This document discusses estuaries and estuarine fisheries in India. It defines an estuary and notes that India has over 55 estuaries along its eastern and western coasts, totaling approximately 30,000 square kilometers. Several major river systems like the Ganges, Mahanadi, Godavari and Krishna form highly productive estuarine ecosystems. The document examines the fish production and ecology of estuaries like the Hooghly, Krishna, Godavari, Mahanadi, Chilka, Pulicat Lake, and Kerala backwaters. It provides details on fish catches, species diversity, and threats like overfishing in several of India's important estuarine systems.