7 fish/ 100 m of netYN/A
Zemlak and Cowie, 2013Omineca Arm- Williston Lake, BC200645524.3 fish/100 m of netYN/A
Zemlak and Cowie, 20136 mile Bay – Williston Reservoir, BC20064327.8 fish/100 m of netYN/A
Zemlak and Cowie, 2013Chuchi Lake, BC200643211.2 fish/100 m of netYN/A
Zemlak and Cowie, 2013Arctic Lake, BC2006463.3 fish/100 m of netYN/A
Weir pers. comm., 2014Kootenay Lake. BC’93, ’97, ’00, ’03, ’05, 0958N/ANN/A
Weir pers. comm., 2014Lower Arrow Lake, BC’89, ’90, ’92, ’98, ’00, ’01, ’02, ’03, ’09, ‘115159N/ANN/A
Weir pers. comm., 2014Upper Arrow Lake, BC’90, ’93, ’02, ’06, ’08, ‘09515N/ANN/A
Weir pers. comm., 2014Okanagan Lake, BC’89, ’91, ’94, ’98, ’99, ‘00535N/ANN/A
Weir pers. comm., 2014Slocan Lake, BC200254N/ANN/A
Blanchfield et al., 2014Winnange Lake, ON20086a3N/ANN/A
Blanchfield et al., 2014Winnange Lake, ON20096a1N/AYN/A
Blanchfield et al., 2014Winnange Lake, ON20106a,b102.5/100m of netYN/A
Sheldon et al., 2008Lake 258, ON200460n/aNN/A
Sheldon et al., 2008Lake 259,ON200470n/aNN/A
Sheldon et al., 2008Lake 310,ON200470n/aNN/A
Sheldon et al., 2008Eagle Lake, ON200470n/aNN/A
Sheldon et al., 2008Teggau Lake, ON200470n/aNN/A
Vecsei and Panayi, 2014Bluefish Lake, NWT2012861.3/100m of netNN/A

a Fishing Method:

1) Boat electrofishing conducted over 5 reaches covering ~45 km river known to contain Pygmy Whitefish;

2) Standard multi-mesh gillnet set overnight;

3a) Sinking monofilament gill nets consisting of three 2.4 m deep x 15.24 m long panels of 14, 19, and 25 mm were set depth stratified; shallow (perpendicular to shore) and deep to assess spatial distribution of Pygmy Whitefish. Additional nets of 32 and 38 mm were deployed to target larger fish. Nets set perpendicular to shore had the 14 mm net shallowest and the 25 mm net directed towards deeper waters;

3b) Trap nets (4 m long, 6.1 m side wings and a 30.5 m center wing, mesh size 3.1 mm) set on the lake bottom and fished for 24h;

4) Sinking monofilament gill nets consisting of three 2.4 m deep x 15.24 m long panels of 14, 19, and 25 mm were set perpendicular to shore with the 14 mm net shallowest and the 25 mm net directed towards deeper waters;

5) Mid-depth for Kokanee (Oncorhynchus nerka) – incidental capture, number of fish captured is summed for all years sampled;

6a) Overnight sets of single gang variable mesh experimental gill nets: 1.8 m high and consisting of 6 duplicate panels (each 7.5 m long) of 3 different mesh sizes 13, 19, and 25 mm. Nets were set parallel to shore in 25-40 m of water;

6b) Overnight sets of gill nets: 1.8 m high consisting of 2 gangs, each 12.5 long that consisted of five 2.5 m panels of the following mesh sizes 13, 19, 25, 32, and 38 mm. Nets were set on the bottom at 4 depth strata (1-3, 3-6, 6-12,12-20m) and perpendicular to depth contours;

7) In each lake: 15-30 collapsible fish traps baited with dog biscuits set for at least 12 h and reset up to 5 times; a 10 mm gill net (1m high x 15 m long) set on lake bottom for 12 h; and a minimum of two 10 minute bottom trawls (weather permitting);

8) Bottom-set, graded-mesh gill nets (1.8 m high x 75 m long) composed of five 15 m panels of 21.5, 45.8, 70.1, 97.5 and 120.4 mm stretched mesh. Nets were set overnight for <12 h.


DU1 – Southwestern Yukon Beringian populations

Search effort to identify populations within DU1 has been very low; the presence of the divergent clade within Canada is based on samples from seven lakes in southwestern Yukon and northern British Columbia, but the clade is widespread in several lakes in adjacent regions of southwestern Alaska (Witt et al. 2011; Gowell et al. 2012). The occurrence of this DU requires further genetic analyses and it may well expand into other nearby Yukon lakes (e.g., Sekulmnn Lake, Kluane Lake). A sample of 329 fish from an additional 12 Yukon lakes analyzed in 2016 led to the identification of five (of the 7) additional lakes with Pygmy Whitefish in this clade (Taylor pers. comm. 2016).

DU2 – Yukon River populations

Pygmy Whitefish have been found in the stomachs of Lake Trout (Salvelinus namaycush) and captured incidentally in YT, but studies directed towards its capture have not been conducted.

DU3 – Pacific populations

Pygmy Whitefish have been captured incidentally in trawls targeting Kokanee (freshwater resident Sockeye Salmon, Oncorhynchus nerka) in Kootenay, Okanagan, and Upper and Lower Arrow lakes between 1989 to 2011 (Table 1; Weir pers. comm. 2014). Surveys targeting Pygmy Whitefish have not been conducted in DU3.

DU4 – Western Arctic populations

General fish surveys have been conducted in approximately 360 lakes within the Williston Reservoir Watershed. As part of the Peace/Williston Fish and Wildlife Compensation Program many lakes and the Williston Reservoir have been sampled with multimesh gillnets and downhaul traps (Zemlak and McPhail 2006). Of these, 13 lakes along with Williston Reservoir and the Kwadacha River have been confirmed to contain Pygmy Whitefish. Sinking monofilament gill nets were set depth stratified; shallow (perpendicular to shore) and deep to assess spatial distribution of Pygmy Whitefish. Additional nets were deployed to target larger fish (Zemlak and McPhail 2006). Trap nets (were set on the lake bottom and fished for 24h (Zemlak and McPhail 2006). The watershed is large (~70,000 km2), many lakes are accessible only by air, and fish identification in historical records is questionable (Zemlak and McPhail 2006). Consequently, the distribution of Pygmy Whitefish within the Williston Reservoir watershed may be broader, but additional targeted surveys are required.

Boat electrofishing surveys were conducted along five separate reaches of the Athabasca River between Snaring River and Solomen Creek in 2008. A total of 11,240 m were sampled capturing 19 Pygmy Whitefish (overall catch rate of 0.17 Pygmy Whitefish/100 m) (Sullivan 2011).

Recent observations of Pygmy Whitefish from Bluefish Lake, NWT, were a result of incidental capture (Table 1) in bottom-set gillnets (Vecsei and Panayi 2014).

DU5 – Great Lakes – Upper St. Lawrence populations

The United States Geological Survey (USGS) has conducted daytime nearshore bottom trawl surveys (12-m Yankee bottom trawl) annually in Lake Superior throughout Canada and the U.S. since 1963. Trawl depths had a range of 2.8 m to 168 m. Seven to 89 trawls successfully captured Pygmy Whitefish annually (data courtesy of Vinson 2014). Trawl surveys are part of a long-term study monitoring trends of relative abundance and biomass of the fish community in Lake Superior; as such, trawls were not specifically targeting Pygmy Whitefish.

DU6 – Waterton Lake populations

Pygmy Whitefish surveys were conducted in Waterton Lake in 2007 using standard multi-mesh gillnets set overnight, capturing 42 individuals (Rasmussen et al. 2009).

DU7 – Saskatchewan - Nelson River populations

Sampling occurred in the summer and fall of 2008, 2009, and 2010 in Winnange Lake, ON (Blanchfield et al. 2014). Sampling conducted in 2008 and 2009 used overnight sets of single, gang, variable mesh experimental gill nets set parallel to shore in 25 - 40 m of water. In 2010, nets were set on the bottom at four depth strata (1 - 3, 3 - 6, 6 - 12, and 12 -20m) and perpendicular to depth contours (Blanchfield et al. 2014). In 2014, a single specimen was captured from Mameigwess Lake, ON, as part of the Ontario Ministry of Natural Resources and Forestry (OMNRF) broad-scale monitoring program (BSM) (Royal Ontario Museum Accession Number 8049). Approximately 10% of the 752 lakes in northwestern Ontario with potentially suitable deep, coldwater habitat (identified by the presence of Lake Trout, Salvelinus namaycush) is regularly sampled by the OMNRF BSM program (Chu pers. comm. 2016). In 2016, Pygmy Whitefish was found in two additional lakes (Delaney Lake, Silver Lake) (Reid pers. comm. 2016).

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