Some 36 harbour porpoises, 72 seals and a young minke whale washed up on the Belgian coast in 2024, said the Royal Belgian Institute of Natural Sciences in its annual report on marine mammals published on Monday.
The number of stranded porpoises continues the downward trend observed since 2017. The year 2024 was the second lowest in terms of strandings over the last 22 years, after 2023 (26 strandings). The reasons for this decrease remain unclear, according to the Institute.
The number of porpoises observed in Belgian waters in 2024 was relatively low, with just 5,200 individuals last April, compared to three to four times that number in some peak years. The species is thought to be particularly sensitive to disturbances caused by shipping, even at a distance.
Conversely, the number of seals found dead along Belgian beaches has increased. In 2024, 72 dead seals were reported by beach attendants, the second highest number in the last 30 years, after 2021. This increase is thought to be due to the growth of seal populations in neighbouring countries.
A young minke whale also washed up in Ostend on 13 May 2024. The animal, which was very young, is believed to have lost its mother and died of starvation, according to the Institute.
A dead marine mammal is only left in place if it is a common species, in an advanced state of decomposition and unlikely to generate repeated reports, which is not the case in summer or in busy areas, the organisation explained.
The Institute of Natural Sciences emphasised that, apart from porpoises, the presence of other cetaceans remains rare in our waters. However, in 2024, one dead and two live humpback whales, two live minke whales, several bottlenose dolphins, one common dolphin and a group of white-beaked dolphins were observed off the Belgian coast.
