The penguins of Boulders Beach have been placed under threat by the H5N8 strain of avian influenza.
State veterinarian of epidemiology Dr Laura Roberts said that 18 penguin deaths are suspected to be linked to avian influenza. Only four deaths have been confirmed to be as a result of the outbreak, she said.
The outbreak was first identified on January 29, 2018 when the first penguin was found to be a carrier of the H5N8 strain.
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Roberts said that containing the virus would present a challenge.
"All possible precautions are being taken to limit the spread of the virus by people and their activities. As these are wild birds, containing the natural spread of the virus is not possible," she said.
Avian influenza is spread from bird to bird via mucus and faeces.
There are no indications that the virus will affect humans, but a small risk of infection remains.
"There have not been any confirmed human cases anywhere in the world, but there is a small chance the virus can adapt so we advise caution when handling sick birds," said Roberts.
"Also, humans can carry the virus on their clothes and hands and infect other birds," she said.