Estimation of discard mortality of sablefish (Anoplopoma fimbria) in Alaska longline fisheries

Stachura, Megan M. and Lunsford, Chris R. and Rodgveller, Cara J. and Heifetz, Jonathan (2012) Estimation of discard mortality of sablefish (Anoplopoma fimbria) in Alaska longline fisheries. Fishery Bulletin, 110(2), pp. 271-279.

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Abstract

Sablefish (Anoplopoma fimbria) are often caught incidentally in longline fisheries and discarded, but the extent of mortality after release is unknown, which creates uncertainty for estimates of total mortality. We analyzed data from 10,427 fish that were tagged in research surveys and recovered in surveys and commercial fisheries up to 19 years later and found a decrease in recapture rates for fish originally captured at shallower depths (210–319 m) during the study, sustaining severe hooking injuries, and sustaining amphipod predation injuries. The overall estimated discard mortality rate was 11.71%. This estimate is based on an assumed survival rate of 96.5% for fish with minor hooking injuries and the observed recapture rates for sablefish at each level of severity of hook injury. This estimate may be lower than what actually occurs in commercial fisheries because fish are likely not handled as carefully as those in our study. Comparing our results with data on the relative occurrence of the severity of hooking injuries in longline fisheries may lead to more accurate accounting of total mortality attributable to fishing and to improved management of this species.

Item Type: Article
Title: Estimation of discard mortality of sablefish (Anoplopoma fimbria) in Alaska longline fisheries
Personal Creator/Author:
CreatorsEmail
Stachura, Megan M.
Lunsford, Chris R.
Rodgveller, Cara J.
Heifetz, Jonathan
Refereed: Yes
Journal or Publication Title: Fishery Bulletin
Volume: 110
Number: 2
Page Range: pp. 271-279
Date: April 2012
ISSN: 0090-0656
Issuing Agency: United States National Marine Fisheries Service
Subjects: Biology
Ecology
Fisheries
Item ID: 8685
Depositing User: Patti M. Marraro
Date Deposited: 07 Jun 2012 14:47
Last Modified: 07 Jun 2012 14:47
URI: http://aquaticcommons.org/id/eprint/8685

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