Estimating purse seine volume during capture: implications for fish densities and survival of released unwanted catches
High fish densities negatively impact catch welfare and the survival of unwanted catches released from purse seines. To avoid overcrowding fish before being released, regulations have been implemented in the Northeast Atlantic mackerel and herring fisheries that limit the proportion of the seine tha...
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Language: | English |
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Online Access: | https://hdl.handle.net/11250/2657656 https://doi.org/10.1093/icesjms/fsz119 |
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ftsintef:oai:sintef.brage.unit.no:11250/2657656 2023-05-15T17:41:28+02:00 Estimating purse seine volume during capture: implications for fish densities and survival of released unwanted catches Tenningen, Maria Pobitzer, Armin Handegard, Nils Olav de Jong, Karen 2019 application/pdf https://hdl.handle.net/11250/2657656 https://doi.org/10.1093/icesjms/fsz119 eng eng Norges forskningsråd: 243885 urn:issn:1054-3139 https://hdl.handle.net/11250/2657656 https://doi.org/10.1093/icesjms/fsz119 cristin:1728485 © International Council for the Exploration of the Sea 2019. All rights reserved. For permissions, please email: journals.permissions@oup.com ICES Journal of Marine Science Catch welfare Purse seines Fish density Journal article Peer reviewed 2019 ftsintef https://doi.org/10.1093/icesjms/fsz119 2021-08-04T11:59:55Z High fish densities negatively impact catch welfare and the survival of unwanted catches released from purse seines. To avoid overcrowding fish before being released, regulations have been implemented in the Northeast Atlantic mackerel and herring fisheries that limit the proportion of the seine that can be retrieved before catches are released. However, it is yet unknown how seine volume, and thus fish density, relates to proportion of seine retrieved. In this study, we have estimated the in-water volume of purse seines used in the Norwegian mackerel and herring fisheries as a function of proportion seine hauled and seine size. Purse seine geometry was monitored with multibeam sonar at sea and a log-linear mixed effects model was applied to the estimated seine volumes. The results indicate a 33-fold decrease in contained volume from 10 to 80% seine hauled and a threefold difference in volume between the largest and smallest measured seines. Fish densities in the seine were predicted to vary greatly depending on seine and catch size and under some conditions exceed safe crowding levels before the catch release limit is reached. This study questions the rationale of having the same catch release limit for all seine and catch sizes. acceptedVersion Article in Journal/Newspaper Northeast Atlantic SINTEF Open (Brage) ICES Journal of Marine Science 76 7 2481 2488 |
institution |
Open Polar |
collection |
SINTEF Open (Brage) |
op_collection_id |
ftsintef |
language |
English |
topic |
Catch welfare Purse seines Fish density |
spellingShingle |
Catch welfare Purse seines Fish density Tenningen, Maria Pobitzer, Armin Handegard, Nils Olav de Jong, Karen Estimating purse seine volume during capture: implications for fish densities and survival of released unwanted catches |
topic_facet |
Catch welfare Purse seines Fish density |
description |
High fish densities negatively impact catch welfare and the survival of unwanted catches released from purse seines. To avoid overcrowding fish before being released, regulations have been implemented in the Northeast Atlantic mackerel and herring fisheries that limit the proportion of the seine that can be retrieved before catches are released. However, it is yet unknown how seine volume, and thus fish density, relates to proportion of seine retrieved. In this study, we have estimated the in-water volume of purse seines used in the Norwegian mackerel and herring fisheries as a function of proportion seine hauled and seine size. Purse seine geometry was monitored with multibeam sonar at sea and a log-linear mixed effects model was applied to the estimated seine volumes. The results indicate a 33-fold decrease in contained volume from 10 to 80% seine hauled and a threefold difference in volume between the largest and smallest measured seines. Fish densities in the seine were predicted to vary greatly depending on seine and catch size and under some conditions exceed safe crowding levels before the catch release limit is reached. This study questions the rationale of having the same catch release limit for all seine and catch sizes. acceptedVersion |
format |
Article in Journal/Newspaper |
author |
Tenningen, Maria Pobitzer, Armin Handegard, Nils Olav de Jong, Karen |
author_facet |
Tenningen, Maria Pobitzer, Armin Handegard, Nils Olav de Jong, Karen |
author_sort |
Tenningen, Maria |
title |
Estimating purse seine volume during capture: implications for fish densities and survival of released unwanted catches |
title_short |
Estimating purse seine volume during capture: implications for fish densities and survival of released unwanted catches |
title_full |
Estimating purse seine volume during capture: implications for fish densities and survival of released unwanted catches |
title_fullStr |
Estimating purse seine volume during capture: implications for fish densities and survival of released unwanted catches |
title_full_unstemmed |
Estimating purse seine volume during capture: implications for fish densities and survival of released unwanted catches |
title_sort |
estimating purse seine volume during capture: implications for fish densities and survival of released unwanted catches |
publishDate |
2019 |
url |
https://hdl.handle.net/11250/2657656 https://doi.org/10.1093/icesjms/fsz119 |
genre |
Northeast Atlantic |
genre_facet |
Northeast Atlantic |
op_source |
ICES Journal of Marine Science |
op_relation |
Norges forskningsråd: 243885 urn:issn:1054-3139 https://hdl.handle.net/11250/2657656 https://doi.org/10.1093/icesjms/fsz119 cristin:1728485 |
op_rights |
© International Council for the Exploration of the Sea 2019. All rights reserved. For permissions, please email: journals.permissions@oup.com |
op_doi |
https://doi.org/10.1093/icesjms/fsz119 |
container_title |
ICES Journal of Marine Science |
container_volume |
76 |
container_issue |
7 |
container_start_page |
2481 |
op_container_end_page |
2488 |
_version_ |
1766143051167694848 |