期刊
SCIENTIA MARINA
卷 67, 期 -, 页码 83-88出版社
CONSEJO SUPERIOR INVESTIGACIONES CIENTIFICAS-CSIC
DOI: 10.3989/scimar.2003.67s283
关键词
chick and egg predation; competition; diet overlap; purse seine boats; scavenging; seabird; fisheries interactions; trawler discards
Interactions between yellow-legged Larus cachinnans and Audouin's Larus audouinii gulls and fisheries operating around the Chafarinas Islands, located 4.5 km off the Moroccan Mediterranean coast, are reviewed. At the Chafarinas archipelago two distinct types of fisheries operate: trawlers and purse seines. Gulls take advantage of both fisheries. They scavenge trawler discards and congregate around shoals of fish attracted to the surface by the purse-seine lamps. When both trawlers and purse-seine boats are in operation, the diet of both gull species is similar, with epipelagic fish accounting for over 60% of the biomass, partially collected in association with the purse-seine fishery. When only trawlers operated yellow-legged gulls. but not Audouin's gulls, augmented their diet mainly with human waste from refuse dumps, suggesting that competition for food between the two species is mainly limited to the periods when resources made available by fishery activities are abundant. Likewise, when only trawlers operated, there was an increase in the predation pressure on eggs and chicks of Audouin's gulls. In particular, during the week of celebrations for the holy lamb festival when neither fishery operated, egg losses of Audouin's gull increased dramatically, suggesting that severe food shortage caused by the cessation of fishing can result in an increased predation pressure by yellow-legged gulls, affecting Audouin's gull productivity. These results suggest a novel socio-ecological link between gulls, fisheries and local feasts.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据