Brucellosis Found in Antarctic Seals

SANTIAGO, Chile, January 18, 2000 (ENS) - The serious reproductive disease, brucellosis, may have infected Antarctic seals.

Chilean scientists are further investigating a discovery of Brucella antibodies found in five of 16 fur seals and a Weddell seal examined by the scientists from Instituto Antartico Chileno (INACH). The discovery was reported in a paper to the Antarctic Treaty's Commission for the Conservation of Antarctic Living Resources (CCAMLR).

It was the first ever finding in Antarctic seals of antibodies to this disease, which usually affects the reproductive system of cattle and other hoofed mammals, generating sterility in males and causing pregnant females to abort. It can infect humans, mainly with mild results.

No evidence of the full blown disease itself has yet been described in Antarctica.

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Weddell seals (Photo by O. Ertok courtesy Polar Mist Expeditions)
Studies of the Antarctic seals were undertaken at a big Antarctic Fur Seal breeding colony at Cape Shirreff, on the northern coast of Livingston Island in the South Shetland group. Occasionally Weddell seals visited the area, and as only one was tested for the antibodies, its positive result was said to show either that they were highly susceptible, or that the result was an extreme coincidence.

Olivia Blank-Hidber, of INACH, and other authors said in the paper it was remarkable that brucella bacteria had been found in wild marine mammals off Scotland, and in captive U.S. marine mammals.

The paper said that brucella transmission on land occurs by direct contact between animals, and there was no clear pattern that could explain its movement from the northern hemisphere to Antarctica.

It concluded, "the finding of brucella infection that we report outlines a new element for the conservation problems that affects the Southern Ocean fauna, that must be considered under the Antarctic Treaty system."

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Baby fur seal (Photo by John van den Luft courtesy Polar Mist Expeditions)
INACH's Professor Daniel Torres said Blank-Hidber returned to Livingston Island this summer to collect further samples in an attempt to discover whether the brucella was a new species or one already described. "As soon as possible the results obtained by her will be analysed, and their results given to CCAMLR as well as to the SCAR Group of Specialists on Seals."

Meanwhile Antarctic tourist guides have been warned to take extra precautions to deal with potential contact. The International Association of Antarctic Tour Operators has issued an advisory note proposing extra care with disinfection procedures, and to avoid touching any seal remains.

It is not the first discovery of antibodies to an exotic disease in Antarctic wildlife. In 1996 Australian scientists announced the presence of Infectious Bursal Disease Virus at Adelie and Emperor penguin colonies near Mawson Station in East Antarctica.

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Map of Antarctica showing the South Shetland group of islands where the infected seals were found. (Map courtesy CIA World Factbook)
Cape Shirreff, where the brucellosis infected seals were found, is an ice-free peninsula lying to the north of the northern margin of the permanent ice cap on Livingston Island, between Barclay Bay and Hero Bay.

It has been designated for protection as a site of special scientific interest because both Antarctic fur seal and penguin breeding colonies, and krill fisheries within the foraging range of these species must be part of the ecosystem monitoring network to help meet the objectives of the Convention for the Conservation of Antarctic Marine Living Resources. Cape Shirreff supports a diversity of plant and animal life, including many invertebrates, and a substantial population of elephant seals.

{Published in cooperation with The Antarctican.}