Inter-calibration experiment between the R/V Cornide de Saavedra and the R/V Miguel Oliver

Versión de edito

Results on main elasmobranch species captured during the 2001-2009 Porcupine Bank (NE Atlantic) bottom trawl surveys

This paper presents the results on nine of the most important elasmobranch fish species of the nine years (2001-2009) of the Porcupine bank Spanish surveys. The main species in biomass terms in Porcupine bank bottom trawl survey, in decreasing biomass abundance order, are: blackmouth catshark, birdbeak dogfish, velvet belly, Knifetooth dogfish, lesser spotted dogfish, bluntnose sixgill shark, sandy ray, cuckoo ray and common skate. Many of these species occupy mainly the deep areas covered in the survey, especially birdbeak dogfish, knifetooth dogfish and velvet belly. Less confined to deeper grounds are blackmouth catshark and sandy ray, while lesser spotted dogfish and cuckoo ray inhabit mainly the shallower grounds close to the Irish shelf or the central mound in the bank. Length distributions of these species along the survey series are also presented and discussed. The few available data on siki sharks from the Porcupine bank survey are also summarized.Versión del edito

Results on Argentine (Argentina spp.), Bluemouth (Helicolenus dactylopterus), Greater forkbeard (Phycis blennoides) and Spanish ling (Molva macrophthalma) from 2008 Porcupine Bank (NE Atlantic) survey

This paper presents the results on four of the most important deep fish species of the last Porcupine Spanish survey carried in 2008, and updates the document presented in the previous year with the information on the first seven years (2001-2007) of the Porcupine Spanish surveys. The document presents total abundances in weight, length frequencies and geographical distributions for Argentina spp. (mostly A. silus), bluemouth, greater fork-beard and Spanish ling.Versión de edito

Results on Argentine (Argentina spp.), Bluemouth (Helicolenus dactylopterus), Greater forkbeard (Phycis blennoides) and Spanish ling (Molva macrophthalma) from 2011 Porcupine Bank (NE Atlantic) survey

This paper presents the results on four of the mostimportant deep fish species of the last Porcupine Spanish survey carried in 2011, and updates the document presented in previous years with the information on the first ten years (2001-2010) of the PorcupineSpanish surveys. The document presents total abundances in weight, length frequencies and geographical distributions for Argentina spp. (mostly A. silus, results on A. silus/A. sphiraena distribution in last surveys are provided), bluemouth, greater fork-beard and Spanish ling. Also information on records of Blue ling during the survey series is shown.Versión de edito

Results on Argentine (Argentina spp.), Bluemouth (Helicolenus dactylopterus), Greater forkbeard (Phycis blennoides) and Spanish ling (Molva macrophthalma) from 2010 Porcupine Bank (NE Atlantic) survey

This paper presents the results on four of the mostimportant deep fish species in the Porcupine bottom trawl survey organized by the Spanish Institute of Oceanography in 2010, and updates the documents presented in previous years with the information on the first nine years (2001-2009) of the Porcupine Spanish surveys. The document presents total abundances in weight, length frequencies and geographical distributions for Argentina spp. (mostly A. silus, results on A. silus/A. sphiraena distribution in last survey is presented), bluemouth, greater fork-beard and Spanish ling and information on records of blue ling during the survey series.Versión de edito

Results on Argentine (Argentina spp.), Bluemouth (Helicolenus dactylopterus), Greater forkbeard (Phycis blennoides) and Spanish ling (Molva macrophthalma) from 2012 Porcupine Bank (NE Atlantic) survey

This paper presents the results on four of the mostimportant deep fish species of the last Porcupine Spanish survey carried in 2012, and updates the documents presented in previous years with the information on the eleven years (2001-2011) of the Porcupine Spanish bottom trawl surveys on the Porcupine Bank. The document presents total abundances in weight, length frequencies and geographical distributions for Argentina spp. (mostly A. silus, results on proportions by Argentina species distribution in last surveys are provided),bluemouth, greater fork-beard and Spanish ling. All species considered present increases in their abundances, that are especially remarkable in the case of greater forkbeard and Spanish ling, confirming the good recruitments detected in 2011 survey. Besides both species have shown new recruitment peaks in 2012 survey.Versión de edito

Distribution patterns of bottom trawl faunal assemblages in Porcupine bank: implications for Porcupine surveys stratification design.

The distribution patterns of bottom trawl faunal assemblages in Porcupine bank is addressed using data from two bottom trawl surveys performed in the area. Hierarchical cluster analyses and canonical ordination analyses are applied respectively to define the different assemblages and to evaluate the main structuring environmental factors using information on depth, latitude, longitude, bottom temperature and salinity. Analyses are performed with two different matrices one in numbers of individuals per species in each haul and another in biomass of main commercial species in each haul. Three large assemblages are discriminated by hierarchical cluster analyses: shelf, outer-shelf and shelf-break, with some subgroups within each of them consistent in the results of both data matrices. Depth is the main structuring environmental factor in the area. Longitude has also an important effect on the bottom trawl assemblages distribution pattern, this effect is more likely to be related with relief structure and ground types differences in both sides of Porcupine bank. The original strata design used in Porcupine surveys, based on previous information on commercial catches, does not agree with the results of this study, but more information on the bathymetry in the area is needed to implement new bathymetric strata.Versión de edito

John Dory Zeus faber (Linnaeus, 1758) feeding off Galicia and in the Cantabrian Sea: Dietary shifts with size

Between 1990 and 1997, stomach contents of 647 Atlantic John Dory Zeus faber (Linnaeus, 1758) measuring from 5-58 cm, were analysed volumetrically. The species was found to be almost entirely icthyophagous: fishes constituted more than 99 % of its diet by volume, or 75 % in terms of number. Among these, there are some commercially and ecologically important gadoids and clupeoids. Using clustering and multi-dimensional scaling methods, four length ranges with a different diet composition were found: smaller fishes, measuring 5-9 cm, fed mainly on invertebrates (mysids and Allotheutis spp.) and small benthic fishes (e.g., gobiids and Callionymus maculatus Rafinesque-Schmaltz, 1810). In the transitional length range, 9-12 cm, Gadiculus argenteus Guichenot, 1850 replaced the invertebrates. From 12-30 cm, Z. faber's diet basically comprised gadoids, such as Micromesistius poutassou (Risso, 1826), G. argenteus and Merluccius merluccius (Linnaeus, 1758), whereas specimens longer than 30 cm fed on larger fishes, including M. poutassou, clupeoids (mainly Sardina pilchardus Walbaum, 1792), and Cepola rubescens Linnaeus, 1766. Feeding was more intense in the smallest length range, and within each length range, a different diet composition by depth strata was also observed.Entre 1990 Y 1997 se analizaron, con un método volumétrico, los contenidos estomacales de 647 ejemplares de pez de San Pedro Zeus faber (Linnaeus, 1758), abarcando un rango de tallas entre 5 y 58 cm. Se trata de una especie muy icliófaga: su dieta está compuesta por peces en más del 99 % en volumen y del 75 % en número. Dentro de ella destacan gadiformes y clupeiformes de importancia, tanto ecológica como comercial. Utilizando análisis de clúster y MDS se identifican cuatro rangos de talla con composiciones de la dieta diferentes: los individuos menores, entre 5 y 9 cm, se alimentan principalmente de invertebrados (misidáceos y Allotheutis spp) junto a pequeños peces bentónicos (Gobiidae y Callionymus maculatus Rafinesque-Schmaltz, 1810); a continuación, hay un rango de transición, de 9 a 12 cm, en el que el Gadiculus argenteus Guichenot, 1850 reemplaza a los invertebrados; entre 12 y 29 cm la dieta se compone fundamentalmente de gadiformes como Micromesistius poutassou (Risso, 1826), G. argenteus y Merluccius merluccius (Linnaeus, 1758); mientras, la alimentación entre los individuos mayores de 30 cm se basa en peces de mayor tamaño, entre los que destacan M. poutassou, clupeiformes (fundamentalmente Sardina pilchardus Walbaum, 1792) y Cepola rubescens Linnaeus, 1766, entre otros. También se observa mayor intensidad de alimentación en los peces del rango menor de tallas y diferentes composiciones de la dieta por estratos de profundidad dentro de cada rango de tallas.Instituto Español de Oceanografí

Results on Argentine (Argentinaspp.), Bluemouth (Helicolenus dactylopterus), Greater forkbeard (Phycis blennoides), Spanish ling (Molva macrophthalma) and ling (Molva molva) from 2014 Porcupine Bank (NE Atlantic) survey

This working document presents the results on four of the most significant deep fish species of the last Porcupine Spanish survey carried in 2014, as well as it updates previous documents presented with the information on the fourteen years (2001-2014) of the Spanish bottom trawl survey on the Porcupine Bank. The document presents total abundances in weight, length frequencies and geographical distributions for Argentinaspp. (mostly A. silus, results on proportions by Argentine species distribution in last surveys are provided), Bluemouth (Helicolenus dactylopterus), Greater fork-beard (Phycis blennoides) and Spanish ling (Molva macrophthalma). Argentinaspp. and Spanish ling presented a decrease in their abundances, whereas Bluemouth remained stable and Greater forkbeard increased slightly. In terms of recruitment 2014 showed larger values than previous years for A. sphyraena, Helicolenus dactylopterusand Molva macrophtalmabut weaker for Phycis blennoides, and A silus. Furthermore results for ling (Molva molva) on the Spanish Porcupine Bank survey are summarizedpresenting the results to the WG so their utility for the assessment could be considered.Versión de edito