To reduce the practice of discarding commercially fished organisms, several measures such as a discard ban and extra allowances on top of landings quotas (“catch quota”) have been proposed by the European Commission. However, for their development and successful implementation, an understanding of discard patterns on a European scale is needed. In this study, we present an inter-national synthesis of discard data collected on board commercial, towed-gear equipped vessels operating under six different national flags spanning from the Baltic to the Mediterranean Seas mainly between 2003 and 2008. We considered discarded species of commercial value such as Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus), European hake (Merluccius merluccius), and European plaice (Pleuronectes platessa). Comparisons of discard per unit effort rates expressed as numbers per hour of fishing revealed that in the Mediterranean Sea minimum size-regulated species such as hake are generally discarded in much lower numbers than elsewhere. For most species examined, variability in discard rates across regions was greater than across fisheries, suggesting that a region-by-region approach to discard reduction would be more relevant. The high uncertainty in discard rate estimates suggests that current sampling regimes should be either expanded or complemented by other data sources, if they are to be used for setting catch quotas.
SUMMARY: The western Mediterranean Sea is an important fishing area for the Spanish drifting longline fleet, targeting swordfish (Xiphias gladius), bluefin tuna (Thunnus thynnus) and albacore (T. alalunga). Some seabird species can be captured incidentally as bycatch marine fauna. From July 1999 to August 2000 information on 554 surface longline sets was collected by onboard observers of the Spanish Oceanographic Institute (IEO) on 18 longline fishing boats working within the Spanish Mediterranean fishing area. Eleven yellow-legged gulls (Larus cachinnans), 9 Cory's shearwaters (Calonectris diomedea) and 1 Northern gannet (Morus bassanus) were captured incidentally. Bycatch rates ranged from 0.002 to 0.023 birds/1000 hooks.
Discards refer to the part of the catch not retained on board during commercial fishing operations, but returned to the sea. The proposed European Union Common Fisheries Policy reform, to be implemented in 2014, sets out a gradual elimination of discards by reducing unwanted catches and ensuring that all catches are landed. To develop successful discard mitigation measures, it is necessary to identify the reasons for discarding. Here, we have developed a simple model that can be applied to data from observer programmes (ObsPs) to establish the contribution of different drivers of discarding behaviour. The analysis makes inferences on the causes of discarding by partitioning discards into four categories based on the length of the fish and the associated regulatory restrictions. The drivers are defined as: fish discarded below the legal minimum landing size; fish for which there is no market and that do not have a minimum landing size; fish for which there are inconsistencies in market and sorting practices; and discards that can be attributed to fishers' responses to quota restrictions. The approach is applied to data generated from ObsPs from five European Member States. All the inferred drivers contribute to the total discard quantity. Their relative contributions vary widely across countries, areas, gears, and species.
SUMMARY: The occurrence of scavenger seabirds at fishing trawlers was studied off Galicia, Spain. A total of 9,368 seabirds of 23 species were recorded during 92 fishing operations in 1998 and 1999. The most common species were the yellow-legged and lesser black-backed gull (Larus cachinnans and L. fuscus), Sabine's gull (L. sabini), the northern gannet (Morus bassanus), the great shearwater (Puffinus gravis), sooty shearwater (P. griseus), the Manx and Balearic shearwater (P. puffinus and P. mauretanicus), the great skua (Catharacta skua) and terns (mainly Sterna hirundo and S. paradisaea). Other species occurred in small numbers: Leach´s petrel (Oceanodroma leucorhoa), the storm petrel (Hydrobates pelagicus), the little shearwater (Puffinus assimilis), Cory's shearwater (Calonectris diomedea), the parasitic skua (Stercorarius parasiticus), the pomarine skua (S. pomarinus), the black-headed gull (Larus ridibundus), the glaucous gull (L. hyperboreus), the kittiwake (Rissa tridactyla), the sandwich tern (Sterna sandvicensis), the black tern (Chlidonias niger), the guillemot (Uria aalge) and the little auk (Alle alle). The maximum number of seabirds recorded at a haul was 320. The maximum number of a particular species ranged from 120 great shearwaters to 250 yellow-legged/lesser black-backed gulls during a single haul. The differences in ship-follower species abundance are related to migratory movements but fisheries could also have a strong influence at a smaller scale on the distribution of seabirds off Galicia. The degree to which seabirds rely on fishery discards as food was not quantified, but may be important for several species.Key words: discards, seabirds, marine fisheries, Atlantic, Galicia. RESUMEN: ASOCIACIÓN DE LAS AVES MARINAS CON LOS DESCARTES DE LAS PESQUERÍAS DE ARRASTRE ENLA PLATAFORMA Y TALUD CONTINENTAL DE GALICIA, NW ESPAÑA. -Este trabajo estudia la asociación de aves marinas con barcos arrastreros que faenan sobre la plataforma y parte superior del talud continental de Galicia, NW España, desde junio de 1998 a marzo de 1999. Se registraron un total de 9.368 aves marinas de 23 especies durante 92 operaciones de pesca en 1998 y 1999. Las especies más comunes fueron el grupo gaviota patiamarilla y gaviota sombría (Larus cachinnans y L. fuscus), la gaviota de Sabine (L. sabini), el alcatraz atlántico (Morus bassanus), la pardela capirotada (Puffinus gravis), la pardela sombría (P. griseus), la pardela pichoneta y la balear (P. puffinus y P.mauretanicus), el págalo grande (Catharacta skua) y los charranes (principalmente Sterna hirundo y Sterna paradisea). Otras especies se observaron en menor número: el paiño de Leach (Oceanodroma leucorhoa), el paiño europeo (Hydrobates pelagicus), la pardela chica (Puffinus assimilis), la pardela cenicienta (Calonectris diomedea), el págalo parásito (Stercorarius parasiticus), el págalo pomarino (S. pomarinus), la gaviota reidora (Larus ridibundus), el gavión hiperbóreo (L. hyperboreus), la gaviota tridáctila (Rissa tridactyla), el charrán patinegro (Sterna sa...
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