The cold-water coral Lophelia reef (Lophelia pertusa) is one of the major habitat-building species which produces three dimensional structures in the deep sea. It is widespread in the North Eastern Atlantic and the Mediterranean. Its reefs harbour a biodiversity equal to tropical coral reefs and create rich feeding grounds for several animals which provide important ecosystem services and for commercially important fish species.
The Lophelia reef is a subtype of reef listed in Annex I of the Habitats Directive and the species is listed as critically endangered on the Swedish national Red List. An estimated 3050% of the reef areas in Scandinavia have been damaged by bottom trawling. Four out of six known reefs in the project area are dead, and the remaining two reefs harbour live coral over only small areas. The species grows slowly and needs centuries to fully recover, as well as elevated hard substrates to settle. Any reefs which have been reduced to rubble hamper or inhibit recovery of the species and so the deployment of artificial reefs which restore their three dimensional topography may aid progress.
The long-term objective of the project is to achieve a network of viable reproductive reef sites which are able to exchange larvae to maintain rejuvenation, and to update the national Red List status of Lophelia pertusa in Sweden from critically endangered to endangered or better.
These objectives will be carried out by:
- developing an efficient and cost-effective method to restore Lophelia pertusa reefs by finding the optimal design and placement of artificial reef structures which maximise the contact and attachment rate of Lophelia larvae;
- implementing this method to restore all the six known reef sites over at least 25ha in the Natura 2000 Kosterfjorden-Vderfjorden, re-establishing ecosystem services and providing blue infrastructure;
- assessing the use of Calcium Carbonate (CaCO3)-rich industrial by-product metallurgical slag rich in cold-water coral restoration efforts.
This project will support the Habitat Directive on the conservation of natural habitats and wild fauna. It will also contribute to achieving good environmental status according to the Marine Framework Directive.
- a cost-efficient method for restoring Lophelia pertusa reef habitats has been developed and published in a handbook, describing the method and instructions on optimal shape, placement and surface structure of artificial reefs;
- industrial by-product metallurgical slag has been tested for use in production of artificial reefs for cold-water coral recruitment and habitat restoration;
- Lophelia pertusa has been reintroduced at all known reef sites within the Natura 2000 Kosterfjorden-Vderfjorden at an ecologically significant scale (25ha);
- the deployed artificial reefs have increased the habitat complexity and number of available substrates for larval settling;
- the public has become more aware of the existence of cold-water coral reefs, the ecosystem services they provide and the threats they face.