Wetenschap - 15 april 2020

Studying seals from a ‘flying limousine’

tekst:
Tessa Louwerens

How can you do science while keeping to the 1.5 metres rule? Researcher Sophie Brasseur counted seals from an extra large airplane. ‘Like sitting on the back seat of a limousine.’

Brasseur took photos from a plane of the thousands of seals on the sandbanks between Terschelling and Vlieland. Photo: Sophie Brasseur


Each year, Sophie Brasseur, a researcher at Wageningen Marine Research, and her colleagues count seals from above the Wadden islands. Brasseur: ‘At this time of year the grey seals are moulting and they come on land more, which makes them easier to count. Because there are so many seals, we take photos from the air and count them later at our leisure on a large screen.’
As of 1 April, people sitting in an airplane also have to keep 1.5 metres apart. This was not possible in the usual research plane so the pilot arranged a larger plane so that the first count of the year could still go ahead. ‘It took a bit of getting used to,’ says Brasseur. ‘Normally there are several of us researchers piled in together in the small plane. Now there was no one except me right at the back and the pilot at the front. It was like a flying limousine.’

Less quiet than expected
Brasseur flew over the sandbanks in the Wadden Sea and along the islands’ North Sea beaches in fine weather on Sunday 5 April. ‘It wasn’t as quiet as I’d expected on the beaches given the coronavirus measures. I had hoped there would be a lot of seals on the beach because of the lack of people but that wasn’t the case. There were even cars driving on the beach. The worst was Ameland, where we counted 17 cars in short succession.’

En masse on the sandbanks
However, the Wadden Sea marinas were deserted and there were hardly any boats on even the busiest shipping route between Vlieland and Terschelling. ‘That might have been because of lower visitor numbers or because of the nice weather,’ says Brasseur. ‘But the seals had gathered en masse on the sandbanks. The coronavirus measures are probably fantastic for the animals living in the Wadden Sea.’ The survey results are now being processed. Brasseur is doing that at her home on Texel.