SUMMARY:The composition and abundance of megabenthic fauna caught by the commercial trawl fleet in the Alboran Sea were studied. A total of 28 hauls were carried out at depths ranging from 50 to 640 m. As a result of a hierarchical classification analysis four assemblages were detected: (1) the outer shelf group (50-150 m), characterised by Octopus vulgaris and Cepola macrophthalma; (2) the upper slope group (151-350 m), characterised by Micromesistius poutassou, with Plesionika heterocarpus and Parapenaeus longirostris as secondary species; (3) the middle slope group (351-640 m), characterised by M. poutassou, Nephrops norvegicus and Caelorhincus caelorhincus, and (4) the small seamount Seco de los Olivos (310-360 m), characterised by M. poutassou, Helicolenus dactylopterus and Gadiculus argenteus, together with Chlorophthalmus agassizi, Stichopus regalis and Palinurus mauritanicus. The results also revealed significantly higher abundances in the Seco de los Olivos seamount, probably related to a higher food availability caused by strong localised currents and upwellings that enhanced primary production. Although depth proved to be the main structuring factor, others such as sediment type and food availability also appeared to be important. Differences between shelf and slope assemblages could be in part related to a greater dependence on benthic resources in the former and a higher use of planktonic resources in the latter.Keywords: demersal fish, epibenthos, bathymetric distribution, discards, western Mediterranean, Alboran Sea, Seco de los Olivos seamount. Los resultados revelan una abundancia de megafauna significativamente mayor en Seco de los Olivos, probablemente relacionada con una mayor disponibilidad de alimento provocada por las fuertes corrientes y afloramientos que tienen lugar en la zona, y que generan un aumento en la producción primaria. Aunque la profundidad constituye el principal factor estructurante de las comunidades, también son importantes el tipo de sedimento y la disponibilidad de alimento. Las diferencias encontradas entre las comunidades de plataforma y de talud podrían estar en parte relacionadas con una mayor dependencia de los recursos bentónicos en la primera, y un mayor aprovechamiento de los recursos planctónicos en la segunda. RESUMEN: AGRUPACIONES DEMERSALES Y BENTÓNICAS DE LOS FONDOS ARRASTRABLES DEL MAR DE ALBORÁN (MEDITERRÁNEO OCCIDENTAL)Palabras clave: peces demersales, epibentos, distribución batimétrica, descartes, Mediterráneo occidental, mar de Alborán, montaña submarina Seco de los Olivos.

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Punzón, A., Hernández, C., Abad, E., Castro, J., Pérez, N., and Trujillo, V. 2010. Spanish otter trawl fisheries in the Cantabrian Sea. – ICES Journal of Marine Science 67: 1604–1616 A non-hierarchical classification technique (clustering large applications, CLARA) was used to identify four fishing tactics of Spanish otter trawlers in the Cantabrian Sea (ICES Division VIIIc) from 1983 to 2004: mixed fishing, blue whiting fishing, horse mackerel fishing, and mackerel fishing. There were no significant differences in the fishing tactics employed by two trawl fleets identified using a non-hierarchical classification technique (partition around medoids). There was, however, a decline in the use of the blue whiting fishing tactic from 2000 on, perhaps as a result of competition with pairtrawls, a gear whose main target species is blue whiting. There was an increase in the number of trips using the mackerel fishing tactic from 1996, a change possibly caused by improved market conditions. Between 2000 and 2004, the fleets had two distinct behaviour patterns, identified depending on the area in which they operated. The study area could therefore be subdivided into two areas based on the prevalence of the fishing tactic followed. The horse mackerel fishing tactic was more commonly used in the west, and the mixed fishing tactic in the east.

Knowledge of stock structure is a priority for effective assessment of commercially-fished cephalopods. Loligo forbesii squid are thought to migrate inshore for breeding and offshore for feeding and long-range movements are implied from past studies showing genetic homogeneity in the entire neritic population. Only offshore populations (Faroe and Rockall Bank) were considered distinct. The present study applied mitchondrial and microsatellite markers (nine loci) to samples from Rockall Bank, north Scotland, North Sea, various shelf locations in Ireland, English Channel, northern Bay of Biscay, north Spain, and Bay of Cadiz. No statistically significant genetic sub-structure was found, although some non-significant trends involving Rockall were seen using microsatellite markers. Differences in L. forbesii statolith shape were apparent at a subset of locations, with most locations showing pairwise differences and statoliths from north Ireland being highly distinct. This suggests that (i) statolith shape is highly sensitive to local conditions and (ii) L. forbesii forms distinguishable groups (based on shape statistics), maintaining these groups over sufficiently long periods for local conditions to affect the shape of the statolith. Overall evidence suggests that L. forbesii forms separable (ecological) groups over short timescales with a semi-isolated breeding group at Rockall whose distinctiveness varies over time.

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After the sinking of the oil carrier 'Prestige', which occurred in November 2002, approximately 60,000 mt of heavy oil (type M-100) were spilled into the ocean. Immediately after the accident, a series of management measures were applied to fisheries in the area, resulting in the establishment of various closed areas. Four of the most important fleets operating in the north and north-east of the Iberian Peninsula were affected (otter trawl, pair trawl, purse seine and hand line fishing gears). These fleets exploit important fisheries resources, some of them currently beyond their biological security limits. Reductions in effort were observed in all of them, particularly in the first three months of the ban and in the north-eastern area. However, apart from the hand line fleet, this did not involve a considerable reduction in the total effort produced by each of the fleets in 2003. The pair trawlers perform two trip types, but no differences in the specific composition were observed in any of them during the three years under analysis. Five types of trawling trip were identified, but important reductions were only observed for Norwegian lobster, with the fleet targeting this species as well as hake, megrim and monkfish.

SUMMARY:The classification and identification of all the Spanish fishing activity targeting deep-sea species was conducted using a non-hierarchical classification technique designed for large matrices (CLARA). Otter trawl and set longlines were the main gears used in deep-sea ecosystems. The otter trawl fleet conducted 3 deep-sea fishing tactics. The only otter trawl fishing tactic targeting deep-sea species was that working in the VI ICES Division and targeting Alepocephalus baiirdi. The other 2 otter trawl fishing tactics targeted shallower shelf demersal resources, deep-sea species being secondary (Phycis blennoides). The longline fleet carried out 7 fishing tactics targeting deep-sea species (Molva spp.; deep water sharks; P. blennoides; Pagellus bogaraveo; and Trichiuridae) and 2 fishing tactics targeting Conger conger, which perform as deepsea fishing tactics in the narrow continental shelf area. This classification, together with knowledge regarding their seasonal performance and spatial distribution, may help to design fisheries sampling protocols and to improve the management of these fleets, thus reducing their impact on deep-sea habitats.Keywords: Northeast Atlantic, métiers, fisheries, deep sea, trawl, longline, multivariate. RESUMEN: Pesquerías españolas de gran profundidad en el Atlántico Nordeste. Estacionalidad y distribución espacial. -Para la clasificación e identificación de todas las pesquerías españolas que actúan sobre especies de gran profundidad se ha utilizado una técnica de cluster no jerárquica diseñada para grandes matrices (CLARA). El arrastre con puertas y el palangre de fondo fueron los aparejos más importantes. Solamente la táctica pesquera de arrastre con puertas desarrollada en la División VI del ICES está dirigida a especies de profundidad, siendo la especie objetivo Alepocephalus baiirdi. Las otras dos tácticas pesqueras con arrastre de puertas son mixtas, teniendo como objetivo especies típicas de plataforma, y teniendo las especies de profundidad como secundarias (Phycis blennoides). La flota de palangre desarrolla siete tácticas pesqueras dirigidas a especies de profundidad: Molva spp.; tiburones de profundidad; P. blennoides; Pagellus bogaraveo; Trichiuridae; y dos pesquerías dirigidas a Conger conger, que se comportan como tácticas pesqueras de profundidad en las zonas de plataforma estrecha. Esta clasificación junto con el conocimiento acerca de su comportamiento estacional y espacial, ayudarán al diseño de los protocolos de muestreo de estas pesquerías así como a la mejora de la gestión de estas pesquerías contribuyendo a una reducción de su impacto en los hábitats profundos.