Yearly stranding reports

As part of the implementation of the Royal Decree on marine species protection in the Belgian national waters, the institute produces annual reports on observations and strandings of marine mammals in Belgium. These reports are available in Dutch and French on this web page (previous reports only in Dutch). Printed copies can be requested at

Report of 2017

The newest marine mammal report presents an overview of marine mammals and remarkable fish in Belgium in 2017. It also focusses on the causes of death of beached animals and the revalidation of animals that were taken into care, and contains opinion pieces about Arctic climate refugees and the grey seal in our coastal waters.

In 2017, the number of stranded harbour porpoises more or less equalled the average of the past 10 years. Nearly 60% of the 93 harbour porpoises that stranded along the Belgian coast in 2017, died due to predation by the grey seal or incidental catch.

Two observations of white-beaked dolphins were documented in 2017, while bottle-nosed dolphins were reported more regularly. Also one deceased individual of both these species washed ashore. A dead minke whale floated through Belgian waters, and eventually washed ashore in the Netherlands.

With 10 common seals, 8 grey seals and 19 non-identified seals, the number of dead or dying seals exhibits a rising trend. Additionally, 22 common and 6 grey seals were taken into temporary care at SEALIFE Blankenberge. A remarkably high number of seals that had been injured by fishing hooks was observed in the port of Nieuwpoort.

The bowhead whale that stayed off the coastal towns of Ostend and Middelkerke on 31 March and 1 April was the first ever to be reported for the entire North Sea. Barely a year after the stranding of a narwhal, the sighting of this animal, of a species that inhabits very northerly waters, instigates a lot of speculation about the effects of climate change on marine life in the Arctic, and perhaps at a global scale.

Report of 2016

The newest marine mammal report presents an overview of marine mammals and remarkable fish washed ashore in Belgium in 2016. It also focuses on the causes of death, revalidation and release of animals that were taken into care, and briefly introduces the research on the influence of offshore windmill parks on the harbour porpoise.

The most remarkable stranding of 2016 undoubtedly concerned a narwhal, an Arctic animal that was last observed in the North Sea almost 70 years ago. Also two humpback whales were seen, and a basking shark and two ocean sunfishes washed ashore.

With 137 animals, the number of harbour porpoises that washed ashore was again very high. The major causes of death were incidental catch in fishing gear and predation by grey seals. Harbour porpoises were shown to avoid an area up to a distance of 20 km during the construction of offshore wind turbines.

White-beaked dolphins were reported on one day only, in contrast to bottlenose dolphins that were regular and prominent guests again. In April a severely decomposed male bottlenose dolphin washed ashore, followed by a heavily decomposed dolphin along the Scheldt a few days later. The species could not be determined anymore.

The number of strandings of dead and dying seals remained similar to previous years: six harbour seals, 11 grey and 12 unidentified seals. SEA LIFE Blankenberge took care of record high numbers: 15 grey and 24 common seals, including an albino animal. No less than 12 grey and 20 common seals could be returned to the wild after revalidation.