The coastal marine environment
The coastal marine environment, consisting of intertidal regions, the estuaries, seaweed and seagrass beds, mangrove forests, and coral reefs has a direct impact on human society because it provides social and economic benefits. In addition to the phytoplankton in the water column, larger, multicellular intertidal and benthic algae are important primary producers in coastal ecosystems. Two of the major ecosystems that are important along the Indian coast are the mangroves and the coral reefs. Mangrove vegetations protect land against erosion (Fig. 34). Major mangrove forests are found on the Indian east coast: these include the Sunderbans in the Gangetic delta and the mangroves along the Krishna-Godavari delta. The west coast of India also had extensive mangroves, but many have been converted
into rice paddies or shrimp culture lots.
Coral reefs are a virtual underwater paradise. The diversity of life in coral reefs is often comparable to that of tropical rain forests (Fig. 35). Fringing coral reefs are most abundant around the Andaman and Nicobar islands in the Bay of Bengal, while coral atolls occur in the Lakshadweep islands in the Arabian Sea (Fig. 36). High primary production and abundance of life in coral reef atolls, despite their location right in the middle of an ocean that is poor in essential mineral nutrients, reminds one of an oasis in the middle of a desert. This remarkable affluence of the ecosystem despite limiting resources is a result of its efficient functioning, nutrients being tightly conserved and recirculated without much loss to the surroundings. Thus, the functions of organisms in coral reefs are tightly coupled to one another.