The fishermen had left them behind, and now science confirms it: Natural or artificial reefs promote marine biodiversity. Hence the convenience of preserving them and restoring them when appropriate. A study conducted in Denmark concluded that: Installing new reefs could help create a hundred times more reefs fish some species.
Just six months after the National Water Resources Institute (DTU Aqua) at the Technical University of Denmark and various local organizations established new reefs at Bredgrund in the south of the country, researchers noted: a hundred times more cod than normal.
The original reefs in Denmark have shrunk after decades of human activity. DTU Communications Director Christina Tækker said that in the last 100 years alone, 8.3 million cubic meters of stone have been removed to expand the country’s ports and produce concrete.
According to a study conducted by this university, these figures removal of at least 55 square kilometers of habitat for plants and animalsIt is approximately the size of the Bermuda Islands and almost twice the area of the Canary Island La Graciosa.
The loss of stones causes the absence of hiding places for marine animals and places for species such as algae and mussels to cling to.. And if the algae disappear, fewer small marine creatures and fish such as cod usually remain.
The absence of stone reefs and kelp forests means that cod is present. fewer places to hide from predators such as cormorants and seals. The result is clear: stone reefs need to be restored.
Expensive and complex construction
In order to restore the reefs, DTU Aqua, in harmony with local actors, used rocks, mussels, concrete, etc. initiated a series of projects investigating its components.
One of the projects is the reefs protect the coast And encouraging more marine life. Answer Yes, help increase biodiversitywith improving fish spawning and growth areas already Creating value for sport fishermen and divers.
“We are in the middle of an event biodiversity crisisWhere Species are becoming extinct at the same rate as dinosaurs. “I am therefore pleased with the results of the study, which show that cod thrive around rock reefs and are able to hide and feed better than before,” said lead researcher Jon C. Svendsen.
“We are currently in a pilot phase developing and testing various reefs and documenting how they work. We are moving in the right direction, but progress is slow because stone reef construction is expensive and complex“, To add.
Reef formation began 15 years ago in Denmark. Today, greater emphasis is placed on reefs across Europe because European Union (EU) member states are obliged to protect and restore vanishing reefs. Habitats Directivewhich protects them in Natura 2000 areas.
There are two types of reefs. Someone ‘geogenic‘ It consists of rocks. To recreate these reefs, rocks are quarried and transported to the chosen location by boat. The other type is ‘biogenic‘ consists of living organisms such as oysters or mussels and provides important habitats for various fish species.
Protection against climate change
Another DTU project, called Barreef, aims to determine whether artificial reefs can be used as well as promoting biodiversity. protect the coast. DTU is testing the first coastal protection reef in the North Sea. Researchers believe this will have an impact Balancing and restorative effect on the shore.
The project incorporates two sustainability principles: ‘nature-inclusive design’ and ‘nature-based solutions’. “Taking these two principles into consideration, it would be good to build reefs that also serve as coastal protection in the future. Be better prepared as sea levels rise due to climate change“, emphasizes Svendsen.
A. concrete reef. Scientists hope it forms a natural breeding ground for marine creatures because it resembles coral reefs and seashells.
“The expectation is that the construction industry will be able to benefit from the experience gained in the future. coastal protection projectsperhaps bridges, tunnels and offshore wind farms that can be optimally designed to offer new habitats for fish, mussels and algae… Because we need to act now,” explains Svendsen.”
Previously, we saw the sea as an inexhaustible room where we could catch the fish we wanted and pour lots of waste water into it. Moreover We have eliminated basic living conditions“It is in the form of stone reefs used as habitats for fish and small sea creatures,” he says.
“Every year we are causing oxygen depletion in the seas, extracting sand from the seabed for coastal protection and construction purposes. We have reached the point where we can no longer take it from the sea. We need to give back, learn better and be more. Be careful, otherwise We could have a lifeless ocean“, warns Svendsen.
130 artificial reefs in Spain
The beginning of the installation of artificial reefs in Spain dates back to the early eighties of the last century. This activity starts with the setup. pioneer reefs Project “Escorpora” (1981) and Sa Riera-Begur (1982), both in Catalonia.
The rest of the decade saw slow progress, with ten new reef installations: three in Catalonia (L’ampolla, Salou and Medas), three in Valencia (Santa Pola, Tabarca and Torrevieja), two more in Catalonia. one in the Canary Islands (Tazacorte and Arguineguin), one in the Balearic Islands (Cap Regana) and one in Andalusia (Conil).
In the nineties, artificial reefs were definitively incorporated. fisheries management measure, we set up 93 for the entire decade. As such, there are currently 133 registered reef initiatives, 17 of which are the responsibility of the Government of Spain and the remaining autonomous communities.
The priority area of action in Spain is the artificial protection of reefs. Artificial reefs developed in other countries often associate the dual function of protection and production with the same type of modules, since due to their volume and weight, production reefs also form a reef. drag deterrentIt details the Ministry of Agriculture, Fisheries and Food.
University of Cantabria It was produced in their own laboratory three years ago. 3D printer and under a European programme, a total of 36 artificial reefs have been installed on the seabed of Santander Bay and three other locations in France, the UK and Portugal.
–Artificial reefs managed by central government: https://www.mapa.gob.es/es/pesca/temas/proteccion-recursos-pesqueros/arrecifes-artificiales/arrecifes-artificiales-instalados-por-la-sgp/ default .aspx
–List of artificial reefs managed by autonomous communities: https://www.mapa.gob.es/es/pesca/temas/proteccion-recursos-pesqueros/aa_ccaa_tcm30-278059.pdf
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