Eelgrass Functions, Services, and Considerations for Compensatory Mitigation

Coastal-marine eelgrass habitat is a critical resource within New England and throughout the world. Eelgrass habitat provides functions and services including providing structure, biogeochemical cycling, erosion reduction, habitation provision, and water quality improvement. Declines in eelgrass distribution are often due to anthropogenic processes impacting temperature and water quality. Declines in distribution and abundance highlight the importance of protecting the existing eelgrass, improving environmental conditions allowing for ecosystem restoration, and identifying viable in-kind and out-of-kind compensatory mitigation measures. Considering the limited availability of New England sites for in-kind compensatory mitigation, additional approaches for out-of-kind compensatory mitigation should be considered. These include (1) creation of alternative plant or kelp habitat, (2) using a multi-pronged, multi-habitat and structure approach, (3) contributing to the development of water quality improvement initiatives to encourage current eelgrass bed expansion over time, (4) reduce physical impacts to eelgrass habitat, (5) and identifying locations for future eelgrass habitat suitability based on climate predictions and investing to create future compensatory mitigation habitat in these locations.