New record of a bloom forming, genotoxic strain Nodularia strain (KT447209) from Andaman and Nicobar Islands, India.

Cyanobacteria blooms in marine waters are limited to only a few taxa; with the genus Nodularia (Nostocales) being one among the most commonly observed and widely studied species. A bloom of Nodularia sp. was observed across a vast area along the coast of the Andaman and Nicobar Islands. The bloom occurred during the summer when salinity was >30‰. This differed to previous reports where blooms have crashed at such high salinities. The molecular phylogeny revealed the Nodularia species to be a novel one. A crude extract from the bloom demonstrated lowed toxicity with an LC50 of 5 mg/ml at 48 h towards Artemia salina and slight genotoxicity when tested against human lymphocytes.