Catch, bycatch and discards of the Galapagos Marine Reserve small-scale handline fishery
Fisheries bycatch is a significant marine conservation issue as valuable fish are wasted and protected species harmed with potential negative ecological and socio-economic consequences. Even though there are indications that the small-scale handline fishery of the Galapagos Marine Reserve has a low...
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PeerJ Inc.
2015-06-01
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| Online Access: | https://peerj.com/articles/995.pdf |
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| author | Johanna S. Zimmerhackel Anna C. Schuhbauer Paolo Usseglio Lena C. Heel Pelayo Salinas-de-León |
| author_facet | Johanna S. Zimmerhackel Anna C. Schuhbauer Paolo Usseglio Lena C. Heel Pelayo Salinas-de-León |
| author_sort | Johanna S. Zimmerhackel |
| collection | DOAJ |
| description | Fisheries bycatch is a significant marine conservation issue as valuable fish are wasted and protected species harmed with potential negative ecological and socio-economic consequences. Even though there are indications that the small-scale handline fishery of the Galapagos Marine Reserve has a low selectivity, information on its bycatch has never been published. We used onboard monitoring and interview data to assess the bycatch of the Galapagos handline fishery by estimating the bycatch ratio, determining species compositions of landings and bycatch, identifying fishers’ reasons for discarding certain individuals, and revealing historical trends in the bycatch ratio. The estimated bycatch ratio as a function of biomass of 0.40 and a diverse species composition of target catch and bycatch confirmed the low selectivity of this fishery. Most individuals were not landed for economic motivations, either because species (77.4%) or sizes (17.7%) are unmarketable or for regulatory reasons (5.9%). We found that bycatch contributes to growth overfishing of some target species because they are discarded or used as bait before reaching their first maturity. Moreover, over half of interviewees perceived a historical decrease in bycatch ratios that was explained by a diversification of the target catch due to the reduction in abundance of the traditionally most important target species. As some target species show signs of overfishing and to date there are no specific regulations for the finfish fishery species in place, we recommend the implementation of a series of management measures to protect critical life stages of overexploited species and to improve the selectivity of the Galapagos handline fishery. |
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| format | Article |
| id | doaj.art-e4060d53cae94cb4ac2b8247b3b91920 |
| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T06:39:42Z |
| publishDate | 2015-06-01 |
| publisher | PeerJ Inc. |
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| series | PeerJ |
| spelling | doaj.art-e4060d53cae94cb4ac2b8247b3b919202023-12-03T10:53:54ZengPeerJ Inc.PeerJ2167-83592015-06-013e99510.7717/peerj.995995Catch, bycatch and discards of the Galapagos Marine Reserve small-scale handline fisheryJohanna S. Zimmerhackel0Anna C. Schuhbauer1Paolo Usseglio2Lena C. Heel3Pelayo Salinas-de-León4Department of Marine Science, Charles Darwin Research Station, Puerto Ayora, Galapagos Islands, EcuadorDepartment of Marine Science, Charles Darwin Research Station, Puerto Ayora, Galapagos Islands, EcuadorFisheries Ecology Research Lab, University of Hawaii at Manoa, Hawaii, USADepartment of Marine Science, Charles Darwin Research Station, Puerto Ayora, Galapagos Islands, EcuadorDepartment of Marine Science, Charles Darwin Research Station, Puerto Ayora, Galapagos Islands, EcuadorFisheries bycatch is a significant marine conservation issue as valuable fish are wasted and protected species harmed with potential negative ecological and socio-economic consequences. Even though there are indications that the small-scale handline fishery of the Galapagos Marine Reserve has a low selectivity, information on its bycatch has never been published. We used onboard monitoring and interview data to assess the bycatch of the Galapagos handline fishery by estimating the bycatch ratio, determining species compositions of landings and bycatch, identifying fishers’ reasons for discarding certain individuals, and revealing historical trends in the bycatch ratio. The estimated bycatch ratio as a function of biomass of 0.40 and a diverse species composition of target catch and bycatch confirmed the low selectivity of this fishery. Most individuals were not landed for economic motivations, either because species (77.4%) or sizes (17.7%) are unmarketable or for regulatory reasons (5.9%). We found that bycatch contributes to growth overfishing of some target species because they are discarded or used as bait before reaching their first maturity. Moreover, over half of interviewees perceived a historical decrease in bycatch ratios that was explained by a diversification of the target catch due to the reduction in abundance of the traditionally most important target species. As some target species show signs of overfishing and to date there are no specific regulations for the finfish fishery species in place, we recommend the implementation of a series of management measures to protect critical life stages of overexploited species and to improve the selectivity of the Galapagos handline fishery.https://peerj.com/articles/995.pdfGalapagos marine reserveSmall-scale fisheriesBycatchMultispecies fisheriesBycatch mortalityHandline fishery |
| spellingShingle | Johanna S. Zimmerhackel Anna C. Schuhbauer Paolo Usseglio Lena C. Heel Pelayo Salinas-de-León Catch, bycatch and discards of the Galapagos Marine Reserve small-scale handline fishery PeerJ Galapagos marine reserve Small-scale fisheries Bycatch Multispecies fisheries Bycatch mortality Handline fishery |
| title | Catch, bycatch and discards of the Galapagos Marine Reserve small-scale handline fishery |
| title_full | Catch, bycatch and discards of the Galapagos Marine Reserve small-scale handline fishery |
| title_fullStr | Catch, bycatch and discards of the Galapagos Marine Reserve small-scale handline fishery |
| title_full_unstemmed | Catch, bycatch and discards of the Galapagos Marine Reserve small-scale handline fishery |
| title_short | Catch, bycatch and discards of the Galapagos Marine Reserve small-scale handline fishery |
| title_sort | catch bycatch and discards of the galapagos marine reserve small scale handline fishery |
| topic | Galapagos marine reserve Small-scale fisheries Bycatch Multispecies fisheries Bycatch mortality Handline fishery |
| url | https://peerj.com/articles/995.pdf |
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