Seal Management

The Wadden Sea is a habitat for two seal species, the harbour seal and the grey seal. In the framework of the Trilateral Wadden Sea Cooperation, the conservation and management of the Wadden Sea seal populations is of high importance.

Seal Agreement

Under the umbrella of the Convention on the Conservation of Migratory Species of Wild Animals (Bonn Convention) a trilateral Seal Agreement has been concluded between Denmark, Germany and the Netherlands. The Agreement entered into force in 1991 with the aim to cooperate closely in achieving and maintaining a favourable conservation status for the harbour seal population of the Wadden Sea. It contains provisions, amongst others, on research and monitoring, taking, protection of habitats and awareness.

Seal Management Plan

According to Article IV of the Seal Agreement the Parties shall develop, on the basis of scientific knowledge, a conservation and management plan for the harbour seal population. This plan shall contain a comprehensive statement of actions which are or are to be undertaken by the Parties to achieve the goals of this Agreement.  The Parties shall keep the plan under review and amend it as may be required, taking into consideration, the results of scientific research in particular. The current Seal Management Plan (SMP), is valid for the period 2018-22. Since the grey seal population increased significantly in recent years and its requirements in terms of habitat protection are similar to the harbour seal, it has been included in the SMP. The objectives of the SMP are

  • to achieve and maintain a comprehensive conservation and management of both harbour and grey seal populations in the Wadden Sea through common, coordinated measures of the responsible authorities; and
  • to achieve and maintain a public understanding and awareness of the Wadden Sea seal populations as an entity and as an integrated part of the ecosystem

In accordance with the management plan, a.o. seal reserves have been established in the whole Wadden Sea, which are closed for all activities during the whelping and nursing period, basically from May to September.


The number of counted seals in the Wadden Sea is published every year under the aegis of the Trilateral Seal Expert Group (TSEG) in close cooperation with the Common Wadden Sea Secretariat (CWSS) and is available here.

Guidelines: Taking and Releasing of Seals (LD §60)

The ministers at the Leeuwarden Conference reaffirmed that the rehabilitation and release of seals is not necessary from the biological and wildlife management point of view and that the current level of taking, since the Seals Agreement has entered into force, is too high to be justified. Therefore, the ministers agreed to the following decisions:

LD § 60:
"To reduce the current number of seals taken from and released to the Wadden Sea to the lowest level possible by applying guidelines for handling diseased or weakened seals or evidently abandoned pups, and to release seals based on the precautionary approach, referred to under § 58 to be elaborated in the framework of the Conservation and Management Plan for the Wadden Sea Seal Population 1996-2000. The guidelines shall be based upon the following principles:
60.1 only a very limited number of persons in each country shall be authorized to decide on the handling of diseased or weakened seals or abandoned pups, including taking and releasing of the animals, and only such animals may be taken which have a chance to survive;
60.2 seals rehabilitated shall only be released into the wild on a permit granted by the national authority responsible for nature conservation and management if the following criteria are met:
(i) the seal has not been treated with specific groups of medicine to be further specified in the framework of the Conservation and Management Plan for the Seals which will be amended in 1995;
(ii) the seal does not carry pathogens alien to the wild population;
(iii) the seal is released as soon as possible but not later than half a year after it has been brought in for rehabilitation;
(iv) the seal has not been kept in a center where species of animals alien to the Wadden Sea, or marine mammals not resident in the Wadden Sea, are held;
60.3 seals should only be released in the areas where they were found;
60.4 seals shall not be transported between subregions of the Wadden Sea;
60.5 seals held in captivity shall, in principle, not be released into the wild;
60.6 seals born in captivity shall not be released into the wild; exemptions can only be allowed after the approval of the competent authorities."