Occurrence and Conservation of the Dugong (Sirenia: Dugongidae) in New South Wales

摘要

Recent sightings of dugongs well beyond the southern limit of their accepted range (～27°S) on the Australian east coast prompted a review of past records of dugongs and their current conservation status in New South Wales. While archaeological analyses have identified bones of Dugong dugon in Aboriginal middens at Botany Bay (～34°S) and colonial records indicate stranded animals as far south as Tathra (～36.5°S), there were no verified sightings of live individuals in NSW waters for some years; however, five separate sightings of individuals and pairs were documented in the austral summer of 2002/03 in estuaries on the NSW central coast (～32-33.5°S). It is suggested that conditions such as warm sea temperatures and low rainfall (promoting seagrass growth) may be facilitating explorative ranging south by dugongs. The IUCN lists dugongs as 'vulnerable' at a global scale and they are also classified 'vulnerable' under the Threatened Species Conservation Act NSW 1995, yet they are not routinely considered in risk assessments for inshore development in this State. Threatening processes such as shark meshing persist. The importance of considering dugongs in future impact assessments for inshore marine and estuarine developments is emphasized.