Using reproductive values to define optimal harvesting for multisite density-dependent populations: example with a marine reserve
A new method for determining optimal harvest from age-structured populations with a density-dependent stock-recruit relationship is presented. The theoretical optimal harvest comes from removing the age-class with the smallest ratio of reproductive value to weight. The method is derived from conside...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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2002
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Online Access: | http://dx.doi.org/10.1139/f02-058 http://www.nrcresearchpress.com/doi/pdf/10.1139/f02-058 |
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crcansciencepubl:10.1139/f02-058 2023-12-17T10:30:24+01:00 Using reproductive values to define optimal harvesting for multisite density-dependent populations: example with a marine reserve Brooks, Elizabeth N 2002 http://dx.doi.org/10.1139/f02-058 http://www.nrcresearchpress.com/doi/pdf/10.1139/f02-058 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 59, issue 5, page 875-885 ISSN 0706-652X 1205-7533 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 2002 crcansciencepubl https://doi.org/10.1139/f02-058 2023-11-19T13:39:03Z A new method for determining optimal harvest from age-structured populations with a density-dependent stock-recruit relationship is presented. The theoretical optimal harvest comes from removing the age-class with the smallest ratio of reproductive value to weight. The method is derived from considering the sensitivity of equilibrium egg production to harvest using results for density-dependent Leslie matrices. The method holds in both single- and multi-site contexts and is derived for both Ricker and BevertonHolt recruitment functions. I illustrate the method for a one-site model of Arcto-Norwegian cod (Gadus morhua) and obtain the same optimal strategy as previous methods, namely that age-class 6 should be harvested 45%. Including age-specific selectivities, the best constrained yields occur at a harvest rate of 11% on ages 512. This yield is 73% of the theoretical optimum. I considered the same model when a reserve is established and found that high transfer rates out of the reserve (where spawners attain a higher fecundity) produced greater yields that were 86% of the one-site (no reserve) yield. Also, if overfishing occurs at 1.5 and 2.0 times the optimal level in the one-site case, then most yields from the reserve model are greater than those from the one-site model. Article in Journal/Newspaper Gadus morhua Canadian Science Publishing (via Crossref) Canadian Journal of Fisheries and Aquatic Sciences 59 5 875 885 |
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Open Polar |
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Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Aquatic Science Ecology, Evolution, Behavior and Systematics Brooks, Elizabeth N Using reproductive values to define optimal harvesting for multisite density-dependent populations: example with a marine reserve |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
A new method for determining optimal harvest from age-structured populations with a density-dependent stock-recruit relationship is presented. The theoretical optimal harvest comes from removing the age-class with the smallest ratio of reproductive value to weight. The method is derived from considering the sensitivity of equilibrium egg production to harvest using results for density-dependent Leslie matrices. The method holds in both single- and multi-site contexts and is derived for both Ricker and BevertonHolt recruitment functions. I illustrate the method for a one-site model of Arcto-Norwegian cod (Gadus morhua) and obtain the same optimal strategy as previous methods, namely that age-class 6 should be harvested 45%. Including age-specific selectivities, the best constrained yields occur at a harvest rate of 11% on ages 512. This yield is 73% of the theoretical optimum. I considered the same model when a reserve is established and found that high transfer rates out of the reserve (where spawners attain a higher fecundity) produced greater yields that were 86% of the one-site (no reserve) yield. Also, if overfishing occurs at 1.5 and 2.0 times the optimal level in the one-site case, then most yields from the reserve model are greater than those from the one-site model. |
format |
Article in Journal/Newspaper |
author |
Brooks, Elizabeth N |
author_facet |
Brooks, Elizabeth N |
author_sort |
Brooks, Elizabeth N |
title |
Using reproductive values to define optimal harvesting for multisite density-dependent populations: example with a marine reserve |
title_short |
Using reproductive values to define optimal harvesting for multisite density-dependent populations: example with a marine reserve |
title_full |
Using reproductive values to define optimal harvesting for multisite density-dependent populations: example with a marine reserve |
title_fullStr |
Using reproductive values to define optimal harvesting for multisite density-dependent populations: example with a marine reserve |
title_full_unstemmed |
Using reproductive values to define optimal harvesting for multisite density-dependent populations: example with a marine reserve |
title_sort |
using reproductive values to define optimal harvesting for multisite density-dependent populations: example with a marine reserve |
publisher |
Canadian Science Publishing |
publishDate |
2002 |
url |
http://dx.doi.org/10.1139/f02-058 http://www.nrcresearchpress.com/doi/pdf/10.1139/f02-058 |
genre |
Gadus morhua |
genre_facet |
Gadus morhua |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 59, issue 5, page 875-885 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f02-058 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
59 |
container_issue |
5 |
container_start_page |
875 |
op_container_end_page |
885 |
_version_ |
1785583371562254336 |