Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/32307
Title: Impact of fisheries on activity, diet and predatory interactions between yellow-legged and Audouin's gulls breeding at the Chafarinas Is.
Author: González-Solís, Jacob
Keywords: Gavines
Indústria pesquera
Predació (Biologia)
Fauna marina
Gulls
Fishing industry
Predation (Biology)
Marine fauna
Issue Date: 2003
Publisher: Consejo Superior de Investigaciones Científicas (CSIC)
Abstract: 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.
Note: Reproducció del document publicat a: htp://dx.doi.org/10.3989/scimar.2003.67s283
It is part of: Scientia Marina, 2003, vol. 67, num. Suppl. 2, p. 83-88
Related resource: http://dx.doi.org/10.3989/scimar.2003.67s283
URI: http://hdl.handle.net/2445/32307
ISSN: 0214-8358
Appears in Collections:Articles publicats en revistes (Biologia Evolutiva, Ecologia i Ciències Ambientals)

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