Surge in Nitrogen Has Turned Sargassum into the World’s Largest Harmful Algal Bloom

Scientists have discovered dramatic changes in the chemistry and composition of Sargassum, floating brown seaweed, transforming this vibrant living organism into a toxic “dead zone.” Results suggest that increased nitrogen availability from natural and anthropogenic sources, including sewage, is supporting blooms of Sargassum and turning a critical nursery habitat into harmful algal blooms with catastrophic impacts on coastal ecosystems, economies, and human health. Globally, harmful algal blooms are related to increased nutrient pollution.

Ocean Algae Get “Coup de Grace” from Viruses

Scientists have long believed that ocean viruses always quickly kill algae, but Rutgers-led research shows they live in harmony with algae and viruses provide a “coup de grace” only when blooms of algae are already stressed and dying. The study, published in the journal Nature Communications, will likely change how scientists view viral infections of algae, also known as phytoplankton – especially the impact of viruses on ecosystem processes like algal bloom formation (and decline) and the cycling of carbon and other chemicals on Earth.

Life could have emerged from lakes with high phosphorus

Life as we know it requires phosphorus, which is scarce. How did the early Earth supply this key ingredient? A University of Washington study, published Dec. 30 in the Proceedings of the National Academy of Sciences, finds answers in certain types of carbonate-rich lakes.