Biomass and length distribution for Roughhead grenadier, Thorny skate and White hake from the surveys conducted by Spain in NAFO 3NO

• Main Authors: González-Troncoso, D. (Diana), González-Iglesias, M.C. (María de la Concepción), Paz, X. (Xabier)
• Format: Report
• Language: English
• Published: Centro Oceanográfico de Vigo 2011
• Subjects: Hake; North Atlantic; Northeast Atlantic
• Online Access: http://hdl.handle.net/10508/629

Data for Roughhead grenadier (Macrourus berglax), Thorny skate (Amblyraja radiata) and Withe hake (Urophycis tenuis) from Spanish Spring survey are presented. The abundance and biomass were estimated for the period 1997-2010 for Roughhead grenadier and Thorny skate, and 2001-2010 for White hake. The length distribution was obtained and presented in numbers per haul stratified mean catches. The indices of Roughhead grenadier present no trend along the years until 2003, with an increase in years 2004-2006, mainly in 2004. In 2007 the biomass were on the level of 2003 value, with a slight increase since then broken with a new decrease in 2010, reaching again the level of 2007 values. Thorny skate indices starts the series with poor values, increasing constantly up to the historical maximum in 2000, following with a decrease since 2001 until 2003, increased for 2004-2006 and decreased again since 2007. For White hake, there were great catches in 2001, and a sharp decrease since then, broken in 2005 for an increase in the indices, but a new decrease reaching the minimum values of the series in 2008. In 2009 there was a sligth increase, reaching a value between the 2006 and the 2007 biomass, following with a new slight decrease in 2010. Only in 2004 we can see a good presence of individuals between 16 and 26 cm.