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MartinHarper

With Brexit negotiations due to start next week, I want to put a spotlight on a few key issues that the new Government will have to address if it is to ensure that the new arrangements help rather than hinder its environmental ambitions.  Today, my colleague, Dr Euan Dunn offers his thoughts on the implications of new research on the relationship between fishing intensity and kittiwake breeding success.

Image courtesy of Anthony Griffiths.

There is a lively debate about how the UK should manage its fisheries once the UK leaves the European Union.  Seabirds, like fish, range freely across the borders of territorial waters, which poses the challenge of how best to ensure their needs are met in the post-Brexit settlement for the seas surrounding these islands.  

New research led by the RSPB, published in Aquatic Conservation: Marine and Freshwater Ecosystems (http://onlinelibrary.wiley.com/doi/10.1002/aqc.2780/full) throws this challenge into sharp relief.  It suggests a link between the amount of sandeels (a small shoaling fish that is vital prey for our internationally important seabird populations) caught by fishermen and the breeding success of kittiwakes (a small species of gull, currently red-listed in the UK), with higher intensity fishing leading to lower numbers of chicks being produced.

Image courtesy of Anthony Griffiths.

In the North Sea, sandeels provide a vital food source for breeding seabirds but are also the target of an industrial fishery conducted mainly by Denmark.  We found that individual kittiwakes electronically tracked from Yorkshire colonies at Filey and Flamborough ranged as far as the legendary Dogger Bank – a massive area of high sandeel density about 100 miles off the coast – to feed on sandeels for themselves and their chicks .    

The Dogger Bank is also a prime target area for the Danish fleet targeting sandeels for processing into fish meal and oil (now mainly destined for fish farming), raising the prospect that the fishery could adversely affect the birds' populations.   Denmark is alone among North Sea fishing countries in fishing commercially for sandeels in the North Sea, the UK fleet having no interest in this fish species.

Critically, our study found that higher kittiwake breeding success at colonies was correlated with lower sandeel fishing intensity, suggesting that, at times over the last 30 years, fishing levels may at times have been high enough to reduce the number of chicks raised by Yorkshire kittiwakes.

We need to ensure that the fishery on the Dogger Bank is sustainable both for the sandeels and the  seabirds that rely on them, especially in the face of climate change which we know is reducing sandeel abundance widely across the North Atlantic.  In a nutshell, we need to make sure that the sandeel fishery is not adding to the kittiwake’s problems, especially in a flagship site like Flamborough Head and Bempton Cliffs which host the largest surviving colony in the UK, making it outstandingly important for the potential future recovery of this species whose numbers have crashed nationwide. 

Clearly, the management of the Danish sandeel fishery and the fate of our seabirds are joined at the hip.  As we leave the EU, and anticipate the substitution of a UK fisheries policy for the EU’s Common Fisheries Policy, we look forward to working with our new Secretary of State, Michael Gove, to ensure that the UK government continues to reach out to Denmark and our other European fishing neighbours to maintain the health of our seas, interlinked as they are across national borders.  Our thinking must be as seamless as the seas on which we and our marine wildlife all rely.