Question

Why are coral reefs not found in the regions from west Bengal to Andhra Pradesh but are found in Tamil Nadu and on the east coast of India?

Answer 1

High salinity, optimal temperature and less siltation are essential to colonise corals. If siltation and freshwater inflow are very high, the corals don't colonise. In contrast, when the siltation and freshwater inflow by the rivers are very less, the coral do colonise.