Marine

Journal article on “Evaluating the effectiveness of a seasonal spawning area closure” published

August 17, 2015 by Marine Scotland Communications No Comments | Category Marine Directorate general, Marine Directorate Science

A study into measures introduced over a decade ago to protect spawning cod in the Firth of Clyde by researchers from the University of Glasgow and Marine Scotland Science has found no evidence that it had led to local recovery of cod numbers by 2010. The study, published in the ICES Journal of Marine Science, compared data on the number of adult fish regularly found in the Clyde and compared it to data on the two other sub-populations of cod off the west coast of Scotland. The annual closure of the spawning ground was introduced in March 2001 to allow cod to reproduce without being caught by trawlers, while still allowing the targeting of scampi and scallops, in the greater part of the area. By the time of closure cod numbers were already very low in the west of Scotland stock.

Before the closure there was a clear seasonal peak in fishing effort, with high catch rates, corresponding to the spawning time of cod in this area but this was stopped by the closure. As such the spawning closure was justified on the basis that it did reduce targeted fishing effort on spawning cod, and prevented displaced fishing effort from an Irish Sea closure. Nevertheless, total mortality on cod remained high. While we don’t know the full reasons preventing the Clyde cod recovery, the study concludes that such closures are generally more successful when implemented before stocks have declined to low levels, and the Scottish Government welcomes this research which will help to inform our next steps in tackling this challenge.

Further Information

• Glasgow University Press release
• Marine Scotland Science

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