Northern Shrimp (Pandalus borealis) on Flemish Cap Surveys 2020

• Main Author: Casas-Sánchez, J.M. (José Miguel)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Centro Oceanográfico de Vigo 2020
• Subjects: Lofoten; northern shrimp; Pandalus borealis
• Online Access: http://hdl.handle.net/10508/15315

A stratified random bottom trawl survey on Flemish Cap was carried out from June 24th to August 4th 2020. The area surveyed was extended up to depths of 800 fathoms (1450 meters) following the same procedures as in previous years. This year a total of 181 valid hauls were made by the vessel R/V Vizconde de Eza with the usual survey gear (Lofoten), 120 up to 730 meters depth. The surveyed area has properly prospected the 32 strata planned. The general indexes for shrimp were estimated taken into account the traditional swept area (strata 1-19, up to depths of 730 m.) and the total area surveyed (strata 1-34, up to depths of 1450 m.). As the last years the strata 26 and 27sited in the southeast of the bank with depths from 600 to 800 fathoms (1100- 1400 m.) will not be surveyed due to the presence in the bottoms of great quantities of mud and sponges. The results concerning shrimp are presented and compared to those from previous years of the same series. The total biomass index decreased 27%, breaking the upward trend of recent years. Despite the decrease in biomass the stock continue above Blim and it is from 2018 outside the collapse zone defined by the NAFO PA framework. The total and female biomass indexes were 6 734 t and 6 048 t respectively. As in previous years the youngest specimens (age 1, around 10 mm CL) barely appeared in the catches and the abundance at age 2 from the main gear increased around 19% from 2019. This increase at age 2 was very higher from the small bag attached on the cod-end where was recorded the second highest value in the survey series that it could confirm the upward trend in the recent recruitments initiated from 2014. However unlike 2019 the abundance at age 1 in the small mesh size bag attached on the cod-end was below average in the series. Considering the overall increasing trend of the stock from 2014 above Blim and the uncertainty about the future recruitments in the fishable stock the next years, Scientific Council agrees not to change the advice from last year and that ...