The biomass of mackerel has more than halved from 4.8 million tonnes in 2010 to 2.4 million tonnes in 2018. The quantity of new fish (recruits) entering the fishery was high in 2014, but the last 4 years the amount of new fish has been at a lower level.
The advice is therefore that the catches in 2019 should not exceed 318,403 tonnes. This is a reduction of 42 % from the 2018 advice of 550,948 tonnes. From ICES’ calculations a decline in the stock size was expected, because the total global catches once again in 2017/2018 were not sustainable. However, the downturn was greater than expected.
The large reduction of the advice is partly due to the fact that the catches in 2018 are 83 % higher than the advice from ICES, and the biomass of mackerel has become much smaller in recent years. Furthermore, there are fewer fish entering the fishery in recent years (from 2015). The latest tagging-recapture-data is the primary source indicating that the decline was larger than expected. ICES has set up a special working group to scrutinise this in January/February 2019.
The mackerel overwinter and spawn mainly west of the British Islands and visit the Nordic Oceans, including Greenland, to feed on plankton in the summer. Last spring was cold, which probably affected the north-western migration of the mackerel. Despite the smaller stock, the commercial fishery in East Greenland has maintained high catch rates in 2018, which may be due to increased efficiency of the Greenlandic fleet. This year’s Greenlandic surveys of pelagic fish and plankton are coordinated with other countries’ surveys of the total stock, which is spread throughout the North-East Atlantic.
The Greenlandic fleet has been fishing mackerel since 2011 (see Tabel 1).
For more information, please contact:
Senior researcher at Department of Fish and Shellfish Teunis Jansen on phone +45 21314997 or e-mail: email@example.com.