title: Relative abundance and distribution of fisheries influence risk of seabird bycatch.
abstract: Fisheries provide an abundant and predictable food source for many pelagic seabirds through discards, but also pose a major threat to them through bycatch, threatening their populations worldwide. The reform of the European Common Fisheries Policy (CFP), which intends to ban discards through the landing obligation of all catches, may force seabirds to seek alternative food sources, such as baited hooks from longlines, increasing bycatch rates. To test this hypothesis we performed a combined analysis of seabird-fishery interactions using as a model Scopoli's shearwaters Calonectris diomedea in the Mediterranean. Tracking data showed that the probability of shearwaters attending longliners increased exponentially with a decreasing density of trawlers. On-board observations and mortality events corroborated this result: the probability of birds attending longliners increased 4% per each trawler leaving the longliner proximity and bird mortality increased tenfold when trawlers were not operating. Therefore, the implementation of the landing obligation in EU waters will likely cause a substantial increase in bycatch rates in longliners, at least in the short-term, due to birds switching from trawlers to longliners. Thus the implementation of the landing obligation must be carefully monitored and counterbalanced with an urgent implementation of bycatch mitigation measures in the longline fleet.
authors.affiliation: Institut de Recerca de la Biodiversitat (IRBio), Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain.|Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall Campus TR10 9EZ, UK.
authors.forename: Andrea
authors.initials: A
authors.lastname: Soriano-Redondo
authors.affiliation: Institut de Recerca de la Biodiversitat (IRBio), Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain.
authors.forename: Verónica
authors.initials: V
authors.lastname: Cortés
authors.affiliation: Institut de Recerca de la Biodiversitat (IRBio), Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Reyes-González
authors.affiliation: Institut de Recerca de la Biodiversitat (IRBio), Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain.
authors.forename: Santi
authors.initials: S
authors.lastname: Guallar
authors.affiliation: SEO/BirdLife - Marine Programme, C/Murcia 2-8, local 13. 08026 Barcelona, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Bécares
authors.affiliation: SEO/BirdLife - Marine Programme, C/Murcia 2-8, local 13. 08026 Barcelona, Spain.|Canary Islands' Ornithology and Natural History Group (GOHNIC), La Malecita s/n, 38480 Buenavista del Norte, Tenerife, Canary Islands, Spain.
authors.forename: Beneharo
authors.initials: B
authors.lastname: Rodríguez
authors.affiliation: SEO/BirdLife - Marine Programme, C/Murcia 2-8, local 13. 08026 Barcelona, Spain.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Arcos
authors.affiliation: Institut de Recerca de la Biodiversitat (IRBio), Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain.
authors.forename: Jacob
authors.initials: J
authors.lastname: González-Solís
mesh_terms: D000818:Animals; D001717:Birds / Q000502:physiology*; D003247:Conservation of Natural Resources; D017753:Ecosystem; D005247:Feeding Behavior / Q000502:physiology*; D005398:Fisheries; D005843:Geography; D062312:Islands; D008522:Mediterranean Sea; D011157:Population Dynamics; D012307:Risk Factors; D013030:Spain