Los descartes pesqueros: causas y medidas de reducción

MAGRAMAPostprin

Sampling protocol for skeletal structures of North Atlantic albacore tuna (Thunnus alalunga) and ageing interpretation

This paper presents a standardized protocol for sampling skeletal hard parts (dorsal fin ray and otoliths), preparation and age interpretation of albacore first dorsal fin ray. Ageing of albacore is focused in interpretation and reading of annual temporal marks (translucent bands) in first ray of dorsal fin. Preparation of fin ray sections (spines) is presented in detail using two different methods. The spines are usually cut individually using a low speed cutter. Depending of the size of spines, a new procedure has been developed for small spines based on encasing spines in a matrix of plastic resin allowing multiple spines cutting. Interpretation of growth marks on spine sections is explained and examples are presented for a range of size of albacore aged using this method.Ce document présente un protocole standardisé pour l’échantillonnage des pièces dures du squelette (rayon de la nageoire dorsale et otolithes), la préparation et l’interprétation de l’âge du rayon du premier rayon de la nageoire dorsale du germon. La détermination de l’âge du germon se centre sur l’interprétation et la lecture des marques temporelles annuelles (bandes translucides) du premier rayon de la nageoire dorsale. La préparation des sections du rayon de la nageoire (épines) est présentée en détail à l’aide de deux méthodes différentes. Les épines sont généralement sectionnées individuellement en utilisant un couteau basse vitesse. Selon la taille des épines, une nouvelle procédure a été élaborée pour les petites épines, consistant à enfermer les épines dans une matrice en résine plastique qui permet le découpage de plusieurs épines. L’interprétation des marques de croissance sur les sections des épines est expliquée et des exemples sont donnés pour une gamme de tailles de germon dont l’âge a été déterminé à l’aide de cette méthode.En este documento se presenta un protocolo estandarizado para el muestreo de partes duras del esqueleto (otolitos y rayo de la aleta dorsal) y para la preparación e interpretación de la edad del primer rayo de la aleta dorsal del atún blanco. La determinación de la edad del atún blanco se centra en la interpretación y lectura de las marcas temporales anuales (bandas traslucidas) en el primer rayo de la aleta dorsal. Se presenta en detalle la preparación de las secciones del rayo de la aleta (espinas) utilizando dos métodos diferentes. Las espinas suelen cortarse generalmente de forma individual utilizando un cortador de baja velocidad. Dependiendo del tamaño de las espinas, se ha desarrollado un nuevo procedimiento para las espinas pequeñas, que consiste en introducir las espinas en una matriz de resina plástica que permite cortar espinas múltiples. Se explica la interpretación de las marcas de crecimiento en las secciones de espinas y se presentan ejemplos para una gama de tallas de atún blanco cuya edad se determinó utilizando este método

Estimates of Spanish bottom otter trawl boarfish (Capros aper) discards by area in the Northeast Atlantic area.

Discard estimates for the Spanish bottom otter trawl fleets fishing in the Northeast Atlantic are presented for boarfish (Capros aper). Information was obtained by observers on board under different discard sampling programmes carried out by the Spanish research institute IEO. Raising based on effort (number of trips) was used to estimate total discards in weight and associated coefficients of variation (CV) and number for the fleet. Discards length distributions are presented by year and fishing area. Total estimates indicates different trends in discarding, showing a decreasing trend in north coastal Spanish waters and a increasing trend in western Ireland waters

Eledone cirrhosa and SPICT or why it is not easy to assess a short lived cephalopod species

Poster.-- Iberian Symposium on Modeling and Assessment of Fishery Resources, 19-22 October, Vigo, SpainAlthough some cephalopods have had always commercial value and others started to increase in value in recent years, unlike European Atlantic stocks of many commercially important finfish and crustaceans, they are not routinely assessed and no specific management measures are applied to fleets catching cephalopods, with the exception of some regional harvest control rules for artisanal fleets. Among the species that has been gaining importance in landings is the horned octopus Eledone cirrhosa. This octopus represents an important bycatch for several North Spanish otter trawl fisheries, appearing in landings but also in discards. Like other cephalopods, E. cirrhosa is a short-lived and fast growing species, and previous studies showed that its abundance varies in relation to physical and environmental conditions. As a first step towards its possible future inclusion in the ICES annual assessment system, a simple assessment model has been tested in the ICES Working Group on Cephalopod Fisheries and Life History (WGCEPH). The chosen model was SPICT (Surplus Production model in Continuous Time). Using landings and two abundance indices (from a commercial fleet and a scientific bottom trawl survey), preliminary results have been obtained. Overall, although the model converged and all the diagnostics were acceptable, the estimated parameters obtained very wide confidence intervals, suggesting that improvements in the model are needed. Further work, including testing other assessment models or selecting other tuning indices, will help in the assessment process for this speciesN

Contribución al estudio biológico de la tintorera (Prionace glauca) capturada accidentalmente en la pesquería de palangre de superficie de pez espada en el Mediterráneo occidental

Blue shark (Prionace glauca) bycatches in the Spanish surface longline fisheries in the Mediterranean targeting swordfish (Xiphias gladius) from 1999 to 2001 represented 2% of the total catch. Information from onboard observers during 861 fishing sets in 26 longliners indicated that the highest catches were made in area 4-35000 (Alboran Sea) which represents 75.6% of the total observed catch of blue shark. The observed CPUE are from 5.5 to 34.1 kg/1000 hooks. Mean size at capture (LJFL) was 141.6 cm (SD=35.88). The proportion of females from the total was 0.5.Les prises accessoires de requin peau-bleue (Prionace glauca) des pêcheries espagnoles à la palangre de surface qui ciblent l’espadon (Xiphias gladius) dans la Méditerranée entre 1999 et 2001 ont représenté 2% de la capture totale. L’information recueillie par les observateurs à bord de 26 palangriers visant l’espadon durant 861 opérations de pêche a indiqué que les plus fortes captures se produisent dans la zone 4-35000 (mer d’Alboran) qui représente 75,6% du total de la capture observée du requin peau-bleue. Les CPUE observées se situent entre 5,5 et 34,1 kg/1.000 hameçons. La taille moyenne de capture (LJFL) était de 141,6 cm (DS=35,88). Le pourcentage des femelles par rapport au total était de 0,5.Las capturas de tintorera (Prionace glauca) como especie accesoria en las pesquerías españolas de palangre de superficie dirigido al pez espada (Xiphias gladius) en el Mediterráneo entre 1999 y 2001 representó el 2% de la captura total. La información tomada por observadores a bordo durante de 861 caladas en 26 palangreros de pez espada indicó que las mayores capturas se producen en el área 4-35000 (Mar de Alborán) que representa el 75.6% del total de captura observada de la especie. Las CPUE observadas se encuentran entre 5.5 y 34.1 kg/1000 anzuelos. La talla media de captura (LJFL) fue de 1 41.6 cm (DE=35.88). El porcentaje de hembras respecto al total fue de 0.5