Marine and Coastal Biodiversity

The oceans cover 71% of the planet’s surface area, and 95% of the biosphere. They produce a third of the oxygen that we breathe, offer a valuable source of proteins , and are among the largest natural resources of Carbon dioxide and moderates global climatic change. Some species, such as the great auk and the sea mink, are extinct; others, notably the great whales, have been hunted to fractions of their original populations. Species diversity is known to be as high as 1000 per square metre in the Indo-Pacific Ocean, and new oceanic species are continuously being discovered, particularly in the deep sea. Tropical marine ecosystems of Kerala coasts includes lagoons, mangrove swamps, sandy and rocky shores and open sea front. Apart from fishes Kerala coast has a rich array of Crustaceans, corals, echinoderms, mollusks, turtles etc.

Marine Biodiversity of Kerala

Sl No	Group	Approx number of species
1	Phytoplankton	468
2	Sea weeds	118
3	Mangroves	33
4	Zooplankton	251
5	Sponges	91
6	Coelentrates	151
7	Annelida	154
8	Crustacea	218
9	Echinodermata	112
10	Gorgonids	34
11	Mollusca	730

(Joshi et al, 2015)

Marine vertebrates – India & Kerala

Marine

Taxonomic group	India	Kerala**	Percent in Kerala
Fishes	2546	716 (28.1%)	28.1
Reptiles	35	9 (25.7%)	25.7
Mammals	25	23 (92 %)	92.0

(Nameer et al , 2015)

Major threats to marine and coastal ecosystems include:

• Land-based pollution

• Overfishing, destructive fishing, and illegal, unreported and unregulated fishing

• Invasions of exotic species

• Global climate change