According to experts, the population of seals in the Wadden Sea has decreased by twelve percent compared to the previous year. A total of 23,652 harbor seals were sighted across the area in August – the lowest number since 2011, the Wadden Sea Secretariat announced on Tuesday. Surveys of this seal species, which is the most well-known in the Wadden Sea, are carried out in June and during the moulting period in August, when the seals can be observed more frequently on the sandbanks at low tide.

“Around ten percent could be natural fluctuations,” said a spokeswoman for the Secretariat. The hot summer may have led to fewer animals lying on the sandbanks. “We are not alarmed,” she emphasized. However, one would observe very closely how the population changes. A limit to growth may have been reached. Increasing ship traffic could also be a criterion.

Declining population throughout the Wadden Sea

The counting results from June had shown a decrease in offspring by 22 percent, while 8514 young animals were counted in the Wadden Sea. The year before it was 10,903. Declining numbers were observed in all parts of the Wadden Sea: in Denmark the number of young animals fell by 18 percent, in Schleswig-Holstein by 25 percent, in Lower Saxony and Hamburg by 17 percent.

At the annual molting in August, the number of seals counted also decreased in almost all areas. An increase was only recorded in Denmark. In Schleswig-Holstein 8384 seals were counted (-5 percent) and on Helgoland 98 seals (-16). In Lower Saxony and Hamburg, the number fell significantly to 4822 (-42). In this region, changes in survey methods in part of the area may have resulted in fewer animals being counted, the statement said. However, this change can only partially explain the decline in numbers.

The stock is possibly approaching the capacity limit of the Wadden Sea and is being constrained by limited resources such as food.

Seals are considered an important bioindicator for the Wadden Sea habitat. The number and state of health also allow conclusions to be drawn about the water quality and the fish population.