Disease and Antarctic wildlife

Recent developments

In 1997, Australia presented an information paper to Antarctic Treaty Consultative Meeting XXI reporting serological evidence that Adélie penguins and emperor penguins at some locations had been exposed to Infectious Bursal Disease Virus (IBDV). The observation was based on antibody reactions and the virus causing the reaction has not been positively isolated. However, the discovery focused attention on the increasing risk of disease introduction due to the greater number of people travelling to Antarctica. Australia offered to host a workshop to discuss the issues of disease and to report the outcomes of the workshop at a later Antarctic Treaty Consultative Meeting.

Disease workshop

The workshop, convened in 1998 by the Australian Antarctic Division in Hobart, was the first international meeting to consider disease in Antarctic wildlife. The meeting was open to all interested parties and was attended by 52 participants from 8 different countries. Participants included Antarctic biologists, legal and policy specialists, scientists with experience of wildlife disease in other regions and quarantine procedures, members of non-government environmental organisations and an Antarctic tourist operator. The objectives of the workshop were to identify the potential for disease incursion into Antarctic wildlife and to develop a series of recommendations to reduce the risk of disease introduction, and to limit the chance of disease establishment and spread.

Major findings of the workshop

Risks of disease introduction and spread

There are a number of direct and indirect mechanisms for human activity in Antarctica to be the cause of disease outbreaks. People could act as vectors for infectious agents, either by bringing non-indigenous pathogens into the region or by translocating indigenous pathogens. In addition, stress caused by human activity could reduce immunity, increase pathogenicity and could cause the expression of an indigenous disease that might otherwise not have revealed itself. Stress may be the result of direct human disturbance, food shortage (perhaps caused by fisheries competing for the same food stocks), exposure to pollutants and possibly, in the longer term, as a result of climate change.

The nature of activities in Antarctica is changing in ways that could increase the risk of disease introduction or spread. Access to the continent is becoming easier with the introduction of new intercontinental air transport facilities and rapid movement around the continent is possible using both helicopters and fixed wing aircraft. Tourism interest in the Antarctic is increasing and aggregations of wildlife are a major attraction for tourists, with many itineraries including visits to several colonies around the Antarctic coast. Sequential visits to a number of colonies could facilitate the transfer of disease from one colony to another if precautions are not taken.

The remoteness of the Antarctic continent may have isoloated its wildlife from many diseases that are common elsewhere. A possible consequence of this isolation could be that Antarctic species have limited immunity and are more susceptible to disease once they are exposed to infectious agents. The highly contagious viral diseases (such as morbillivirus, Newcastle disease and influenza), the immunosuppressant diseases (such as infectious bursal disease, morbillivirus and retrovirus) and agricultural and zoonotic diseases (such as brucellosis, tuberculosis and leptospirosis) are considered to be the greatest potential risk to the health of Antarctic wildlife. Non-infectious agents such as pollutants and toxins discharged from stations and ships might be the direct cause of unusual mortality events or they might be just one contributing factor leading to the expression of disease that might otherwise remain dormant.