Biodiversité

D'après une étude publiée dans Nature Climate Change, certains groupes d'animaux sauvages – neuf au total – possèderaient un "effet multiplicateur" dans l'absorption du CO2 de l'atmosphère et le stockage du carbone au sein des écosystèmes naturels, contribuant à la lutte contre le réchauffement climatique. Mais les données scientifiques à la base de cette conclusion sont fragiles.

One of the perks of having a window seat in an airplane at night is looking out at the lights below. All that bright light underneath is actually a form of light pollution, or excessive artificial light. Like other forms of pollution, light pollution impacts both terrestrial and aquatic ecosystems. In fact, as of 2010, over 20 percent of Earth’s coastlines were lit up artificially at night. As the human footprint on the planet continues to increase, the impact of light pollution on ecosystems remains a concern. 

Ocean warming affects the life history and fitness of marine organisms by, among others, increasing animal metabolism and reducing oxygen availability. In coastal habitats, animals live in close association with photosynthetic organisms whose oxygen supply supports metabolic demands and may compensate for acute warming. Using a unique high-frequency monitoring dataset, we show that oxygen supersaturation resulting from photosynthesis closely parallels sea temperature rise during diel cycles in Red Sea coastal habitats.

The influence of depth and associated gradients in light, nutrients and plankton on the ecological organization of tropical reef communities was first described over six decades ago but remains untested across broad geographies. During this time humans have become the dominant driver of planetary change, requiring that we revisit historic ecological paradigms to ensure they capture the dynamics of contemporary ecological systems. Analysing >5,500 in-water reef fish surveys between 0 and 30 m depth on reef slopes of 35 islands across the Pacific, we assess whether a depth gradient consistently predicts variation in reef fish biomass.

Une semaine consacrée à La Réunion

De toutes les familles d’oiseaux, ceux qui vivent au-dessus des mers sont ceux qui disparaissent le plus massivement. Ils ont décliné de 70 % entre 1950 et 2010. Comme la faune sous-marine, ils subissent directement les maux de l’océan : invasion de plastique et pollutions multiples, réchauffement et acidification, destruction d’écosystèmes comme les récifs coralliens et les mangroves.