A research reviews hundreds of habitat restoration interventions in marine areas made all over the world: only 9% have failed.
The restoration interventions of marine ecosystems work. And they are also an profitable investment for the economy, as well as for the environment. This is stated by an international study, recently published on Nature Communications. A group of 24 marine biologists went into the examination 764 Marine habitat recovery interventions all over the world. Result: they had a average success rate of 64%with higher tips for coral reefs and mangrove forests. The bankruptcies were on average 9%, with higher tips for the seaside fans of fans, followed by brackish swamps and oyster beds. In the remaining cases, there is a partial success: the species survive but do not expand.
Objective 30%. In most cases, therefore, The native species reintroduced in the restored areas have survivedwith beneficial effects on underwater life. It is not a little, given the complexity of marine ecology. The restoration interventions were effective regardless of the size of the protected areaits geographical location and the type of protected habitat (submerged meadows, deep waters, tropical coral reefs).
Good news, which bodes well to be able to achieve the goal of the UN agenda to protect and restore at least 30% of the seas by 2030. Although the road to go is still long: today we are only 8.3% according to the Marine Protection Atlas.
Successes and failures. “Research,” says the first author, Roberto Danovaro, director of the Department of Life and Environment Sciences at the Polytechnic University of the Marche region, “wanted to take stock of the measures of Restoration of marine ecosystems, practiced for thirty years. It took a long time to understand which approaches were effective and which are not to recover degraded environments ». Among the interventions examined by scientists, the major success rates (up to 74%) were recorded in the Recovery of coral reefs (very rich habitats), ecosystems of deep waters and macroalga forests; interventions at the greatest risk of failure (over 17%) were recorded instead for the Fanserogame meadows (marine plants), brackish swamps and mangroves.
Lessons learned. “One of the lessons learned from this study”, explains Danovaro, “is that it is not necessary to immediately remove the disturbing elements on the environment, such as polluting activities: recovery and protection interventions are effective immediately in recovering the biodiversity of a habitat. We detected it in the Maritime area of Bagnoli, where we immersed the metal networks that are used as banks in the streets to make you play the plants of Posidonia, which grew despite the environment was contaminated with hydrocarbons and heavy metals.
This is an important discovery, because the mere removal of the polluting elements, the so -called “passive restoration”, has an effect only on very long periods, often from 100 years upwards, while active recovery interventions can greatly accelerate this process ».
Habitat transplant. Among the active interventions, the Whole portions of habitats – a methodology used only recently – has proved to be an effective strategy. “It can be done with Posidonia, but not with the gorgonies and white corals,” warns Dantovaro. Interventions of this kind consist in theInstallation of tropical coral reefs, in the cultivation of gray, algae, mangrovie, or with the breeding of oysters to reconstruct the benches.
Maintenance. Equally important, for the success of an intervention, is maintenance: “Making a remediation is not enough, if you don’t keep it,” adds Dance. “Different interventions have failed because noneafter a storm, an invasion of predators or the spread of pathologies or new impacts, he had monitored the area marina and taken measures. Maintenance is essential, but In many cases it is not made for lack of funds: but to this you can remedy by monitoring the areas with submarine drones and sensors, or relying on the collaboration with local fishermen ». One last, important success factor is the creation of bearing areas (for example, protected marine areas, limited fishing areas), “but this strategy was adopted only in 2% of the cases examined”, underlines the research.
Costs and benefits. But how much does it cost An intervention to recover an underwater habitat? From 0.45 to 23 million euros per hectareif done in non -profound waters. But, underline the researchers, every 100 dollars invested in the sea, they return between 5% and 170%. And the Quadruplica performance The initial investment if the coral reefs are recovered: “Usually the protection and protective interventions are seen as a subtraction of resources, instead it is exactly the opposite: a recovered marine environment improves bathing and therefore tourism, as well as increasing fish fauna, with beneficial repercussions also on fishing”, underlines Damn. The restoration of the mangrove forest of the Mekong Delta (1,500 km) and the Macroalghe forests (1 million hectares) could provide economic benefits estimated from 53 to 177,000 euros per hectare per year.
Mines on the seabed. The situation is complicated, however, when we have to intervene at high depths: The restoration of abysmal ecosystems requires the support of large boats and sophisticated technologieswhich can cost 5 to 50 times more than coastal ecosystems: up to 68 million euros per hectare.
A scenario that could be necessary given that the international seabed authority (International Seabed Authority) has authorized 21 companies of 8 countries (United States, China, Russia, India, France, the United Kingdom, Germany and Belgium) to extract polymented nodules, polymented sulfurs and iron-manganese iron crusts in the Pacific, Atlantic and Indian oceans.
«To extract those resources, the companies will use cinged underworld vehicles as large as a building, up to 5 thousand meters deep: they will be equipped with powerful aspirators who will turn back on the support ships on the surface all the minerals of the seabed. Their impact on underwater life will be the most serious and massive ever perpetrated in history: How to use a bulldozer to collect a handful of porcini mushrooms. Also for this reason we have activated a European research project, Redress, financed by the EU with 8.6 million euros: through pilot experiments we can identify good practices to restore deep marine environments, on which little is known ».
Mediterranean little protected. But the problems are not limited to mineral appetites. All the seas of the planet, in fact, are besieged by 3 threats: The global warmingwhich enhances the coral reefs and many habitats of the Mediterranean; there indiscriminate train fishingwhich damages the ecosystems of the seabed; the impact of waste and pollution. Suffice it to say that the only indiscriminate train fishing physically damages about 4.9 million km2 Sea: a larger area of the entire territory of the European Union. And, about Europe, The old continent has established protection measures only on 12.3% of its seas: the central Mediterranean and the Adriatic are protected only to 7.9% of their surface.
And Italy? Despite having 8,300 km of coast, our country is In the last European positions for quantity of protected marine areas. Why? And what can be done? “The scarcity of protected marine areas depends on two factors: the lack of funds to invest in recovery and monitoring, and the fear of eroding spaces for fishing and tourism,” replies Danovaro. “But there is a way to overcome the impasse: Italy has 94 proposals to establish offshore wind farms, for a total area of 1,000 km2. If the authorities authorized them all, our country would double its protected areasbecause wind farms would become protected marine areas against private individuals: it is An extraordinary opportunity to produce clean energy while defending nature».
