Protecting marine coastlines is a vital need due to increasing development, overfishing, pollution and climate change but it requires both knowing the value of the ecosystems to be protected and the resilience of locations to protect. Here I provide an example of unusual value for coastal seagrasses in supporting both human health and blue food goals and our work to assess resilience to decline.

Our work shows the hygiene and nursery services of seagrass protect coastal biodiversity and humans. Corals grown in seagrass meadows have fewer diseases than adjacent outside corals and levels of pathogenic bacteria are reduced by half in seagrass meadows in Indonesia. Marine bivalves, a prominent blue food, have lower levels of pathogenic bacteria in urban locations with seagrass compared to locations without seagrass. Evidence for the sanitation services provided by seagrass ecosystems to benefit public health outcomes is mounting and a growing number of studies recognize the role seagrasses play in reducing waterborne bacterial species with human pathogenicity from terrestrial sources.

Despite tremendous value of seagrass ecosystems, they are endangered by ocean warming through increased risk of infectious disease. Eelgrass (Zostera marina) meadows provide essential coastal habitat and are vulnerable to a temperature-sensitive wasting disease caused by waterborne transmission of the protist Labyrinthula zosterae. We assessed wasting disease sensitivity to warming temperatures across a 3,500 km study range by combining long-term satellite remote sensing of ocean temperature with field surveys from 32 meadows along the Pacific coast of North America. Disease prevalence was 3x higher in locations with warm temperature anomalies. Our surveys further show that seagrass meadows in the San Juan Islands, Washington, USA, have declined steeply over the last decade.

The combination of high value blue carbon and hygiene co-benefits make eelgrass meadows a priority for conservation, but climate impacts show the need to assess resilience of seagrass meadows in conservation planning

The event will take place in person in the Isabella Abbott Lecture Hall, located in the Boat Works building at Hopkins Marine Station and will be broadcasted in the Mitchell 350/372 room on Main Campus.