Seagrass as a carbon sponge?

In a pair of studies, U-M researchers evaluated the impact of nitrogen and phosphorus on seagrass, short, turf-like grasses that live in shallow, coastal areas. They found that nutrients can increase seagrass's ability to store carbon. However, in a second study, the researchers also found that an overload of nitrogen could lead to increased phytoplankton growth, which can shade out and kill seagrass.