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SOS Dolfijn – Rescue & Rehabilitation of Cetaceans in the Netherlands

Small cetaceans stranded alive on the Dutch coast have been rehabilitated at the Dolfinarium in Harderwijk since 1967.

In early years, animals rescued were treated in side pools of the marine mammal park. In 1991 a separate isolated facility was built, designed and equipped to rescue and rehabilitate stranded cetaceans. Primary objective of the centre is to reduce suffering, rehabilitate and release the animal in its natural environment. Education and research are further important objectives. Since 2004 the charity foundation SOS Dolphin supports and supervises the centre’s efforts. Animals stranded on German, Belgian and French shores have also been brought to the rehabilitation centre.


Over the past 44 years, the rehabilitation centre has been involved in the rescue of 170 animals. 143 of these (84%) were harbour porpoises (Phocoena phocoena), the most common cetacean in the North Sea and an endemic species to coastal and shelf waters of the Netherlands. Stranded animals of 6 other species have also been treated in Harderwijk (table). 41 Harbour porpoises, 3 white-beaked dolphins and a striped dolphin have been released after rehabilitation.

​Harbour porpoises (Phocoena phocoena)


​White-beaked dolphins (Lagenorhynchus albirostris)


Striped dolphins (Stenella coeruleoalba)


​Atlantic white-sided dolphins (Lagenorhynchus acutus)


Sowerby’s beaked whales (Mesoplodon bidens)


​Common dolphin (Delphinus delphis)


Killer whale (Orcinus orca)


Stranding counts

From 1994 onwards a continuous increase in live stranded harbour porpoises on the Dutch coast has been observed. This trend correlates with total stranding counts (including dead animals). Surveys such as SCANS II and coastal sighting counts suggest there has been a redistribution of harbour porpoises in the North sea over the last 15 years, with a significant density increase in southern regions. Until early 1990’s an average of 1-2 animals a year was treated in Harderwijk. Over the last decade this increased to an average of about 8 animals.

Success rates

In addition to 41 releases, 15 rehabilitated harbour porpoises were declared non-releasable and were adopted in the collection of the Dolfinarium. The rehabilitation success rate over 44 years for harbour porpoises is 39%. From 1967 to 1997 success rates are between 10 and 20 %. Numbers of successfully rehabilitated animals over the past 10 years indicate that specialized facilities, developments in medical treatment and increased experience with veterinary and husbandry techniques effect increased success rates, presently more than 50%. No successful recovery of neonates (n=10) has been achieved. Rehabilitation of animals in this age class will no more be attempted until new insights in nutritional needs have been gained or new neonate feeding strategies have been developed.


The rehabilitation centre is designed with large windows for visitors to witness all husbandry and medical procedures. In 2005 an outdoor exhibit for non releasable harbour porpoises was opened at the Dolfinarium exposing the visiting public to this generally little known species. Education and increase of conservation awareness is achieved by offering information during guided tours, animal presentations, on-site displays and available educational material on paper and on the website. SOS Dolfijn is working hard to develop educational projects visiting schools and events, informing the public about harbour porpoises, their natural environment and the threats facing the animals. A special feature in educational activities is a workshop for kids in which they learn how to rescue a stranded dolphin and take care of it.


The outdoor exhibit and rehabilitation centre also facilitate unique opportunities for scientific activities. Research in the past and present focuses on acoustics, pathology and veterinary studies. The SOS Dolfijn foundation cooperates closely with the Erasmus University in Rotterdam and the Forschungs- und Technologiezentrum Westküste in Büsum, Germany to realize research projects. Consequently SOS Dolfijn not merely aids stranded cetaceans but fulfils a more sophisticated role in conservation problems.


The Charity foundation SOS Dolphin is dependent on donations and sponsoring. The rehabilitation process is an expensive process. Educational projects and scientific research also require funding. Therefore the organisation intensifies efforts to raise funds and sponsorships and needs to put large effort in becoming a mature charity. This includes good pr-, communication and marketing strategies. SOS Dolfijn has great potential as an NGO that can contribute to environmental protection and conservation, especially for the harbour porpoise in the North sea.


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