In the discreet folds of the Mediterranean, researchers, residents, and simple curious individuals are organizing. The goal: to preserve what can still be preserved in a sea that is suffocating. Long relegated to the background of environmental policies, marine biodiversity in the Mediterranean is now attracting renewed attention. A seal in Greece, a seagrass in Corsica, Tunisian sharks, or cameras at the bottom of the abyss: everywhere, the same urgency is evident — no more time to lose.
This article, about marine wildlife, is a summary of 4 articles published in 22-med, available in the 11 languages used on the site.
The Marine National Park of Alonissos, a precious friend of the Mediterranean seal: by Kelly Fanarioti
Volunteers to spot underwater species: by Agathe Perrier
Replanting posidonia to save it: by Maëva Danton
The shark, essential to the marine ecosystem: by Lilia Blaise
The Mediterranean is not just a closed sea. It is a trapped sea. By tourist flows, invisible pollution, trawlers that plow the seabed, boats that scrape the seagrass beds, fishing campaigns that empty the nets. It is also a sea that resists. Not by miracle. By work. By science. By stubbornness.
Here, fishermen are adapting their practices. There, scientists are planting seeds hoping for a seagrass bed. And elsewhere, anonymous individuals spend their evenings scrutinizing abyssal images on their screens. Nothing heroic. But everything is vital.
A seal and an island
Only a handful of monk seals remain in the Mediterranean, making it one of the most endangered marine mammals in Europe. Just sixty individuals in the marine park of Alonissos, in the northern Aegean Sea. Not enough to talk about a comeback, but sufficient to hope. This protected area, the largest in the Mediterranean both terrestrial and marine, was designed for them. For their caves. For their tranquility.
Since the park's creation in 1992, fishing has been limited and nets must be adapted. The islet of Piperi, where seals give birth, is off-limits except to researchers. The result: about ten births each year. A modest number, but stable.
And what protects the seals also benefits humans. The park's director, Ioannis Mitsopoulos, speaks of local renewal: “Before, young people left. Today, some become marine guides. Fishing boats have been converted to tourism. The island lives differently.” The seal, by re-establishing itself, has reopened the horizon.
Scrutinizing the abyss from your couch
At 1700 meters deep, it is dark, it is cold, and yet life circulates there. Crustaceans, fish, bacteria, corals. But who observes them? Since 2023, a bit of everyone thanks to the platform Ocean Spies. Designed by IFREMER, this citizen science program invites individuals to scrutinize, image by image, life in the seabed to identify the species that live there.
The idea arose from a lack: too much data, not enough personnel to process it. Immersed cameras, hours of videos, thousands of pictures. So, we keep an eye out, we click, we identify. Each image is submitted to multiple users to cross-check observations.
Result: 23,000 annotated images. 4,200 volunteers. Algorithms trained to recognize species. And, in passing, a gentle awareness: “We show the public areas they will never visit. But that need to be defended nonetheless,” explains Catherine Borremans, project coordinator. To see is already to protect a little.
Replanting without damaging
Underwater, some plants resemble forests. Posidonia, for example. A seagrass that fixes carbon, slows beach erosion, produces sand, and shelters a whole fauna. But it is fading, victim of boat anchoring, concrete, trawlers, and warming.
In 2023, taking advantage of an exceptional bloom, the GIS Posidonia decided to act. Rather than letting the seeds wash up on the beaches, the team collects and replants them in the bay of Marseille and at Bonifacio. By hand, gently, without machinery. A fragile gesture, but with great potential.
“It’s not like cutting projects that can destroy more than they repair,” insists Charles-François Boudouresque, marine biologist. If it works, great. If not, no harm done. In Corsica, monitoring is ongoing. In Marseille, some seeds have already germinated. But to restore a seagrass bed, it will take a hundred years.
The shark, the unloved
It is filmed, tracked, sold. In Tunisia, the shark is feared. And it pays dearly: over the past 50 years, 80% of Mediterranean sharks have disappeared. Its presence creates a buzz on social media, between fear, mockery, and ignorance. Yet, it is essential. A natural scavenger, regulator of species, indicator of healthy waters. It is especially vulnerable.
Causes include overfishing, accidental catches, and habitat destruction. Tunisia, despite being a signatory of the Barcelona Convention, struggles to enforce bans. The result: shark can still be found in markets.
NGOs are raising the alarm, particularly in the Gulf of Gabès, a proven breeding ground. Mayssa Sandli, an engaged journalist, advocates for changing the animal's image. She recounts: “We published a fictional article written by a shark, ‘Salem’. He talks about his life, what he endures. Over 300,000 likes. We touch something.”
But emotion alone is not enough. WWF launched a national action plan for cartilaginous fish in 2024. Too late? Perhaps. But without a strengthened legal framework, the shark will have no story left to tell.
Preserve today to avoid rebuilding tomorrow
From the Greek islands to the Tunisian coast, passing through the French seabeds, the Mediterranean seems engaged in a long-distance race. It is not only about repairing the damage already done but especially about avoiding new ones. At a time when the climate crisis makes every action crucial, these local initiatives outline a different relationship with the sea: less predatory, more attentive, often participatory.
But all agree on one idea: preserving is better than restoring. And for that, sometimes you have to know how to do nothing — or just watch, understand, transmit.
Cover photo: in 50 years, 80% of Mediterranean sharks have disappeared © xiSerge-de-Pixabay
Indexing: Library of Mediterranean Knowledge
Biodiversity and ecological recovery
Lilia Blaise – Agathe Perrier – Kelly Fanarioti – Maëva Danton
22-med
July 23, 2025
• In Alonissos, the monk seal is regaining ground in a marine park that has become a model of coexistence between nature and residents.
• In the Mediterranean, citizens are becoming “ocean spies” by annotating underwater images to map life.
• In Marseille and Bonifacio, posidonia seeds are being replanted at sea to attempt to restore a vanished seagrass bed.
• In Tunisia, biologists and activists are advocating for the protection of sharks, essential to the balance of marine ecosystems.
• Four initiatives to slow down the erosion of life in a sea under high ecological pressure.
Alonissos (Greece), Brest/Marseille/Bonifacio (France), Gabès (Tunisia)
Ioannis Mitsopoulos, Catherine Borremans, Charles-François Boudouresque, Mayssa Sandli
#biodiversity, #mediterranean, #wildlife, #research, #ecosystems, #seal, #shark, #posidonia, #protected area, #citizen science