In a collaborative study between the University of Helsinki and the EU Joint Research Centre, researchers for the first time, have modelled the future distribution of brown seaweeds and seagrasses at the global scale. They predict that by 2100 climate change will drive a substantial redistribution of both groups globally: Their local diversity will decline by 3-4% on average and their current distribution will shrink by 5-6%.
As climate change is severely threatening macrophyte habitats and the services they provide, we urgently need to understand how both brown seaweeds and seagrasses will respond to changing climatic conditions in the coming decades. Surprisingly, and contrary to our expectations, our models did not predict severe losses of brown seaweed or seagrass diversity in the tropics but rather at intermediate and high latitudes, such as along the Atlantic coasts of Europe and in the Baltic Sea. This indicatshat end-of-century climatic conditions in these regions might exceed the tolerance limits of resident macrophyte species. The Baltic Sea is at the forefront in the rate at which climate change is influencing the ecosystem.