In previous years, ICES advice on mackerel has been based on the management plan agreed by Norway, Faroe Islands, and European Union (EU). This year, however, ICES was unable to give advice in relation to the plan as there was no accepted analytical assessment for mackerel.
"ICES is trying to produce useful advice while still being precautionary. All indications are that the mackerel stock has increased in recent years despite catches in excess of those advised by ICES. There are technical issues with the input data for the assessment used until 2012 and continuing to use it would imply catch advice markedly lower than current catches," explains ACOM Vice-Chair John Simmonds.
"In the short term ICES is advising no rise in landings for one year to allow scientific work to be completed. ICES is already developing alternative modelling approaches to take account of these data issues," Simmonds continues.
Today's advice based on recent landings is seen as an interim measure. ICES will attempt to incorporate more stock size information into an appropriate assessment model as part of a benchmark process in 2014.
Mackerel stock on the rise
Data from recent years indicate that mackerel stocks have expanded north-westwards to spawn and for the summer feeding migration. This change in distribution likely reflects an increased stock size coupled with changes in the physical environment and in the zooplankton concentration and distribution.
This has had an effect on fisheries. Traditionally, the fishing areas with higher mackerel catches have been in the northern North Sea, around the Shetland Islands, and off the west coast of Scotland and Ireland and extending into Faroese waters to the west. The southern fishery off Spain's northern coast has also accounted for significant catches. In recent years though, substantial catches have been made in Icelandic waters, areas where almost none were reported prior to 2008. In 2012, catches in this area constituted approximately half of the total reported landings. Those made from Greenland were reported for the first time in 2011, and have increased in 2012.
The advice on Northeast Atlantic mackerel is available on the ICES website.