Seals on the move: Research reveals key data for offshore development and international ecology

(Press-News.org)

New research led by the University of St Andrews has created the most comprehensive maps to date of the distribution of grey and harbour seals in Northwest Europe, encompassing the majority of seal populations on the continental shelf.

The research, published today (16th Dec) in Journal of Applied Ecology, combined GPS data from over 840 seals tracked in the waters of seven European countries (UK, Ireland, France, Belgium, Netherlands, Germany, and Denmark) with counts of seals hauled out on land to generate at-sea density maps for both species.

The study, led by the Sea Mammal Research Unit   (SMRU) alongside a large team of researchers from nine different institutions across Europe, found that seals routinely cross international borders while foraging at sea. However, such transboundary movements are often overlooked in environmental impact assessments and conservation management.

Lead author Dr Matt Carter from SMRU, said: “We wanted to create a set of resources that would allow offshore energy developers, conservation managers, and ecologists to quantify how many seals are likely to be in a given area at any one time, and understand where these seals are likely to be coming from.”

Seals are protected species in the UK and European Union, and any offshore activity, such as the construction of windfarms, requires developers to consider potential impacts to them and sites designated for their protection. However, existing distribution maps are usually restricted to specific countries, and do not account for transboundary movements.

Dr Carter added: “The new maps, which are freely available online, allow users to plot the distribution of seals from each of the countries in the study area, and, for the UK, apportion at-sea density to the different constituent nations and dependencies as well as Seal Monitoring Units and Special Areas of Conservation. This will allow future conservation and management strategies to have a better understanding of how potential impacts at sea might relate to population trends observed on land. In analysing the data, we found that overlooking transboundary distribution can under-represent seal numbers by a factor of ten in some areas.”

Dr Debbie Russell from the University of St Andrews SMRU who co led the study, said: “This important resource represents over a third of world’s grey seals and the majority of Europe’s harbour seals. It’s generation was made possible through the engagement of all the researchers in the area that track seals, and the efforts of many groups and individuals who have monitored seal numbers along upwards of 40,000 kms of coastline.”

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