According to a study published in Nature magazine, more than half of the world's oceans have undergone a significant change in color in recent centuries. This is thought to be an indirect consequence of climate change.
Based on over twenty years of satellite data, a study published in the journal Nature shows that 56% of the world's oceans have changed color as a result of global warming. At the root of this process is the distribution and density of plankton.
Ocean color is largely influenced by the organic matter floating on the surface. This organic matter is composed in particular of phytoplankton, which move with the current. As seas warm, currents become more irregular and water layers more stratified, particularly between warm and cold waters. This makes it harder for water to mix, and plankton movements become more limited.
Climate disruption also leads to the disappearance of certain plankton species, while others thrive or migrate, contributing to changes in ocean color. Other climatic phenomena, such as "El Nino" or "La Nina", also contribute to changes in phytoplankton concentration in a region.
It's too early to know what these color changes might mean for the environment and the seedling itself. However, Stéphanie Dutkiewicz, who helped write the study, points out: "Phytoplankton is the basis of the marine food web. Everything in the ocean needs phytoplankton to exist, so if there is an impact, it will be felt throughout the food chain".
If climate change continues at the same pace, we can expect the oceans of the subtropics to become even bluer, and those of the equatorial and polar zones even greener.
