Factors influencing cannibalism and abundance of walleye pollock (Theragra chalcogramma) on the eastern Bering Sea shelf, 1982–20

Boldt, Jennifer L. and Buckley, Troy W. and Rooper, Christopher N. and Aydin, Kerim (2012) Factors influencing cannibalism and abundance of walleye pollock (Theragra chalcogramma) on the eastern Bering Sea shelf, 1982–20. Fishery Bulletin, 110(3), pp. 293-306.

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Abstract

Cannibalism is thought to be an inf luential top-down process affecting walleye pollock (Theragra chalcogramma) recruitment in the eastern Bering Sea (EBS). In summer, many age-1 pollock occupy the same depths as those of adult walleye pollock, making them vulnerable to cannibalism. We examine factors that inf luence the occurrence and amount of cannibalism, as well as the abundance and co-occurrence of predator and prey walleye pollock. Large walleye pollock were generally found in deeper waters and avoided cold temperatures; whereas, age-1 walleye pollock were found in broader bottom depth and temperature ranges. The occurrence of cannibalism was highest in the area where predator and prey walleye pollock co-occurred and the amount of cannibalism was highest on the middle and outer EBS shelf. Both the occurrence and amount of cannibalism were influenced by location, bottom temperature and bottom depth, and the abundance of prey walleye pollock. The abundance of both large and small walleye pollock decreased during the 1982–2006 survey period in the EBS and, hence, the occurrence and amount of cannibalism also decreased. The occurrence and amount of cannibalism observed in the diet samples from the summer survey were good indicators of year class strength, as estimated by the stock assessment model. There was more cannibalism of age-1 walleye pollock when predicted recruit abundance was highest, indicating that summer cannibalism on age-1 walleye pollock, a top-down process, does not control walleye pollock recruitment in the EBS.

Item Type: Article
Title: Factors influencing cannibalism and abundance of walleye pollock (Theragra chalcogramma) on the eastern Bering Sea shelf, 1982–20
Personal Creator/Author:
CreatorsEmail
Boldt, Jennifer L.
Buckley, Troy W.
Rooper, Christopher N.
Aydin, Kerim
Refereed: Yes
Journal or Publication Title: Fishery Bulletin
Volume: 110
Number: 3
Page Range: pp. 293-306
Date: 2012
ISSN: 0090-0656
Issuing Agency: United States National Marine Fisheries Service
Subjects: Biology
Ecology
Fisheries
Item ID: 8963
Depositing User: Patti M. Marraro
Date Deposited: 03 Aug 2012 18:32
Last Modified: 03 Aug 2012 18:32
URI: http://aquaticcommons.org/id/eprint/8963

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