Spearfishing pressure on fish communities in rocky coastal habitats in a Mediterranean marine protected area

摘要

This study constitutes the first empirical investigation in the Mediterranean Sea quantifying in situ the pressure of spearfishing on fish communities in rocky coastal habitats in the Mediterranean. The investigation was carried out in the Cape Creus Marine Protected Area (MPA). Overall, 20 fish species and I invertebrate species were identified (three were coastal pelagic and the rest rocky benthic or demersal). in terms of abundance, two omnivorous species made up the 44% of the catch but in terms of weight. the main part (77%) of the catches relied on seven piscivorous (i.e. top-predator) fish (with trophic level values greater than 3.80). With the exception of three fish, the specie's intrinsic vulnerability values ranged between 40 and 90 (out of 100), implying a moderate to very high vulnerability to fishing. Spearfishing mainly targets large individuals measuring more than 30 cm in length. It is estimated that the total annual biomass extracted by spearfishing in the MPA is equivalent to ca.40% of the total biomass extracted annually by artisanal (commercial) fishing.Overall, results highlight the pressure spearfishing exerts on the reproductive potential of fish species in rocky habitats along the Mediterranean coast, particularly those that are vulnerable (i.e. long lived and slow growing species with low reproductive potential) and have a higher trophic level. Results support the assumption that spearfishing can induce changes in both the trophic structure and the intrinsic vulnerability of taxa in the catch. Considering the biological implications of spearfishing, management should be supported by additional regulations in order to protect species that are vulnerable and have a higher trophic level. (C) 2008 Elsevier B.V. All rights reserved.