French harbour are equip with underwater nurseries to save Mediterranean fish stocks

Ecocéan, a company involved in preserving the seabed

Created in 2003, Ecocéan is a company whose goal is to develop its know-how, its collection and its rearing of post-larvae in order to allow the development of marine ecosystems. The company has become the world leader in PCC technology Post-Larval Capture and Culture. This is not as far-fetched as it sounds, because the post-larval stage is the final stage of the pelagic larval phase of coastal marine animals, which ends with the colonization and settlement of the post-larvae into their habitat, usually a reef environment. However, these post-larvae suffer catastrophic mortality rates during the settlement process, with more than 95% dying within the first week of their return, mainly due to predation. By capturing an insignificant proportion of these post-larvae before this mortality phase, we effectively exploit a resource that would otherwise be largely wiped out. The PCC technique is inspired by both wild fishing and aquaculture gathering their advantages without the constraints: diversity of the species collected by fishing and the simplicity for breeding. The collection of a healthy alive fish brings more value than the collection of a dead fish. In addition, if the fish is not collected among genitors but at the post-larval stage, the impact is even more advantageous.

How to protect post-larvae from the actions of humans?

According to a WWF study, the marine animal populations have been reduced by half since 1970. This is due to overfishing, pollution and climate change. Three factors due to human action, which, in the space of 40 years, have had terrible consequences on the seabed. In addition, the urbanization of the seas with the construction and extension of ports is devastating for fish. Indeed, some of the post-larvae are in the sheltered areas of the ports, which seem, at first sight, adapted to their development. However, up to 100% of these post-larvae can disappear because the design of the ports makes them a real trap for these post-larvae left unprotected against predators. In order to help the fish to develop at the very beginning of their life, the Ecocéan company installs in the ports, small cages which allow the fish to hide themselves to protect themselves from the predators. These artificial nurseries contain food to help fish in their growth. At the end of their post-larval period, the fish leave these shelters and disperse in the depths of the oceans.

What is the outcome of this project?

In March 2013, 192 Biohut structures nurseries were installed along the quays and under six pontoons of Mediterranean marinas. The six Ecocean partner ports in this project are : Port de Mèze, Port-Vendres, Port de Barcarès, Port du Cap d’Agde, Port Chichoulet, Port de Six-Fours Le Brusc. Follow-up was done for each location. The result is positive, many species of fish have been seen in nurseries. Biohut contributes significantly to the preservation and generation of biodiversity along coastal infrastructures. Launched by the Ministry of Ecology in 2011, the NAPPEX project Artificial Nurseries for Exemplary Ports was one of 62 winners of the first call for proposals of the National Strategy for Biodiversity. The objective of this call for projects was to support companies specializing in the development of solutions and to allow France to achieve the “Good Green State” project resulting from the Marine Strategy Framework Directive. A goal achieved with brilliance and that gives new hope.

We can now promise a longer life to these marine animals.