Shipments of fresh fruit and vegetables sent to feed scientists working at research stations in the Antarctic may be inadvertently introducing invasive alien species that could spoil its fragile ecosystem.
Kevin Hughes of the British Antarctic Survey and Dr Jennifer Lee, an ecologist at the Centre for Invasion Biology at Stellenbosch University, conclude this in their paper, “Food for Thought: risks non-native species transfer to the Antarctic region with fresh produce”, published in the journal Biological Conservation.
They detail how the importation of fresh foods into the Antarctic has the potential to pose a “biosecurity risk” by transporting soil, micro-organisms and invertebrates that originate from across the world.
Antarctica is the least invaded continent, according to the research, but this is changing with an exponential increase in the number of visitors and global climate change, which favours the establishment of non-indigenous species.
Fresh foods imported regularly to the Antarctic include fruit, vegetables and eggs.
The research reveals that 51 varieties of fresh produce from 130 locations throughout the world are transported into the Antarctic, including aubergines, avocadoes, bananas and parsnips.
The researchers examined and tested more than 11 250 items of fruit and vegetables sent to nine research stations in Antarctica and the sub-Antarctic islands. Their results showed that 12 percent of food items had soil on their surface, 28 percent showed microbial infection resulting in rot and more than 56 invertebrates were recorded, mainly from leafy produce.
Each gram of soil could contain over a billion bacteria and potentially thousands of microbial strains new to the Antarctic. The research also shows that insects may readily be transported to research stations by both aircraft and ship.
“The number of insects caught per month was highest following the major ship resupply of the station in late December 2005 when the (research) station population was high and fresh food consumption was close to its greatest level for the year. But during the winter months, when ship/aircraft operation ceased, almost no flying insects were caught.”
They also note that about 30 percent of identified fungi sampled from infected foods were not previously recorded from within the Antarctic region “although this may reflect limited knowledge of Antarctic fungal diversity”.
Lee said the potential threat of introduction of non-native species through cargo, vehicles, visitors’ clothing and personal equipment had been acknowledged but little was known about the consequences.
“It is probably one of the major risks,” Lee told the Saturday Star. “Just the amount of fresh produce means the risk is quite high. The only real way to absolutely stop species being introduced into the region is to stop fresh produce getting there altogether. But this is quite radical, because South Africa is committed. That’s not the case for the sub-Antarctic islands owned by other countries.”
South Africa is taking the lead in ensuring strict controls are in place when its teams venture to the Antarctic. For example, in 1996 South Africa implemented precautionary bans on fresh produce on Marion and Prince Edward Islands.
- Saturday Star