Celebrating 25 Years of Action for Biodiversity

The agricultural land farmed organically has increased by about four to five times in the last 18 years [ ] 92 The Blue Reef Habitat Restoration Project Reefs are very valuable marine oases, and are home to a diversity of species. In Denmark, they are protected in accordance with the Habitats Direc- tive and are also listed as sites in the Natura 2000 designation platform. The Blue Reef Habitat Restoration Project has restored and protected a large reef, covering almost 7ha, at Læsø Trindel in a Natura 2000-desig- nated area 11km north-east of the is- land of Læsø in northern Kattegat. An area of about 6ha of the pre-existing reef is now stabilised. 86,000 tons of rock were deposited on the reef dur- ing the project, which was completed in 2013. The aim was to rehabilitate the reef and provide good living conditions for creatures living in the benthic zone — the seabed-dwelling algae and fish. The effects of the project are moni- tored, and conditions before and after restoration have been assessed. It is clear that restoration has generally increased biodiversity on the reef and the number of characteristic species has increased. Based on measure- ments made in 2007 and 2012 the estimated total biomass on the reef has increased by approximately three tons of animals and six tons of algae. Reinstatement of the reef means that there are now more species of perennial seaweed in the algae communities than there were before restoration and there are signs of greater stability in the habitat. New species have migrated to the reef. For example, there are now large occurrences of the plumose anemone (Metridium senile), a soft coral that was not previously extant on the reef. Shoals of cod near the reef have increased since its restoration. The number of fish more closely associ- ated with reefs, primarily wrasses (Labridae), has also increased while numbers of flatfish have fallen in the shallow parts of the reef. No new species of fish have migrated to the reef, but the constellation of species has changed. The results of fish investigations show that Læsø Trindel is increasing- ly becoming a growth area for sev- eral species of fish, such as cod and Atlantic pollock, and these tend to attract more fish from local areas that find food on the reef. Reefs are also a favourite habitat for lobster. However, as lobsters grow slowly, it is too early to determine whether restoration has been beneficial for this species. Porpoise have been observed more frequently and for longer periods since than before restoration. This is interpreted as an improvement of the reef’s ecological standard. T oday, the vast majority of Denmark’s open landscape consists of semi- or fully-cultivated land, with two-thirds of the total land area of Denmark used for agricultural purposes. Although this limits biological diversity in the country, there remains some remarkable natural areas with a rich diversity of species. Notably, Denmark’s coastline is of unique natural value within Europe as it holds a major proportion of the areas of dunes, saltmarsh and shallow marine waters, of crucial importance to specialised lichens, plants, fungi and invertebrates, as well as waterbirds. Denmark’s forests, which cover 14 per cent of the national territory, hold the largest number of Danish species, including those endangered. There are currently four national parks: Mols Bjerge, Skjoldungernes, Vadehavet, and Thy. Wildlife in Denmark Marjorie Teo on Unsplash Denmark