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In the Netherlands stranded whales and dolphins are reported to the National Museum of Natural History that is situated in Leiden. Just as in Great Britain, we have in the Netherlands a history of collecting stranding records and stranded specimens that goes back for about a century.
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Photo © J. Krol
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On April 12th 2005 at 9.00 AM Dr Chris Smeenk, curator of mammals, got a phone call that a large whale was found stranded at Ameland. This is one of the Dutch Wadden Islands in the north of our country. In this digital age such reports are often sent with a few photographs and the first impression was that it was a Sowerby’s beaked whale (Mesoplodon bidens). This species strands on the Dutch coast every 5 to 10 years or so. However, on these first photographs the jawline of the stranded animal had a shape different from a Sowerby’s beaked whale, which has a relatively straight jawline. |
Photo © J. Krol
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So we started thinking, and ended up suspicious that this might be a Blainville’s beaked whale (Mesoplodon densirostris), which has a far more strongly arched rear half of the lower jaw.
This also gave us a problem. Blainville’s inhabit tropical and warm temperate waters. Only 7 previous strandings are known from Europe so we had to be very certain of our identification before telling this to the world. We sent the photographs to several colleagues and they confirmed our identification.
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Photo © J. Krol
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This morning (April 13) the animal was dissected by a team that included people from our institute, from Rotterdam University and from a local natural history museum. The animal was a female 435 cm long and she turned out to be pregnant, a 118 cm foetus was retrieved from the uterus. A complete necropsy was carried out. The skull will be put in an MRI machine to see if there is any evidence of damage by sonar (in recent years some sudden strandings of Mesoplodons are thought to have been caused by exposure of the animals to a new type of navy sonar). The skeleton and other remains of the animal will be transported to Leiden tonight. Tomorrow we will continue studying the animal, we will open the stomach to look for food remains. |
Photo © J. Krol |
The foetus will be kept as a specimen in alcohol after we take a few samples for toxicology studies. The skeleton will then be prepared.
Although field studies of this species have begun around the Bahamas, we still know very little about these animals and in fact know very little basic biology about the whole Mesoplodon genus. So the stranding of this pregnant whale will help us to acquire some new knowledge about sexual maturity, food choice and several other biological questions.
More information on this fascinating and rare stranding will be made available by Marjan over the next few days. |
The stomach did not contain any large otholiths, however it did contain a small piece of plastic.
Samples have been taken from the foetus for toxicology, virology and histopathology tests and MRI scans will be taken of the adult ovaries. The skeleton will be preserved so that it can be displayed to the public.
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Posted 13th April 2005
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