Irrawaddy Dolphins, Orcaella brevirostris in Chilika Lagoon, India : Conservation in a complex socio-ecological system.
My research focussed on combining conservation strategies with the sustainable use of resources by the local people. The Irrawaddy dolphin which is critically endangered, occurs shallow muddy coastal waters, lagoons and freshwater river systems. Fishermen from 44 villages associated with the Chilika Lagoon were interviewed. This indicated that the major causes of mortality were fishing nets, habitat loss and motorised boats. Many local people like to observe dolphins and to a certain extent revere them.
Mark-Recapture analysis was used to study the population estimated to have about 110 individuals. The dolphins concentrated their use into 2 core areas of the lagoon, site fidelity was high with more than 80% of individuals remaining within 10 km of the mean centre. Thus the quality and carrying capacity of the habitat plays an important role in the long term survival and health of dolphins of Chilika. Average group size was 3-4 individuals with 25% of the observations consisting of solitary individuals.
Members of the dolphin watching industry were interviewed to assess ways in which the industry could help in the conservation of dolphins. Results indicated that removal of obstructions to dolphin movements would be the most effective conservation strategy as well as increasing the free movement of roe and fish into the Lagoon. The community needs to be aware of the linkage between fishing, tourism and dolphin persistence. Management requires the support of policy-makers to reduce cross-scale conflict rather than top-down enforcement of protection, to enable the dolphin population, habitat quality and livelihood of the villages to be sustained.