Seagrasses form vast underwater meadows that provide habitat for countless other organisms and directly influence key ecosystem processes like carbon storage and erosion control. But seagrasses are also under threat from human-caused changes in the environment such as warming temperature and cloudy water. Jay Stachowicz seeks to understand how genetic diversity within eelgrass, a seagrass found throughout the northern hemisphere, provides resilience to this species and the ecosystems it supports.