Marsh et al. 2007:

"This survey provides the first survey of the distribution and abundance of the dugong on the remote coast of Queensland from Cooktown north including Torres Strait in a single field season. The results of previous surveys of sections of this region have been difficult to interpret because of the confounding influences of unpredictable dugong movements between areas within the region. Taken together, the results for the 2006 survey of the whole region of almost 56,000 km² suggest a total population of some 23500 ± 2900 dugongs close to the estimate of some 23000 ± 2600 for the combined 2000 survey of the northern Great Barrier Reef and 2001 surveys of Torres Strait. Both these estimates were generated using the methodology of Pollock et al. (2006), which corrects for the spatial heterogeneity of sighting conditions within and between regions and reduces the noise in the data that may otherwise obscure trends in the dugong population.

The aerial surveys of the northern Great Barrier Reef conducted since the mid 1980s have not demonstrated a significant decline in dugong numbers despite ongoing concern about the sustainability of the traditional harvest of dugongs in this region (Heinsohn et al. 2004) and the lack of significant management arrangements to regulate this harvest to date. Taylor et al. (2007) demonstrate that scientists’ ability to detect declines in marine mammal stocks is weak, even when the decline is precipitous. Thus the fact that this time series of aerial surveys has not detected a decline in abundance does not prove that the present levels of harvest are sustainable, especially if the rate of decline is low (which if decline is occurring it almost certainly is)."

---

Citation and/or URL

Marsh, H., Hodgson, A., Lawler, I.R., Grech, A. & Delean, S. 2008, Condition, status and trends and projected futures of the dugong in the northern Great Barrier Reef and Torres Strait: including identification and evaluation of the key threats and evaluation of available management options to improve its status, Reef and Rainforest Research Centre on behalf of the Australian Government’s Marine and Tropical Sciences Research Facility., Marine and Tropical Sciences Research Facility Report: , Cairns, Qld.

Spatial Coverage

Cooktown, Queensland north to Torres Strait (some data for Hervey Bay, Queensland)

Temporal Coverage

 1987 - 2006

Update Frequency

 Surveys conducted every five years.

Other Information

Grech, A. & Marsh, H. 2007.  'Prioritising areas for dugong conservation in a marine protected area using a spatially explicit population model'. Applied GIS 3(2): 1-14.