More reports of sea mammals in trouble; Reason unclear

SOS Dolfijn, the Dutch organization that helps stranded and hurt dolphins, seals, and whales, receives more reports every year about sea mammals in trouble. The organization cannot point to a single, clear cause for the rise, NU.nl reports.

SOS Dolfijn first started keeping track of the number of reports it received in 2010. That year, there were 20, director Annemarie van den Berg told the newspaper. In recent years, the organization received around 200 reports annually. “This year, we have already reached 150.”

There are various possible factors behind the increase in reports of sea mammals in trouble. “SOS Dolfijn has become better known and more accessible,” Van den Berg said. “People can find us very easily, and if they find something, we are called more quickly.”

She added that it's very difficult to say what other factors are at play. “When we receive a report, the animal is often sick, weak, or emaciated,” Van den Berg explained. That could be because the animal was already weakened, was then rejected from the population, and washed ashore. But it could also be that the animal was temporarily deafened by noise pollution, for example, and then weakened. That is difficult to determine.”

Biologist Lonneke IJsseldijk of Utrecht University confirmed the complexities around determining why there are more animals in trouble. In some incidents, such as a collision, there is often an injury that is easy to identify. But when it comes to larger factors, like climate change and offshore windfarm construction, there are no simple indications. “Climate change is often an indirect cause,” IJSseldijk told NU.nl. “For example, it can cause a reduction in prey species. But if an emaciated dolphin washes ashore, it is difficult to link that to that. There may also be other causes.”

“Where 30 years ago there were one or two main threats, they can no longer be counted on one hand,” the biologist continued. “That is the biggest concern. And I think it is dangerous that we cannot investigate that concern because we simply do not know very well what that combination of causes does to different animals.”

Information from organizations like SOS Dolfijn is therefore essential, IJsseldijk said. “The knowledge that is gained there is almost impossible to get anywhere else.”