Biomass and length distribution for roughhead grenadier, thorny skate and white hake from the surveys conducted by Spain in NAFO 3NO

Data for roughhead grenadier (Macrourus berglax), thorny skate (Amblyraja radiata) and white hake (Urophycis tenuis) from the Spanish Spring survey are presented. Abundance and biomass were estimated for roughhead grenadier and thorny skate for the period 1997-2013 and for white hake for the period...

Full description

Bibliographic Details
Main Authors: González-Troncoso, D. (Diana), Paz, X. (Xabier)
Other Authors: Northwest Atlantic Fisheries Organization (NAFO)
Format: Article in Journal/Newspaper
Language:English
Published: Centro Oceanográfico de Vigo 2014
Subjects:
Online Access:http://hdl.handle.net/10508/2475
Description
Summary:Data for roughhead grenadier (Macrourus berglax), thorny skate (Amblyraja radiata) and white hake (Urophycis tenuis) from the Spanish Spring survey are presented. Abundance and biomass were estimated for roughhead grenadier and thorny skate for the period 1997-2013 and for white hake for the period 2001-2013. The length distribution is presented as numbers per haul stratified mean catches for the last five years (2009-2013). The roughhead grenadier indices show no trend during the entire period, reaching a maximum in 2004 - 2006 and afterwards stabilised at levels slightly higher than in the early years. Thorny skate indices follow a large oscillating trend, dropping in 2007 and being since then more or less stables at a low level. White hake biomass index was highest in 2001 and showed an overall decreasing trend since then to 2008, reaching almost the level of 2002 in 2013, although at very low levels compared with the 2001 one. A small recruitment event was detected in 2004 and in 2013, with individuals between 16 - 26 cm.