Seabird danger from overfishing in post-Brexit seas
NEW research from the RSPB shows that British seabird populations could be adversely affected by the amount of sand-eels caught in the North Sea by industrial fisheries, the charity has revealed.
The study suggests there is a link between the number of sand-eels caught by fishermen and the breeding success of Kittiwakes, with higher-intensity fishing leading to lower numbers of chicks being produced. This small gull species is Red-listed as a Bird of Conservation Concern in the UK.
Kittiwake, Bempton Cliffs RSPB, East Yorkshire, (Photo: John Dickenson.)
Sand-eels provide a vital food source for breeding seabirds in the North Sea, but these small fish are also the target of an industrial fishery conducted mainly by Denmark. Tracking data of individual breeding Kittiwakes by RSPB scientists indicates that the most productive sand-eel fishing grounds, located in an area known as Dogger Bank, overlap with foraging areas of Kittiwakes from eastern English colonies, raising the prospect that the fishery could adversely affect the birds' populations. This highlights the importance of continuing to work with other countries on fisheries management after leaving the European Union.
Dogger Bank is the largest sandbank in the North Sea, straddling the waters of the UK (about 100 miles off the Yorkshire coast), The Netherlands and Germany, and supporting a high density of sand-eels.
The RSPB's Principal Conservation Scientist, Dr Mark Bolton, said: "Using small tracking devices known as GPS tags, we followed individual Kittiwakes from colonies at Filey and Flamborough in Yorkshire to see where they went to feed during the breeding season. We found that they travelled much further from the coast than we had previously realised and were often actually going all the way to Dogger Bank to catch sand-eels for themselves and their chicks. This added up to more than a 125-mile round trip each time."
Kittiwake, Seahouses, Northumberland, (Photo: Graham Joyce).
Using data collected between 1986 and 2014, the RSPB found that higher Kittiwake breeding success at colonies was correlated with lower sand-eel fishing intensity. This suggests that, at times over the last 30 years, particularly in the early 2000s when catches were much larger, the fishing levels may have been high enough to reduce the gulls' breeding success. Rising sea temperatures due to climate change also threaten sand-eels, so Kittiwake food supplies could be affected by both local and large-scale processes.
Dr Euan Dunn, the RSPB's Marine Policy Specialist, commented: "Future management of the sand-eel fishery needs to ensure that the intensity of exploitation on Dogger Bank is sustainable. If our internationally important populations of seabirds are going to cope with climate change, then we need to make sure industrial fisheries are not adding to their problems.
"This is an example of why fisheries policy is vital to the health of our seas. As we leave the EU, we will need to replace EU policies with UK ones that protect our marine wildlife. We look forward to working with our new Secretary of State, Michael Gove, to help save the UK's seabirds by ensuring that our government continues to work with the other European countries that fish the North Sea after Brexit. Our thinking must be as joined up as the seas on which we all rely."
Reference
Carroll, M J, Bolton, M, Owen, E, Anderson, G Q A, Mackley, E K, Dunn, E K, and Furness, E W. 2017. Kittiwake breeding success in the southern North Sea correlates with prior sandeel fishing mortality. Aquatic Conservation: Marine and Freshwater Ecosystems Early view https://doi.org/10.1002/aqc.2780.
Kittiwake, Bempton Cliffs RSPB, East Yorkshire, (Photo: Gordon Bowes).
