Results for Greenland halibut and American plaice of the Spanish survey in NAFO Div. 3NO for the period 1997-2009.

Abstract

Greenland halibut (Reinhardtius hippoglossoides) and American plaice (Hippoglossoides platessoides) indices from the bottom trawl survey that Spain carries out in Spring since 1995 in div. 3NO of the NAFO Regulatory Area are presented. Mean catch per town, biomass, length and age distributions for both species are presented since 1997, year in wich the survey extended the depth strata. In 2001, the R/V Vizconde de Eza replaced the C/V Playa de Menduíña in the execution of the survey. We present the transformed to the R/V Vizconde de Eza series for the period 1997-2000, and the original obtained data for the period 2002-2009. In 2001, there are data from the two vessels. Greenland halibut biomass and abundance estimates present a decreasing trend since 1999, cut in year 2007 with a sligth increase and a high increase in 2008 and 2009, reaching the highest value in 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. For American plaice we can see an increasing trend along the whole period, reaching a maximum of biomass and number in 2006, following by the 2008 indices, cut in 2009 with a decrease in the indices, remains in a lower value than in the year 2003. The greatest recruitment in the presented series occurred in 2004 and we can follow their mode along the years, reaching its maximum in 2008.