Tourism and other shipping could be a threat to fragile Antarctic ecosystem. Photo / Getty Images
Tourism and other shipping could be a threat to fragile Antarctic ecosystem. Photo / Getty Images
Tourists are returning to continental Antarctica after being frozen out by the long Coronavirus pandemic, but there are concerns they aren't the only ones hitching a ride to the ice.
A new paper suggests that tourist vessels are providing a way for pests and invasive species to reach the pristine white ecosystem.
The study revealed that Antarctica is now connected by 1,581 ports of origin, outside the South Sea.
As a continent without a border force or biosecurity, researchers from the University of Cambridge are concerned that the species that live there could be at risk from alien invaders.
"Antarctica is globally connected," says DPhil candidate Arlie McCarthy.
While there are a number of 'Gateway Cities' such as Christchurch which provide important links to the ice, the study suggests that Antarctica is being "increasingly exposed to the negative effects of shipborne human activity."
63 per cent of voyages to Antarctica depart from 5 ports known as 'gateway cities', of which Christchurch's port of Lyttelton is one. As the location of most of the Antarctic research programmes and specialised polar industries, the majority of Antarctic shipping passes through these ports.
The study reveals that there is a growing amount of traffic bound for Antarctica, from around the world. The remaining 37 per cent came from 70 other ports, outside the South Sea network.
Over the last five years Antarctica has seen direct traffic from global ports as far away as Busan and Singapore.
Three per cent of shipping came from non Antarctic Treaty countries.
This has possibly been sped up by the Coronavirus pandemic and travel restrictions such as New Zealand's 'Maritime Border Order', which have seen vessels take new resupply routes from all over the world.
While the largest focus of shipping was across the Drake Passage, New Zealand's Ross Dependency was not far behind.
"After the Antarctic Peninsula and South Shetland Islands the Ross Sea is the next most connected and visited area," said McCarthy.
We have a cling-on, captain!
Although any stowaway species - such as rats and insects - are a concern, the study was focused on marine ecology.
Ships' hulls can be an unwitting vector for transporting invasive species.
Barnacles, algae and other marine creatures attach themselves to hulls and can be transported long distances. The transfer of non-native species by this method is referred to as "biofouling".
Alien invasion: Biofouling refers to non-native marine species like barnacles, transported on a ship's hull. Photo / Wikimedia Commons
The increase of tourism vessels were seen as a high risk factor for transporting alien species to the Antarctic, due to their more frequent and shorter itineraries which tended to be during warmer seasons.
According to the International Association of Antarctic Tour Operators (IATO), the summer prior to the 2020 pandemic saw 70,000 visitors arrive in Antarctica.
Nathan Russ of Heritage Expeditions said that tourism operators were less of a concern, and already subject to strict bioscreening measures, particularly in New Zealand.
"New Zealand already has the highest threshold of screening for biofouling set by MPI, in order to enter the country. This is on top of the standards set by the Department of Conservation and Southland."
Heritage's polar expedition ships relocate from the Northern Hemisphere to the South, following the polar summer seasons. Tourists, who are transported to the Ross Dependency and New Zealand Subantarctic islands, must also be screened for stowaway species.
Regular drydocking and diving is undertaken to inspect for non-native species, says Russ. It's an "academic exercise" which doesn't get the practicalities of travelling to Antarctica. "It's any ship and every ship," says Russ "Tourism operators in our industry, particularly those based out of Gateway cities, are very aware of biofouling as a whole. Fishing vessels would probably be a larger risk."
McCarthy agrees that while the volume and type of ship is quite different to heavily visited areas such as the Antarctic Peninsula and South Shetlands, but "there is still some risk for the Ross Sea area."
"The vessels that visit the Ross Sea are predominantly research and fishing vessels, which may pose a slightly different risk."
Should the Antarctic Gateways be gatekeepers?
As Antarctica has no recognised ports or biosecurity checks, it is up to the ports of departure to oversee bioscreening.
"An Antarctic tourist vessel sailing from those gateways - such as Ushuaia and Punta Arenas - will be held to the standards of their port of departure," says Russ.
Impenetrable pack ice means the Ross Sea region is only accessible to tourists for around two months each summer. Photo / Heritage Expedi
Vessels sailing from elsewhere in the world for fishing and resupply are likely to bypass gateway countries and their biofouling measures.
A trend accelerated by Covid maritime border restrictions, Antarctica is likely to receive shipping from more exotic ports over the next decade as the shipping routes become busier with base redevelopments.
New Zealand, Australia and the US are among the countries which have ambitious redevelopments planned for their Antarctic Programme facilities.
The study concluded that rather than restricting shipping departing from non-gateway ports, more cities should be given 'gateway' status.
It suggested that the two largest sources of Antarctic traffic - Port Stanley in the Falklands and Monte Video in Uruguay - be recognised as gateway cities and shipping held to the same standards.
"We recommend that for biosecurity and environmental considerations, the recognition of Gateway cities or responsible port states to be expanded to include at least these seven nations and their ports," said the report.
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