Title

Organochlorine and heavy metal pollutant concentrations in dugongs (Dugong dugon) and the implications for species management

Objectives

1. To assess pollutant concentrations in key dugong habitat along the Queensland coast.

   1. To document concentrations of organochlorine pesticides, PCBs, dioxins, atrazine and heavy metals in key tropical Queensland coastal environments (nearshore sediments and seagrass meadows);
   2. To correlate environmental pollutant burdens with human activity; and
   3. To use pollutant partitioning models to investigate movement of pollutants between sediments, seagrass and biota.

2. To document pollutant concentrations in dugongs along the Queensland coast.

   1. To document concentrations of organochlorines, PCBs, dioxins, PAHs and heavy metals in blubber and liver samples collected from stranded dugongs;
   2. To compare body burdens of pollutants from geographically disjunct dugong populations to identify areas of contamination risk to dugongs; and
   3. To correlate pollutant body burdens with other key dugong anatomical measurements and data.

3. To produce a risk assessment for Queensland dugong habitat.

   1. To develop a risk assessment for dugongs from pollutants incorporating data obtained from this study and elsewhere; and
   2. To assess health risks to Indigenous communities from consumption of contaminated dugong tissue.

Methodology

Tissue samples to be collected opportunistically from dugongs reported stranded along the marine park seaboard and elsewhere between September 1996 and July 2000. Carcass recovery will be carried out in conjunction with Queensland Parks and Wildlife Service staff. Following analysis, temporal and spatial variation in dugong pollutant body burdens will be examined and correlated with animal sex, age, condition and home range. Potential hazard to human health from tissue consumption will also be examined.

Sediment and seagrass samples were collected from 17 sites from Torres Strait to Moreton Bay between February and June 1997.

Sites selected include:

All sites selected (with the exception of Cairns) are recognised dugong habitat and are under a range of human urban and agricultural influences. Samples will be collected using clean techniques and be analysed for organochlorines, PCBs, dioxins, atrazine and heavy metals during 1997. This data will then be combined with other information to carry out risk assessment for dugong habitat and stocks within Queensland waters. Partitioning models will be used to develop pollutant mass balances for Marine Park waters.

Time

Three years

Funding

The project was initially (1997–1998) funded through the Great Barrier Reef Marine Park Authority Water Quality Programs and is being continued through an ARC SPIRT grant.