Results for Greenland halibut, American plaice and Atlantic cod of the Spanish survey in NAFO Div. 3NO for the period 1997-2018

• Main Authors: González-Troncoso, D. (Diana), Garrido, I. (Irene), Gago-Fernández, A. (Ana), Román-Marcote, E. (Esther)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Centro Oceanográfico de Vigo 2019
• Subjects: Greenland; atlantic cod; Gadus morhua
• Online Access: http://hdl.handle.net/10508/15322

Greenland halibut (Reinhardtius hippoglossoides), American plaice (Hippoglossoides platessoides) and Atlantic cod (Gadus morhua) indices from the bottom trawl survey that Spain carries out in Spring since 1995 in Div. 3NO of the NAFO Regulatory Area are presented. Biomass, stratified mean catches and mean number per tow for the three species are presented since 1997, year in which the survey extended the depth strata. Mean catch per tow, length distribution and age distribution are presented for the last five years (2014-2018). Greenland halibut biomass and abundance estimates presented a decreasing trend since 1999, cut in 2007-2009 with a high increase. In 2011 the biomass drops under the 2008 value, being stable since then until 2014 with a slight increase in 2015-2018 comprising a big increase in 2017, reaching the maximum of the series. In last years it can be seen a presence of juveniles, mainly in 2004, but the greatest lengths have failed, although in 2009 there is a quite good presence of individuals of ages 6-7 and in 2010 between 5-7. In 2011-2018 the presence of all ages is poor, although in 2015-2016 an increase in the range of the length can be seen with regards to last years. For American plaice we can see a stable trend from 1999 to 2015, reaching a maximum of mean catch and number in 2006, and a severe decline since 2016. The greatest recruitment in the presented series occurred in 2004 and we can follow their mode along the years. No good recruitments were seen since then. The 2016 ALK for American plaice was not sexed. The 2017 and 2018 ALKs for American plaice are not available yet, so the 2016 ALK was used. In last years the level of all the ages is low. For Atlantic cod, it can be seen a low biomass until 2008, being higher and variable since then, reaching a historical maximum in 2014. From 2015, biomass decreased reaching in 2018 poor values at the level of the 2006 biomass. In 2007-2008 the youngest length classes were much over the rest of the length classes. With the 2006 cohort the ...