Skip Navigation

ICES Journal of Marine Science: Journal du Conseil 1994 51(4):493-504; doi:10.1006/jmsc.1994.1050
© 1994 by ICES/CIEM International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Swain, D. P.
Right arrow Articles by Chouinard, G. A.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Swain, D. P.
Right arrow Articles by Chouinard, G. A.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Changes in catchability of Atlantic cod (Gadus morhua) to an otter-trawl fishery and research survey in the southern Gulf of St Lawrence

D. P. Swain, G. A. Nielsen, A. F. Sinclair and G. A. Chouinard

Department of Fisheries and Oceans, Gulf Fisheries Centre PO Box 5030, Moncton, New Brunswick E1C 9B6, Canada

For each year from 1971 to 1991 and age from 3 to 8+, we estimated catchability of Atlantic cod (Gadus morchua) to an otter-trawl fishery (q) and a research survey (k) using SPA-based abundance estimates (N) and catch rates to the fishery (U) or survey (R). q tended to be highest early in the time series for young cod (ages 3 and 4), late in the time series for old cod (ages 7 and 8+), and at the two extremes of the time series for cod of intermediate ages (5 and 6). k tended to be higher later in the time series for all ages of cod. We tested for density dependence of q and k by comparing InU or InR to InN. The slope of the regression of InU versus InN was significantly less than 1.0 for ages 3 to 5 and greater than 1.0 for ages 8+, indicating an inverse relationship between q and N for the younger ages and a positive relationship for the older age. The slope of the regression of InR on InN was significantly greater than 1.0 for ages 5 to 7, indicating a positive relationship between k and N for these ages of cod. An SPA calibration model assuming a non-linear relationship between catch rate and abundance led to the same conclusions about the density dependence of q and k. We discuss possible causes of these apparent changes in q and k, and relate density-dependent changes in k to previous reports of density-depedent changes in spatial distribution for this population.

Keywords: catchability, Atlantic cod, bottom trawl, density-dependent

Received 31 May 1993; accepted 14 April 1994.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 ICES J. Mar. Sci.Home page
Y. Jiao, K. Reid, and T. Nudds
Variation in the catchability of yellow perch (Perca flavescens) in the fisheries of Lake Erie using a Bayesian error-in-variable approach
ICES J. Mar. Sci., January 1, 2006; 63(9): 1695 - 1704.
[Abstract] [Full Text] [PDF]

Home page
 ICES J. Mar. Sci.Home page
M. Casini, M. Cardinale, J. Hjelm, and F. Vitale
Trends in cpue and related changes in spatial distribution of demersal fish species in the Kattegat and Skagerrak, eastern North Sea, between 1981 and 2003
ICES J. Mar. Sci., January 1, 2005; 62(4): 671 - 682.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.