Hatchery for project 'Sharks and rays back in the North Sea'

In June 2015 the project 'Sharks and rays back in the North Sea' was started, a collaboration in which the World Wildlife Fund takes the lead. Blue Linked acts as coordinator in fish culture for the project.

In our facilities of the Experimental hatchery (Utrecht), we keep egg capsules of sharks and rays for their development into juvenile fish. The egg capsules are donated by the Dolfinarium (Harderwijk, the Netherlands). On 1 May 2016 the first rays were born. Presently, about 300 Thornback rays (Raja clavata) are growing up in our hatchery. We carefully monitor their development for optimizing the circumstances in captivity.

Film left: vlogger Niels Roozen visits the hatchery (Zapp Your Planet - WWF action 'Gehaaid') (in Dutch).

'Sharks and rays back in the North Sea' is a project arising from the Sharks Action Plan that was erected by the World Wildlife Fund in the Netherlands, the Ministry of Economic Affairs and other partners. Aim of the project is: 'A North Sea with a restored ecosystem, with healthy populations of sharks and rays. This aim should be realized by the year 2030.' (preliminary translation)

We regularly publish news items about this project on our website. Please check our news page.

Egg capsules Thornback ray (Raja clavata) (photo: P. Verhoog).
Egg capsules Thornback ray (Raja clavata) (photo: P. Verhoog).
Thornback ray (Raja clavata), dorsal view (photo: P. Verhoog).
Thornback ray (Raja clavata), dorsal view (photo: P. Verhoog).
Thornback ray (Raja clavata), ventral view (photo: P. Verhoog).
Thornback ray (Raja clavata), ventral view (photo: P. Verhoog).
Attachment of a tag on a Thornback ray (photo: P. Verhoog).
Attachment of a tag on a Thornback ray (photo: P. Verhoog).
In July 2017 we started with tagging the rays in order to find out the ones that are most suitable. The fish react perfectly to this intervention: they eat well and don't show any signs of stress.

The tagging is carried out by Sportvisserij Nederland and meets all necessary permits. Aim of the tagging is to be able to monitor the rays in the wild.

Release of the rays is part of a pilot project to gain knowledge and experience about the possibility to reinforce fish populations in the wild with cultured specimen. Nowhere in the world similar research is carried out.
Oyster tanks in Yerseke (photo: P. Verhoog).
Oyster tanks in Yerseke (photo: P. Verhoog).
Prior to release of the Thornback rays this autumn in the Oosterschelde, the fish are allowed to adapt to outdoor circumstances. We are permitted to use oyster tanks in Yerseke to do so.

Just behind the dike, the rays swim in large basins and learn how to find their own food. Experiments in our hatchery have shown that the fish are perfectly capable to switch from frozen food to live prey. We expect that these preparations will help the rays to adapt easier to their life in the wild.

Partners in the project 'Sharks and rays back in the North Sea' are: World Wildlife Fund, The North Sea Foundation, Blue Linked, Sportvisserij Nederland, Dutch Shark Society.

WWF-Netherlands brochure about the project (in Dutch).

Media attention for sharks and rays

Swiss Public Radio (1 August 2017)
Omroep Zeeland (8 June 2017)
Het Parool (20 May 2017)
Television programme Tijd voor MAX (11:40-18:45) (3 May 2017)
Algemeen Dagblad (7 April 2017)

Television programme Vroege Vogels (first seven minutes) (4 April 2017)

Radio programme Vroege Vogels (07:20-09:30) (April 2015)