A natural barrier made of mussels to combat coastal erosion. This is the solution that Belgium is trying, thanks to a consortium of research institutes and companies. Mussel structure can limit the harmful effects of strong North Sea currents while improving biodiversity. This solution may also attract the attention of Italy, which is struggling with alarming coastal erosion, especially in the Northeastern regions, and where marine consumption is aggravated by illegal construction and excessive touristic activities.
rope barrier
The basic idea is to place ropes at the edge of deep water where mussel larvae can cling. At this point, the growth of molluscs grouped on vertical lines occurs naturally. Therefore, a natural barrier against currents is gradually created, located in an intermediate space between shallow and deep water, where sand is dragged with force. In many places sand-saving techniques are traditionally developed and applied for the protection of coasts: dune planting, artificial sandboxes of all kinds.
However, these solutions are not always accessible. The scientific experiment, called Coastbusters, is the result of research by the Research Institute of Agriculture, Fisheries and Food (Ilvo) and Vliz, which is linked to Belgian companies specializing in the construction of offshore structures. The results of the six-year study, conducted two kilometers off the coast of La Panne station near the French border, were presented in October in the town of Ostend on Belgium’s north coast, where the country’s main sea trials are taking place. The experimental project, financed with two million euros of public funds from the Flanders region and one million euros of funds from private organizations, now aims to attract governments to develop it on a large scale with the necessary financing.
A new ecosystem
The experiment also includes a second phase. The mussels, which become too heavy to be carried with a rope, fall to the bottom of the water alone in piles, giving life to a new ecosystem. “A habitat for all living species develops around the mussels, and it is the fact that they sink to the bottom that will create the coral reef,” said Ilvo researcher Alexia Semeraro. What is formed is a “biogenic barrier” that serves to stabilize suspended sediments on the ground. In this way, erosion is limited in a sea area affected by strong currents and waves sometimes exceeding several meters in height. Mussels and sandwall worms have proven to be better reef-building pioneer species than oysters and seaweed.
Due to climate change, the Belgian coast, like other countries including Italy, is increasingly exposed to the risk of storms of increasing intensity. As Tomas Sterckx, coordinator of the Coastbusters project, explains, the mussel ropes form “underwater biocontainment lines” constructed using aquaculture techniques. The manager, who is an expert in the field of innovation and research, however, stated that this system will not replace the addition of sand to strengthen the beach. Rather, mussel reefs represent the “first line of defense against storms,” playing a key role in the fight against erosion. “We now see coastal zone management as a comprehensive approach to the entire coastal zone. We are proving that underwater biological protection lines are a promising technique,” Sterckx emphasized.
Compatibility with the environment and fisheries
Since the North Sea is one of the roughest seas, the possibility of materials being damaged and entering the marine ecosystem can never be ruled out. That is why the company Sioen participated in the Coastbusters project, which can identify bioplastics that slowly biodegrade in marine conditions. Buoys and anchors connecting the lines to two experimental reefs built off the coast of La Panne since 2017 have been removed. This is to comply with the requirements for the protection of fauna and flora, given that it is an area classified as Natura 2000 and therefore particularly sensitive at the environmental level. According to the researchers, the positive effects of the mussel reef have already yielded two possible environmental benefits.
“The research areas attract a lot of marine life and therefore successfully support biodiversity. Secondly, mussels are filter animals that get their nutrients from the water. So the net effect is clean sea water,” said Alexia Semerano, marine researcher at Ilvo. highlighted. However, this system poses a problem for the fishing industry as the coastal protection barrier strip will not be suitable for trawling. Therefore, the combination of latest generation passive fishing is being investigated. The Flemish Institute has already investigated the feasibility of pot fisheries aimed at recovering cuttlefish and lobsters, as well as suspension culture of mussels and oysters.
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Source: Today IT
Karen Clayton is a seasoned journalist and author at The Nation Update, with a focus on world news and current events. She has a background in international relations, which gives her a deep understanding of the political, economic and social factors that shape the global landscape. She writes about a wide range of topics, including conflicts, political upheavals, and economic trends, as well as humanitarian crisis and human rights issues.
