Disentangling the causes of protected-species bycatch in gillnet fisheries.
Gillnet fisheries are widely thought to pose a conservation threat to many populations of marine mammals, seabirds, and turtles. Gillnet fisheries also support a significant proportion of small-scale fishing communities worldwide. Despite a large number of studies on protected-species bycatch in recent decades, relatively few have examined the underlying causes of bycatch and fewer still have considered the issue from a multitaxon perspective. We used 3 bibliographic databases and one search engine to identify studies by year of publication and taxon. The majority of studies on the mechanisms of gillnet bycatch are not accessible through the mainstream published literature. Many are reported in technical papers, government reports, and university theses. We reviewed over 600 published and unpublished studies of bycatch in which causal or correlative factors were considered and identified therein 28 environmental, operational, technical, and behavioral factors that may be associated with high or low bycatch rates of the taxa. Of the factors considered, 11 were associated with potential bycatch reduction in 2 out of the 3 taxa, and 3 factors (water depth, mesh size, and net height) were associated with trends in bycatch rate for all 3 taxa. These findings provide a basis to guide further experimental work to test hypotheses about which factors most influence bycatch rates and to explore ways of managing fishing activities and improving gear design to minimize the incidental capture of species of conservation concern while ensuring the viability of the fisheries concerned.
Sea Mammal Research Unit, Scottish Oceans Institute, School of Biology, University of St Andrews, Bute Building, St Andrews, KY16 9TS, U.K.
Simon
S
Northridge
Sea Mammal Research Unit, Scottish Oceans Institute, School of Biology, University of St Andrews, Bute Building, St Andrews, KY16 9TS, U.K.
Alex
A
Coram
Sea Mammal Research Unit, Scottish Oceans Institute, School of Biology, University of St Andrews, Bute Building, St Andrews, KY16 9TS, U.K.
Al
A
Kingston
BirdLife International Marine Programme, The Lodge, Sandy, Bedfordshire, SG19 2DL, U.K.
Rory
R
Crawford
D000818:Animals; D003247:Conservation of Natural Resources; D005398:Fisheries; D005399:Fishes; D014426:Turtles
análisis bibliográfico; bibliographic analysis; bycatch reduction; equipo de pesca; especies protegidas; fishing gear; meta-analysis; meta-análisis; protected species; redes estáticas; reducción de la pesca colateral; static nets