Eastern-western Baltic cod: Improved management based on stock discrimination of eastern and western Baltic cod (Øst-Vesttorsk) (38989)

Description

Theaim of this project was to improve the management of western Baltic cod byincorporating stock identification routines in order to discriminate betweeneastern and western Baltic cod stocks. 
Inrecent years evidence from fishery patterns and otolith structures haveindicated an increasing degree of mixing between the two cod stocks which upuntil 2013 were managed as two separate stocks. Changes in fishing pressure andpatterns would therefore result in a risk for local depletion of the smallerwestern stock. 
Stockidentification methods were based on established approaches using geneticdiscrimination and otolith shape analysis, and improved by linking thesemethods. This method provides a tool to estimate the degree of stock mixingusing the existing otolith archives. This approach documented an increase ofeastern Baltic cod from 30% to > 80% in the eastern part of the westernBaltic Sea management area. As a consequence of this stock mixing, a newprocedure incorporating stock mixing on an annual basis was set in place in, withthe aim to improve stock exploitation and reduce the risk of local depletion.The knowledge gained also influenced recent management regulations,particularly a prolongation of spawning closer of the fishery in 2016.
The project was coordinated by Centre for Environment, Fisheries & Aquaculture Science, UK.
The project was funded by the Danish Minestry of Food, Agriculture and Fisheries and the European Fisheries Fund (EFF).
StatusFinished
Effective start/end date27/06/201129/03/2013

Keywords

  • Research area: Marine Populations and Ecosystem Dynamics --- Research area: Marine Living Resources --- Research area: Population Genetics --- Research area: Fisheries Management