Fish Distribution and Catchability: What Is the Appropriate Measure of Distribution?
Catchability to commercial fisheries has been predicted to be density dependent due to density-dependent variation in stock area. Previous studies have used indices of stock area based on thresholds of absolute density. These indices will increase with abundance even if density increases uniformly o...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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Canadian Science Publishing
1994
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Online Access: | http://dx.doi.org/10.1139/f94-104 http://www.nrcresearchpress.com/doi/pdf/10.1139/f94-104 |
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crcansciencepubl:10.1139/f94-104 2024-06-23T07:51:05+00:00 Fish Distribution and Catchability: What Is the Appropriate Measure of Distribution? Swain, D. P. Sinclair, A. F. 1994 http://dx.doi.org/10.1139/f94-104 http://www.nrcresearchpress.com/doi/pdf/10.1139/f94-104 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 51, issue 5, page 1046-1054 ISSN 0706-652X 1205-7533 journal-article 1994 crcansciencepubl https://doi.org/10.1139/f94-104 2024-06-13T04:10:51Z Catchability to commercial fisheries has been predicted to be density dependent due to density-dependent variation in stock area. Previous studies have used indices of stock area based on thresholds of absolute density. These indices will increase with abundance even if density increases uniformly over all areas. We show that spatially uniform changes in abundance can affect catchability given certain models for the distribution of fishing effort, but that this effect is slight compared with the effect of changes in the spatial spread of fish distribution. We describe an index of distribution that depends only on spatial spread: the minimum area over which a specified percentage of the population is spread. We tested the density dependence of this index using data on Atlantic cod (Gadus morhua) in the southern Gulf of St. Lawrence. Results depended on the percentage of the population for which the index was evaluated. The area containing most (90 or 95%) of the population was density dependent, expanding as population size increased. The area of highest cod concentration (i.e., the area containing 50% of the population) did not expand significantly as population size increased. Article in Journal/Newspaper atlantic cod Gadus morhua Canadian Science Publishing Canadian Journal of Fisheries and Aquatic Sciences 51 5 1046 1054 |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
Catchability to commercial fisheries has been predicted to be density dependent due to density-dependent variation in stock area. Previous studies have used indices of stock area based on thresholds of absolute density. These indices will increase with abundance even if density increases uniformly over all areas. We show that spatially uniform changes in abundance can affect catchability given certain models for the distribution of fishing effort, but that this effect is slight compared with the effect of changes in the spatial spread of fish distribution. We describe an index of distribution that depends only on spatial spread: the minimum area over which a specified percentage of the population is spread. We tested the density dependence of this index using data on Atlantic cod (Gadus morhua) in the southern Gulf of St. Lawrence. Results depended on the percentage of the population for which the index was evaluated. The area containing most (90 or 95%) of the population was density dependent, expanding as population size increased. The area of highest cod concentration (i.e., the area containing 50% of the population) did not expand significantly as population size increased. |
format |
Article in Journal/Newspaper |
author |
Swain, D. P. Sinclair, A. F. |
spellingShingle |
Swain, D. P. Sinclair, A. F. Fish Distribution and Catchability: What Is the Appropriate Measure of Distribution? |
author_facet |
Swain, D. P. Sinclair, A. F. |
author_sort |
Swain, D. P. |
title |
Fish Distribution and Catchability: What Is the Appropriate Measure of Distribution? |
title_short |
Fish Distribution and Catchability: What Is the Appropriate Measure of Distribution? |
title_full |
Fish Distribution and Catchability: What Is the Appropriate Measure of Distribution? |
title_fullStr |
Fish Distribution and Catchability: What Is the Appropriate Measure of Distribution? |
title_full_unstemmed |
Fish Distribution and Catchability: What Is the Appropriate Measure of Distribution? |
title_sort |
fish distribution and catchability: what is the appropriate measure of distribution? |
publisher |
Canadian Science Publishing |
publishDate |
1994 |
url |
http://dx.doi.org/10.1139/f94-104 http://www.nrcresearchpress.com/doi/pdf/10.1139/f94-104 |
genre |
atlantic cod Gadus morhua |
genre_facet |
atlantic cod Gadus morhua |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 51, issue 5, page 1046-1054 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f94-104 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
51 |
container_issue |
5 |
container_start_page |
1046 |
op_container_end_page |
1054 |
_version_ |
1802642079210274816 |