Marsh and Lawler, 2006:

"If an objective of the current management arrangements is dugong population maintenance then these arrangements appear successful; if the objective is population recovery they are not.

In response to the difficulties in estimating trends in the population size of marine mammals, Wade (1998) developed the PBR method of setting targets for sustainable levels of anthropogenic mortality. A recovery factor of < 1 allocates a proportion of expected net production towards population growth and compensates for uncertainties and biases in the data that might prevent population recovery, including errors in estimating population size (which should be less for dugongs using the method of Pollock et al. (2006) than the earlier method of Marsh & Sinclair (1989)).

The resultant estimates of the PBR for urban coast of Queensland range from 2 to 114 (Table 4), illustrating the importance of stakeholder consensus about the appropriate level of the recovery factor. If the agreed recovery factor is 0.1, management should be implemented with the aim of achieving an anthropogenic mortality target of zero."

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Citation and/or URL

Marsh H.D, and Lawler I.R., 2006. Dugong distribution and abundance on the urban coast of Queensland:  a basis for management.  Final report to Marine and Tropical Research Facility Interim Projects 2005-6. 1-85, James Cook University.

Spatial Coverage

 Cooktown south to Queensland/NSW border

Temporal Coverage

 1986 - 2005

Update Frequency

 Surveys conducted every five years

Other Information

Grech, A. and 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