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What’s up with all the whale strandings in the Netherlands lately?

Posted on 13-12-2017 by Julie de Graaf

An interview with the Naturalis mammals collection curator and dissection team coordinator Pepijn Kamminga.

Last week, a big sperm whale stranded and died on the beach in Zeeland (South-Holland). A few weeks earlier, the body of a dead minke whale was found floating in the sea near Friesland. Naturalis collection curator and coordinator of the dissection team Pepijn Kamminga brings us up to speed about the recent whale strandings.

What happened to these whales? And why do they die near the Dutch coast?
“Well, the minke whale could have died at a number of places really. Its body could have floated here on a current. It was already dead for several weeks when it was discovered. The sperm whale, however, probably took a wrong exit and got stuck in the North Sea by accident. The North Sea is too shallow for sperm whales; with a depth of just 200 meters, it is very likely that their echolocation doesn’t function properly and they get lost. This sperm whale wasn’t completely healthy either, Utrecht University discovered an intestinal infection.”

Do whales often strand on the Dutch coast, or is it a fluke that two big dead whales are found within weeks of each other?
“It doesn’t happen that often, but it is the season for whale strandings. From september on, whales migrate from northern seas to southern waters. And every year at least one of them strands on our shores. We’re never happy about a dead whale, but in the bigger scheme of things, it is a good sign for our biodiversity that we are spotting more and more of them in the North Sea.

Apart from defective echolocation, what are the most frequent causes of death?
"Mostly collisions with ships. We see a lot of dead whales with bruises and broken ribs. A few years ago, a ship even entered a harbour with a dead whale still on its bow. In the United States researchers are plotting the migration routes of whales so that ships can avoid them. But here in our little North Sea there is less room to avoid them and collisions happen."

When and why does Naturalis get involved when a whale is stranded?
"We only get a call when a stranded whale has died. I then gather up the team and we basically start a giant dissection. We clean up the remains and gather the skeleton, or parts of it, for our collection. Researchers from all over the world can use our whale collection to perform DNA and morphological research. We often work together with Utrecht University and Wageningen Marine Research. They look at the cause of death, stomach content and take samples when the whale is still in one piece. We assist them and then it is our turn to decide what parts we want to keep and collect." 

And then?
"Well, then it is time to start cutting. We remove the bones and make sure the remains are cut up for waste processing. Because we’re there with quite a big team, we don’t want to leave with only one vertebra. Most of the time we go for the skeleton or the skull, or both."

What would surprise people about your work?
"First of all: the smell… And also the amount of work it takes to dissect a whale. With eight people cutting, it takes three days to take out the skeleton of a sperm whale, and then we still have to clean up the remains. Back at Naturalis, it will take months to clean the bones completely and add them to our collection."

So it is - wait for it - a whale of a job. Thanks Pepijn!