Seal Count 2012: more seals than ever before in the Wadden Sea

In 2012 the greatest number of Harbour and Grey seals since the beginning of the Wadden Sea-wide seal count in 1975 has been counted, informs the Trilateral Seal Expert group, consisting of experts from the Netherlands, Germany and Denmark. This year’s results mark the ninth year of a continuous growth of the seal population in the trilateral Wadden Sea area since the great seal epidemic in 2002, in which more than half of the population died.

The total count of 26,220 Harbour seals in the Wadden Sea was composed of 3,966 (570 pups) in Denmark, 9,268 (3,247) in Schleswig-Holstein, 6,457 (1,977) in Lower Saxony and Hamburg, and 6,529 (1,473) in the Netherlands. This is an increase of almost 11% compared to 2011. The number of pups born in 2012 has also grown, but less significantly. During the peak in pupping in June, 7,267 pups were counted, which is 3% more than last year. “We are again excited about this year’s continued growth, a sign that our common efforts to protect the seals and their habitats are effective”, - says Jens Enemark, head of the Common Wadden Sea Secretariat in Wilhelmshaven, which is responsible for the seal monitoring coordination.  – “Since the inscription of the Dutch-German Wadden Sea into UNESCO World Heritage list in 2009, we have an obligation toward the world community to take great care of this unique nature area”.

The general increase is however unevenly distributed. It spans from 10% growth in Schleswig-Holstein to 37% in Lower Saxony and Hamburg, whereas the seal number in the Netherlands decreased by 12%. This clearly demonstrates the value of coordinated counts that provide a single most accurate estimate of the entire Wadden Sea seal population within a few days in August. Since seals are very mobile, migration within the Wadden Sea and into adjacent waters is seen as a potential reason for observed differences.

The Harbour seals are counted when the majority of the animals rest on sandbanks during low tide, while some are in the water. It is estimated that the total number of seals counted, corrected with those in the water, is around 38,500.

The number of grey seals for the entire Wadden Sea has also increased. During the moult in March-April, 4,039 animals were counted, which is equivalent to a growth of 22% compared to 2011. Although pup numbers increased at the same time, it is expected that the growing population is partly based on immigration of the animals from UK waters.

Grey seals have a different life cycle than the Harbour seals. The pups are born in mid-winter with a characteristic white fur. Like the Harbour seals, the pups suckle for 3-4 weeks, after which the pups may stay ashore for up to a month. As they stay on sandbanks they can be washed off by storms or flee into the water caused by disturbance. If this happens within the first weeks of their life, a pup can lose contact with its mother.

Source: CWSS
Photo: (c) Klaus Janke