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COSEWIC Assessment and Status Report on the Rougheye Rockfish sp. type I and sp. type II in Canada

Technical Summary

Sebastes sp. type I

Rougheye rockfish type I

Sébaste à oeil épineux du type I

Range of Occurrence in Canada: Pacific Ocean (BC continental shelf/slope between 170 and 650 m)


Extent and Area Information

Extent of occurrence (EO) (km2)
Flat-surface area between isobaths 500 and 1 600 m
37 000 km2
Specify trend in EO (km2)No change
Are there extreme fluctuations in EO?No
Area of occupancy (AO) (km2)
Grid of fish density (CPUE) using commercial trawl data
35 000 km2
Specify trend in AONo change
Are there extreme fluctuations in AO?No
Number of known or inferred current locationsContinuous distribution
Specify trend in #Not applicable
Are there extreme fluctuations in number  of locations?Not applicable
Specify trend in area, extent or quality of habitatNo change


Population Information

Generation time
(average age of parents in the population)
48 years
Number of mature individualsUnknown
Total population trendNo trend observed
% decline over the last/next 10 years or 3 generations
Catch per unit effort in commercial fisheries: stable or increasing since 1996
No trend observed
Are there extreme fluctuations in number of mature individuals?No
Is the total population severely fragmented?No
Specify trend in number of populationsA single population assumed
Are there extreme fluctuations in number of populations?No
List populations with number of mature individuals in eachNot applicable


Threats (actual or imminent threats to populations or habitats)

Fishing mortality on a long-lived species; lack of knowledge of distribution, abundance and threats for one of a recently discovered cryptic species pair


Rescue Effect (immigration from an outside source)

Status of outside population(s)?
USA: Declining (?) based on other rockfish species
Is immigration known or possible?Unknown, but possible
Would immigrants be adapted to survive in Canada?Probably
Is there sufficient habitat for immigrants in Canada?Unknown, probably
Is rescue from outside populations likely?Possible


Quantitative Analysis

See Haigh et al. (2005)
 


Current Status

COSEWIC: Special Concern (2007)


Status and Reason for Designation

Status:
Special Concern
Alpha-numeric code:
not applicable
Reason for designation:
This species is a relatively large (reaching 90 cm length) rockfish species and among the longest-lived, estimated to approach 200 years. It is one of two sympatric species which have been identified within the described species Sebastes aleutianus. It ranges from northern Japan to southern California in depths 200 to 800+ m along the shelf break. In Canadian waters abundance information is derived from surveys and from the commercial fishery that has maintained a relatively constant reported catch of between 1000 and 2000 tonnes annually over the last 2 decades. Abundance indices and biomass estimates are uncertain, compromised by short time series and survey techniques not always appropriate for the species. No strong abundance trends are observed in the available indices. There is evidence of truncation of the age distribution over the last decade, suggesting that mortality from all sources may have doubled (4.5% y-1 to 9.1% y-1). Long-lived, low-fecundity Sebastes species are particularly susceptible to population collapse and recovery may be compromised when the age- and size-distribution is truncated (i.e. when the number of spawners declines) through fishing. Difficulty in separating the two species increases the risk of potential impacts on one of the species going unnoticed.


Applicability of Criteria

Criterion A (Declining Total Population):
Not met - no indications of decline in available abundance indices.
Criterion B (Small Distribution, and Decline or Fluctuation):
Not met - extent of occurrence and area of occupancy larger than thresholds.
Criterion C (Small Total Population Size and Decline):
Not met - population size estimate not available but certainly larger than threshold.
Criterion D (Very Small Population or Restricted Distribution):
Not met.
Criterion E (Quantitative Analysis):
Not undertaken.

 

Sebastes sp. type II

Rougheye rockfish type II

Sébaste à oeil épineux du type II

Range of Occurrence in Canada: Pacific Ocean (BC continental shelf/slope between 170 and 650 m)


Extent and Area Information

Extent of occurrence (EO) (km2)
Flat-surface area between isobaths 500 and 1 600 m
37 000 km2
Specify trend in EO (km2)No change
Are there extreme fluctuations in EO?No
Area of occupancy (AO) (km2)
Grid of fish density (CPUE) using commercial trawl data
35 000 km2
Specify trend in AONo change
Are there extreme fluctuations in AO?No
Number of known or inferred current locationsContinuous distribution
Specify trend in #Not applicable
Are there extreme fluctuations in number  of locations?Not applicable
Specify trend in area, extent or quality of habitatNo change


Population Information

Generation time
(average age of parents in the population)
48 years
Number of mature individualsUnknown
Total population trendNo trend observed
% decline over the last/next 10 years or 3 generations
Catch per unit effort in commercial fisheries: stable or increasing since 1996
No trend observed
Are there extreme fluctuations in number of mature individuals?No
Is the total population severely fragmented?No
Specify trend in number of populationsA single population assumed
Are there extreme fluctuations in number of populations?No
List populations with number of mature individuals in eachNot applicable


Threats (actual or imminent threats to populations or habitats)

Fishing mortality on a long-lived species; lack of knowledge of distribution, abundance and threats for one of a recently discovered cryptic species pair


Rescue Effect (immigration from an outside source)

Status of outside population(s)?
USA: Declining (?) based on other rockfish species
Is immigration known or possible?Unknown, but possible
Would immigrants be adapted to survive in Canada?Probably
Is there sufficient habitat for immigrants in Canada?Unknown, probably
Is rescue from outside populations likely?Possible


Quantitative Analysis

See Haigh et al. (2005)
 


Current Status

COSEWIC: Special Concern (2007)


Status and Reason for Designation

Status:
Special Concern
Alpha-numeric code:
not applicable
Reason for designation:
This species is a relatively large (reaching 90 cm length) rockfish species and among the longest-lived, estimated to approach 200 years. It is one of two sympatric species which have been identified within the described species Sebastes aleutianus. It ranges from northern Japan to southern California in depths 200 to 800+ m along the shelf break. In Canadian waters abundance information is derived from surveys and from the commercial fishery that has maintained a relatively constant reported catch of between 1000 and 2000 tonnes annually over the last 2 decades. Abundance indices and biomass estimates are uncertain, compromised by short time series and survey techniques not always appropriate for the species. No strong abundance trends are observed in the available indices. There is evidence of truncation of the age distribution over the last decade, suggesting that mortality from all sources may have doubled (4.5% y-1 to 9.1% y-1). Long-lived, low-fecundity Sebastes species are particularly susceptible to population collapse and recovery may be compromised when the age- and size-distribution is truncated (i.e. when the number of spawners declines) through fishing. Difficulty in separating the two species increases the risk of potential impacts on one of the species going unnoticed.


Applicability of Criteria

Criterion A (Declining Total Population):
Not met - no indications of decline in available abundance indices.
Criterion B (Small Distribution, and Decline or Fluctuation):
Not met - extent of occurrence and area of occupancy larger than thresholds.
Criterion C (Small Total Population Size and Decline):
Not met - population size estimate not available but certainly larger than threshold.
Criterion D (Very Small Population or Restricted Distribution):
Not met.
Criterion E (Quantitative Analysis):
Not undertaken.