Fish Kill Mystery: Algal Bloom Suspected

A significant fish mortality event occurred along the Boyapadu coastline in Anakapalle district on June 20, 2026. Thousands of dead fish, predominantly Leiognathus, were found washed ashore. Preliminary investigations by the Visakhapatnam Regional Centre of the Central Marine Fisheries Research Institute (CMFRI) revealed high densities of Trichodesmium cells in collected water samples.

The CMFRI team observed a large aggregation of dead fish, with nearly 94% belonging to the Leiognathus species. Their assessment suggests that the presence of Trichodesmium and a froth-like appearance near the shore could be attributed to hypoxic conditions, leading to the fish kills. The open-mouth condition of the dead fish is consistent with symptoms of low dissolved oxygen.

While local fishermen have raised concerns about potential industrial effluent, current findings are insufficient to establish this as the definitive cause. Intermittent rains may have contributed to temperature and salinity stratification, potentially triggering a Trichodesmium bloom. The decay of this bloom could have led to oxygen depletion and the release of toxins, affecting benthic fauna.

Comprehensive water quality and toxicological investigations are necessary to fully understand the cause of this large-scale mortality event. Regular monitoring of local industrial outlets and discharge points for phosphates, iron, and nitrogen levels is also recommended to assess their potential contribution to eutrophication.