abstract

Marine mammals are regarded as good bioindicators of environmental changes. However, the information available about the health status of the Antarctic marine mammals is very scarce and fragmented. In addition, human derived activities such as tourism and global warming could be compromising these populations. In this sense there is a worldwide scientific consensus regarding the importance of health monitoring the Antarctic fauna.

The aim of this study was to evaluate the health status of Antarctic pinnipeds from Deception Island, and other areas in the South Shetland Islands and the Antarctic Peninsula. The animal species studied included Weddell seals (Leptonychotes weddelli), crabeater seals (Lobodon carcinophagus), leopard seals (Hydrurga leptonyx), Southern elephant seals (Mirounga leonina) and Antarctic fur seals (Arctocephalus gazella). Besides the clinical assessment of individuals, some population and morphology parameters were gathered. Faecal samples were collected from 222 animals during the Antarctic summers of 2006 and 2007. In addition, 50 animals were physically restrained for a general physical exam, blood collection and swab sampling from rectum, genitals, conjunctiva and nostrils.

Most relevant lesions detected were genital and ocular pathologies. Few animals showed inflammatory profile changes in haemograms. Overall, animals presented high infection rates by gastrointestinal parasites (nematodes, cestodes, and acanthocephalans) which are currently being identified. Preliminary microbiologic analyses included the isolation of Campylobacter lari and Campylobacter insulaenigrae from Antarctic fur seals, and the detection of Mycobacterium sp. by PCR in Southern elephant seals. On the other hand, all faecal samples were negative to Salmonella spp. and Yersinia spp. A general scan of faecal enteric bacteria revealed cold tolerant organisms commonly found in fish-eating mammals such as Vibrio spp., Aeromonas spp., Pasteurella spp., Edwardsiella spp. as well as Clostridium perfringens and different enteric bacteria, mainly Escherichia coli. In the case of the ocular and nasal swabs, Staphylococcus spp. and Streptococcus spp. were the most important bacteria isolated. Additional analyses as well as serological tests are currently being carried out.