|
|
|
|
|
Bowlby, Heather D.; Benoît, Hugues P.; Joyce, Warren; Sulikowski, James; Coelho, Rui; Domingo, Andrés; Cortés, Enric; Hazin, Fabio; Macias, David; Biais, Gerard; Santos, Catarina; Anderson, Brooke. |
Accurately characterizing the biology of a pelagic shark species is critical when assessing its status and resilience to fishing pressure. Natural mortality (M) is well known to be a key parameter determining productivity and resilience, but also one for which estimates are most uncertain. While M can be inferred from life history, validated direct estimates are extremely rare for sharks. Porbeagle (Lamna nasus) and shortfin mako (Isurus oxyrinchus) are presently overfished in the North Atlantic, but there are no directed fisheries and successful live release of bycatch is believed to have increased. Understanding M, post-release mortality (PRM), and variables that affect mortality are necessary for management and effective bycatch mitigation. From 177... |
Tipo: Text |
Palavras-chave: Natural mortality; Recovery period; Lamnid sharks; Atlantic; Survival; Mitigation; Bycatch. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00688/80020/83005.pdf |
| |
|
|
Brophy, Deirdre; Haynes, Paula; Arrizabalaga, Haritz; Fraile, Igaratza; Fromentin, Jean-marc; Garibaldi, Fulvio; Katavic, Ivan; Tinti, Fausto; Karakulak, F. Saadet; Macias, David; Busawon, Dheeraj; Hanke, Alex; Kimoto, Ai; Sakai, Osamu; Deguara, Simeon; Abid, Nouredinne; Santos, Miguel Neves. |
Two stocks of bluefin tuna (Thunnus thynnus) inhabit the north Atlantic; the western and eastern stocks spawn in the Gulf of Mexico and the Mediterranean Sea respectively. Trans-Atlantic movements occur outside spawning time whereas natal homing maintains stock structure. Commercial fisheries may exploit a mixed assemblage of both stocks. The incorporation of mixing rates into stock assessment is precluded by uncertainties surrounding stock discrimination. Otolith shape descriptors were used to characterise western and eastern stocks of Atlantic bluefin tuna in the present study and to estimate stock composition in catches of unknown origin. Otolith shape varied with length and between locations and years. Within a restricted size range (200-297-cm fork... |
Tipo: Text |
Palavras-chave: Elliptical Fourier analysis; Population structure; Stock mixture analysis. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00346/45745/45381.pdf |
| |
|
|
|