Although little is known about diseases in marine wildlife, animals are susceptible to them. Identifying a specific disease is very difficult. Often carcasses of dugongs, whales, dolphins and turtles wash ashore on beaches but are too decomposed for an accurate determination of the cause of death.

Diseases diagnosed from marine wildlife in the Great Barrier Reef and Hervey Bay include morbilliviruses, Toxoplasmosis and a Cryptosporidium protozoan. Whilst such organisms have been implicated elsewhere in the world in epidemics amongst other marine mammals, like seals and dolphins, their significance for the Great Barrier Reef is unknown.

Any decline in water or habitat quality could initiate or enhance disease in marine wildlife. There is some risk of disease transmissions between marine wildlife and humans when they come in contact with untreated human waste, but the degree of risk is difficult to assess.

The presence of toxic substances in the environment, or other factors that cause stress on marine wildlife, may increase their susceptibility to contracting disease, for example by impairing their immune systems. Disease outbreaks can also affect marine wildlife such as green turtles and dugongs indirectly, such as loss of seagrass species.

Actions:

• The Great Barrier Reef Marine Park Authority (GBRMPA) and Queensland Government agencies, with support from aquariums and veterinarians, coordinate a marine mammal and turtle strandings programme that involves the rehabilitation of live animals and determination of cause of injury or, if a carcass is involved, death. Rehabilitated animals are either released to the wild or retained in captivity for educational purposes if they have been rescued as young calves. Annual reports about the programme are available at the Environmental Protection Agency (EPA) website
• An EPA Hotline is operated as part of the strandings programme. If a dugong or turtle is found, the public should phone 1300 130 372 with details of location, what animal it is (if known), and whether it is dead or alive.

The GBRMPA operates a Marine Wildlife Stranding Listserver to quickly inform interested people about strandings. Subscribers are provided with details such as a description of the animal, the location of the incident and, if available, biological information (for example, species, size, sex, reproductive status) and an appraisal of cause of death. Automatic free subscription is available through the GBRMPA website.