Interaction Between Stock Area, Stock Abundance, and Catchability Coefficient
The relationship between commercial catch-rates and population density upon which many stock assessment models depend assumes that stock area (A) is constant and independent of population abundance. Starting from a theoretical demonstration that the catchability coefficient (q) is inversely proporti...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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Canadian Science Publishing
1985
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Online Access: | http://dx.doi.org/10.1139/f85-124 http://www.nrcresearchpress.com/doi/pdf/10.1139/f85-124 |
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crcansciencepubl:10.1139/f85-124 2024-04-28T08:32:45+00:00 Interaction Between Stock Area, Stock Abundance, and Catchability Coefficient Winters, G. H. Wheeler, J. P. 1985 http://dx.doi.org/10.1139/f85-124 http://www.nrcresearchpress.com/doi/pdf/10.1139/f85-124 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 42, issue 5, page 989-998 ISSN 0706-652X 1205-7533 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 1985 crcansciencepubl https://doi.org/10.1139/f85-124 2024-04-02T06:55:50Z The relationship between commercial catch-rates and population density upon which many stock assessment models depend assumes that stock area (A) is constant and independent of population abundance. Starting from a theoretical demonstration that the catchability coefficient (q) is inversely proportional to A, we establish the empirical basis of this relationship through comparisons of q and A of various Northwest Atlantic herring (Clupea harengus harengus) stocks and, in more detail, for Fortune Bay herring. For these stocks the relationship was of the form q = cA −b . For Atlantic herring stocks, levels of b were in excess of 0.80. In Fortune Bay herring, reductions in abundance were accompanied by proportional reductions in A, which in turn was inversely correlated with changes in q. School size, measured as catch per set, also declined as population levels declined but the change was not proportional. Published findings indicate that pelagic stocks in particular, and fish stocks in general, exhibit a common response of reductions in A with interactive increases in the q during periods of rapid population decline. We conclude that the conventional assumption of a constant stock area is usually violated due to the systematic interaction between A and population abundance which is reflected in an inverse relationship between stock abundance and q. Calibration of sequential population models should therefore be restricted to research vessel data collected in a standard manner and covering the distributional area of the stock. Article in Journal/Newspaper Northwest Atlantic Canadian Science Publishing Canadian Journal of Fisheries and Aquatic Sciences 42 5 989 998 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Aquatic Science Ecology, Evolution, Behavior and Systematics Winters, G. H. Wheeler, J. P. Interaction Between Stock Area, Stock Abundance, and Catchability Coefficient |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
The relationship between commercial catch-rates and population density upon which many stock assessment models depend assumes that stock area (A) is constant and independent of population abundance. Starting from a theoretical demonstration that the catchability coefficient (q) is inversely proportional to A, we establish the empirical basis of this relationship through comparisons of q and A of various Northwest Atlantic herring (Clupea harengus harengus) stocks and, in more detail, for Fortune Bay herring. For these stocks the relationship was of the form q = cA −b . For Atlantic herring stocks, levels of b were in excess of 0.80. In Fortune Bay herring, reductions in abundance were accompanied by proportional reductions in A, which in turn was inversely correlated with changes in q. School size, measured as catch per set, also declined as population levels declined but the change was not proportional. Published findings indicate that pelagic stocks in particular, and fish stocks in general, exhibit a common response of reductions in A with interactive increases in the q during periods of rapid population decline. We conclude that the conventional assumption of a constant stock area is usually violated due to the systematic interaction between A and population abundance which is reflected in an inverse relationship between stock abundance and q. Calibration of sequential population models should therefore be restricted to research vessel data collected in a standard manner and covering the distributional area of the stock. |
format |
Article in Journal/Newspaper |
author |
Winters, G. H. Wheeler, J. P. |
author_facet |
Winters, G. H. Wheeler, J. P. |
author_sort |
Winters, G. H. |
title |
Interaction Between Stock Area, Stock Abundance, and Catchability Coefficient |
title_short |
Interaction Between Stock Area, Stock Abundance, and Catchability Coefficient |
title_full |
Interaction Between Stock Area, Stock Abundance, and Catchability Coefficient |
title_fullStr |
Interaction Between Stock Area, Stock Abundance, and Catchability Coefficient |
title_full_unstemmed |
Interaction Between Stock Area, Stock Abundance, and Catchability Coefficient |
title_sort |
interaction between stock area, stock abundance, and catchability coefficient |
publisher |
Canadian Science Publishing |
publishDate |
1985 |
url |
http://dx.doi.org/10.1139/f85-124 http://www.nrcresearchpress.com/doi/pdf/10.1139/f85-124 |
genre |
Northwest Atlantic |
genre_facet |
Northwest Atlantic |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 42, issue 5, page 989-998 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f85-124 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
42 |
container_issue |
5 |
container_start_page |
989 |
op_container_end_page |
998 |
_version_ |
1797589834978557952 |