With people come plagues

日期:2017-06-26 02:24:11 作者:诸厶 阅读:

By Ian Anderson in Hobart HUMAN food and sewage are threatening Antarctica’s unique wildlife with devastating diseases. Scientists have become so alarmed that they are pressing for international agreement on a wide-ranging set of measures designed to keep the continent free of dangerous pathogens. The proposals, adopted last week in Hobart, Tasmania, at a gathering of 50 Antarctic specialists, will be presented in May 1999 to the next meeting of the Antarctic Treaty nations in Lima, Peru. “With the growing number of scientists and tourists going to Antarctica, there is cause for concern,” says Knowles Kerry of the Australian Antarctic Division in Hobart, whose work helped set the alarm bells ringing. In May 1997, Kerry and his colleagues reported finding antibodies to a virus commonly found in chickens in the blood of Emperor penguin chicks and adult Adélie penguins near the Australian base of Mawson (Nature, vol 387, p 245). This infectious bursal disease virus (IBDV) suppresses birds’ immune systems, making them susceptible to other diseases. The Hobart meeting reviewed mounting evidence that animals in Antarctica and subantarctic islands are being exposed to new pathogens. A team from Umeå University in Sweden has found Salmonella and Campylobacter bacteria in faecal samples collected since 1996 from Antarctic fur seals, gentoo and macaroni penguins, skuas, and black-browed albatrosses on Bird Island, off South Georgia. Last year, Argentinian scientists reported that 19 brown and south polar skuas died from infection with a hyphomycete fungus at Hope Bay in the northern Antarctic Peninsula. And in one of the largest outbreaks reported to date, 1345 New Zealand sea lion pups and 85 adults died in January and February this year from septicaemia on the Auckland Islands, 600 kilometres south of New Zealand. Biopsies revealed Salmonella and a second, unidentified bacterium. Although scientists can’t be sure that people are spreading the pathogens, circumstantial evidence suggests that they are. For instance, Kerry and his colleagues detected no IBDV antibodies in emperor and Adélie penguins at a remote colony in the Ross Sea rarely visited by people. The Hobart meeting proposed a package of precautionary measures. Everyone visiting Antarctica should be briefed on how to avoid spreading disease. All equipment and clothing, especially boots, should be cleaned after visiting wildlife sites. Poultry, which can contain pathogens even after processing, poses a particular threat. Certification schemes should be introduced to ensure that poultry products shipped to Antarctica come from flocks that are free of dangerous diseases. The other main threat is sewage, which is discharged untreated from most scientific bases. The meeting called for bases to install some form of treatment. According to James Smith of Montana Microbiological Services in Bozeman, who has studied the discharge of sewage from the American McMurdo Station (This Week, 13 June, p 21), human faeces should be boiled at 100 °C for five minutes. The proposals also include procedures for responding to disease outbreaks, to be coordinated by a central agency,