Enhancing the ecological basis for conservation management of dugongs (C1.4.3.1a)

Task leader: Dr Ivan Lawler, James Cook University.

Task associate: Dr Kirsten Dobbs, Great Barrier Reef Marine Park Authority.

This project aims to quantify fine-scale foraging activities of dugongs in the Great Barrier Reef region of Australia in order to develop a grazing model that will describe where and when dugongs feed, why they choose those areas and the costs and benefits involved in doing so. Dugongs are seagrass specialists and understanding the interaction between dugongs and their food supply is crucial to their conservation. The seagrasses on which dugongs depend are extremely variable in abundance, community structure and chemical composition over small and large spatial and temporal scales. Studying the interaction between dugongs and their seagrass food requires knowledge of the movements and diving behaviour of dugongs at scales relevant to both dugongs and managers. This has not been possible in the past because of the difficulties of direct observation of dugongs and the low resolution of telemetric equipment. This project proposes a fine scale study that will capitalise on recent developments incorporating accurate GPS technology into tracking equipment to monitor the habitat use of up dugongs at a resolution of a few metres several times each hour throughout the day. This will provide the ability to model and map dugong habitat use in the inshore waters of the Great Barrier Reef and adjacent Hervey Bay and to assess the relative importance of different seagrass meadows and parts of meadows to dugongs at scales that are suitable for informing policy on the management of human activities including boating, traditional hunting, and commercial gill netting.