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, that runs up to 2019.

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.

On 14 October  2017 the culturing programme reached a milestone: the first Thornback rays were set free in the Oosterschelde (the Netherlands). And a batch of new eggs are developing in our hatchery. In this pilot project a total of ca. 1,000 Thornback rays will be released in the wild.

'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 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.
Photo: P. Verhoog Photo: P. Verhoog Under much media attention, the first Thornback rays were set free in the Oosterschelde on 14 October 2017. For example, RTL NieuwsJeugdjournaal and Omroep Zeeland were there.
Director Sportvisserij Nederland Joop Bonger and WWF-Netherlands director Kirsten Schuijt (photo left) and project leader Monique van de Water and Georgina Wiersma (Dutch Shark Society) (photo right) release a Thornback ray.

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 the project

Sportvisserij Nederland (16 October 2017)
Vismagazine (16 October 2017)
Reformatorisch Dagblad (16 October 2017)
RTL Nieuws (14 October 2017)
Jeugdjournaal (14 October 2017)
Omroep Zeeland (14 October 2017)
Provinciaalse Zeeuwse Courant (14 October 2017)
Trouw (12 October 2017)
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)
Zapp Your Planet (28 April 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)