Análisis de las tasas de captura de la merluza europea Merluccius merluccius (L., 1758) del stock norte: estandarización del esfuerzo de las flotas españolas arrastreras y palangreras que faenan en la subárea VII del CIEM

Standardization of catch per unit effort (cpue) series using a generalized linear model (GLM) for Northern European hake Merluccius merluccius (L., 1758) in International Council for the Exploration of the Sea (ICES) subarea VII, based on catch and effort data from the Spanish trawler and longliner fleets from 1986 to 2000, are presented. Data were collected from trawler and longliner fleets targeting hake off the Spanish ports of La Coruña, Burela, and Celeiro. Main factors in the models created include a factor for engine Horse Power, to adjust for characteristics that determine fishing power; Year and Month factors for La Coruña’s trawler fleet; and the factors Month, Year, Vessel, and Fishing Days for the Spanish longliner fleet as a whole. Moreover, both models indicate that interactions between the Year and Month factors also had a significant impact on hake catch rates. The total proportions of variance explained by these models were 55% for La Coruña’s trawler fleet, and about 48 % for Spanish longliner fleet. The results showed similar patterns comparing nominal and standardized catch rates[Resumen] Análisis de las tasas de captura de la merluza europea Merluccius merluccius (L., 1758) del stock norte: estandarización del esfuerzo de las flotas españolas arrastreras y palangreras que faenan en la subárea VII del CIEM Se muestra la aplicación de un modelo lineal generalizado (GLM) para la estandarización de la captura por unidad de esfuerzo (cpue) de la merluza europea Merluccius merluccius (L., 1758) del stock norte en la subárea VII del Consejo Internacional para la Exploración del Mar (CIEM) durante el periodo 1986-2000. Los datos de esfuerzo y captura proceden de las flotas de arrastre y de palangre de los puertos de A Coruña, Burela y Celeiro (en el noroeste de España) dirigidas a la pesca de merluza del stock norte. En el modelo para la flota arrastrera del puerto de A Coruña se incluyeron los factores año, mes y categoría del barco, que relacionan la potencia del motor con su poder de pesca, y en el modelo para la flota palangrera de los puertos de A Coruña, Burela y Celeiro se incluyeron los factores año, mes, barco y días de pesca. Ambos modelos reflejan interacciones significativas entre los factores año-mes; así, el 55 % de la variación total observada se explica con el modelo para la flota arrastrera del puerto de A Coruña, y el 48 % se explica con el modelo para la flota palangrera. Las dos tipificaciones demuestran, así mismo, tendencias interanuales similares en las tasas de capturas estandarizadas y nominalesInstituto Español de Oceanografí

Spatio-temporal variability in the cannibalistic behaviour of European hake Merluccius merluccius: the influence of recruitment abundance and prey availability

Cannibalistic behaviour of European hake Merluccius merluccius was studied through the analysis of 49 836 gut contents belonging to individuals from 6 to 82 cm in total length (LT). Samples were collected every autumn between 1993 and 2009. The results showed that the consumption of conspecific individuals was consistent over space and time. The abundance, spatial distribution patterns and LT structure of M. merluccius recruits were the main variables involved in M. merluccius cannibalism. A geographical pattern was found since increasing cannibalism was observed in areas of recruit aggregations. The LT spectrum of recruits in autumn was also a key factor and dependent on the spawning period. When adults spawned from late spring to summer, an increasing cannibalism trend was found in autumn, due to the ideal size structure of the prey (M. merluccius recruits) for predators. Depth was also a significant variable, and a cannibal peak was detected at depths ranging between 50 and 200 m, coinciding with a spatial overlap of predator (pre-adults) and prey (recruits). The cannibalistic behaviour of M. merluccius began at c. 12 cm, although 75% were mid-sized individuals between 16 and 30 cm. Additionally, 90% of prey-hake were recruits <18⋅5 cm. Some biological and ecological aspects such as growth rate, spawning period, predation and competition interactions and the effect of some oceanographic events on M. merluccius cannibalism are also discussed.En prens

Updating the Master Management Plan for El Cachucho MPA (Cantabrian Sea) using a spatial planning approach

Located in the Cantabrian Sea (NE Atlantic), 30 nm off the Asturian coast, “El Cachucho” was the first off-shore Marine Protected Area (MPA) to be declared in Spain. The area includes Le Danois Bank and its intraslope basin. It joined the OSPAR Network of MPAs in 2009 and, thereafter, was included in the Natura 2000 Network in 2011. The main reason for its declaration as MPA was the presence of the 1170 Reefs habitat included in Annex I of the EU Habitats Directive. In 2018, the MPAs Master Management Plan was under revision and its design criteria were subjected to evaluation. We used Marxan decision support tool to evaluate the MPA's management design criteria. This tool selects the most important conservation features, while minimizing the socioeconomic cost. First, the 1170 Reefs habitat was defined as the main environmental value. Specifically, we took into account the six large sized target species that are more representative of this habitat in the area: the sponges Asconema setubalense, Geodia cf. barretti and Phakellia robusta, the anthipatarian Leiopathes glaberrima, and the gorgonians Placogorgia sp. and Callogorgia verticillata. A spatial distribution map was produced for each species using Generalized Additive Models (GAM). We also considered the presence of spawning stocks of fish species which are present in the area as an important conservation value. Their spatial distribution was modeled through Maxent software. Additionally, for the socioeconomic cost, fishing effort of the different fisheries operating in the area was estimated linking VMS/Logbook data before and after the MPA was declared. The first results obtained with the Marxan tool were presented in public consultation, in the context of the LIFE + INTEMARES Project, to help in decision making within the new Management Plan. Thus, to improve the management measures aimed at the conservation of the environmental values of the MPA, an enlargement of the protected area to the West was proposed, and a more reasonable use of the buffer area to fishermen than that defined in the former Management Plan was suggested. Involving all stakeholders in the development of the management plan for this MPA is a decisive step for the creation and consolidation of an important network of MPAs in Spain.En prensa2,08

Benthic litter distribution on circalittoral and deep sea bottoms of the southern Bay of Biscay: Analysis of potential drivers

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Range extension of the Atlantic herring Clupea harengus (Clupeiformes: Clupeidae) southern part of the Northeast Atlantic Ocean

The atlantic herring Clupea harengus linnaeus, 1758 is a pelagic clupeid, schooling, plankton-feeding species that inhabits the coastal areas from inshore to well offshore waters, at depths to 200 m (Whitehead, 1986). This target species has been crucial for food security and economic development in northern europe (Martinez-Barrio et al., 2016). Its fishery currently ranks among the five largest fisheries in the world, with nearly 2 million tons of fish landed annually in the last years (Fao, 2010-2019). This species is distributed on both sides of the north atlantic ocean. In the western atlantic, it ranges from labrador to cape Hatteras; in the eastern atlantic, from the northern part of the Bay of Biscay to Greenland, and to the east into the Barents sea (Whitehead, 1985, 1986). In the northeastern atlantic, a large number of intraspecific groups (races, stocks, and populations) are distinguished by their spawning grounds and seasons, otolith morphology and meristic characters (Berg et al., 2017).En prensa0,40

Aggregated Clumps of Lithistid Sponges: A Singular, Reef-Like Bathyal Habitat with Relevant Paleontological connections

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