Beluga whale (Delphinapterus leucas) COSEWIC assessment and status report: chapter 15


Technical Summary - (1) St. Lawrence Estuary Population

Delphinapterus leucas

Beluga
béluga

(1) St. Lawrence Estuary population

Range of Occurrence in Canada: Gulf of St. Lawrence, Quebec / Atlantic Ocean


Extent and Area Information

Extent of occurrence (EO)(km2)

36 000 km2 (approx.)


Specify trend in EO

Stable


Are there extreme fluctuations in EO?

No


Area of occupancy (AO)(km2)

5 000 km2


Specify trend in AO

Stable?


Are there extreme fluctuations in AO?

No


Number of known or inferred current locations

Not applicable


Specify trend in #

Not applicable


Are there extreme fluctuations in number of locations?

No


Specify trend in area, extent or quality of habitat

Stable



Population Information

Generation time (average age of parents in the population)

14 years


Number of mature individuals

571 (60% x 952)


Total population trend:

?


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

Not applicable


Are there extreme fluctuations in number of mature individuals?

No


Is the total population severely fragmented?

No


Specify trend in number of populations

Not applicable


Are there extreme fluctuations in number of populations?

Not applicable



Threats (Actual or Imminent Threats to Populations or Habitats)

Chemical pollution, loss of habitat, vessel traffic, in-breeding, developing commercial fisheries


Rescue Effect (Immigration from an Outside Source)

Status of outside population(s)?

Not at Risk to Endangered


Is immigration known or possible?

Yes


Would immigrants be adapted to survive in Canada?

Yes


Is there sufficient habitat for immigrants in Canada?

Yes


Is rescue from outside populations likely?

Not very



Quantitative Analysis

Not applicable


Other Status

COSEWIC: Endangered, April 1997


Status and Reasons for Designation

Status: Threatened

Alpha-numeric code: D1

Reasons for Designation: The population was severely reduced by hunting, which continued until 1979. High contaminant loads may have also contributed to the population decline. Aerial surveys since 1973 suggest that the decline has ceased, but do not provide clear evidence of a significant increase in numbers. Levels of many contaminants remain high in beluga tissues. The whales and their habitat are threatened by contaminants, vessel traffic, and industrialization of the St. Lawrence watershed.


Applicability of Criteria

Criterion A (Declining Total Population): no.

Criterion B (Small Distribution, and Decline or Fluctuation): no

Criterion C (Small Total Population Size and Decline): no

Criterion D (Very Small Population or Restricted Distribution): Threatened D1, less than 1000 mature individuals.

Criterion E (Quantitative Analysis): not applicable


Technical Summary - (2) Ungava Bay Population

Delphinapterus leucas

Beluga
béluga

(2) Ungava Bay Population

Range of Occurrence in Canada: Quebec / Arctic and Atlantic Oceans


Extent and Area Information

Extent of occurrence (EO)(km2)

51 000 km2 (approx.)


Specify trend in EO

Unknown


Are there extreme fluctuations in EO?

No


Area of occupancy (AO)(km2)

12 000 km2


Specify trend in AO

Unknown


Are there extreme fluctuations in AO?

No


Number of known or inferred current locations

Unknown


Specify trend in #

Unknown


Are there extreme fluctuations in number of locations?

No


Specify trend in area, extent or quality of habitat

Stable



Population Information

Generation time (average age of parents in the population)

14 years


Number of mature individuals

Probably less than 30 (60% x 50)


Total population trend:

Decrease over 3 generations, currently unknown


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

Unknown


Are there extreme fluctuations in number of mature individuals?

No


Is the total population severely fragmented?

No


Specify trend in number of populations

Not applicable


Are there extreme fluctuations in number of populations?

Not applicable



Threats (Actual or Imminent Threats to Populations or Habitats)

Past overexploitation, continuing exploitation, potential hydro-electric development, noise disturbance


Rescue Effect (Immigration from an Outside Source)

Status of outside population(s)?

Not at Risk to Endangered


Is immigration known or possible?

Yes


Would immigrants be adapted to survive in Canada?

Yes


Is there sufficient habitat for immigrants in Canada?

Yes


Is rescue from outside populations likely?

Not very



Quantitative Analysis

Not applicable


Other Status

COSEWIC: Endangered, April 1988


Status and Reasons for Designation

Status: Endangered

Alpha-numeric code: A2a; D1

Reasons for Designation: All signs indicate that the population residing in Ungava Bay is very low and may be extirpated. However, it is difficult to definitively conclude that they have been extirpated because beluga from other populations may visit Ungava Bay. Hunting caused the population decline and continues in Ungava Bay, posing a threat to any remaining beluga.


Applicability of Criteria

Criterion A (Declining Total Population): Endangered A2a.

Criterion B (Small Distribution, and Decline or Fluctuation): not applicable (unknown current range).

Criterion C (Small Total Population Size and Decline): not applicable, because no estimation of trend.

Criterion D (Very Small Population or Restricted Distribution): Endangered D1.

Criterion E (Quantitative Analysis): not applicable


Technical Summary - (3) Eastern Hudson Bay Population

Delphinapterus leucas

Beluga
béluga

(3) Eastern Hudson Bay Population

Range of Occurrence in Canada: Quebec / Nunavut / Arctic and Atlantic Oceans


Extent and Area Information

Extent of occurrence (EO)(km2)

221 000 km2 (approx.)


Specify trend in EO

Stable


Are there extreme fluctuations in EO?

No


Area of occupancy (AO)(km2)

41 000 km2


Specify trend in AO

Stable


Are there extreme fluctuations in AO?

No


Number of known or inferred current locations

Not applicable


Specify trend in #

Decline (fewer estuarine habitats)


Are there extreme fluctuations in number of locations?

No


Specify trend in area, extent or quality of habitat

Stable



Population Information

Generation time (average age of parents in the population)

14 years


Number of mature individuals

1227 (60% x 2045)


Total population trend:

Declining


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

36% decline 1985-2001 indicates 2.6%/yr or 66% decline over 3 generations


Are there extreme fluctuations in number of mature individuals?

No


Is the total population severely fragmented?

No


Specify trend in number of populations

Not applicable


Are there extreme fluctuations in number of populations?

Not applicable



Threats (Actual or Imminent Threats to Populations or Habitats)

Overexploitation, hydro-electric development of rivers, noise disturbance


Rescue Effect (Immigration from an Outside Source)

Status of outside population(s)?

Not at Risk to Endangered


Is immigration known or possible?

Yes


Would immigrants be adapted to survive in Canada?

Yes


Is there sufficient habitat for immigrants in Canada?

Yes


Is rescue from outside populations likely?

Not very



Quantitative Analysis

Substantial chance of extirpation 10-15 years (Hammill 2001, Bourdages et al. 2002)


Other Status

COSEWIC: Threatened, April 1988


Status and Reasons for Designation

Status: Endangered

Alpha-numeric code: A2d; C1; E

Reasons for Designation: The population was reduced by at least 50% and continues to decline. Overhunting continues throughout its summer and migratory range. Mathematical models predict that it will likely disappear under present hunting levels in less than 10 to 15 years. Concerns have been expressed about habitat degradation of estuaries by hydroelectric projects, and by small vessel traffic disturbance.


Applicability of Criteria

Criterion A (Declining Total Population): Endangered A2d.

Criterion B (Small Distribution, and Decline or Fluctuation): no

Criterion C (Small Total Population Size and Decline): Endangered C1.

Criterion D (Very Small Population or Restricted Distribution): no (nearly D1 Threatened).

Criterion E (Quantitative Analysis): Endangered E, extinction likely under current harvest levels within 20 years.


Technical Summary - (4) Western Hudson Bay Population

Delphinapterus leucas

Beluga
béluga

(4) Western Hudson Bay Population

Range of Occurrence in Canada: Manitoba / Nunavut / Ontario / Arctic and Atlantic Oceans


Extent and Area Information

Extent of occurrence (EO)(km2)

770 000 km2 (approx.)


Specify trend in EO

Stable


Are there extreme fluctuations in EO?

No


Area of occupancy (AO)(km2)

51 000 km2


Specify trend in AO

Stable


Are there extreme fluctuations in AO?

No


Number of known or inferred current locations

Not applicable


Specify trend in #

Not applicable


Are there extreme fluctuations in number of locations?

No


Specify trend in area, extent or quality of habitat

Stable



Population Information

Generation time (average age of parents in the population)

14 years


Number of mature individuals

>30 000 (60% x 30 000)


Total population trend:

Unknown


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

Not applicable


Are there extreme fluctuations in number of mature individuals?

No


Is the total population severely fragmented?

No


Specify trend in number of populations

Not applicable


Are there extreme fluctuations in number of populations?

Not applicable



Threats (Actual or Imminent Threats to Populations or Habitats)

Possibly more than one population subjected to seasonal harvesting, including during spring and autumn migrations


Rescue Effect (Immigration from an Outside Source)

Status of outside population(s)?

Not at Risk to Endangered


Is immigration known or possible?

Yes


Would immigrants be adapted to survive in Canada?

Yes


Is there sufficient habitat for immigrants in Canada?

Yes


Is rescue from outside populations likely?

Not very



Quantitative Analysis

Not applicable


Other Status

COSEWIC: Not at Risk, April 1993.


Status and Reasons for Designation

Status: Special Concern

Alpha-numeric code: Not applicable

Reasons for Designation: The population appears to be relatively abundant, although it has not been surveyed for 15 years and may consist of more than one population. The population is subject to substantial removals by hunting in parts of its range, and is potentially threatened by shipping and hydroelectric dams.


Applicability of Criteria

Criterion A (Declining Total Population): no.

Criterion B (Small Distribution, and Decline or Fluctuation): no

Criterion C (Small Total Population Size and Decline): no

Criterion D (Very Small Population or Restricted Distribution): no.

Criterion E (Quantitative Analysis): not applicable


Technical Summary - (5) Eastern High Arctic – Baffin Bay Population

Delphinapterus leucas

Beluga
béluga

(5) Eastern High Arctic – Baffin Bay Population

Range of Occurrence in Canada: Nunavut / Arctic Ocean


Extent and Area Information

Extent of occurrence (EO)(km2)

250 000 km2 (approx.)


Specify trend in EO

Stable


Are there extreme fluctuations in EO?

No


Area of occupancy (AO)(km2)

49 000 km2


Specify trend in AO

Stable


Are there extreme fluctuations in AO?

No


Number of known or inferred current locations

Not applicable


Specify trend in #

Not applicable


Are there extreme fluctuations in number of locations?

No


Specify trend in area, extent or quality of habitat

Stable



Population Information

Generation time (average age of parents in the population)

14 years


Number of mature individuals

12 729 (60% x 21 213)


Total population trend:

Decline?


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

Unknown


Are there extreme fluctuations in number of mature individuals?

No


Is the total population severely fragmented?

No


Specify trend in number of populations

Not applicable


Are there extreme fluctuations in number of populations?

Not applicable



Threats (Actual or Imminent Threats to Populations or Habitats)

Overharvesting off West Greenland


Rescue Effect (Immigration from an Outside Source)

Status of outside population(s)?

Not at Risk to Endangered


Is immigration known or possible?

Yes


Would immigrants be adapted to survive in Canada?

Yes


Is there sufficient habitat for immigrants in Canada?

Yes


Is rescue from outside populations likely?

Not very



Quantitative Analysis

Not applicable


Other Status

COSEWIC: Special Concern, April 1992


Status and Reasons for Designation

Status: Special Concern

Alpha-numeric code: Not applicable

Reasons for Designation: The population overwinters in Baffin Bay and west Greenland and may consist of two distinct populations. It is heavily hunted in west Greenland. However, most of the population winters in Baffin Bay and the High Arctic where it is not hunted. Hunting pressure in Canadian waters is low in summer


Applicability of Criteria

Criterion A (Declining Total Population): might qualify for Threatened A2d or A3d as inferred from recent estimate of High Arctic summering population (21 213 animals), and catches, mainly off west Greenland (650-941 per year) in winter. The part of the population off West Greenland declined about 50% between 1981-1994, roughly one generation, suggesting an approximate 7/8 decline over three generations; as the West Greenland wintering animals number about 15% of the current population, this suggests a decline of [1-1/(0.85 +8x0.15)]x100=51% decline over three generations. Alternatively, the catch (roughly 795.5 off west Greenland and <100 in Canada, plus struck and lost animals) constitutes about 4.2% of the population per year (895.5/21 213), an excess of 1.2% over the median postulated maximum potential rate of increase (3% per year). A decline of 1.2%/year over 42 years (3 generations) is 40%. Both of these calculations make questionable assumptions (about the effects of past and future catches respectively).

Criterion B (Small Distribution, and Decline or Fluctuation): no

Criterion C (Small Total Population Size and Decline): no

Criterion D (Very Small Population or Restricted Distribution): no.

Criterion E (Quantitative Analysis): no.


Technical Summary - (6) Cumberland Sound Population

Delphinapterus leucas

Beluga
béluga

(6) Cumberland Sound Population

Range of Occurrence in Canada: Nunavut / Arctic Ocean


Extent and Area Information

Extent of occurrence (EO)(km2)

27 000 km2 (approx.)


Specify trend in EO

Stable


Are there extreme fluctuations in EO?

No


Area of occupancy (AO)(km2)

9 000 km2


Specify trend in AO

Stable


Are there extreme fluctuations in AO?

No


Number of known or inferred current locations

Not applicable


Specify trend in #

Not applicable


Are there extreme fluctuations in number of locations?

No


Specify trend in area, extent or quality of habitat

Stable



Population Information

Generation time (average age of parents in the population)

14 years


Number of mature individuals

928 (60% x 1 547)


Total population trend:

Stable


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

 


Are there extreme fluctuations in number of mature individuals?

No


Is the total population severely fragmented?

No


Specify trend in number of populations

Not applicable


Are there extreme fluctuations in number of populations?

Not applicable



Threats (Actual or Imminent Threats to Populations or Habitats)

Overexploitation, noise disturbance


Rescue Effect (Immigration from an Outside Source)

Status of outside population(s)?

Not at Risk to Endangered


Is immigration known or possible?

Yes


Would immigrants be adapted to survive in Canada?

Yes


Is there sufficient habitat for immigrants in Canada?

Yes


Is rescue from outside populations likely?

Not very



Quantitative Analysis

Model exists but does not predict extinction at current harvest levels


Other Status

COSEWIC: Endangered, April 1990.


Status and Reasons for Designation

Status: Threatened

Alpha-numeric code: D1

Reasons for Designation: Numbers of belugas using Cumberland Sound have declined by about 1500 individuals between the 1920s and present. The population decline is believed to have been caused by hunting by the Hudson Bay Company into the 1940s and by the Inuit until 1979. Hunting has been regulated since the 1980s. Current quotas (41 in 2003) appear to be sustainable. Concerns have been raised about increased small vessel traffic and the associated noise of outboard motors, as well as fishery removals of Greenland halibut, a food of belugas.


Applicability of Criteria

Criterion A (Declining Total Population): no decline since 1960.

Criterion B (Small Distribution, and Decline or Fluctuation): no

Criterion C (Small Total Population Size and Decline): no

Criterion D (Very Small Population or Restricted Distribution): Threatened under D1, less than 1000 mature individuals.

Criterion E (Quantitative Analysis): Model exists but does not predict extinction at current harvest levels.


Technical Summary - (7) Eastern Beaufort Sea Population

Delphinapterus leucas

Beluga
béluga

(7) Eastern Beaufort Sea Population

Range of Occurrence in Canada: NT / Arctic Ocean


Extent and Area Information

Extent of occurrence (EO)(km2)

591 000 km2 (approx.)


Specify trend in EO

Stable


Are there extreme fluctuations in EO?

No


Area of occupancy (AO)(km2)

445 000 km2


Specify trend in AO

Stable


Are there extreme fluctuations in AO?

No


Number of known or inferred current locations

Not applicable


Specify trend in #

Not applicable


Are there extreme fluctuations in number of locations?

No


Specify trend in area, extent or quality of habitat

Stable



Population Information

Generation time (average age of parents in the population)

14 years


Number of mature individuals

≥~23 555 (60% x 39 258)


Total population trend:

Unknown


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

Not applicable


Are there extreme fluctuations in number of mature individuals?

No


Is the total population severely fragmented?

No


Specify trend in number of populations

Not applicable


Are there extreme fluctuations in number of populations?

Not applicable



Threats (Actual or Imminent Threats to Populations or Habitats)

Offshore oil and gas exploration and exploitation


Rescue Effect (Immigration from an Outside Source)

Status of outside population(s)?

Not at Risk to Endangered


Is immigration known or possible?

Yes


Would immigrants be adapted to survive in Canada?

Yes


Is there sufficient habitat for immigrants in Canada?

Yes


Is rescue from outside populations likely?

Not very



Quantitative Analysis

None


Other Status

COSEWIC: Not at Risk, April 1985.


Status and Reasons for Designation

Status: Not at Risk

Alpha-numeric code: Not applicable

Reasons for Designation: This population is currently large and hunted at sustainable levels under an international agreement.


Applicability of Criteria

Criterion A (Declining Total Population): no.

Criterion B (Small Distribution, and Decline or Fluctuation): no

Criterion C (Small Total Population Size and Decline): no

Criterion D (Very Small Population or Restricted Distribution): no.

Criterion E (Quantitative Analysis): not applicable

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