Decline of the Shortjaw Cisco in Lake Superior: The Role of Overfishing and Risk of Extinction

Autor: Philip J. Schneeberger, Charles R. Bronte, Wayne E. Thogmartin, Michael H. Hoff, Thomas N. Todd, Owen T. Gorman
Rok vydání: 2010
Předmět:
Zdroj: Transactions of the American Fisheries Society. 139:735-748
ISSN: 1548-8659
0002-8487
DOI: 10.1577/t09-019.1
Popis: Recent reviews have further documented the decline of the shortjaw cisco Coregonus zenithicus in Lake Superior. This fish was the most abundant deepwater cisco species in Lake Superior in the early 1920s but presently makes up less than 1% of all deepwater ciscoes (i.e., including shortjaw cisco, bloater C. hoyi, and kiyi C. kiyi) captured in biological surveys. Directed overfishing of deepwater cisco species during the 1930s and again during the mid-1960s and 1970s has been suggested as the cause of the shortjaw cisco's demise. In this paper, we re-examined the overfishing hypothesis by using historical and recent survey data to estimate the proportion of the historical commercial fishery landings that comprised shortjaw ciscoes. We developed time series of estimated harvest and relative abundance for all statistical districts in Michigan waters of Lake Superior during 1929–1996, for which aggregate catch and effort data were available but not previously examined. The spatial distribution of the...
Databáze: OpenAIRE
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