Distribution and abundance of Norwegian spring-spawning herring during the spawning season in 2022

Abstract

Toktnummer 2022821 og 2022822

Distribution and abundance of Norwegian spring-spawning herring during the spawning season in 2022

During the period 14-27th of February 2022 the spawning grounds of Norwegian spring-spawning herring from Møre (62º15ˊN) to Troms (71ºN) were covered acoustically by the commercial vessels MS Eros and MS Vendla. The estimated biomass was about 18 % lower, and the estimated total number was about 29 % lower this year compared to the last year’s survey. The uncertainty of the estimates in 2022 was approximately equal to last year. The surveyed population of NSS herring was dominated by the 2016 year class; 52 % in numbers and 46 % in biomass. The 2016 year class was reduced by 37 % in numbers from last year’s survey. Most of the spawning stock was found outside Lofoten and Vesterålen this year, further north and more concentrated than usual. The observed maturity indicates a bit later spawning compared to last year and like last year a more northern spawning than normal. As usual, the herring in the southern part of the spawning area were older than those found in the northern part. The estimates of relative abundance from the survey in 2022 are recommended to be used in this year’s ICES stock assessment of Norwegian spring-spawning herring.