COVID has reached Antarctica. Scientists are extremely concerned for its wildlife

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Michelle Power, Macquarie University and Meagan Dewar, Federation University Australia

In December, Antarctica lost its status as the last continent free of COVID-19 when 36 people at the Chilean Bernardo O’Higgins research station tested positive. The station’s isolation from other bases and fewer researchers in the continent means the outbreak is now likely contained.

However, we know all too well how unpredictable — and pervasive — the virus can be. And while there’s currently less risk for humans in Antarctica, the potential for the COVID-19 virus to jump to Antarctica’s unique and already vulnerable wildlife has scientists extremely concerned.

We’re among a global team of 15 scientists who assessed the risks of the COVID-19 virus to Antarctic wildlife, and the pathways the virus could take into the fragile ecosystem. Antarctic wildlife haven’t yet been tested for the COVID-19 virus, and if it does make its way into these charismatic animals, we don’t know how it could affect them or the continent’s ecosystem stability.

Bernardo O Higgins Station in Antarctica, where 36 people tested positive to COVID-19.
Stone Monki/Wikimedia, CC BY-SA

Jumping from animals to humans, and back to animals

The COVID-19 virus is one of seven coronaviruses found in people — all have animal origins (dubbed “zoonoses”), and vary in their ability to infect different hosts. The COVID-19 virus is thought to have originated in an animal and spread to people through an unknown intermediate host, while the SARS outbreak of 2002-2004 likely came from raccoon dogs or civets.

Given the general ubiquity of coronaviruses and the rapid saturation of the global environment with the COVID-19 virus, it’s paramount we explore the risk for it to spread from people to other animals, known as “reverse zoonoses”.

The World Organisation for Animal Health is monitoring cases of the COVID-19 virus in animals. To date, only a few species around the globe have been found to be susceptible, including mink, felines (such as lions, tigers and cats), dogs and a ferret.

Whether the animal gets sick and recovers depends on the species. For example, researchers found infected adolescent cats got sick but could fight off the virus, while dogs were much more resistant.

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Researchers and tourists

While mink, dogs or cats are not in Antarctica, more than 100 million flying seabirds, 45% of the world’s penguin species, 50% of the world’s seal populations and 17% of the world’s whale and dolphin species inhabit the continent.

Tourists visit penguin roosts in large numbers.
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In a 2020 study, researchers ran computer simulations and found cetaceans — whales, dolphins or porpoises — have a high susceptibility of infection from the virus, based on the makeup of their genetic receptors to the virus. Seals and birds had a lower risk of infection.

We concluded that direct contact with people poses the greatest risk for spreading the virus to wildlife, with researchers more likely vectors than tourists. Researchers have closer contact with wildlife: many Antarctic species are found near research stations, and wildlife studies often require direct handling and close proximity to animals.

Tourists, however, are still a concerning vector, as they visit penguin roosts and seal haul-out sites (where seals rest or breed) in large numbers. For instance, a staggering 73,991 tourists travelled to the continent between October 2019 and April 2020, when COVID-19 was just emerging.

Each visitor to Antarctica carries millions of microbial passengers, such as bacteria, and many of these microbes are left behind when the visitors leave. Most are likely benign and probably die off. But if the pandemic has taught us anything, it takes only one powerful organism to jump hosts to cause a pandemic.

How to protect Antarctic wildlife

There are guidelines for visitors to reduce the risk of introducing infectious microbes. This includes cleaning clothes and equipment before heading to Antarctica and between animal colonies, and keeping at least five metres away from animals.

These rules are no longer enough in COVID times, and more measures must be taken.

The first and most crucial step to protect Antarctic wildlife is controlling human-to-human spread, particularly at research stations. Everyone heading to Antarctica should be tested and quarantined prior to travelling, with regular ongoing tests throughout the season. The fewer people with COVID-19 in Antarctica, the less opportunity the virus has to jump to animal hosts.

Cetaceans, such as orcas, are more susceptible to COVID infections than sea birds and seals.
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Second, close contact with wildlife should be restricted to essential scientific purposes only. All handling procedures should be re-evaluated, given how much we just don’t know about the virus.

We recommend all scientific personnel wear appropriate protective equipment (including masks) at all times when handling, or in close proximity to, Antarctic wildlife. Similar recommendations are in place for those working with wildlife in Australia.

Migrating animals that may have picked up COVID-19 from other parts of the world could also spread it to other wildlife in Antarctica. Skuas, for example, migrate to Antarctica from the South American coast, where there are enormous cases of COVID-19.

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And then there’s the issue of sewage. Around 37% of bases release untreated sewage directly into the Antarctic ecosystem. Meanwhile, an estimated 57,000 to 114,000 litres of sewage per day is dumped from ships into the Southern Ocean.

Fragments of the COVID virus can be found in wastewater, but these fragments aren’t infectious, so sewage isn’t considered a transmission risk. However, there are other potentially dangerous microbes found in sewage that could be spread to animals, such as antibiotic-resistant bacteria.

Ships dump 114,000 litres of sewage into the water, each day.
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We can curb the general risk of microbes from sewage if the Antarctic Treaty formally recognises microbes as invasive species and a threat to the Antarctic ecosystem. This would support better biosecurity practices and environmental control of waste.

Taking precautions

In these early stages of the pandemic, scientists are scrambling to understand complexity of COVID-19 and the virus’s characteristics. Meanwhile, the virus continues to evolve.

Until the true risk of cross-species transmission is known, precautions must be taken to reduce the risk of spread to all wildlife. We don’t want to see the human footprint becoming an epidemic among Antarctic wildlife, a scenario that can be mitigated by better processes and behaviours.

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Michelle Power, Associate Professor in the Department of Biological Sciences, Macquarie University and Meagan Dewar, Lecturer, Federation University Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Australia must control its killer cat problem. A major new report explains how, but doesn’t go far enough

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Sarah Legge, Australian National University; Chris Dickman, University of Sydney; Jaana Dielenberg, Charles Darwin University; John Woinarski, Charles Darwin University, and Tida Nou, The University of Queensland

Australia is teeming with cats. While cats make great pets, and can bring owners emotional, psychological and health benefits, the animals are a scourge on native wildlife.

Cats kill a staggering 1.7 billion native animals each year, and have played a major role in most of Australia’s 34 mammal extinctions. They continue to pose an extinction threat to at least another 120 species.

The long-nosed potoroo is extremely vulnerable to cats.
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A recent parliamentary inquiry into the problem of feral and pet cats in Australia has affirmed the issue is indeed of national significance. The final report, released last week, calls for a heightened, more effective, multi-pronged and coordinated policy, management and research response.

As ecologists, we’ve collectively spent more than 50 years researching Australia’s cat dilemma. We welcome most of the report’s recommendations, but in some areas it doesn’t go far enough, missing major opportunities to make a difference.

Night curfews aren’t good enough

The report recommends Australia’s 3.8 million pet cats be subject to night-time curfews. This measure would benefit native nocturnal mammals, but won’t save birds and reptiles, which are primarily active during the day.

Wes Mountain/The Conversation, CC BY-ND

Pet cats kill 83 million native reptiles and 80 million native birds in Australia each year. From a wildlife perspective, keeping pet cats contained 24/7 is the only responsible option.

It’s clearly possible: one third of Australian pet cat owners already keep their pets contained all the time.

Stopping pet cats from roaming is also good for the cats, which live longer, safer lives when kept exclusively indoors. It would also substantially reduce the number of people falling ill from cat-dependent diseases each year.

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Other strategies for improving pet cat management proposed in the report include pet cat registration, subsidised programs for early age desexing, public education campaigns to promote responsible pet cat ownership, and improving the consistency of rules and legislation nationally.

Indoor cats live longer than cats allowed to roam.
Jaana Dielenberg

The report is also unambiguously opposed to “trap-neuter-release” programs, in which un-owned cats in urban areas are desexed and then released. We agree with this finding, as these programs aren’t effective at reducing the population of stray cats, nor preventing those cats from killing wildlife and spreading disease.

We need more wildlife havens

One of the inquiry’s flagship recommendations is a national conservation project dubbed “Project Noah”. This would involve an ambitious expansion of Australia’s existing network of reserves free from introduced predators, both on islands and in mainland fenced areas. The reserves provide havens — or a fleet of “arks” — for vulnerable native wildlife.

This measure is vital. 2019 research found Australia has more than 65 native mammal species and subspecies that can’t persist, or struggle to persist, in places with even very low numbers of cats or foxes. This includes the bilby, numbat, quokka, dibbler and black-footed rock wallaby.

Boodies used to occur across two-thirds of Australia, but now only exist within havens.
McGregor/Arid Recovery

Australia already has more than 125 havens, 100 of which are islands. These have prevented 13 mammal species from going extinct, such as boodies and greater stick-nest rats. In total, these havens have protected populations of 40 mammal species susceptible to cats and foxes.

This is a good start, but we need more investment in havens to prevent extinctions. More than 25 species are highly sensitive to cat and fox predation, but aren’t yet protected in the haven network. This includes the central rock-rat, which is more likely than not to become extinct within 20 years without new action.

What’s more, some species, such as the long-nosed potoroo, exist in just one haven. To avoid issues such as inbreeding and to ensure disasters like a fire at any single haven don’t take out an entire species, each species should be represented across several havens, in reasonable population sizes.

The report didn’t specify how the havens network should be expanded. But 2019 research found to get each species needing protection into at least three havens, Australia requires at least 35 new, strategically located islands or mainland fenced areas.

The predator proof fence at the Australian Wildlife Conservancy’s Newhaven Sanctuary, one of the largest cat- and fox-free havens on mainland Australia.
Australian Wildlife Conservancy

What about the rest of the country?

Havens cover less than 1% of Australia. So what we do in the other 99% of the landscape — including across conservation reserves like national parks — is vital.

Yet the parliamentary inquiry report lacks clear recommendations to expand cat control more broadly, including at important conservation sites such as in Kakadu National Park.

The impact of roaming pet cats on Australian wildlife.

The report reaffirms the need to cull feral cats, and to set new targets for culling, without specifying what those targets are. We agree some culling is important, especially at sites with very vulnerable threatened wildlife.

But in many parts of Australia, broad-scale habitat management is a more cost-effective way to reduce cat harm. This involves making habitat less suitable for cats and more suitable for native wildlife, for example, by reducing rabbit numbers, fire frequency and grazing by feral herbivores such as cattle and horses.

Research has shown fewer rabbits leads to fewer cats. Rabbits are a favoured prey of many cats, so they boost feral cat numbers, which then also hunt native wildlife.

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And cats gravitate to areas with less vegetation because it’s easier to catch prey. These areas include those with frequent fires, or where feral herbivores have reduced vegetation through grazing and trampling.

Better habitat with more vegetation gives native animals places to hide from predators, and more food and shelter. It’s a bit like giving the last little pig a house of bricks instead of trying to fist-fight the wolf.

Feral horses, such as these in Kakadu National Park, eat and damage vegetation making conditions more favourable for cats to hunt.
Jaana Dielenberg

A major step forward

Over the past two decades, Australia has slowly woken up to the damage cats cause to nature. This has led to more research, management and policy to address the problem.

Some state governments, environment groups and scientists have worked hard to develop feral cat control options, and the 2015 Australian Threatened Species Strategy did much to focus national attention and resourcing to the issue.

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The parliamentary inquiry is a major step forward, and many recommendations are sound. But overall, its recommendations call for incremental improvement.

Australia’s laws clearly fail to provide a safety net for wildlife. The cat issue is part of a larger problem with how we manage habitat, biodiversity and threats to nature – and fixing that requires wholesale change.

Sarah Legge, Professor, Australian National University; Chris Dickman, Professor in Terrestrial Ecology, University of Sydney; Jaana Dielenberg, University Fellow, Charles Darwin University; John Woinarski, Professor (conservation biology), Charles Darwin University, and Tida Nou, Project officer, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Australia: Kakadu Crisis