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The commercial harvest of ice-associated seals in the Sea of Okhotsk, 1972-1994

Sealing log books from 75 out of 79 commercial harvest cruises carried out between 1972 and 1994 in the Sea of Okhotsk, Russia, were analyzed to describe spatial and temporal allocation of ice-associated seal harvest effort, species composition of catches, total harvest rates, and related parameters...

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Autores principales: Trukhanova, Irina S., Grachev, Aleksey I., Somov, Aleksandr G., Burkanov, Vladimir N., Laidre, Kristin L., Boveng, Peter L.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5552157/
https://www.ncbi.nlm.nih.gov/pubmed/28796843
http://dx.doi.org/10.1371/journal.pone.0182725
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author Trukhanova, Irina S.
Grachev, Aleksey I.
Somov, Aleksandr G.
Burkanov, Vladimir N.
Laidre, Kristin L.
Boveng, Peter L.
author_facet Trukhanova, Irina S.
Grachev, Aleksey I.
Somov, Aleksandr G.
Burkanov, Vladimir N.
Laidre, Kristin L.
Boveng, Peter L.
author_sort Trukhanova, Irina S.
collection PubMed
description Sealing log books from 75 out of 79 commercial harvest cruises carried out between 1972 and 1994 in the Sea of Okhotsk, Russia, were analyzed to describe spatial and temporal allocation of ice-associated seal harvest effort, species composition of catches, total harvest rates, and related parameters for species including ringed (Pusa hispida), ribbon (Histriophoca fasciata), bearded (Erignathus barbatus) and spotted (Phoca largha) seal. Variations in catch per unit effort were explored in relation to year, sea ice conditions, day of the year, and geographic location. In most years, the harvest was predominantly represented by ringed seals (mean = 0.43, range 0.25–0.67), followed by ribbon (mean = 0.31, range 0.15–0.43), spotted (mean = 0.19, range 0.11–0.35) and bearded seals (mean = 0.07, range 0.03–0.14). The struck-and-lost percentages were as high as 30–35% for ringed, bearded and spotted seals and 15–20% for ribbon seals. Catch per unit effort (number of seals/skiff*day) for ringed, ribbon, and spotted seals had a similar seasonal pattern with a distinct spike in catches for spotted seals in the first week of May, for ribbon seals in the last week of May, and for ringed seals in the second week of June. Catches of bearded seals showed a less pronounced temporal structure with a gradual increase toward the end of the harvest season in the majority of years. Spatial distribution of harvest effort followed closely with seal distribution obtained from aerial surveys. These data could be used as a source of information on seal herd location throughout the breeding and molting seasons and for more complex demographic or life-table models. We did not find any evidence of the decline of catch per unit effort over the study period. Timely introduction of state regulations and efficient harvest management apparently prevented severe depletion of ice-associated seal populations in the Sea of Okhotsk during the periods of their intense exploitation.
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spelling pubmed-55521572017-08-25 The commercial harvest of ice-associated seals in the Sea of Okhotsk, 1972-1994 Trukhanova, Irina S. Grachev, Aleksey I. Somov, Aleksandr G. Burkanov, Vladimir N. Laidre, Kristin L. Boveng, Peter L. PLoS One Research Article Sealing log books from 75 out of 79 commercial harvest cruises carried out between 1972 and 1994 in the Sea of Okhotsk, Russia, were analyzed to describe spatial and temporal allocation of ice-associated seal harvest effort, species composition of catches, total harvest rates, and related parameters for species including ringed (Pusa hispida), ribbon (Histriophoca fasciata), bearded (Erignathus barbatus) and spotted (Phoca largha) seal. Variations in catch per unit effort were explored in relation to year, sea ice conditions, day of the year, and geographic location. In most years, the harvest was predominantly represented by ringed seals (mean = 0.43, range 0.25–0.67), followed by ribbon (mean = 0.31, range 0.15–0.43), spotted (mean = 0.19, range 0.11–0.35) and bearded seals (mean = 0.07, range 0.03–0.14). The struck-and-lost percentages were as high as 30–35% for ringed, bearded and spotted seals and 15–20% for ribbon seals. Catch per unit effort (number of seals/skiff*day) for ringed, ribbon, and spotted seals had a similar seasonal pattern with a distinct spike in catches for spotted seals in the first week of May, for ribbon seals in the last week of May, and for ringed seals in the second week of June. Catches of bearded seals showed a less pronounced temporal structure with a gradual increase toward the end of the harvest season in the majority of years. Spatial distribution of harvest effort followed closely with seal distribution obtained from aerial surveys. These data could be used as a source of information on seal herd location throughout the breeding and molting seasons and for more complex demographic or life-table models. We did not find any evidence of the decline of catch per unit effort over the study period. Timely introduction of state regulations and efficient harvest management apparently prevented severe depletion of ice-associated seal populations in the Sea of Okhotsk during the periods of their intense exploitation. Public Library of Science 2017-08-10 /pmc/articles/PMC5552157/ /pubmed/28796843 http://dx.doi.org/10.1371/journal.pone.0182725 Text en https://creativecommons.org/publicdomain/zero/1.0/ This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 (https://creativecommons.org/publicdomain/zero/1.0/) public domain dedication.
spellingShingle Research Article
Trukhanova, Irina S.
Grachev, Aleksey I.
Somov, Aleksandr G.
Burkanov, Vladimir N.
Laidre, Kristin L.
Boveng, Peter L.
The commercial harvest of ice-associated seals in the Sea of Okhotsk, 1972-1994
title The commercial harvest of ice-associated seals in the Sea of Okhotsk, 1972-1994
title_full The commercial harvest of ice-associated seals in the Sea of Okhotsk, 1972-1994
title_fullStr The commercial harvest of ice-associated seals in the Sea of Okhotsk, 1972-1994
title_full_unstemmed The commercial harvest of ice-associated seals in the Sea of Okhotsk, 1972-1994
title_short The commercial harvest of ice-associated seals in the Sea of Okhotsk, 1972-1994
title_sort commercial harvest of ice-associated seals in the sea of okhotsk, 1972-1994
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5552157/
https://www.ncbi.nlm.nih.gov/pubmed/28796843
http://dx.doi.org/10.1371/journal.pone.0182725
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