The guardians of the underwater forests to the rescue of the Mediterranean

Even in the middle of the morning, activity at the fishermen's guild of Blanes is frantic: a coming and going of boxes full of anchovies and sardines, and mullets and other fish, arriving at this Girona fish market for auction. Unaware of this hustle and bustle and sheltered under the piers, about forty individuals rest, impassive, in enormous water tanks. Some have been there for a short time and are recovering, waiting for their moment to come. Others are already prepared and will return to the sea soon.

Most are gorgonians, sea fans of beautiful colors that resemble trees; there are also other species of corals, sponges, some curious sea feather, and bryozoans. Not long ago, all these invertebrate animals lay at the bottom of the Mediterranean, tens of meters deep, forming part of veritable three-dimensional underwater forests, where fish and crustaceans find shelter, food, and a place to reproduce.

Accidentally, however, at some point they got caught in fishing nets, which tore them from the seabed. Years ago, they would have ended up dead on the pier or thrown back into the sea without any possibility of survival. Today, however, their fate is, fortunately, different.

La Marina takes a specimen from the first water tank, a kind of saltwater ICU at 13°C. With great care, she observes it, admires it, and places it on a slate with a ruler drawn on it. “It's an Eunicella cavolini, an orange gorgonian, very delicate. If we keep it out of the water for too long, it turns black,” she explains. Sofia nods, takes a photo of it, and enters it into the registry of recovered species. Quickly, they put it back in the aquarium. It is one of the last individuals brought by the fishermen from Blanes. “When they catch one, they notify us through a WhatsApp group we have, and they bring it here, to the aquarium,” they tell us.

Both Marina Biel and Sofia Faramelli are doctoral students at the Institute of Marine Sciences (ICM-CSIC) and have been visiting fishing guilds along the Catalan coast for three days. They started in Llançà, then visited those in Port de la Selva, Cadaqués, Roses, Palamós, and Sant Feliu de Guíxols, and today they have arrived at the one in Blanes. End of the journey. In two weeks' time, they will start again, doing the same route. Meanwhile, another team from the University of Barcelona will be in charge of the animals in the aquariums installed in the fishing guilds of Arenys de Mar and Vilanova i la Geltrú.

Once these organisms have been recovered, they are attached with a special resin to pebbles to ensure that when they are thrown back into the sea, they will remain upright. They have named it the badminton method and this, Sofia and Marina assure, contributes to their survival, because "if they are left lying down they suffocate". When fishermen go out to fish, they take them and return them in some of the fishing grounds distributed along the Catalan coast. When they do, they send them a photo and GPS coordinates, so that scientists can track them.

First conserve, then restore

This scene, of recovering accidentally captured animals, caring for them to then return them to their habitat with the necessary conditions to guarantee their survival, summarizes a profound paradigm shift in marine conservation. Because if for decades efforts were concentrated on protecting ecosystems so that they would stop degrading due to human action, now scientists assume that this is no longer enough and they are working against the clock to rebuild them. The titanic challenge is how to do it.

In fact, this is what the European project Life ECOREST, coordinated by theICM-CSIC, which since its launch in 2022 has already managed to return around 10,000 animals to the Mediterranean in collaboration with Catalan fishermen. The aquariums we have just visited in Blanes are part of it.

“We carry out monitoring campaigns of these actions that have allowed us to know that more than 90% of the animals we reintroduce survive and that the habitats we restore act as a refuge for biodiversity again,” points out with satisfaction Jordi Grinyó, Beatriu de Pinós postdoctoral researcher at ICM, at the head of this initiative.

The final objective of Life ECOREST, which will conclude next year, is to restore nearly 30,000 hectares of vulnerable deep marine habitats along the Catalan coast.

This idea, in fact, began to take shape more than 10 years ago, when the fishermen themselves realized how various fishing stocks on the country's coast were on the verge of collapse or in accelerated decline. And even then, in collaboration with researchers from the ICM, they decided to establish the first enclosures, areas completely protected from fishing.

“It is a fairly unique fact in the entire Mediterranean, because it has not been an imposition by the administration, but the result of a consensus process with the fishing sector,” assures Grinyó, who highlights that in our country “we have one of the highest densities of reserves”.

The first trials in Roses, where a 50 km² enclosure was established, showed that in just two years fishing recovered. “The biomass of juvenile hake, for example, increased 10 times compared to outside the reserve in two years," says the marine ecologist, who points out as an explanation: “It is giving species a space to reproduce and live without pressure”.

The idea of establishing more enclosures along the Catalan coast began to take shape. However, the exploration of these protected reserves with underwater robots showed that sessile fauna, the kind that lives attached to the seabed, which forms veritable forests that are home to biodiversity, was not recovering at the same rate as some commercial species that had been evaluated. This led to the launch of Life Ecorest, in which 8 Catalan fishing guilds currently participate.

“We see how many species use these restored organisms to lay their eggs. We have seen gorgonians that we had returned to the sea completely covered in catshark eggs, egg masses from cephalopods, and juveniles of other species among the branches,” adds the ICM-CSIC researcher, summarizing four years of the project's operation.

The success of the Life Ecorest experience is proof that restoration can recover not only organisms but also the ecological functions of the system. And it has already inspired similar actions in other parts of the State, such as the Balearic Islands, Valencia, and Galicia, and they are now launching a similar project in Cadiz. In the Azores and Mexico, they are applying the same methodology but at greater depths, 400 meters. 

Recover the ecosystem

The aquariums distributed by Catalan fishermen's guilds will not by themselves reverse decades of Mediterranean degradation, but they symbolize a major challenge. “For many years we thought that conserving was enough. But we were wrong,” states emphatically marine biologist Emma Cebrian from the Blanes Advanced Studies Centre (CEAB-CSIC), one of the pioneers in restoration. “Nobody questions that after a fire, a forest needs to be restored. With the sea, we must start thinking the same way”.

However, restoring, Cebrian emphasizes, goes far beyond replanting. "It involves improving water quality, having few invasive species, managing anchoring and fishing, among other things. Planting is the last action and must be done strategically".

It is in this sense that Cebrian began working 15 years ago on macroalgae forests, which are her specialty. With her research group, she managed to restore Cala Teurela, in the bay of Maó, in Mallorca, a forest of cystoseira algae in a spot where it was documented to have existed at the beginning of the last century and which had disappeared due to pollution. It was a multi-year project with which they managed to recover biodiversity, and the processes of oxygen production and carbon capture. An extraordinary feat, because once forests, whether of corals, gorgonians, or macroalgae, are lost, it is extremely difficult to recover them.

Unfortunately, it continues to be, for now, the only successful example. “Planting organisms where they have been lost does not guarantee the recovery of an ecosystem and its ecological functioning,” emphasizes the researcher.

And it is that these coastal ecosystems are not just underwater landscapes, but natural infrastructures that support a large part of marine life. They oxygenate the water, fix sediments, and help protect beaches from erosion. They act as a refuge and breeding ground for numerous species, including many fish and crustaceans that are the basis of artisanal and commercial fishing. Furthermore, they concentrate a large part of Mediterranean biodiversity.

Therefore, Cebrian insists, “restoring the sea is not an aesthetic issue or an obsession of biologists. It is an investment in quality of life”.

A national plan for marine conservation

Now this marine biologist coordinates the first restoration plan for marine habitats in Catalonia, Peremcat, a pioneering project in the Mediterranean that has an investment of over three million euros from the Department of Maritime Policy and Sustainable Fishing of the Generalitat and which aims to first know which marine habitats exist, what state they are in, and what threats they face, in order to then decide what actions need to be taken in each case. "We could not start restoring without having a country plan, it would be like starting to build roads and highways without having a mobility plan," argues Cebrian.

For the moment, they have divided the Catalan coastline into 31 water bodies, from Les Cases d’Alcanar to Cap de Creus, and they have already mapped the existing habitats and their state of health. “We have discovered macroalgae forests that we didn't even know existed in Catalonia, which are in very good condition and, therefore, we can still act to preserve them,” states this marine biologist.

They now work to identify the threats each one faces. “It’s common sense: before restoring, the cause that causes degradation must be eliminated. It’s useless to replant seagrass in places where boats continue to anchor, nor to return gorgonians if they will be uprooted again later,” considers the marine biologist from CEAB. Each habitat needs a different strategy and prioritization will be necessary.

Once what causes degradation has been stopped, one can opt for the system to recover on its own or to carry out an active intervention by reintroducing organisms. “Restoring is not simply planting, but achieving an ecosystem to function again,” says Cebrián.

This paradigm shift is no longer just scientific, but also a legal obligation. The European Union has approved the Nature Restoration Law, which obliges member states to promote the recovery of degraded ecosystems. Among the objectives is to recover at least 20% of terrestrial and marine habitats of community interest before 2030. Catalonia is already moving towards this goal. For decades we have tried to prevent the Mediterranean from continuing to degrade. Now it's time to start rebuilding it.