Marine Mammals and Fisheries Interactions In: ICAR Sponsored Winter School on Recent Advances in Fishery Biology Techniques for Biodiversity Evaluation and Conservation, 1-21 December 2018, Kochi.

The term marine mammal includes members of five different mammalian groups: Cetaceans (whales, dolphins, and porpoises), Pinnipeds (seals, sea lions and walruses), Sirenians (manatees, dugongs, and sea cows), Sea otters and Polar bear. Marine mammals are probably one of the best sentinel organisms in aquatic and coastal environments because many species have long life spans and have extensive fat stores that can serve as depots for anthropogenic toxins. Many marine mammals are at the top of the food chain, putting them at risk of accumulating high levels of contaminants in their tissues over their lifetime or assimilating biotoxins present in their prey. These toxic levels indicate not only the health of the marine mammals, but also the condition of the ecosystems. Marine mammals have also been used in navy. Navy trains these animals to perform tasks such as ship and harbour protection, mine detection and clearance, and equipment recovery. The Indian seas support a variety of marine mammals, which include baleen whales, toothed whale, dolphins, porpoise and dugong. Stranding and sighting records show that the Indian seas are a habitat for 26 species of cetaceans and one species of sirenian (sea cow). Of the 26 species of cetaceans six are Mysticeti (baleen whales) and the rest are Odontoceti, which includes Delphinidae, Physeteridae, Kogiidae, Ziphiidae, Phocoenidae and Platanistidae. Until the year 2003, knowledge of marine mammals of India was restricted to incidental catch of various species in fishing gear