Seagrass Habitat Response Monitoring to Evaluate Land-Based Sources of Pollution Management Effectiveness on Culebra Island, Puerto Rico

This report presents the key findings of work conducted between 2014 and 2022 to provide reference data of seagrass habitat metrics for the Island of Culebra, Puerto Rico. This work is an integral component of the Culebra Ridge-to-Reef Monitoring Program, a spatiotemporally coordinated effort designed to evaluate the effectiveness of NOAA management strategies and actions in priority watersheds to reduce land-based sources of pollution (LBSP) impacts to the nearshore marine ecosystems of the island. This ridge-to-reef monitoring framework implements a multiple-lines-of-evidence approach consisting of (1) monitoring LBSP stressors that are being managed through NOAA funding, including sediment accumulation at unpaved road stabilization projects, water quality monitoring at key points throughout the watershed, and watershed modeling to estimate pollutant loads into the nearshore coastal environment; (2) monitoring LBSP exposure through nearshore water quality and sediment trap monitoring at nearshore fixed stations; and (3) monitoring nearshore habitat responses that are co-located with the aforementioned nearshore water quality fixed stations and include data collection via seagrass monitoring transects. In this context, seagrass communities are characterized and tracked because they are closer to the sources of LBSP pollution than the coral reef, which is ultimately the focal point of NOAA’s LBSP management efforts on Culebra.