Aquatic ecology and Biodiversity

Unit 12- Aquatic biodiversity and conservation

12.1.4. Aquatic biodiversity
Aquatic biodiversity encompasses freshwater ecosystems, including lakes, ponds, and reservoirs, rivers and streams, groundwater, and wetlands. It also consists of marine ecosystems, including oceans, estuaries, salt marshes, sea grass beds, coral reefs, kelpbeds and mangrove forests.
In summary, aquatic biodiversity includes all unique species and habitats and the interaction between them.
Fishes exhibit enormous diversity in size, shape, biology and in the habitats. They comprise bony fishes, mainly teleosts. In addition, there are around 800 species of cartilaginous and 70 species of jawless fishes (lampreys and hagfishes). It is believed that out of 60,000 species of vertebrates recognized world over, 22000 are fish species; of which 8411 are fresh water while 11650 are marine. As per the report more than 24500 fin fish species exist throughout the world. However, there is prediction of around 28500 fish species representing more half of the vertebrate diversity. They surveys emphasized that there could well be at least 5000 species more to be discovered.
In India 2163 species of finfish have been recorded from upland cold (157; 7.26%), warm waters of the plain (454; 20.99%), brackish water (182; 8.41%) and marine environment (1370; 63.3%).In terms of habitat, fishes live in almost all conceivable aquatic habitats, ranging from Antarctic icecap to hot springs as well as fresh to saline waters.
Aquatic biodiversity is greatly threatened due to modifications of environment, overexploitation, habitat loss, exotic species and others. In order to preserve threatened areas and species for future generations, immediate action in the form of aquatic biodiversity conservation strategies are necessary. In general, aquatic conservation strategies should support sustainable development by protecting biological resources in ways that will preserve habitats and ecosystems. It is essential to prevent further decline of fish resources by devising all possible measures of conservation and rehabilitation. The conservation policy should promote the management practices that maintain integrity of aquatic ecosystem, prevent endangerment and enhance recovery of the threatened species. Principal elements or tasks in the recovery programmes have been to be identified as