Rougheye rockfish species types I and II COSEWIC assessment and status report: chapter 13
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 AO | No change |
Are there extreme fluctuations in AO? | No |
Number of known or inferred current locations | Continuous distribution |
Specify trend in # | Not applicable |
Are there extreme fluctuations in number of locations? | Not applicable |
Specify trend in area, extent or quality of habitat | No change |
Population Information
Generation time (average age of parents in the population) |
48 years |
Number of mature individuals | Unknown |
Total population trend | No 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 populations | A single population assumed |
Are there extreme fluctuations in number of populations? | No |
List populations with number of mature individuals in each | Not 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 (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.
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.
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.
Not met - population size estimate not available but certainly larger than threshold.
Criterion D (Very Small Population or Restricted Distribution):
Not met.
Not met.
Criterion E (Quantitative Analysis):
Not undertaken.
Not undertaken.
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 AO | No change |
Are there extreme fluctuations in AO? | No |
Number of known or inferred current locations | Continuous distribution |
Specify trend in # | Not applicable |
Are there extreme fluctuations in number of locations? | Not applicable |
Specify trend in area, extent or quality of habitat | No change |
Population Information
Generation time (average age of parents in the population) |
48 years |
Number of mature individuals | Unknown |
Total population trend | No 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 populations | A single population assumed |
Are there extreme fluctuations in number of populations? | No |
List populations with number of mature individuals in each | Not 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 (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.
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.
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.
Not met - population size estimate not available but certainly larger than threshold.
Criterion D (Very Small Population or Restricted Distribution):
Not met.
Not met.
Criterion E (Quantitative Analysis):
Not undertaken.
Not undertaken.
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