Biodiversité

Une équipe de chercheurs de plusieurs établissements, dont l'Office français de la biodiversité (OFB), a développé une nouvelle approche de modélisation pour mieux connaître la répartition en mer des poissons migrateurs amphihalins. La méthode appliquée à ces espèces menacées, comme les aloses ou l’anguille européenne, a permis des avancées importantes pour leur gestion en mer.

It is becoming increasingly clear that humankind must do more to protect our ocean. It generates about half of the planet’s oxygen, regulates our climate, and is home to 80% of all life on Earth. Yet, ocean health is critically threatened by human activities that are driving the collapse of fisheries, the loss of biodiversity, and the acidification of seawater.

Nous avons constaté qu'en dépit du cadre mis en place pour protéger le milieu marin, les actions de l'UE n'avaient pas permis de rétablir le bon état écologique des mers, ni d'y ramener partout la pêche à des niveaux durables: ce constat recoupe celui dressé par l'Agence européenne pour l'environnement dans un rapport publié alors que nous achevions nos travaux d'audit, selon lequel la biodiversité marine reste menacée dans les mers européennes. De nombreuses évaluations des espèces et des habitats marins continuent de révéler un état de conservation «défavorable», voire «inconnu». Si nous avons pu établir que l'action de l'UE avait abouti à des progrès sensibles dans l'Atlantique, la Méditerranée est quant à elle restée largement surexploitée; par ailleurs, seule une petite partie du Fonds européen pour les affaires maritimes et la pêche a été utilisée pour financer la conservation du milieu marin.

Tropical coral reefs are subject to multiple pressures from both natural and anthropogenic sources. These pressures have caused widespread declines in reef health, resulting in the increased use of spatial management tools such as marine protected areas (MPAs). MPAs have proven generally effective if well designed and enforced, but there are limited long-term studies investigating how the presence of small-scale MPAs affects fish populations and reef communities. Using a 12-year time series, we found that small-scale (10–50 ha) community-managed MPAs along the Danajon Bank of the Philippines preserved average fish biomass within their boundaries over time relative to surrounding fished reefs. Unprotected areas are, however, showing significant long-term biomass decline. MPAs were also found to preserve more key trophic groups and larger-bodied commercially targeted reef fish families.

• La deadline du concours "Stop collision" est reportée au 30 novembre 2020
• Projet TURSMED - Formations embarquées 2020 à destination des gestionnaires d'AMPs
• La vidéo bilan des Rencontres 2019 est en ligne !

The International Union for the Conservation of Nature, a global environmental organization, lists approximately 1,200 marine species worldwide that are considered vulnerable, threatened, or at-risk of extinction. Many are provided legal protection through national laws requiring research and management measures aimed at recovering and maintaining the species at a sustainable population level. Integral to the policy decision process involving the management and recovery of marine species is the consideration of trade-offs between the economic and ecological costs and benefits of protection. This suggests that economics, at its core the study of trade-offs, has a significant role. In the U.S. a somewhat traditional use of economics in protected species research and management has involved cost minimization or cost-effectiveness analyses to help select or prioritize conservation actions.

20 scientifiques internationaux se retrouvent à Brest, du 15 au 19 octobre, pour identifier des zones de protection pour les mammifères marins du grand sud.

Understanding the relative effectiveness and enabling conditions of different area-based management tools is essential for supporting efforts that achieve positive biodiversity outcomes as area-based conservation coverage increases to meet newly set international targets. We used data from a coastal social–ecological monitoring program in 6 Indo-Pacific countries to analyze whether social, ecological, and economic objectives and specific management rules (temporal closures, fishing gear-specific, species-specific restrictions) were associated with coral reef fish biomass above sustainable yield levels across different types of area-based management tools (i.e., comparing those designated as marine protected areas [MPAs] with other types of area-based management).

Decision-making products that support effective marine spatial planning are essential for guiding efforts that enable conservation of biodiversity facing increasing pressures. Key Biodiversity Areas (KBAs) are a product recently agreed upon by an international network of organizations for identifying globally important areas.

The establishment of multiple zones offering different protection levels within a Marine Protected Area (MPA) can minimize social conflicts while maintaining associated biodiversity benefits such as fish population replenishment. Parrotfishes are among one of the most ecologically important reef fishes; yet extremely overexploited worldwide. In this context, well-designed priority management areas allowing no fishing activity (no-take zones) could help recover fish species, such as parrotfishes, through a MPA zoning process.

In the French West Indies, more than 20 species of cetaceans have been observed over the last decades. The recognition of this hot spot of biodiversity of marine mammals observed in the French Exclusive Economic Zone of the West Indies motivated the French government to create in 2010 a marine protected area (MPA) dedicated to the conservation of marine mammals: the Agoa sanctuary. Threats that cetacean populations face are multiple but well-documented. Cetacean conservation can only be achieved if relevant and reliable data are available, starting by occurrence data. 

En Méditerranée, seules 0,1 % des aires marines protégées le sont réellement, avec à la clef des bénéfices écologiques tangibles, selon une étude récente. Reportage dans la réserve naturelle de Banyuls-sur-Mer (Pyrénées-Orientales).

Les activités humaines ont un impact global sur les requins de récif. La création de sanctuaires et d'aires marines protégées de très grande taille font partie des mesures susceptibles de restaurer les populations de ces prédateurs essentiels à l'équilibre des écosystèmes côtiers des zones tropicales.

One hectare of ocean in which fishing is not allowed (a marine protected area) produces at least five times the amount of fish as an equivalent unprotected hectare, according to new research published today.

This outsized effect means marine protected areas, or MPAs, are more valuable than we previously thought for conservation and increasing fishing catches in nearby areas.