Tropical fish and corals insufficiently protected
The global network of marine protected areas is insufficient to preserve the biodiversity of corals and tropical fish, according to a recent study.
Marine life is threatened by human activity: we already knew that. Fortunately, "marine protected areas" are being established all over the world. There are now 3,625 such areas on coral reefs, covering a total area of 942,568 km² (5.9% of the world's coral reefs). These areas, where human activities are regulated, meet nature conservation objectives and provide refuges for ecosystems and their biodiversity.
Very partially preserved “trees of life”
But is this really the case for biodiversity as a whole? As far as fish and corals are concerned, the verdict is in: on a global scale, many species are insufficiently protected by these refuges. In an article published in Nature Communications on January 12, researchers from the University of Montpellier, IRD, EPHE, and CNRS demonstrate that the global network of marine protected areas is insufficient to conserve the genetic diversity of corals and tropical fish. This diversity is fundamental to maintaining the long-term functioning of coral ecosystems.
The international team of researchers led by David Mouillot, professor at the University of Montpellier and at UMR MARBEC, studied the geographical distribution areas of 805 species of corals and 452 species of fish and looked at their coverage by the global network of marine protected areas. It examined the level of protection of the "tree of life"—i.e., the genetic diversity—of these species. The result: only 1.7% of the tree of life of corals and 17.6% of that of fish have the minimum thresholds of coverage by protected areas to ensure their preservation.
Unevenly distributed areas
“Marine areas only protect closely related species, i.e. those from the same families. Other species families receive little or no protection,” summarizes David Mouillot. The reason is simple: in the absence of a global conservation strategy, marine protected areas are very unevenly distributed across the planet. Very present around Europe, or between Australia and New Caledonia for example, they are sorely lacking in the South, particularly in the Caribbean and Africa.
These disparities often correspond to inequalities in economic development, but also to political will: in the northern hemisphere, and for developed countries with a strong environmental commitment, protection efforts are substantial, while in the South, some countries are lagging behind in the actions they are implementing."We need to refocus the creation of areas on priority zones: regions with a high concentration of ancient and poorly protected lineages that are highly exposed to human activities, particularly in the Atlantic, the Southeast Pacific, and the Indian Ocean," says David Mouillot. "To preserve genetic heritage and the functioning of ecosystems, areas must now incorporate the evolutionary history of species into their objectives."