– strengthening the population and increasing knowledge about one of our endangered species.
Havet Hus has over 20 years of experience in breeding and releasing endangered species. For the past few years, a project aimed at conserving the thornback ray has been underway.
The Thornback ray is endangered in European waters. It is completely prohibited to catch and land it in Sweden. Due to its size, it easily becomes entangled in trawl nets, and already as young it is large enough to be accidentally caught. In addition to trawling, changes in habitats or a lack of food could be potential reasons for the decline of the Thornback ray. Like most rays, the Thornback ray has difficulty recovering as it takes a long time to reach sexual maturity, and its reproductive rate is considerably low.
At Havet Hus, we have several large Thornback rays that lay fertilized eggs. In January 2016, the first Thornback ray was born at Havet Hus, and since then, more have been born. In the summer of 2021, our first home-bred Thornback rays were released into the wild. The goal is to breed and release Thornback rays in the same way we do with the Small-spotted catsharks.
Release of thornback rays will take place in December 13th 2024 and in June 2025.
To improve the conditions for breeding, the large Tunnel aquarium will be renovated during the winter of 2025-26. This aquarium houses both the parent rays of those we release, as well as our largest Cod, Pollock, Atlantic sturgeon, and other large fish.
Aurena Laboratories in Karlstad has had a long-standing partnership with Havet Hus. Since 2011, the clean saltwater from Gullmarsfjorden has been used in some of the company’s products. The water is collected from a depth of 32 meters and filtered at Havet Hus before being collected by Aurena.
In November 2024, a deeper collaboration began, where Aurena supports Havet Hus’ efforts in preserving marine biodiversity. This includes providing support for breeding and releasing endangered species, as well as raising awareness about the importance of marine biodiversity.
In practical terms, this collaboration ensures that the crucial renovation of the Thornback ray aquarium can be carried out, strengthening the ability to release Thornback rays into Skagerrak.
Additionally, the collaboration allows Aurena’s customers to contribute to the preservation of marine biodiversity by supporting the projects at Havet Hus.
The conservation work for Thornback rays is part of Havet Hus’ ongoing partnership with the World wildlife fund Sweden (WWF).
WWF – Endangered Species Conservation | World Wildlife Fund
Thornback Ray being fed in the tunnel aquarium.
For more information about conservation projects at Havets Hus