Seagrass meadows as proxy for assessment of ecosystem health

Seagrass meadows of the Palk Bay region are biological sentinels that are widespread with 14 identified species. Health of major seagrass meadows along Palk Bay on the southeast coast of India was examined by assessing their ecological functions through ecosystem health indices. Water Quality Index (WQI), Sea Life Index (SLI) and Coral Health Index (CHI) were used to relate the key ecological and biogeochemical processes in addition to the assessment of human impacts on the meadows. Seagrass meadows are very efficient in trapping suspended particles and absorbing dissolved nutrients. However, nutrient enrichment and competitive interactions of epiphytes lead to a regime shift in seagrass communities in shallow waters (up to 0.5 m depth) of Palk Bay. Results highlight that the proliferation of epiphytes has significant negative impacts on the health of seagrass ecosystems. The study demonstrated that the status of seagrass can serve as an ecological proxy in assessing the health of adjoining coral reef ecosystems.