Seagrass ecosystem services show complex spatial patterns and associations

Abstract

Seagrass beds support rich biodiversity and provide a range of important ecosystem services, and thus widespread seagrass degradation and decline has prompted broader efforts to protect and restore these habitats. Limited resources for seagrass management and restoration could be better directed by leveraging information about the potential patterns of ecosystem service supply. However, compared to many terrestrial and marine ecosystems, the spatial patterns and relationships among different seagrass ecosystem services are still poorly understood. Focusing on the Florida Gulf Coast as a study system, we performed one of the first spatially explicit assessments of multiple ecosystem services provided by seagrass beds. We developed or modified existing spatial models for five ecosystem services: biodiversity enhancement, nursery habitat, blue carbon, recreation, and coastal protection, using a combination of empirical and model datasets. Using these spatial models, we identified key predictors and quantified the marginal effect of seagrasses on each service. Our models revealed that seagrasses significantly enhance the supply of multiple services, but that there was considerable spatial variation within and among these services, resulting in distinct hotspots where seagrasses are most valuable in providing different services. Contrary to the expectation that all seagrass services will be positively correlated with one another because they are strongly related to seagrass characteristics, we also found positive and negative associations among services, revealing the potential for both co-benefits and trade-offs associated with seagrass management decisions. Finally, we found that biodiversity was not a reliable proxy for most services, as is sometimes assumed, highlighting the need for direct assessments of seagrass services. Our findings emphasize the importance of considering distinct predictors of different ecosystem services when assessing potential delivery from seagrasses and other foundation species, especially when planning and prioritizing ecosystem conservation and restoration projects.