Wetenschap - 30 april 2015

Searching for porpoises

Rob Ramaker

Who? Mardik Leopold, DLO researcher at Imares
What? Discovered that there are currently no porpoises swimming off the Dutch coast, for the first time in decades.
Where are they? Elsewhere in the North Sea but no-one knows where exactly

How did you find out the porpoises were gone?
‘We dissect porpoises that have been washed ashore for the Ministry van Economic Affairs. Since we started in 2006, we’ve been getting more and more of them. Last year, we had a warehouse full of dead porpoises so we agreed to just examine the 50 “best” porpoises. The ink was barely dry when they suddenly stopped being washed up altogether.’

Interesting to see that porpoises can be so mystifying?
‘Yes, we stand on the beach, look at the sea and think we understand them. Then nature makes a move and you suddenly get a break in the trend. It forces you to face the facts again. The sea for a porpoise is so much bigger than the bit we see. If conditions are not so good here or better elsewhere, they just leave.’

So time for a new study?
‘If only it were that simple. New research is very expensive. There is money for one so-called plane count. We want to bring that forward to find out where the porpoises have got to.’