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- Marine litter in the upper São Vicente submarine canyon (SW Portugal): abundance, distribution, composition and fauna interactionsPublication . Oliveira, Frederico; Monteiro, Pedro; Bentes, Luis; Sales Henriques, Nuno; Aguilar, Ricardo; Gonçalves, J. M. S.Marine litter has become a worldwide environmental problem, tainting all ocean habitats. The abundance, distribution and composition of litter and its interactions with fauna were evaluated in the upper S. Vicente canyon using video images from 3 remote operated vehicle exploratory dives. Litter was present in all dives and the abundance was as high as 3.31 items100m(-1). Mean abundance of litter over rock bottom was higher than on soft substrate. Mean litter abundance was slightly higher than reported for other canyons on the Portuguese margin, but lower in comparison to more urbanized coastal areas of the world. Lost fishing gear was the prevalent type of litter, indicating that the majority of litter originates from maritime sources, mainly fishing activity. Physical contact with sessile fauna and entanglement of specimens were the major impacts of lost fishing gear. Based on the importance of this region for the local fishermen, litter abundance is expected to increase.
- Semi-pelagic Longline and Trammel Net Elasmobranch Catches in Southern Portugal: Catch Composition, Catch Rates and DiscardsPublication . Coelho, Rui; Erzini, K; Bentes, Luis; Correia, Carla; Lino, Pedro; Monteiro, Pedro; Ribeiro, Joaquim; Gonçalves, J. M. S.In Portugal, elasmobranch landings have decreased substantially in recent years. In this work, elasmobranch catches in semi-pelagic longlines (1997 and 1998) were compared with those in trammel nets (2000) in the Algarve, southern Portugal areas. In the semi-pelagic longline fi shery, 7 elasmobranch species represented 33.4% (2 185 specimens) of the total fi sh catches. Among the elasmobranch species, the most abundant were Galeus melastomus (63.3%), Etmopterus pusillus (21.7%) and Scyliorhinus canicula (14.2%). Most of these elasmobranchs were discarded (68.3% in total). In the trammel net fi shery, 16 different elasmobranch species represented 4.3% (597 specimens) of total fi sh catches and the most important species were Raja undulata (43.6%) and S. canicula (10.2%). The majority of the elasmobranchs caught in trammel nets had commercial value, and only 5.4% were discarded. In both fi sheries, intra-specifi c catch rates varied with depth. Length-frequency distributions for the only species with relatively high catches in both fi sheries, S. canicula, showed that, in general, trammel nets catch larger specimens and in a narrower length range than do longlines.