Invasive species `hitchhiking' on tourist and research ships threaten Antarctica's unique ecosystems

Date:
January 10, 2022
Source:
University of Cambridge
Summary:
Marine life hitching a ride on ocean-crossing ships poses a threat
to Antarctica's pristine ecosystems, with the potential for invasive
species to arrive from almost anywhere across the globe, say the
authors of a new study.



FULL STORY ========================================================================== Marine life hitching a ride on ocean-crossing ships poses a threat to Antarctica's pristine ecosystems, with the potential for invasive species
to arrive from almost anywhere across the globe, say the authors of a
new study.


==========================================================================
New research by the University of Cambridge and the British Antarctic
Survey has traced the global movements of all ships entering Antarctic
waters. It reveals that Antarctica is connected to all regions of
the globe via an extensive network of ship activity. Fishing, tourism,
research and supply ships are exposing Antarctica to invasive, non-native species that threaten the stability of its pristine environment.

The study is published today in the journal PNAS.

The researchers identified 1,581 ports with links to Antarctica, and say
that all could be a potential source of non-native species. The species
-- including mussels, barnacles, crabs and algae -- attach themselves
to ships' hulls, in a process termed 'biofouling'. The finding suggests
that they could arrive in Antarctic waters from almost anywhere across
the globe.

"Invasive, non-native species are one of the biggest threats to
Antarctica's biodiversity -- its native species have been isolated for
the last 15-30 million years. They may also have economic impacts, via the disruption of fisheries," said Professor David Aldridge in the Department
of Zoology at the University of Cambridge, senior author of the report.

The scientists say they are particularly concerned about the movement
of species from pole to pole. These species are already cold-adapted,
and may make the journey on tourist or research ships that spend the
summer in the Arctic before travelling across the Atlantic for the
Antarctic summer season.



==========================================================================
"The species that grow on the hull of a ship are determined by where
it has been. We found that fishing boats operating in Antarctic waters
visit quite a restricted network of ports, but the tourist and supply
ships travel across the world," said Arlie McCarthy, a researcher in
the University of Cambridge's Department of Zoology and the British
Antarctic Survey, and first author of the report.

Research vessels were found to stay at Antarctic ports for longer
durations than tourism vessels. Fishing and supply ships stay for even
longer, on average. Previous research has shown that longer stays increase
the likelihood of non-native species being introduced.

Due to its remote, isolated location, there are many groups of
species that Antarctic wildlife has not evolved the ability to
tolerate. Mussels, for example, can grow on the hulls of ships and
currently have no competitors in Antarctica should they be accidentally introduced. Shallow-water crabs would introduce a new form of predation
that Antarctic animals have never encountered before.

"We were surprised to find that Antarctica is much more globally connected
than was previously thought. Our results show that biosecurity measures
need to be implemented at a wider range of locations than they currently
are," said McCarthy.

She added: "There are strict regulations in place for preventing
non-native species getting into Antarctica, but the success of these
relies on having the information to inform management decisions. We
hope our findings will improve the ability to detect invasive species
before they become a problem." The study combined verified port call
data with raw satellite observations of ship activity south of -60DEG
latitude, from 2014-2018. Vessels were found to sail most frequently
between Antarctica and ports in southern South America, Northern Europe,
and the western Pacific Ocean.

The Southern Ocean around Antarctica is the most isolated marine
environment on Earth. It supports a unique mix of plant and animal
life, and is the only global marine region without any known invasive
species. Increasing ship activity in this region is escalating the threat
of non-native species being accidentally introduced.

Large krill fisheries in the southern oceans could also be disrupted by invasive species arriving on ships. Krill is a major component of the
fish food used in the global aquaculture industry, and krill oil is sold
widely as a dietary supplement.

"Biosecurity measures to protect Antarctica, such as cleaning ships'
hulls, are currently focused on a small group of recognised 'gateway
ports'. With these new findings, we call for improved biosecurity
protocols and environmental protection measures to protect Antarctic
waters from non-native species, particularly as ocean temperatures
continue to rise due to climate change," said Professor Lloyd Peck,
a researcher at the British Antarctic Survey, who was also involved in
the study.

========================================================================== Story Source: Materials provided by University_of_Cambridge. Original
written by Jacqueline Garget. The original text of this story is licensed
under a Creative_Commons License. Note: Content may be edited for style
and length.


========================================================================== Related Multimedia:
* Antarctica's_fragile_ecosystems_at_risk_from_'hitchhiking'_species ========================================================================== Journal Reference:
1. Arlie H. McCarthy, Lloyd S. Peck, David C. Aldridge. Ship traffic
connects Antarctica's fragile coasts to worldwide
ecosystems. Proceedings of the National Academy of Sciences, 2022;
119 (3): e2110303118 DOI: 10.1073/pnas.2110303118 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/01/220110184903.htm
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