An animal scientist wants more Australian sea lions tested for tuberculosis, after one of the creatures was found to have died from the disease on Kangaroo Island.
Key points:
- A sea lion on Kangaroo Island was found to have died from tuberculosis
- The disease can be passed on to humans but only with very close contact
- Scientists who wrote a paper on the discovery hope it prompts more research
The three-year-old juvenile sea lion was found dead on a beach at Kingscote in 2017, but the case was only reported in the Journal of Wildlife Diseases last week.
Paper author Rachael Gray, from the University of Sydney, said tuberculosis had been detected in seals and sea lions around the world but it was rare in Australian waters.
She said the Kangaroo Island case was the first time tuberculosis had been detected in a sea lion’s abdomen, rather than its lungs, in South Australia.
The island is home to one of Australia’s largest colonies of sea lions which are considered endangered by the International Union for Conservation.
Dr Gray said while the discovery of tuberculosis in one of the animals was a public health issue, there was no “need to panic”.
She said the main threat to the public was from finding dead or dying animals, and that the risk at Seal Bay Conservation Park — where tourists can join sea lions on the beach — was “not present”.
“It’s mainly transmitted in people that have really close contact to infected animals — people like me: researchers, people involved in animal rescue, zookeepers,” she said.
However, she warned people not to touch sick or dead seals or sea lions.
“If you found a sea lion or fur seal on a beach in a remote area, you’re better off contacting the appropriate authorities and letting them know an animal is there,” Dr Gray said.
The bacteria that causes tuberculosis in seals and sea lions, Mycobacterium pinnipedii, is different to the one that causes the disease in humans — but humans can catch the seal version.
Zookeepers in Western Australia in the late 1980s and early 1990s caught it from sea lions in captivity.
“If the animal has an intestinal form of tuberculosis, which this case actually did, that the bacteria can also be passed in the faeces and in some cases, [we] also think, in the urine.
“We need to keep in mind safety and hygiene when we deal with any animal, really.”
The South Australian Department for Environment and Water, Biosecurity SA and SA Health were notified of the tuberculosis case after results of the necropsy came back.
An SA Health spokeswoman said the risk to the public was deemed to be “minimal”.
Push for ‘population surveillance’
In their article, Dr Gray and Adelaide-based PhD candidate Scott Lindsay called for “population surveillance” among sea lions to as assess the threat posed to the animals by tuberculosis and other diseases.
“A lot of them will just disappear and die in the ocean rather than actually hauling out on land and in a site [we] can actually find.”
Tony Coppins, who runs tours for people to swim with seals, sea lions and dolphins on Kangaroo Island, said tourists were “fairly well versed in keeping their distance from wild animals”.
Dr Gray said hookworm was a much greater threat to sea lions than tuberculosis.
About 40 per cent of the species failed to reach adulthood, and a considerable proportion of the premature deaths could be attributed to hookworm, she said.
