Relationship between Epibenthic Invertebrate Species Assemblages and Environmental Variables in Boston Harbor's Intertidal Habitat

Document Type


Date of Original Version



The Boston Harbor Islands National Recreation Area has an extensive intertidal zone, with 47% of the area composed of mixed-coarse substrate. Given anticipated climatechange impacts such as sea-level rise and ocean warming, and other stressors associated with the urban environment, the critical ecosystem functions (i.e., species habitat, food-web support) provided by this dominant mixed-coarse habitat of Boston Harbor, and elsewhere throughout the Northeast, have been and will likely be further altered. To evaluate the present-day epibenthic invertebrate communities and to determine what environmental factors of the mixed-coarse substrate affect community structure, we used a stratified random design to sample epibenthic macroinvertebrates along with various physical and environmental variables from the intertidal zone. Epibenthic macroinvertebrate species assemblages and diversity differed significantly between wave-exposed and wave-protected sites, with higher diversity present at protected sites. We also found that environmental variables collectively explained up to 67% of the variation in species assemblages, with elevation, organic content, water content, and sediment type individually explaining up to 56%, 30%, 42%, and 33% of the variation, respectively. This study provides a baseline for long-term monitoring aimed at understanding the response of cobble and mixed-coarse intertidal communities to multiple disturbances, and a foundation to support habitat restoration or other management actions.

Publication Title, e.g., Journal

Northeastern Naturalist