Underwater bloom of toxic cyanobacterium Lyngbya majuscula Harvey ex Gomont, 1892 on coral reefs in Hare Island, Gulf of Mannar Marine Biosphere Reserve

Abstract

Tuft blooms of toxic cyanobacterium Lyngbya majuscula Harvey ex Gomont, 1892 prevalence was documented from coral reefs of southern Hare Island in Gulf of Mannar region, south east coast of Tamil Nadu. Lyngbya majuscula was observed to be overgrowing and dominating dead coral reefs, rubble, rocks, and other floral substrates. The persistence of L. majuscula blooms on dead reefs in southern Hare Island appears to inhibit coral recruitment, as evidenced by the presence of coral recruits in bloom-free areas and their absence in areas with blooms. Further, long-term monitoring and seasonal studies are needed to understand the impact of L. majuscula blooms on reef structure and communities.