Norway’s Institute of Marine Research (IMR) has advised quotas for mackerel that are increased by 22% and for blue whiting that are up by 77%, while its advice on Atlanto-Scandian herring is up by 104%.
New research methodologies have resulted in an upward adjustment, while harvest regulations also allow for both a higher fish mortality rate and an increase in quotas when the population is estimated to be higher.
IMR advises a 646,075 tonne quota for Atlanto-Scandian herring, more than double the amount it advised for 2016, and a 955,302 tonne recommendation for mackerel in 2017. Advice on blue whiting is for a 1,342,330 tonne quota.
‘Blue whiting recruitment has been good for the last five or six years. The stock has risen steadily and evenly since 2010, and is expected to be around 6.80 million tonnes in 2017,’ said Katja Enberg who heads the IMR’s Norwegian Sea research and advice programme and is also currently leading an ICES working group on that provides advice on pelagic stocks.
‘Quota advice reflects the positive trend on blue whiting since 2010, especially the large 2013 and 2014 cohorts. The research cruise index is also significantly higher in 2016 than in 2015, and the mortality rate for MSY has been adjusted upwards, all of which contributes to this quota advice.’
She said that mackerel population growth has levelled off in the last two years, while the mackerel stock stands are nearly 4.60 million tonnes.
‘The three stocks are in good condition, although the trends are slightly different,’ Katja Enberg said, recalling that changes in quotas from one year to reflect the uncertainty associated with stock assessment.
‘This year we have implemented revised methodologies for both herring and blue whiting, and all three species are now calculated using modern statistical calculation. The plans call for management and reference points for herring to be reassessed during the year. We hope this will reduce uncertainty and variations in the estimates from year to year.’
