KIMO member, Aalborg Municipality in Denmark wants to improve their local marine environment, the Limfjord, and increase biodiversity by establishing several small rock reefs. This is being done in collaboration with local farmers and contractors as well as a number of enthusiastic volunteers, known as the “coastal helpers”. The first step is to collect stones in the immediate area.
There used to be many rocks at the bottom of the Limfjord, but after many years of rock extraction, only a few rock reefs remain. At least 8 million cubic metres(!) of stone were removed from Danish waters before 2010, when stone extraction was banned. The Limfjord is no exception. The stones have been used for harbour piers, coastal protection and construction projects.
The missing rock reefs are a problem in relation to biodiversity in the fjord. They form an important element in the marine environment. Project manager Klavs Frederiksen from the Limfjord Council’s Secretariat says:
The rock reefs are like oases in the fjord and form the foundation for much of the marine life. For example, seaweed does not put down roots in the fjord bottom, but attaches itself directly to solid surfaces such as rocks. Without rocks, there is therefore no seaweed to produce oxygen or to function as a hiding place for small animals, crustaceans and fish fry.
The establishment of stone reefs is a costly affair, because the stones are both expensive to buy, transport and place in the right places on the fjord bed. So the Secretariat of the Limfjord Council has thought creatively.
By collecting and recycling stones locally, we save both money and resources in the mineral pits. That is why we have asked farmers and contractors in the local area if they would like to donate their surplus stones to a ‘stone bank’. And it has paid off,
says Klavs Frederiksen. For example, the rural farmers’ associations Agri Nord and LandboNord have just launched a campaign where local farmers can donate field stones to the stone reefs. According to Carl Chr. Pedersen, who is chairman of Agri Nord, the farmers would like to play an active role in improving the water environment in the Limfjord.
The municipality’s own construction department and several private construction companies will also donate excess stone from subdivisions of housing plots, road projects and new buildings. RGS Nordic has already delivered 200 cubic metres of stone, and it is expected that surplus stone from New Aalborg University Hospital can be donated to the “bank”.
But the scheme is not just limited to the municipality’s departments and large construction companies, private citizens can also help. In the spring, locals contributed stones from their gardens for the new stone reefs in the Limfjord. A trial scheme is being created where citizens can drop off stones at selected recycling sites.
When the “stone bank” is full, the actual laying in the fjord will begin. Placement and establishment of rock reefs is done together with volunteer ‘coastal helpers’. Frederik Svendsen from Nibe, together with other volunteer “coastal helpers”, has helped to identify areas both east and west of Aalborg, where the conditions are suitable for laying stones. As a recreational fisherman, he has experienced the decline in the Limfjord’s fish stocks firsthand. Frederik Svendsen explains:
“The good fish stocks in the Limfjord will only come back if we do something ourselves. And laying out stones is something concrete that we, as users of the fjord, can help with. I hope the new stone reefs will have a quick and positive effect on the Limfjord with visible results for the aquatic environment.”
About the collaboration
The effort to collect stones and establish a rock reef near Aalborg is financed by Aalborg Municipality and is coordinated by the Secretariat of the Limfjord Council. At the same time, the effort is part of the Danish Sports Fishermen’s Association’s nationwide project “Coast helper – we give the sea a hand”. The purpose of the project is to create popular ownership of the sea and the coastal areas, where volunteers participate in marine nature restoration. If you want to donate stones, please contact the Limfjord Council’s Secretariat.