Nardo Vicente: “Some invasive species will completely change the ecosystem”

En 1980, his documentary Pollution and nuisances on the Mediterranean coast received the Palme d’Or at the Science Film Festival in Rio de Janeiro, Brazil. Nardo Vicente unveiled in broad daylight “the slow agony of the marine environment” and the suffocation of the posidonia meadow, a victim of human activities. Today, at 86, he measures the progress made. Professor emeritus of biology at the University of Aix-Marseille III, he has greatly contributed to safeguarding the Mediterranean ecosystem within the Paul-Ricard Oceanographic Institute located on the island of Embiez, and of which he is delegate general. A tireless diver, he continues to follow the evolution of the seabed, in particular of the mother-of-pearl, the largest bivalve mollusc in the Mediterranean, which he regrets that he never had the favors of scientific research in France. “It is likely that its size impresses”jokes this academic, who has always liked to swim against the tide.

Point :Forty-two years after your shocking documentary, what is your assessment of the state of the Mediterranean?

Nardo Vicente: The quality of water has improved considerably thanks to the efforts made by many countries, and in particular by the European Union. At the time, everything went to the sea without any treatment, it was an open sewer, it was thought that, in its immensity, the sea could treat everything. Ecosystems have been attacked, some have disappeared. The main one, the posidonia meadow, our forest under the sea, has regressed on the entire coast. Thousands of hectares have disappeared because of discharges, concreting of the coast, dikes. Thanks to the creation of the Port-Cros National Park, the Scandola Nature Reserve and the Blue Coast Marine Park, we are now seeing regeneration in certain sectors. And the efforts continue. For five years, within the Paul-Ricard Institute, we have been running a program financed by the Water Agency for the rehabilitation of Posidonia along the entire coast.

And in Marseilles?

There have been considerable efforts over the past fifteen years with the creation of artificial reefs, in which I took part by including the fishermen, because nothing can be done without them. But in some places, the herbarium remains in difficulty due to overcrowding, windsurfing boards, paddleboards and anchor anchoring which persists despite regulations, including in preserved areas. The herbarium has been protected by law since 1987, in all the captaincies there is a charter which is, for the most part, respected. But in the north of the island of Embiez, for example, the anchorage is still not organised. As a result, there are people who rent a sailboat in the summer without knowing how to sail and who continue to anchor in the seagrass. It’s sad.

Does this mean that the protective measures are not sufficiently effective?

There are too many regulations, we can’t find our way around. An example: octopus fishing has been banned during the breeding season, but this only applies to the Calanques National Park, when there should be a single regulation for the entire coastline. And then there are aberrations. Fishing for sea urchins, which are still in decline in certain sectors, was prohibited between April and November, while they reproduce between November and February, right during the sea urchins! And how many coastal marine protected areas are well managed? We create a lot of reserves but without valid management.

Especially since the European Parliament has given up banning bottom trawling in these areas…

It is absurd. The only form of fishing that fits perfectly into the Mediterranean ecosystem and allows the resource to be maintained is artisanal fishing. And when you see that the matanza persists on tuna in certain countries, whereas we have clearly seen that the establishment of quotas made it possible to restart the species… You just have to see how the grouper has reproduced since it is protected. What is the impact of yachting on biodiversity?

Mentalities have evolved, at least among real boaters. In the port of Les Embiez, they accepted the launch of a program establishing fry cages attached to the quays. They understood that a well-managed port is a source of life.

Besides human activity, there is also the threat of global warming…

Yes. In Port-Cros, we have set up larval sensors which have allowed us to observe that, between 1996 and 2016, malacological biodiversity has been eroded by 60%. The two new threats are rising temperatures for long periods of time and the arrival of alien species – either on their own or through ballast water.

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Precious. Threatened by waste water discharges, parasites or anchors, the mother-of-pearl is one of the protected species in France, as at European level.

Is there a tropicalization of the Mediterranean?

Yes, we first spoke of meridionalization with species coming from the southern shore, but they already existed on the western side, such as the barracuda or the wrasses. What we now see are species from the Indo-Pacific: rabbitfish, flutefish, but also more dangerous species, such as boxfish which look a lot like Japanese fugu and which also produce venom.

What is their effect on the local ecosystem?

Some species will adapt and integrate, others will be invasive and completely modify the ecosystem. We already see it in some coastal ponds of the Peloponnese. For us, it is not yet the case, but it will come. A few years ago, 50% of the Mediterranean fauna was of Atlantic origin, 28% was endemic. These native species will be the first to be affected. I can’t say if the ecosystem will be poorer at the end of this century, but it will be different.

Is the gorgonian threatened with extinction?

It had already been affected by high temperatures in 1999 and 2003 and there had been regeneration. But, I who am a frenzied optimist, I am very worried. We still reached 26°C at a depth of 40 meters this summer and these sea heat waves will be repeated. It is possible that the gorgonians disappear on the first thirty meters.

How did you fall in love with large mother-of-pearl?

It’s the biggest shell, it’s our rhinoceros! I reassembled my first large mother-of-pearl to study it at the age of 13. But it was Commander Philippe Tailliez, one of the pioneers of scuba diving, whom I consider my second father, who alerted me to this species. So I fought to protect it from the anchors, from the discharge of waste water which destroys the larvae. I obtained its protection at national and European level in 1992, at the same time as the grouper. Today it is threatened by a new pest and the rough mother-of-pearl has begun to take its place. We managed to reproduce its development in a controlled environment, but it is not complete, a link is missing. Our institute has just started a Life Pinnarca program which will, in particular, focus on its genetics. But above all, it is necessary to protect the mother-of-pearl where it still persists. Hoping to obtain new individuals to reestablish them in their environment when the parasite has passed is illusory.

Is offshore wind a threat to biodiversity?

It is necessary to diversify the energies of course, but in suitable sites. Here is the sun. Do not multiply the nuisances.

Do you remain optimistic despite everything?

Yes, but the union for the Mediterranean should be real. When I was municipal councilor for Robert Vigouroux, I launched the MedCities network for coastal problems, which brought together 18 towns around the Mediterranean. Since then, there is the Union for the Mediterranean, but the exchanges remain scattered. Me, I would dream of a Mediterranean university…

Lucien MIGNE/REA FOR “LE POINT” – AlbertKok/Wikimedia Commons

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Nardo Vicente: “Some invasive species will completely change the ecosystem”