Sobre la presència de dues espècies de peixos pelàgics associats a objectes flotants en el mar català (Mediterrània nordoccidental)

Abstract not availabl

Primera cita de estadios larvarios de Coryphaena hippurus (Pisces: Coryphaenidae) en el Mar Mediterráneo

The occurrence of early larval stages of Coryphaena hippurus is reported for the first time in Mediterranean waters. Four larvae between 3.25 and 4.80 mm standard length were found in ichthyoplanktonic collections taken off the Balearic Islands between 1985 and 1995. Their capture is discussed in relation to the life cycle proposed for this species in the area.Se cita la primera captura de estadíos larvarios de Coryphaena hippurus en el Mediterráneo. Se han encontrado cuatro larvas de longitud estándar comprendida entre 3.25 y 4.80 mm, en muestras de ictioplancton recolectadas entre 1985 y 1995 en las Islas Baleares. Se discute su distribución espacio-temporal en relación con el ciclo vital propuesto para la especie en el áre

Distribució i abundància de Symphurus nigrescens Rafinesque, 1810 i Symphurus ligulatus (Cocco, 1844) (Pisces, Pleuronectiformes) en el talús del mar Català

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Improving the ecological efficiency of the bottom trawl fishery in the western Mediterranean: it’s about time!

The improvement of fishing technology has been detrimental to the sustainability of fisheries, which is particularly clear for the bottom trawl fishery. Reducing its environmental impact is a key point for the development of a more sustainable fishery. The present work analyzed different possibilities to mitigate the impact of gears on the seabed and to increase the efficiency of the bottom trawl fishery of the Western Mediterranean. The analysis of three experiments showed that innovative technical and regulation measures can lead to benefits such as the reduction of fishing effort, the improvement of the cost-benefit relation and the reduction of the direct impact on the seabed and the indirect effect on the ecosystems through reduce discards and the emission of CO2 into the atmosphere. After years of studies focused on improving the sustainability of this fishery, it's about time to turn this improvement into realityPreprint1,86

N90, a Diversity Index Sensitive to Variations in Beta Diversity Components

Species diversity in a community is mainly related to the number and abundance of species that form it. N90 is a recently developed diversity index based on the results of the similarity percentage (SIMPER) analysis that represents the number of species contributing up to ninety percent of within-group similarity in a group of samples. The calculation of N90 is based on the Bray–Curtis similarity index and involves the number of species and abundances in a group of samples. We have explored the properties of N90 compared to other alpha, beta and gamma diversity indices and to beta diversity measures accounting for nestedness and turnover. We have used a non-real data set to compare the values of all indices with N90 and two real data sets of demersal fish communities along large and short depth gradients with higher influence of turnover and nestedness, respectively, to correlate the same indices with N90. The sensitivity of N90 to reductions in the frequency of occurrence and the evenness of the distribution of species abundances among samples allows the detection of diversity loss due to the fishing-induced retreatment of species populations to localities presenting the most favorable ecological conditions. This property, both in the identification of species replacement and species loss through SIMPER analysis, make N90 a useful indicator to support the Ecosystem Approach to Fisheries within the current context of global changeEn prens

Dades sobre la capture de dues espècies del gènere Tetrapturus (Osteichthyes, Istiophoridae) al mar Balear (Mediterrània occidental)

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Evaluación preliminar de los desembarques y descartes de la pesquería de arrastre de fondo de Turquía en el mar Egeo nororiental (Mediterráneo oriental)

This short-term study on commercial discards was carried out in fishing grounds around Gökçeada Island in the northeastern Aegean Sea, a geographic area where fisheries information is rather limited. A total of 28 bottom trawls were performed between 70 and 410 m depth from December 2009 to February 2010. All the samples were collected on board a commercial trawler under commercial fishing conditions. A total of 3143 kg of biomass was caught in 28 valid hauls. Landings accounted for about 67% of the total catch while the remaining 33% was discarded. Fish species comprised 85% of the total catch and their composition could be divided into four main groups related to depth: shallow shelf (70 to 88 m), deep shelf (155 to 180 m), shelf break (196 to 276 m), and upper slope (307 to 410 m). Fish dominated the abundance and biomass of both landings and discards in all bathymetric strata. Echinoderms also accounted for a large proportion of the discards. Mean total catches varied between 78.4 kg/h on the shallow shelf and 38.1 kg/h on the shelf break with no differences in the landing biomass between groups, but with slightly higher discards over the shallow shelf. Taking into account the preliminary nature of the findings, based on a short-term analysis, the minimum mesh size and minimum landing size currently applied in the Turkish bottom trawl fishery are not sufficient to reduce discards and to protect juveniles of commercially important species in the northeastern Aegean Sea.Este estudio a corto plazo sobre los descartes de la flota comercial de arrastre se llevó a cabo en las zonas de pesca alrededor de la isla Gökçeada en el noreste del mar Egeo, una zona geográfica en la que la información sobre las pesquerías es bastante limitada. Se realizaron un total de 28 pescas de arrastre de fondo entre 70 y 410 m de profundidad de diciembre 2009 a febrero de 2010. Todas las muestras se recogieron a bordo de un embarcación de pesca de arrastre siguiendo las mismas condiciones de pesca comercial. Se capturaron un total de 3143 kg de biomasa en 28 lances válidos. Los desembarques comerciales representaron alrededor del 67% de la captura total, mientras que el resto (33%) se descartó. El 85% de la captura total estuvo compuesta por especies de peces. La composición específica se pudo separar en cuatro grupos principales relacionados con la profundidad : la plataforma poco profunda (70 a 88 m), la plataforma profunda (155-180 m), el borde inferior de la plataforma (196 a 276 m) y el talud superior (307-410 m). Los peces dominaron la abundancia y biomasa tanto de los desembarques comerciales como de los descartes en todos los estratos batimétricos. Además los equinodermos también fueron un grupo importante de los descartes. La media de las capturas totales varió entre 78.4 kg/h en la plataforma poco profunda y 38.1 kg/h en el borde de la plataforma, sin diferencias en la biomasa desembarcada entre los dos grupos, pero siendo los descartes ligeramente superiores en la plataforma poco profunda. Teniendo en cuenta el carácter preliminar de los resultados, obtenidos sobre la base de un análisis a corto plazo, el tamaño mínimo de malla de la red y la talla mínima de las especies comerciales aplicada hoy en día en la pesquería de arrastre de fondo de Turquía no son suficientes para reducir los descartes y proteger a los juveniles de las especies de importancia comercial en el Mar Egeo nororiental

Discards reduction of non-commercial benthic species from a simple net modification

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