Background: The banning of fisheries discards by imposing an obligation to land unwanted catch constitutes a key point of the Common Fishery Policy reform proposed by the European Commission. The effect of such a ban ...Background: The banning of fisheries discards by imposing an obligation to land unwanted catch constitutes a key point of the Common Fishery Policy reform proposed by the European Commission. The effect of such a ban on discards on top marine predators such as seabirds is largely unknown, especially in oligotrophic systems of the Medi?terranean. The current study investigates the presence of scavenging seabirds around fishing trawlers as well as the exploitation of discards produced by bottom trawlers in the eastern Ionian Sea.Methods: On?board observations were randomly conducted in May and December 2014, in order to record the presence and use of fishery discards by two common seabird species, namely, Scopoli's Shearwater(Calonectris diomedea) and the Yellow?legged Gull(Larus michahellis).Results: A total of 3400 seabirds were counted during May of which 2190 individuals were Scopoli's Shearwaters and 1210 were Yellow?legged Gulls. The latter species was the only scavenger observed during winter and in total, 768 individuals were counted. Differences in species abundance in the study area are related to breeding phenology and migratory movements. The number of seabirds attending bottom trawler operations during morning and afternoon hours showed no significant differences for both seabird species. Both scavenging seabirds extensively exploited fishery discards, which were mainly demersal fish, and consumed 70–80% of the total fishery discards biomass; how?ever, they appeared to avoid poisonous species and/or large?sized fish. Yellow?legged Gulls displayed kleptoparasitic behaviour on Scopoli's Shearwater during feeding experiments. The number of such incidents depended on the number of gulls around the fishing vessel, with more than 90% success rates.Conclusions: Considering the average annual biomass of discards estimations and the consumption rate found in this work, 106.1–117.9 t may be offered as a food subsidy to scavenging seabirds in the study area and should support a substantial part of local popul展开更多
The issue of bycatch in the fisheries sector has been a major concern for the marine biologists over few decades in terms of conservation of marine eco-system and sustainability of the fisheries sector and marine biod...The issue of bycatch in the fisheries sector has been a major concern for the marine biologists over few decades in terms of conservation of marine eco-system and sustainability of the fisheries sector and marine biodiversity.As far as the concept of Bycatch is concerned,these are the unwanted species having less commercial importance,which in most of the cases disposed into the seas onboard or are caught during fishing.The article discusses the social,economic,cultural,and environmental impacts in addressing the issue of bycatch.The concern regarding bycatch is relatively new in the horizon in Indian perspective though it is often considered a major issue faced by developed nations since long.The problem of bycatch poses a serious threat to livelihoods and food security as it acts as a precursor to depletion of the food sources for local consumption with adverse social,economic,cultural,and environmental impacts.The adverse effects of by-catch can be mitigated through commercialisation of bycatch and making profits from the sale of bycatch,opening up of new markets for bycatch species or products,uses of bycatch as fishmeal and application of bycatch reduction devices(BRDs).Reorientation of the present monitoring system to collect fisheries data,strengthening technical know-how,bringing effective policy intervention,efficient co-management,and sincere and honest efforts in reducing bycatch and discards may provide a considerable impact towards sustainability of marine eco-system.展开更多
基金performed within the framework of the ECODISC project,entitled“ECOsystem effect of fisheries DISCards”,partially funded by the NSRF 2007-2013 Operational Programme“Education and Lifelong Learning”,which is cofinanced by Greece and the European UnionFisheries data were collected within the framework of the 2014 Greek National Fisheries Data Collection Programme(EPSAD)funded by the Greek Government and the European Union under Regulation 199/2008/EU
文摘Background: The banning of fisheries discards by imposing an obligation to land unwanted catch constitutes a key point of the Common Fishery Policy reform proposed by the European Commission. The effect of such a ban on discards on top marine predators such as seabirds is largely unknown, especially in oligotrophic systems of the Medi?terranean. The current study investigates the presence of scavenging seabirds around fishing trawlers as well as the exploitation of discards produced by bottom trawlers in the eastern Ionian Sea.Methods: On?board observations were randomly conducted in May and December 2014, in order to record the presence and use of fishery discards by two common seabird species, namely, Scopoli's Shearwater(Calonectris diomedea) and the Yellow?legged Gull(Larus michahellis).Results: A total of 3400 seabirds were counted during May of which 2190 individuals were Scopoli's Shearwaters and 1210 were Yellow?legged Gulls. The latter species was the only scavenger observed during winter and in total, 768 individuals were counted. Differences in species abundance in the study area are related to breeding phenology and migratory movements. The number of seabirds attending bottom trawler operations during morning and afternoon hours showed no significant differences for both seabird species. Both scavenging seabirds extensively exploited fishery discards, which were mainly demersal fish, and consumed 70–80% of the total fishery discards biomass; how?ever, they appeared to avoid poisonous species and/or large?sized fish. Yellow?legged Gulls displayed kleptoparasitic behaviour on Scopoli's Shearwater during feeding experiments. The number of such incidents depended on the number of gulls around the fishing vessel, with more than 90% success rates.Conclusions: Considering the average annual biomass of discards estimations and the consumption rate found in this work, 106.1–117.9 t may be offered as a food subsidy to scavenging seabirds in the study area and should support a substantial part of local popul
文摘The issue of bycatch in the fisheries sector has been a major concern for the marine biologists over few decades in terms of conservation of marine eco-system and sustainability of the fisheries sector and marine biodiversity.As far as the concept of Bycatch is concerned,these are the unwanted species having less commercial importance,which in most of the cases disposed into the seas onboard or are caught during fishing.The article discusses the social,economic,cultural,and environmental impacts in addressing the issue of bycatch.The concern regarding bycatch is relatively new in the horizon in Indian perspective though it is often considered a major issue faced by developed nations since long.The problem of bycatch poses a serious threat to livelihoods and food security as it acts as a precursor to depletion of the food sources for local consumption with adverse social,economic,cultural,and environmental impacts.The adverse effects of by-catch can be mitigated through commercialisation of bycatch and making profits from the sale of bycatch,opening up of new markets for bycatch species or products,uses of bycatch as fishmeal and application of bycatch reduction devices(BRDs).Reorientation of the present monitoring system to collect fisheries data,strengthening technical know-how,bringing effective policy intervention,efficient co-management,and sincere and honest efforts in reducing bycatch and discards may provide a considerable impact towards sustainability of marine eco-system.
