Dugongs and Seagrass

Serious concern has been expressed about the vulnerability of the dugong population in the Great Barrier Reef Marine Park. Their dependence on seagrass means that they are associated with shallow, coastal habitats that bring them in contact with human activities. Dugong numbers in the southern Great Barrier Reef appear to be about 3% of that present in the early 1960s.

The Hinchinbrook area has the second largest remaining dugong population in the southern Great Barrier Reef, to safeguard this population a series of management actions have been implemented in the region, including:

• establishment of two Dugong Protection Areas that place restrictions on mesh netting;
• a voluntary moratorium on traditional hunting of dugong;
• encouraging boaties to travel along a marked transit lane to minimise animal displacement;
• encouraging reduced boat speed limits outside the transit lanes when travelling over seagrass; and
• the development of a free brochure explaining the magnificent natural values of the region, which includes a useful map explaining how to use the vessel transit lanes.
  

Seagrass beds

Significant seagrass beds occur in many parts of the Hinchinbrook Planning Area and sustain a rich and diverse fauna and flora. The Hinchinbrook area supports some 12,700 hectares recorded between Dunk Island and Lucinda. Seagrass beds are important nursery habitats for many species, such as prawns. Dugongs depend on healthy seagrass meadows to survive. Threats to the maintenance of adequate seagrass coverage can occur from a variety of vessel-related activities. Examples include: the dragging of an anchor chain along the substrate and the disturbance of sediments from large vessels transiting at speeds over shallow seagrass areas.