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Trawl haul with mackerel and herring
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Record high mackerel estimate

After the ecosystem survey in the Norwegian Sea and surrounding waters this sumer, the scientists at the IMR give a record high abundance estimate of the Northeast Atlantic mackerel stock.  

The international coordinated ecosystem survey in the Norwegian Sea and adjacent areas was performed in July and August 2013 by four vessels; two from Norway, while Iceland and Faroese were participating with one each.

The total swept area estimate of Northeast Atlantic mackerel was 8,8 million tonnes. The geographical coverage was 3,2 million square kilometers in the Nordic Seas from central part of the North Sea in the south to Bear Island in the north and from the Norwegian coast in east and to Irminger Sea in Greenland waters to the west.
The 2010 year class contributed to more than 20 % in number followed by abundant 2006, 2007 and 2011-year classes around 15 % each, respectively. The 2008 year class was also well represented in the catches, contributing with 12 % of the total numbers.

A standardized pelagic trawl swept area method has been developed and used to estimate a swept area abundance estimate of mackerel in the Nordic Seas in recent years. The swept area estimate is one of three different abundance indices available.The scientific method of abundance on mackerel is not yet accepted and will be evaluated in ICES in February 2014.
The ultimate goal is to get accepted and use this combined swept area estimate as an absolute/relative abundance index of spawning stock biomass (SSB) and possibly recruitment index, on an annual basis in the assessment of NEA mackerel after the NEA mackerel benchmark in February 2014.


Other results from the ecosystem survey:

  • The biomass estimate of Norwegian spring-spawning herring showed an increase compared to July and August 2012.
  • Young blue whiting (age 1 and 2 years) was well represented in the summer feeding areas.
  • The temperatures in the Nordic Seas are now close to the long-term average except for in the northern part of the Norwegian Sea with higher temperatures than the average temperature during the last 20 years.
  • The concentrations of zooplankton in the Nordic Seas increased from 6 g/m2 in 2012 up till 8,6 g/m2 in 2013.