Sabiia Seb
PortuguêsEspañolEnglish
Embrapa
        Busca avançada

Botão Atualizar


Botão Atualizar

Registro completo
Provedor de dados:  ArchiMer
País:  France
Título:  Toothed whale and shark depredation indicators: A case study from the Reunion Island and Seychelles pelagic longline fisheries
Autores:  Rabearisoa, Njaratiana
Sabarros, Philippe S.
Romanov, Evgeny V.
Lucas, Vincent
Bach, Pascal
Data:  2018-08
Ano:  2018
Resumo:  Depredation in marine ecosystems is defined as the damage or removal of fish or bait from fishing gear by predators. Depredation raises concerns about the conservation of species involved, fisheries yield and profitability, and reference points based on stock assessment of depredated species. Therefore, the development of accurate indicators to assess the impact of depredation is needed. Both the Reunion Island and the Seychelles archipelago pelagic longline fisheries targeting swordfish (Xiphias gladius) and tuna (Thunnus spp.) are affected by depredation from toothed whales and pelagic sharks. In this study, we used fishery data collected between 2004 and 2015 to propose depredation indicators and to assess depredation levels in both fisheries. For both fisheries, the interaction rate (depredation occurrence) was significantly higher for shark compared to toothed whale depredation. However, when depredation occurred, toothed whale depredation impact was significantly higher than shark depredation impact, with higher depredation per unit effort (number of fish depredated per 1000 hooks) and damage rate (proportion of fish depredated per depredated set). The gross depredation rate in the Seychelles was 18.3%. A slight increase of the gross depredation rate was observed for the Reunion Island longline fleet from 2011 (4.1% in 2007-2010 and 4.4% in 2011-2015). Economic losses due to depredation were estimated by using these indicators and published official statistics. A loss of 0.09 EUR/hook due to depredation was estimated for the Reunion Island longline fleet, and 0.86 EUR/hook for the Seychelles. These results suggest a southward decreasing toothed whale and shark depredation gradient in the southwest Indian Ocean. Seychelles depredation levels are among the highest observed in the world revealing this area as a "hotspot" of interaction between pelagic longline fisheries and toothed whales. This study also highlights the need for a set of depredation indicators to allow for a global comparison of depredation rates among various fishing grounds worldwide.
Tipo:  Text
Idioma:  Inglês
Identificador:  https://archimer.ifremer.fr/doc/00454/56571/75149.pdf

https://archimer.ifremer.fr/doc/00454/56571/75150.xlsx

https://archimer.ifremer.fr/doc/00454/56571/75151.tif

https://archimer.ifremer.fr/doc/00454/56571/75152.tif

https://archimer.ifremer.fr/doc/00454/56571/75153.tif

https://archimer.ifremer.fr/doc/00454/56571/75154.tif

https://archimer.ifremer.fr/doc/00454/56571/75155.tif

https://archimer.ifremer.fr/doc/00454/56571/75156.tif

https://archimer.ifremer.fr/doc/00454/56571/75157.tif

https://archimer.ifremer.fr/doc/00454/56571/75158.tif

https://archimer.ifremer.fr/doc/00454/56571/75159.tif

https://archimer.ifremer.fr/doc/00454/56571/75160.tif

https://archimer.ifremer.fr/doc/00454/56571/75161.tif

https://archimer.ifremer.fr/doc/00454/56571/75162.tif

DOI:10.1371/journal.pone.0202037

https://archimer.ifremer.fr/doc/00454/56571/
Editor:  Public Library Science
Formato:  application/pdf
Fonte:  Plos One (1932-6203) (Public Library Science), 2018-08 , Vol. 13 , N. 8 , P. e0202037. (26p.)
Direitos:  info:eu-repo/semantics/openAccess

restricted use
Fechar
 

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Embrapa
Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco

Valid HTML 4.01 Transitional