A Lake That Is Not Quite a Lake
Chilika is a brackish water lagoon, not a freshwater lake, and that distinction is the biological engine behind everything that lives in it. Spread across roughly 1,100 square kilometres along the Odisha coast, it sits at the meeting point of the Mahanadi river system and the Bay of Bengal. Salinity levels inside Chilika shift with the seasons: fresher during the monsoon as river inflow dominates, saltier in summer as the sea pushes back through the outer channel. That fluctuating salinity gradient creates multiple micro-habitats within a single water body, which is why the species count here is so disproportionately high for its size. The Chilika Development Authority, which has monitored the lagoon's ecology since 1992, records over 800 species of fauna across its three ecological zones: the outer channel, the central sector, and the northern sector near the Mahanadi delta.
