Shastry V. Mallady and C. Jaisankar MADURAI/RAMANATHAPURAM: Oxygen levels in the waters of Gulf of Mannar improved on Monday giving hope that the situation would become normal along the Mandapam-Keezhakarai coast where the mortality of fish occurred in the last few days. The Gulf of Mannar Biosphere Reserve Trust (GOMBRT) has decided to undertake extensive studies on the large-scale blooming of