OUR CURRENT RESEARCH

WWW.DUGONGS.ORG
SAVING ENDANGERED DUGONGS OF THE WESTERN INDIAN OCEAN

ABUNDANCE ESTIMATION & DISTRIBUTION IN THE BAZARUTO ARCHIPELAGO
Recent research has centred on the distribution and abundance of Bazaruto Archipelago Dugong population, which is believed to comprise the only viable population in the Western Indian Ocean region. Twenty seven surveys were flown over the Bazaruto Bay region to define the distribution and estimate the abundance of the species in the area. Over 350 sightings of an estimated 760 dugongs were made during a total of 9052 nautical miles of survey effort. Two core distributions occur within the surveyed area; within the 10 m isobath between the Save River Mouth and 2124 S and in the shallow sandbanks around Santa Carolina Island. Line transect analyses show densities were considerably lower than densities recorded in surveys in Australian waters or in the Arabian Gulf, and a population of 359 dugongs (CV 38.20) was estimated from those surveys carried out under adequate sighting conditions. We aim to continue these surveys to develop trend indices of the population status in the future.

THREATS TO DUGONGS
Little is known of the human-induced changes in the habitat of Bazaruto Archipelago dugongs over the last 40 years, although increased human pressure (including both increased vessel traffic and beach seine-net fishing) is believed to be impacting the area. The greatest current and direct impact appears to be a fishery for shark fins in the Bazaruto Archipelago which uses 40cm stretch size gill nets set overnight in known dugong habitats and has resulted in dugong mortalities. There is also evidence that the catch of dugongs may have developed into a directed fishery in Bazaruto Bay. Catching of dugongs is illegal, and fishers do not openly admit to taking dugongs, however dugong meat is prized and the extent of mortality to the Bazaruto Archipelago dugong population from hunting remains unknown. It is believed to be in the order of four to six individuals per year. We have a current research project to investigate the extent of catches and to address their mitigation through the development of alternative livelihood programmes for fishers.

HABITAT STUDIES
Survival of the Bazaruto dugongs will ultimately depend on the maintenance of adequate habitat. We have an ongoing interest on the seagrass habitats of the Bazaruto Archipelago and the increasing anthropogenic pressure these habitats face.

QUESTIONNAIRE STUDIES
As a component of our conservation initiative on the mitigation of threats to dugongs, we are investigating alternative livelihoods scenarios for gill and purse - seine net fishermen in the Bazaruto Archipelago. Alternative livelihood opportunities lie largely within the tourism industry and we are currently interviewing both tourism operators and tourism clients to assess these opportunities. We would appreciate the assistance of tourism operators in both completion of an operator's questionnaire and in distributing tourist's questionnaires to their clients.

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