Yellowtail flounder, redfish (Sebastes spp.) and witch flounder indices from the Spanish Survey conducted in Divisions 3NO of the NAFO Regulatory Area

Since 1995, Spain carries out a spring stratified random bottom trawl survey in Div. 3NO of the NAFO Regulatory Area. Total mean catches, biomass and mean numbers for yellowtail flounder (Limanda ferruginea) are presented for the period 1995-2019, for redfish (Sebastes spp.) for the period 1997-2019 and for witch flounder (Glyptocephalus cynoglossus) for the period 2002-2019. Detailed indices are presented from 2015. Yellowtail flounder indices do not show a clear trend between 1999 and 2016. The 2017-2019 values were lower than the 1998 one. There has not been good recruitment in recent years. Redfish indices oscillate greatly over time, probably because the gear does not sample adequately aggregating pelagic species. There was a sharp increase in 2009 and since then until 2015, biomass fluctuated maintaining higher values than before 2009. In 2016 biomass dropped and increase again in 2017-2019 to or below the 2012 level. The 3N division comprises around the 90% of the total biomass in the last years. Good year classes have not been registered recently. Abundance by Division shows since 2002 shows the same trend of the biomass; most of the abundance corresponds to Division 3N. Witch flounder is very scarce and its indices fluctuated throughout the series reaching a low level in 2014 and 2018, with an increasing trend in the middle time. The 2019 value is the lowest of the series, being less than 50% of 2014 value. Recruitment was quite good at the beginning of the series but poor in recent years