Shastry V. Mallady and C. Jaisankar MADURAI/RAMESWARAM: Studies conducted in the waters of the Gulf of Mannar point to low levels of oxygen leading to high mortality of fish. The Regional Centre of Central Marine Fisheries Research Institute (CMFRI), Mandapam, has found out that this is due to the blooming of a harmful marine, dinoflagellate (noctiluca scintillans), a minute marine species. Another study undertaken by Madurai Kamaraj University