Destroying vegetation along fences and roads could worsen our extinction crisis — yet the NSW government just allowed it

Euan Ritchie, Deakin University; Ben Moore, Western Sydney University; Jen Martin, The University of Melbourne; Mark Hall, Western Sydney University; Megan C Evans, UNSW, and Ross Crates, Australian National UniversityWhat do koalas, barking owls, greater gliders, southern rainbow skinks, native bees, and regent honeyeaters all have in common? Like many native species, they can all be found in vegetation along fences and roadsides outside formal conservation areas.

They may be relatively small, but these patches and strips conserve critical remnant habitat and have disproportionate conservation value worldwide. They represent the last vestiges of once-expansive tracts of woodland and forests, long lost to the chainsaw or plough.

And yet, the NSW government last week made it legal for rural landholders to clear vegetation on their properties, up to 25 metres from their property boundaries, without approval. This radical measure is proposed to protect people and properties from fires, despite the lack of such an explicit recommendation from federal and state-based inquiries into the devastating 2019-20 bushfires.

This is poor environmental policy that lacks apparent consideration or justification of its potentially substantial ecological costs. It also gravely undermines the NSW government’s recent announcement of a plan for “zero extinction” within the state’s national parks, as the success of protected reserves for conservation is greatly enhanced by connection with surrounding “off-reserve” habitat.

Small breaks in habitat can have big impacts

A 25m firebreak might sound innocuous, but when multiplied by the length of property boundaries in NSW, the scale of potential clearing and impacts is alarming, and could run into the hundreds of thousands of kilometres.

Some plants, animals and fungi live in these strips of vegetation permanently. Others use them to travel between larger habitat patches. And for migratory species, the vegetation provides crucial refuelling stops on long distance journeys.

For example, the roadside area in Victoria’s Strathbogie Ranges shown below is home to nine species of tree-dwelling native mammals: two species of brushtail possums, three species of gliders (including threatened greater gliders), common ringtail possums, koalas, brush-tailed phascogales, and agile antenchinus (small marsupials).

Roadside and fenceline vegetation is often the only substantial remnant vegetation remaining in agricultural landscapes. This section, in northeast Victoria’s Strathbogie Ranges, running north to south from the intersection, is home to high arboreal mammal diversity, including the threatened greater glider.
Google Earth

Many of these species depend on tree hollows that can take a hundred years to form. If destroyed, they are effectively irreplaceable.

Creating breaks in largely continuous vegetation, or further fragmenting already disjointed vegetation, will not only directly destroy habitat, but can severely lower the quality of adjoining habitat.

This is because firebreaks of 25m (or 50m where neighbouring landholders both clear) could prevent the movement and dispersal of many plant and animal species, including critical pollinators such as native bees.

An entire suite of woodland birds, including the critically endangered regent honeyeater, are threatened because they depend on thin strips of vegetation communities that often occur inside fence-lines on private land.

Ecologically-sensitive fence replacement in regent honeyeater breeding habitat.
Ross Crates

For instance, scientific monitoring has shown five pairs of regent honeyeaters (50% of all birds located so far this season) are nesting or foraging within 25m of a single fence-line in the upper Hunter Valley. This highlights just how big an impact the loss of one small, private location could have on a species already on the brink of extinction.

But it’s not just regent honeyeaters. The management plan for the vulnerable glossy black cockatoo makes specific recommendation that vegetation corridors be maintained, as they’re essential for the cockatoos to travel between suitable large patches.

Native bee conservation also relies on the protection of remnant habitat adjoining fields. Continued removal of habitat on private land will hinder chances of conserving these species.

Glossy black cockatoos rely on remnant patches of vegetation.
Shutterstock

Disastrous clearing laws

The new clearing code does have some regulations in place, albeit meagre. For example, on the Rural Fire Service website, it says the code allows “clearing only in identified areas, such as areas which are zoned as Rural, and which are considered bush fire prone”. And according to the RFS boundary clearing tool landowners aren’t allowed to clear vegetation near watercourses (riparian vegetation).

Even before introducing this new code, NSW’s clearing laws were an environmental disaster. In 2019, The NSW Audit Office found:

clearing of native vegetation on rural land is not effectively regulated [and] action is rarely taken against landholders who unlawfully clear native vegetation.

The data back this up. In 2019, over 54,500 hectares were cleared in NSW. Of this, 74% was “unexplained”, which means the clearing was either lawful (but didn’t require state government approval), unlawful or not fully compliant with approvals.

Landholders need to show they’ve complied with clearing laws only after they’ve already cleared the land. But this is too late for wildlife, including plant species, many of which are threatened.

Landholders follow self-assessable codes, but problems with these policies have been identified time and time again — they cumulatively allow a huge amount of clearing, and compliance and enforcement are ineffective.

Vegetation along roadsides and close to fences can be critical habitat for greater gliders.

We also know, thanks to various case studies, the policy of “offsetting” environmental damage by improving biodiversity elsewhere doesn’t work.

So, could the federal environment and biodiversity protection law step in if habitat clearing gets out of hand? Probably not. The problem is these 25m strips are unlikely to be referred in the first place, or be considered a “significant impact” to trigger the federal law.

The code should be amended

Nobody disputes the need to keep people and their assets safe against the risks of fire. The code should be amended to ensure clearing is only permitted where a genuinely clear and measurable fire risk reduction is demonstrated.

Many native bees, like this blue-banded bee (*Amegilla* sp.), will use the nesting and foraging resources available in remnant vegetation patches.
Michael Duncan

Granting permission to clear considerable amounts of native vegetation, hundreds if not thousands of metres away from homes and key infrastructure in large properties is hard to reconcile, and it seems that no attempt has been made to properly justify this legislation.

We should expect that a comprehensive assessment of the likely impacts of a significant change like this would inform public debate prior to decisions being made. But to our knowledge, no one has analysed, or at least revealed, how much land this rule change will affect, nor exactly what vegetation types and wildlife will likely be most affected.

A potentially devastating environmental precedent is being set, if other regions of Australia were to follow suit. The environment and Australians deserve better.

Clarification: some text has been added to clarify the land cleared is on the landowner’s property, not outside their property boundary

Euan Ritchie, Professor in Wildlife Ecology and Conservation, Centre for Integrative Ecology, School of Life & Environmental Sciences, Deakin University; Ben Moore, Senior Lecturer in Ecology, Hawkesbury Institute for the Environment, Western Sydney University; Jen Martin, Leader, Science Communication Teaching Program, The University of Melbourne; Mark Hall, Postdoctoral research fellow, Hawkesbury Institute for the Environment, Western Sydney University; Megan C Evans, Lecturer and ARC DECRA Fellow, UNSW, and Ross Crates, Postdoctoral fellow, Australian National University

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

We name the 26 Australian frogs at greatest risk of extinction by 2040 — and how to save them

Spotted tree frog.
Michael Williams/Its A Wildlife Photography, Author provided

Graeme Gillespie, The University of Melbourne; Conrad Hoskin, James Cook University; Hayley Geyle, Charles Darwin University; Jaana Dielenberg, Charles Darwin University; Nicola Mitchell, The University of Western Australia, and Stephen Garnett, Charles Darwin UniversityAustralia is home to more than 240 frog species, most of which occur nowhere else. Unfortunately, some frogs are beyond help, with four Australian species officially listed as extinct.

This includes two remarkable species of gastric-brooding frog. To reproduce, gastric-brooding frogs swallowed their fertilised eggs, and later regurgitated tiny baby frogs. Their reproduction was unique in the animal kingdom, and now they are gone.

Our new study published today, identified the 26 Australian frogs at greatest risk, the likelihood of their extinctions by 2040 and the steps needed to save them.

Tragically, we have identified an additional three frog species that are very likely to be extinct. Another four species on our list are still surviving, but not likely to make it to 2040 without help.

#1 The northern gastric-brooding frog (*Rheobatrachus vitellinus*) is likely already extinct, primarily due to chytrid fungus disease.
Hal Cogger

The 26 most imperilled frogs

The striking yellow-spotted tree frog (in southeast Australia), the northern tinker frog and the mountain mist frog (both in Far North Queensland) are not yet officially listed as extinct – but are very likely to be so. We estimated there is a greater than 90% chance they are already extinct.

The locations of the top 26 Australian frogs at risk of extinction. ** Species likely to be recently extinct. * Species more likely than not to become extinct by 2040 unless there is action.
Jaana Dielenberg/Threatened Species Recovery Hub

The next four most imperilled species are hanging on in the wild by their little frog fingers: the southern corroboree frog and Baw Baw frog in the Australian Alps, and the Kroombit tinker frog and armoured mist frog in Queensland’s rainforests.

The southern corroboree frog, for example, was formerly found throughout Kosciuszko National Park in the Snowy Mountains. But today, there’s only one small wild population known to exist, due largely to an introduced disease.

Without action it is more likely than not (66% chance) the southern corroboree frog will become extinct by 2040.

#6 The southern corroboree frog (*Pseudophryne corroboree*) is close to extinction.
David Hunter/DPIE NSW

#3 The yellow-spotted tree frog (*Litoria castanea*) is likely extinct. It was once common throughout the New England Tableland and Southern Tablelands region in NSW, and the ACT. It is sensitive to chytrid fungus disease and also impacted by climate change, habitat loss and invasive fish.
David Hunter/DPIE NSW

What are we up against?

Species are suffering from a range of threats. But for our most recent extinctions and those now at greatest risk, the biggest cause of declines is the amphibian chytrid fungus disease.

This introduced fungus is thought to have arrived in Australia in the 1970s and has taken a heavy toll on susceptible species ever since. Cool wet environments, such as rainforest-topped mountains in Queensland where frog diversity is particularly high, favour the pathogen.

The fungus feeds on the keratin in frogs’ skin — a major organ that plays a vital role in regulating moisture, exchanging respiratory gases, immunity, and producing sunscreen-like substances and chemicals to deter predators.

Dead frog — Chrytrid disease killed this green-eyed tree frog.
Robert Puschendorf

#8 Armoured mist frog (*Litoria lorica*) populations have been decimated by chytrid fungus disease. It has been lost throughout former mountainous rainforest habitats where the fungus thrives. Without effective action, it’s likely to be extinct within 20 years.
Conrad Hoskin

Another major emerging threat is climate change, which heats and dries out moist habitats. It’s affecting 19 of the imperilled species we identified, such as the white-bellied frog in Western Australia, which develops tadpoles in little depressions in waterlogged soil.

Climate change is also increasing the frequency, extent and intensity of fires, which have impacted half (13) of the identified species in recent years. The Black Summer fires ravaged swathes of habitat where fires should rarely occur, such as mossy alpine wetlands inhabited by the northern corroboree frog.

Invasive species impact ten frog species. For the spotted tree frog in southern Australia, introduced fish such as brown and rainbow trout are the main problem, as they’re aggressive predators of tadpoles. In northern Australia, feral pigs often wreak havoc on delicate habitats.

#15 The Kuranda tree frog (Litoria myola) is found in a very small area near Cairns. Its primary threat is loss and degradation of habitat due to development.
Conrad Hoskin

#20 The white-bellied frog (*Geocrinia alba*) is the Western Australian frog at greatest risk of extinction. The tadpoles of this tiny terrestrial breeding frog rely on wet soil to develop. Reduced rainfall is contributing to declines.
Emily Hoffmann

So what can we do about it?

We identified the key actions that can feasibly be implemented in time to save these species. This includes finding potential refuge sites from chytrid and from climate change, reducing bushfire risks and reducing impacts of introduced species.

But for many species, these actions alone aren’t enough. Given the perilous state of some species in the wild, captive conservation breeding programs are also needed. But they cannot be the end goal.

#11 A northern corroboree frog in the captive breeding program run by the ACT Government.
Peter Taylor/Threatened Species Recovery Hub

Captive breeding programs can not only establish insurance populations, they can also help a species persist in the wild by supplying frogs to establish populations at new suitable sites.

Boosting numbers in existing wild populations with captive bred frogs improves their chance of survival. Not only are there more frogs, but also greater genetic diversity. This means the frogs have a better chance of adapting to new conditions, including climate change and emerging diseases.

Our knowledge of how to breed frogs in captivity has improved dramatically in recent decades, but we need to invest in doing this for more frog species.

Please save these frogs: The 26 Australian species at greatest risk of extinction.

Finding and creating wild refuges

Another vital way to help threatened frogs persist in the wild is by protecting, creating and expanding natural refuge areas. Refuges are places where major threats are eliminated or reduced enough to allow a population to survive long term.

For the spotted-tree frog, work is underway to prevent the destruction of frog breeding habitat by deer, and to prevent tadpoles being eaten by introduced predatory fish species. These actions will also help many other frog species as well.

The chytrid fungus can’t be controlled, but fortunately it does not thrive in all environments. For example, in the warmer parts of species’ range, pathogen virulence may be lower and frog resilience may be higher.

Chytrid fungus completely wiped out the armoured mist frog from its cool, wet heartland in the uplands of the Daintree Rainforest. But, a small population was found surviving at a warmer, more open site where the chytrid fungus is less virulent. Conservation for this species now focuses on these warmer sites.

This strategy is now being used to identify potential refuges from chytrid for other frog species, such as the northern corroboree frog.

Dr Graeme Gillespie during a survey for the spotted-tree frog.
Michael Williams/Its A Wildlife Photography

No time to lose

We missed the window to save the gastric-brooding frogs, but we should heed their cautionary tale. We are on the cusp of losing many more unique species.

Decline can happen so rapidly that, for many species, there is no time to lose. Apart from the unknown ecological consequences of their extinctions, the intrinsic value of these frogs means their losses will diminish our natural legacy.

In raising awareness of these species we hope we will spark new action to save them. Unfortunately, despite persisting and evolving independently for millions of years, some species can now no longer survive without our help.

Graeme Gillespie, Honorary Research Fellow, The University of Melbourne; Conrad Hoskin, Lecturer/ABRS Postdoctoral Fellow, James Cook University; Hayley Geyle, Research Assistant, Charles Darwin University; Jaana Dielenberg, University Fellow, Charles Darwin University; Nicola Mitchell, Associate Professor in Conservation Physiology, The University of Western Australia, and Stephen Garnett, Professor of Conservation and Sustainable Livelihoods, Charles Darwin University

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

Almost 60 coral species around Lizard Island are ‘missing’ – and a Great Barrier Reef extinction crisis could be next

Zoe Richards, Curtin UniversityThe federal government has opposed a recommendation by a United Nations body that the Great Barrier Reef be listed as “in danger”. But there’s no doubt the natural wonder is in dire trouble. In new research, my colleagues and I provide fresh insight into the plight of many coral species.

Worsening climate change, and subsequent marine heatwaves, have led to mass coral deaths on tropical reefs. However, there are few estimates of how reduced overall coral cover is linked to declines in particular coral species.

Our research examined 44 years of coral distribution records around Lizard Island, at the northern end of the Great Barrier Reef. We found 16% of coral species have not been seen for many years and are at risk of either local extinction, or disappearing from parts of their local range.

This is alarming, because local extinctions often signal wider regional – and ultimately global – species extinction events.

Healthy coral near Lizard Island in 2011, top, then six years later after two bleaching events, bottom.
Zoe Richards

Sobering findings

The Lizard Island reef system is 270 kilometres north of Cairns. It has suffered major disturbances over the past four decades: repeated outbreaks of crown-of-thorns seastars, category 4 cyclones in 2014 and 2015, and coral bleaching events in 2016, 2017 and 2020.

Our research focused on “hermatypic” corals around Lizard Island. These corals deposit calcium carbonate and form the hard framework of the reef.

We undertook hard coral biodiversity surveys four times between 2011 and 2020, across 14 sites. We combined the results with published and photographic species records from 1976 to 2020.

red fleshy coral with blue spots — Micromussa lordhowensis is popular in the aquarium trade.
Zoe Richards

Of 368 hard coral species recorded around Lizard Island, 28 (7.6%) have not been reliably recorded since before 2011 and may be at risk of local extinction. A further 31 species (8.4%) have not been recorded since 2015 and may be at risk of range reduction (disappearance from parts of its local range).

The “missing” coral species include:

Acropora abrotanoides, a robust branching shallow water coral that lives on the reef crest and reef flat has not been since since 2009
Micromussa lordhowensis, a low-growing coral with colourful fleshy polyps. Popular in the aquarium trade, it often grows on reef slopes but has not been seen since 2005
Acropora aspera, a branching coral which prefers very shallow water and has been recorded just once, at a single site, since 2011.

The finding that 59 coral species are at risk of local extinction or range reduction is significant. Local range reductions are often precursors to local species extinctions. And local species extinctions are often precursors to regional, and ultimately global, extinction events.

Each coral species on the reef has numerous vital functions. It might provide habitat or food to other reef species, or biochemicals which may benefit human health. One thing is clear: every coral species matters.

reddish coral underwater — Acropa abrotanoides, one of the corals ‘missing’ from around Lizard Island.
Zoe Richards

A broader extinction crisis?

As human impacts and climate threats mount, there is growing concern about the resilience of coral biodiversity. Our research suggests such concerns are well-founded at Lizard Island.

Coral reef communities are dynamic, and so detecting species loss can be difficult. Our research found around Lizard Island, the diversity of coral species fluctuated over the past decade. Significant declines were recorded from 2011 to 2017, but diversity recovered somewhat in the three following years.

Local extinctions often happen incrementally and can therefore be “invisible”. To detect them, and to account for natural variability in coral communities, long-term biodiversity monitoring across multiple locations and time frames is needed.

Green coral — Acropora aspera has been recorded just once, at a single location, since 2011.
Anne Hoggett

In most locations however, data on the distribution and abundance of all coral species in a community is lacking. This means it can be hard to assess changes, and to understand the damage that climate change and other human-caused stressors are having on each species.

Only with this extra information can scientists conclusively say if the level of local extinction risk at Lizard Island indicates a risk that coral species may become extinct elsewhere – across the Great Barrier Reef and beyond.

Zoe Richards, Senior Research Fellow, Curtin University

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

Australia’s threatened species plan has failed on several counts. Without change, more extinctions are assured

Euan Ritchie, Deakin University and Ayesha Tulloch, University of SydneyAustralia is globally renowned for its abysmal conservation record – in roughly 230 years we’ve overseen the extinction of more mammal species than any other nation. The federal government’s Threatened Species Strategy was meant to address this confronting situation.

The final report on the five-year strategy has just been published. In it, Threatened Species Commissioner Dr Sally Box acknowledges while the plan had some important wins, it fell short in several areas, writing:

…there is much more work to do to ensure our native plants and animals thrive into the future, and this will require an ongoing collective effort.

Clearly, Australia must urgently chart a course towards better environmental and biodiversity outcomes. That means reflecting honestly on our successes and failures so far.

How did the strategy perform?

The strategy, announced in 2015, set 13 targets linked to three focus areas:

feral cat management
improving the population trajectories of 20 mammal, 21 bird and 30 plant species
improving practices to recover threatened species populations.

Given the scale of the problem, five years was never enough time to turn things around. Indeed, as the chart below shows, the report card indicates five “red lights” (targets not met) and three “orange lights” (targets only partially met). It gave just five “green lights” for targets met.

Year Five - Final Report — Summary of the Threatened Species Strategy’s targets and outcomes.
Department of Agriculture, Water and the Environment

Falling short on feral cats

Feral cats were arguably the most prominent focus of the strategy, despite other threats requiring as much or more attention, such as habitat destruction via land clearing.

However, the strategy did help start a national conversation about the damage cats wreak on wildlife and ecosystems, and how this can be better managed.

In the five years to the end of 2020, an estimated 1.5 million feral cats were killed under the strategy – 500,000 short of the 2 million goal. But this estimate is uncertain due to a lack of systematic data collection. In particular, the number of cats culled by farmers, amateur hunters and shooters is under-reported. And more broadly, information is scattered across local councils, non-government conservation agencies and other sources.

Australia’s feral cat population fluctuates according to rainfall, which determines the availability of prey – numbering between 2.1 million and 6.3 million. Limited investment in monitoring makes it impossible to know whether the average of 300,000 cats killed each year over the past five years will be enough for native wildlife to recover.

The government also failed in its goal to eradicate cats from five islands, only achieving this on Dirk Hartog Island off Western Australia. Importantly, that effort began in 2014, before the strategy was launched. And it was primarily funded by the WA government and an industry offset scheme, so the federal government can’t really claim this success.

On a positive note, ten mainland areas excluding feral cats have been established or are nearly complete. Such areas are a vital lifeline for some wildlife species and can enable native species reintroductions in the future.

feral cat holds dead bird — Feral cats were eradicated from just one island under the strategy.
Mark Marathon/Threatened Species Recovery Hub

Priority species: how did we do?

The strategy met its target of ensuring recovery actions were underway for at least 50 threatened plant species and 60 ecological communities. It also made good headway into storing all Australia’s 1,400 threatened plant species in seed banks. This is good news.

The bad news is that, even with recovery actions, the population trajectories of most priority species failed to improve. For the 24 out of about 70 priority species where population numbers were deemed to have “improved” over five years, about 30% simply got worse at a slower rate than in the decade prior. This can hardly be deemed a success.

Mala with baby in pouch — Populations of the mala, or Rufous Hare-wallaby, were improving before the strategy.
Wayne Lawler/Australian Wildlife Conservancy

What’s more, the populations of at least eight priority species, including the eastern barred bandicoot, eastern bettong, Gilbert’s potoroo, mala, woylie, numbat and helmeted honeyeater, were increasing before the strategy began – and five of these deteriorated under the strategy.

The finding that more priority species recovery efforts failed than succeeded means either:

the wrong actions were implemented
the right actions were implemented but insufficient effort and funding were dedicated to recovery
the trajectories of the species selected for action simply couldn’t be improved in a 5-year window.

All these problems are alarming but can be rectified. For example, the government’s new Threatened Species Strategy, released in May, contains a more evidence-based process for determining priority species.

For some species, it’s unclear whether success can be attributed to the strategy. Some species with improved trajectories, such as the helmeted honeyeater, would likely have improved regardless, thanks to many years of community and other organisation’s conservation efforts before the strategy began.

Conservation worker releases woylie — The improved outlook for some species is due to conservation efforts before the federal strategy.
WA Department of Environment and Conservation

What must change

According to the report, habitat loss is a key threat to more than half the 71 priority species in the strategy. But the strategy does not directly address habitat loss or climate change, saying other government policies are addressing those threats.

We believe habitat loss and climate change must be addressed immediately.

Of the priority bird species threatened by land clearing and fragmentation, the trajectory of most – including the swift parrot and malleefowl – did not improve under the five years of the strategy. For several, such as the Australasian bittern and regent honeyeater, the trajectory worsened.

Preventing and reversing habitat loss will take years of dedicated restoration, stronger legislation and enforcement. It also requires community engagement, because much threatened species habitat is on private properties.

Effective conservation also requires raising public awareness of the dire predicament of Australia’s 1,900-plus threatened species and ecological communities. But successive governments have sought to sugarcoat our failings over many decades.

Bushfires and other extreme events hampered the strategy’s recovery efforts. But climate change means such events are likely to worsen. The risks of failure should form part of conservation planning – and of course, Australia requires an effective plan for emissions reduction.

The strategy helped increase awareness of the plight our unique species face. Dedicated community groups had already spent years volunteering to monitor and recover populations, and the strategy helped fund some of these actions.

However, proper investment in conservation – such as actions to reduce threats, and establish and maintain protected areas – is urgently needed. The strategy is merely one step on the long and challenging road to conserving Australia’s precious species and ecosystems.

Euan Ritchie, Professor in Wildlife Ecology and Conservation, Centre for Integrative Ecology, School of Life & Environmental Sciences, Deakin University and Ayesha Tulloch, DECRA Research Fellow, University of Sydney

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

This adorable mouse was considered extinct for over 100 years — until we found it hiding in plain sight

Wayne Lawler/Australian Wildlife Conservancy, Author provided

Emily Roycroft, Australian National UniversityAustralia has the world’s worst track record for wiping out mammals, with 34 species declared extinct since European colonisation. Many of these are humble native rodents, who’ve suffered the highest extinction rate of any mammal group.

But today, we bring some good news: one rodent species, Gould’s mouse (Pseudomys gouldii), is set to be crossed off Australia’s extinct species list. This means the number of Australia’s extinct mammals will drop from 34 to 33.

Our new research compared genome sequences across Australia’s rodents, including eight extinct species and their 42 living relatives. In a case of historical mistaken identity, we found the Gould’s mouse was genetically indistinguishable from another living species, the Shark Bay mouse (Pseudomys fieldi), also known by the Indigenous name “Djoongari” from the Pintupi and Luritja languages.

But it’s not all good news. A lack of genetic diversity in remaining populations means Djoongari are less resilient to changing environments, including from climate change. We can’t let this species die out — this time, there’d be no coming back.

Back from the dead

When Europeans colonised Australia, they rapidly and catastrophically changed the environments in which native species thrived. The introduction of feral cats, foxes and other invasive species, agricultural land clearing, inappropriate fire management, and new diseases decimated native rodent populations.

Along with many other native mammals, some rodent species were also intensely hunted for bounty in the late 19th and early 20th centuries.

DNA from this specimen of Gould’s mouse, collected in 1837 from the Hunter Valley of NSW, reveals the species should no longer be considered extinct.
Trustees of the Natural History Museum, London Photographer: C. Ching, Author provided

In 1837, a Gould’s mouse specimen was collected for the Natural History Museum, London, from the Hunter Valley of New South Wales. The last verified time it was seen alive was in 1857, near the border of Victoria and NSW.

After genomic analysis of these specimens, we found the species has been hiding in plain sight for more than 100 years, under a different name, thousands of kilometres away in Western Australia. Djoongari will now be reclassified under the scientific name Pseudomys gouldii.

Djoongari is a shaggy-coated mouse weighing 45 grams on average, making it twice the size of the invasive house mouse. It’s omnivorous, and feeds on a variety of flowers, leaves, fungi, insects and spiders. It also build tunnels and runways to travel at night, and uses above-ground nests as refuges during the day.

Not safe yet

The resurrection of the Gould’s mouse is positive news given Australia’s alarming rate of recent extinctions, but the species remains at risk.

Once occurring across mainland Australia, it now survives only on predator-free islands in Shark Bay, WA. Islands have been an important refuge for the species, protecting them from cats, foxes, diseases and other threats on the mainland.

Feral and pet cats are huge threats to small native animals. If you own a cat, make sure you keep it indoors to protect Australia’s wildlife.
Shutterstock

Conservation efforts are underway to protect the mouse in Shark Bay, with insurance populations established on other nearby islands.

Now we know Djoongari once roamed as far east as the Hunter Valley in NSW, there’s greater scope to reintroduce the species to predator-proof protected areas on the mainland. This would mean more insurance populations, but also contribute towards restoring natural ecosystems on mainland Australia — also known as “rewilding”.

However, remnant populations of this once widespread species contain only a fraction of its original genetic diversity.

Genetic diversity is often used as a proxy for estimating the resilience of a species to threats and its potential to adapt to changes in its environment. When species have low genetic diversity, or are inbred, they are more susceptible to disease, and more likely to accumulate harmful genetic mutations.

Other eye-opening revelations

Our study also examined the genomes of seven other rodent species lost to extinction: the white-footed rabbit rat, lesser stick-nest rat, Bramble Cay melomys, short-tailed hopping mouse, long-tailed hopping mouse, big-eared hopping mouse and long-eared mouse.

Brown rodent — Bramble cay melomys were declared extinct in 2016.
Ian Bell, EHP, State of Queensland, CC BY-SA

In most cases, we found these now-extinct native rodents had relatively high genetic diversity immediately before they became extinct. High genetic diversity usually means large population sizes, suggesting native rodent populations were stable before European invasion.

This puts an end to any suggestion that these species were already on their way out prior to the arrival of Europeans.

Reports from early naturalists back up our findings. In 1846, John Cotton referred to the now-extinct white-footed rabbit rat as “the common rat of the country”. And in 1866, Gerard Krefft described the now-extinct lesser stick-nest rat as occurring in “great numbers”.

These species went from common to extinct in less than 150 years. That’s alarmingly fast by any standard.

It shows even though genetic diversity in now-extinct rodents was high prior to colonisation, it wasn’t enough. The environment and threats changed so dramatically and rapidly, these species didn’t have the chance to adapt.

There’s a clear lesson in all this

The threats to native wildlife brought by Europeans — including feral cat predation and land clearing — are ongoing. And under climate change, the environment as we know it is set to change further, dramatically.

It’s not enough to only establish insurance populations to save species. We need to control feral predators, protect and restore habitats, and curb emissions, so more species don’t endure a rapid wipe out.

In total, we’ve lost almost 100 species to extinction since 1788, and that’s just those we know about. In native rodents alone, in less than 150 years, the equivalent of more than 10 million years of unique evolutionary history has been lost forever.

Extinction doesn’t usually offer second chances, but we’ve now got another shot to protect Gould’s mouse. We need to act now, before it’s too late.

Emily Roycroft, Postdoctoral Research Fellow, Australian National University

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

Hundreds of Australian lizard species are barely known to science. Many may face extinction

Jane Melville, Museums Victoria and Reid Tingley, Monash UniversityMost of the incredible diversity of life on Earth is yet to be discovered and documented. In some groups of organisms – terrestrial arthropods such as spiders and scorpions, marine invertebrates such as sponges and molluscs, and others – scientists have described fewer than 20% of species.

Even our knowledge of more familiar creatures such as fish and reptiles is far from complete. In our new research, we studied 1,034 known species of Australian lizards and snakes and found we know so little about 164 of them that not even the experts know whether they are fully described or not. Of the remaining 870, almost a third probably need some work to be described properly.

Map of Australia shaded in colours from blue to red. — Return on investment for taxonomic research on lizards and snakes in Australia. Red areas have high numbers of species and high conservation value. Hotspots include the Kimberley in WA, northern tropical savannas and also far north eastern QLD.
R. Tingley, Author provided

Documenting and naming what species are out there – the work of taxonomists – is crucial for conservation, but it can be difficult for researchers to decide where to focus their efforts. Alongside our lizard research, we have developed a new “return on investment” approach to identify priority species for our efforts.

We identified several hotspots across Australia where research is likely to be rewarded. More broadly, our approach can help target taxonomic research for conservation worldwide.

Why we need to look at species more closely

As more and more species are threatened by land clearing, climate change and other human activities, our research highlights that we are losing even more biodiversity than we know.

Conservation often relies on species-level assessments such as those conducted by the International Union for Conservation of Nature (IUCN) Red List, which lists threatened species. Although new species are being discovered all the time, a key problem is that already named “species” may harbour multiple undocumented and unnamed species. This hidden diversity remains invisible to conservation assessment.

The Roma Earless Dragon (*Tympanocryptis wilsoni*), described in 2014, lives only in grasslands in the western Darling Downs QLD and has recently been listed as Vulnerable in Queensland.
A. O’Grady, Author provided

One such example are the Grassland Earless Dragons (Tympanocryptis spp.) found in the temperate native grasslands of south-eastern Australia. These small secretive lizards were grouped within a single species (Tympanocryptis pinguicolla) and listed as Endangered on the IUCN Red List.

But recent taxonomic research split this single species into four, each occurring in an isolated region of grasslands. One of these new species may represent the first extinction of a reptile on mainland Australia and the other three have a high probability of being threatened.

Scientists call documenting and describing species “taxonomy”. Our research shows the importance of prioritising taxonomy in the effort to conserve and protect species.

Taxonomists at work

Many government agencies do take some account of groups smaller than species in their conservation efforts, such as distinct populations. But these are often ambiguously defined and lack formal recognition, so they are not widely used. That’s where taxonomists come in, to identify species and describe them fully.

Our new research was a collaboration of 30 taxonomists and systematists, who teamed up to find a good way of working out which species should be a priority for taxonomic research for conservation outcomes. This new approach compares the amount of work needed with the likelihood of finding previously unknown species that are at risk of extinction.

Barrier Range Dragon (*Ctenophorus mirrityana*), described in 2013, is restricted to rocky ranges in western NSW and is listed as Endangered in NSW.
S. Wilson, Author provided

The research team, who are experts on the taxonomy and systematics of Australia’s reptiles, implemented this new approach on Australian lizards and snakes. This group of reptiles is ideal as a test case because Australia is a global hotspot of lizard diversity – and we also have a strong community of taxonomic experts.

Australia’s lizards and snakes

Of the 1,034 Australian lizard and snake species, we were able to assess whether 870 of them may contain undescribed species. This means we know so little about the remaining 164 species that even the experts could not make an informed opinion on whether they contain hidden diversity. There is so much still to learn!

Of the 870 species experts could assess, they determined 282 probably or definitely needed more taxonomic research. Mapping the distributions of these species indicated hotspot regions for this taxonomic research, including the Kimberley, the Tanami Desert region, western Victoria and offshore islands (such as Tasmania, Lord Howe and Norfolk Islands). Some areas in the Kimberley region had more than 60 species that need further taxonomic research.

In this map, red hotspot areas have lower species diversity but still a very high average return on investment. National hotspots include Tasmania, western Victoria and the Tanami Desert region in WA and NT.
R. Tingley, Author provided

We found 17.6% of the 282 species that need more taxonomic research contained undescribed species that would probably be of conservation concern, and 24 had a high probability of being threatened with extinction. Taxonomists know that there are undescribed species because there is some data available already but the description of these species – the process of defining and naming – has not been done.

These high-priority species belong to a range of families including geckos, skinks and dragons found across Australia.

The high number of undescribed species, especially those with significant likelihood of being endangered, was a shock to even the experts. The IUCN currently estimates only 6.3% of Australian lizards and snakes require taxonomic revision, but this is obviously a significant underestimate.

A race against extinction

Beyond lizards, there is a huge backlog of species awaiting description.

Recent projects have used genetic analyses to discover unknown species, including a $180 million global BIOSCAN effort aiming to identify millions of new species. However, genetics is only a first step in the formal recognition of species.

The taxonomic process of documenting, describing and naming species requires multiple further steps. These steps include a comprehensive diagnostic assessment using a combination of evidence, such as genetics and morphology, to uniquely distinguish each species from another. This process requires a high level of familiarity and scholarship of the group in question.

The Mt Elliot Sunskink (*Lampropholis elliotensis*), described in 2018, is found in leaf litter of highland rainforest above 600m on Mt Elliot in Bowling Green Bay National Park. Queensland, and is probably Vulnerable.
C. Hoskin, Author provided

Among the Australian lizards and snakes alone, there is a backlog of 59 undescribed species for which only the final elements of taxonomic research are awaiting completion.

To work through these taxonomic backlogs – let alone species that are so far entirely unknown – resources need to be invested in taxonomy, including research funding and increased provision of viable career paths.

Without taxonomic research, the conservation assessment of these undocumented species will not proceed. There are untold numbers of species needing taxonomic research that are already under threat of extinction. If we don’t hurry, they may go extinct before we even know they exist.

Jane Melville, Senior Curator, Terrestrial Vertebrates, Museums Victoria and Reid Tingley, Lecturer, Monash University

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

Beautiful, rare ‘purple cauliflower’ coral off NSW coast may be extinct within 10 years

Meryl Larkin, Southern Cross University; David Harasti, Southern Cross University; Steve Smith, Southern Cross University, and Tom R DavisWhen we think of Australia’s threatened corals, the Great Barrier Reef probably springs to mind. But elsewhere, coral species are also struggling – including a rare type known as “cauliflower soft coral” which is, sadly, on the brink of extinction.

This species, Dendronephthya australis, looks like a purple cauliflower due to its pink-lilac stems and branches, crowned with white polyps.

The coral primarily occurs at only a few sites in Port Stephens, New South Wales, and is a magnet for divers and underwater photographers. But sand movements, boating and fishing have reduced the species’ population dramatically.

Recent flooding in NSW compounded the problem – in fact, it may have reduced the remaining coral population by 90%. Our recent research found cauliflower soft coral may become extinct in the next decade unless we urgently protect and restore it.

An ovulid on a cauliflower coral colony. Such coral may be extinct within a decade.
Author supplied

Lilac underwater gardens

Cauliflower soft corals are predominantly found in estuarine environments on sandy seabeds with high current flow. They rely on tidal currents to transport plankton on which they feed.

The species is most commonly found in the Port Stephens estuary, about 200 kilometres north of Sydney. It’s also found in the Brisbane Water estuary in NSW, and has been found sporadically in other locations south to Jervis Bay.

The coral colonies form aggregations or “gardens”. At Port Stephens, these gardens are the preferred habitat for the endangered White’s seahorse and protected species of pipefish. They also support juvenile Australasian snapper, an important species for commercial and recreational fishers.

In recent months, the cauliflower soft coral has been listed as endangered in NSW and nationally.

An alarming decline

Scientists first mapped the distribution of the cauliflower soft coral in 2011. They found none of the biggest colonies in the Port Stephens estuary were protected by “no take” zones – areas where fishing and other extractive activities are banned.

In research in 2016, we found a sharp decline in the extent and distribution of cauliflower soft coral.

Our recent study examined the problem in more detail. It involved mapping the southern shoreline of Port Stephens, using an underwater camera towed by a vessel.

We found the cauliflower soft coral in the Port Stephens estuary has declined by almost 70% over just eight years. It now occurs over 9,300 square metres – down from 28,600 square metres in 2011.

Our subsequent modelling sought to identify what was driving the corals’ decline. We found a correlation between coral loss and sand movements over the last decade.

Human changes to shorelines, such as marina developments, have changed the dynamic of currents across the estuary. For example, previous research found a large influx of sand from the western end of Shoal Bay smothered cauliflower soft coral colonies at two nearby locations. As of 2018, those colonies had disappeared completely.

While diving as part of the project, we identified other causes of damage to the coral. Dropped boat anchors and the installation of moorings had damaged some colonies. Others were injured after becoming entangled in fishing line.

It is possible that disease, and pollution or other water quality issues, may also be contributing to the species’ decline.

Fishing line damaging a colony of cauliflower soft coral in Port Stephens.
Author supplied

Then the floods hit

Some 18 months after our most recent mapping, cauliflower soft corals suffered yet another blow. Major flooding in NSW in March this year caused a massive amount of fresh water to discharge from the Karuah River into the Port Stephens estuary, where sea water is dominant. Fresh water can kill cauliflower soft corals.

Following the floods, we conducted exploratory dives at locations where the cauliflower soft corals had been thriving at Port Stephens. We found much of the coral had disintegrated and disappeared. In fact, we estimated as much as 90% of the remaining cauliflower soft coral population was gone.

We plan to remap the estuary in the coming weeks, and feel confident our initial estimates will be close to the mark. If so, this means less than 5% of the species area mapped in 2011 now remains.

The floods also devastated kelp forests and other canopy-forming habitats in the estuary. Further work by scientists at the NSW Department of Primary Industries is underway to quantify these losses and monitor the recovery.

Monitoring of existing cauliflower coral aggregations is ongoing.
Author supplied

Urgent work required

The cauliflower soft coral urgently needs protecting. This will require ongoing, coordinated research and management.

Clearly, action must be taken to reduce threats such as anchoring, fishing, and development that may magnify sand movement.

Best-practice rehabilitation is also needed. This may involve rearing the coral off-site and transplanting it into suitable habitat. Such trials at Port Stephens have shown promising signs.

Human activities are causing species loss at an alarming rate. We must do everything in our power to prevent the extinction of the cauliflower soft coral, and other threatened species, to preserve the balance of nature and its ecosystems.

Meryl Larkin, PhD Candidate, Southern Cross University; David Harasti, Adjunct assistant professor, Southern Cross University; Steve Smith, Professor of Marine Science, National Marine Science Centre, Southern Cross University, and Tom R Davis, Research Scientist – Marine Climate Change

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

The 50 beautiful Australian plants at greatest risk of extinction — and how to save them

Caley’s grevillea (*Grevillea caleyi*) occurs in Sydney. It needs fire to germinate but burns are hard to carry out near urban areas.
Tony Auld, Author provided

Jennifer Silcock, The University of Queensland; Jaana Dielenberg, Charles Darwin University; Roderick John Fensham, The University of Queensland, and Teghan Collingwood, The University of QueenslandAs far as odds go, things don’t look promising for the slender-nerved acacia (Acacia leptoneura), a spiky plant with classic yellow-ball wattle flowers. With most of its habitat in Western Australia’s wheat belt cleared for agriculture, it was considered extinct for more than 160 years.

Now, just two plants are known in the world, and they’re not even in the same place. This species is among many Australian plants that have come perilously close to extinction.

To help prevent the loss of any native plant species, we’ve assembled a massive evidence base for more than 750 plants listed as critically endangered or endangered. Of these, we’ve identified the 50 at greatest risk of extinction.

The good news is for most of these imperilled plants, we already have the knowledge and techniques needed to conserve them. We’ve devised an action plan that’s relatively easy to implement, but requires long-term funding and commitment.

What’s driving the loss?

There are 1,384 plant species and subspecies listed as threatened at a national level. Twelve Australian plant species are considered probably extinct and a further 21 species possibly extinct, while 206 are officially listed as critically endangered.

Yellow wattle — Two known plants of slender nerved acacia (*Acacia leptoneura*) remain, about 1 kilometre apart. Propagation attempts have been unsuccessful and the genetic diversity is probably very low.
Joel Collins, Author provided

Australian plants were used, managed and celebrated by Australia’s First Nations people for at least 60,000 years, but since European colonisation, they’ve been beset by a range of threats.

Land clearing, the introduction of alien plants, animals, diseases, and interruptions to ecological processes such as fire patterns and flooding have taken a heavy toll on many species. This is particularly the case in the more densely populated eastern and southern parts of the continent.

Close-up of yellow flower — Ironstone pixie mop (*Petrophile latericola*) occurs on a soil type that’s been heavily cleared for agriculture, and is suspected to be susceptible to an introduced root-rot fungus. In 2020 fewer than 200 plants remained, in poor condition.
Andrew Crawford, Author provided

Things aren’t improving. Scientists recently compiled long-term monitoring of more than 100 threatened plant species at 600 sites nationally. And they found populations had declined on average by 72% between 1995 and 2017.

This is a very steep rate of decline, much greater than for threatened mammal or bird populations.

On the brink

Many species listed as threatened aren’t receiving targeted conservation action or even baseline monitoring, so an important first step in preventing extinctions was identifying the species at greatest risk.

To find the top 50, we looked at the evidence: all available published and unpublished information and expert surveys of over 120 botanists and land managers.
They’re targeted by our Action Plan for Australia’s Imperilled Plants.

Action Plan for Australia’s Imperilled Plants.

Thirty of the species in the plan have fewer than 50 mature individual plants remaining.

And 33 are known only from a single location, such as the Grampians pincushion-lily (Borya mirabilis), which occurs on one rocky outcrop in Victoria. This means the entire population could be destroyed by a single event, such as a major bushfire.

A dead-looking gum tree on agricultural land — About 2,000 Morrisby’s gums were growing in the early 1990s, but by 2016 fewer than 50 remained. Climate change and damage from insects and animals threaten those left. Protecting trees with fencing has led to new seedlings.
Magali Wright, Author provided

Fewer than 10 lax leek-orchids (*Prasophyllum laxum*) remain. Declines are ongoing due to drought and wildfire, and the South Australian species only occurs on private property not managed for conservation. Proposed recovery actions include habitat protection and establishing the orchid and its mycorrhizal fungi in conservation reserves.
Shane Graves, Author provided

Fewer than 15 woods well spyridium (*Spyridium fontis-woodii*) shrubs remain on a single roadside in South Australia. Research into threats and germination requirements is urgently needed, plus translocation to conservation reserves.
Daniel Duval/South Australian Seed Conservation Centre, Author provided

So how can we protect them?

Some of the common management actions we’ve proposed include:

preventing further loss of species’ habitat. This is the most important action required at a national scale
regularly monitoring populations to better understand how species respond to threats and management actions
safely trialling appropriate fire management regimes, such as burning in areas where fires have been suppressed
investing in disease research and management, to combat the threat of phytophthora (root-rot fungus) and myrtle rust, which damages leaves
propagating and moving species to establish plants at new sites, to boost the size of wild populations, or to increase genetic diversity
protecting plants from grazing and browsing animals, such as feral goats and rabbits, and sometimes from native animals such as kangaroos.

Once common, the dwarf spider-orchid (*Caladenia pumila*) wasn’t seen for over 80 years until two individual plants were found. Despite intensive management, no natural recruitment has occurred. Propagation attempts have successfully produced 100 seedlings and 11 mature plants from seed. This photo shows botanist Marc Freestone hand-pollinating dwarf spider-orchids.
Marc Freestone, Author provided

Only 21 mature plants of Gillingarra grevillea (*Grevillea sp. Gillingarra*) remain on a disturbed, weedy rail reserve in southwestern WA. Half the population was destroyed in 2011 due to railway maintenance and flooding. Habitat protection and restoration, and translocations to conservation reserves are needed to ensure its survival.
Andrew Crawford, Author provided

Another common issue is lack of recruitment, meaning there’s no young plants coming up to replace the old ones when they die. Sometimes this is because the processes that triggered these plants to flower, release seed or germinate are no longer occurring. This can include things like fire of a particular intensity or the right season.

Unfortunately, for some plants we don’t yet know what triggers are required, and further research is essential to establish this.

Now we need the political will

Our plan is for anyone involved in threatened flora management, including federal, state, territory and local government groups, First Nations, environment and community conservation groups, and anyone with one of these plants on their land.

The Border Ranges lined fern (*Antrophyum austroqueenslandicum*) and its habitat are exceedingly rare. It’s threatened by drought and climate change, and fewer than 50 plants remain in NSW. If the threat of illegal collection can be controlled, the species would benefit from re-introduction to Queensland’s Lamington National Park.
Lui Weber, Author provided

Plants make Australian landscapes unique — over 90% of our plant species are found nowhere else in the world. They’re also the backbone of our ecosystems, creating the rich and varied habitats for our iconic fauna to live in. Plants underpin and enrich our lives every day.

Now we have an effective plan to conserve the Australian plants at the greatest risk of extinction. What’s needed is the political will and resourcing to act in time.

Jennifer Silcock, Post-doctoral research fellow, The University of Queensland; Jaana Dielenberg, University Fellow, Charles Darwin University; Roderick John Fensham, Associate Professor of Biological Sciences, The University of Queensland, and Teghan Collingwood, Research Technician, The University of Queensland

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

Humpback whales may have bounced back from near-extinction, but it’s too soon to declare them safe

Olaf Meynecke, Griffith UniversityThe resurgence in humpback whale populations over the past five decades is hailed as one of the great success stories of global conservation. And right now, the federal Department of Agriculture, Water and the Environment is considering removing the species from Australia’s threatened list.

But humpback whales face new and emerging threats, including climate change. Surveying whales is notoriously hard, and the government has not announced monitoring plans to ensure humpback populations remain strong after delisting. We need a plan to keep them safe.

Australia’s whale season is about to begin. Each year between May and November, the mammals migrate north along Australia’s coastline from their feeding grounds in Antarctica to warmer waters. There, they breed before returning south.

So now’s a good time to take a closer look at the status of this iconic, charismatic species.

A pod of humpback whales lunge feeding. — The resurgence of humpback whales is one of conservation’s greatest success stories.
Shutterstock

A host of threats

Humpback whales live in every ocean in the world, and have one of the longest migrations of any mammal.

Humpback whale numbers dwindled as a result of commercial whaling, which in Australia began in the late 18th Century. Whaling and the export of whale products was Australia’s first primary industry. Between 1949 and 1962 Australia’s whalers killed about 8,300 humpback whales off the east coast, until only a few hundred were left.

The International Whaling Commission banned humpback whaling in the Southern Hemisphere in 1963. By then, humpback populations had fallen to about 5% of pre-whaling numbers. In the years since, some whaling continued, but has now largely ceased.

Today humpback whales face new threats. These include:

underwater noise which interferes with whale communication
pollution
vehicle collisions
getting caught in fishing gear
over-harvesting prey such as krill
marine debris
habitat degradation
climate change.

In particular, the effects of climate change – such as warming waters, shifting currents and ocean acidification – may affect the availability of prey that humpback whales need to survive.

Combined, these worsening threats could disrupt humpback whales’ recent resurgence. Indeed, under one scenario, scientists predict the increase Australia’s humpback numbers could stall — or worse, start declining – in the next five to ten years.

A humpback whale calf caught in a fishing net.
SeaPix, Author provided

The humpback whales’ plight

According to the federal government’s delisting assessment, humpback whales’ strong recovery suggests current threats are not a risk to the population. But this assessment has shortcomings.

It states humpback whales on Australia’s east and west coast have reached, or are exceeding, the original population size – increasing by 10-11% a year over the past decade or longer.

But this information is based on models using data collected prior 2010 for Australia’s west coast, and prior to 2015 for the east coast. This data isn’t readily available to the public and does not include recent population trends.

The predicted population growth from these models doesn’t account for current and future impacts from major threats, including climate change. This is despite recent research and observations suggesting changes in the humpback population.

For example, 2019 research showed potential shifts in calving locations, with newborn humpback whales now frequently spotted outside Australian tropical waters. This — along with the early arrival of migrating humpback whales in Australia in the past years — may be a first sign of changes in breeding and migration habits.

It’s also important to compare humpback whale populations in Australia with those elsewhere, such as in the North Pacific. There, calving rates are declining, and whale abundance and distribution is showing marked shifts. The risk of entanglements with fishing gear is also rising.

A whale tail with a fishing line caught in it — Whales can get caught in fishing gear.
Todd Burrows, Author provided

The problem with counting whales

The pre-whaling population size of humpback whales on the east and west coast of Australia is thought to be between 40,000 and 60,000. But information is limited and the actual number may have been much higher

Today, the estimated numbers from population models are similar: roughly 28,000 on the east cost and up to 30,000 on the west coast. But counting humpback whales accurately is very difficult. For example, on the east coast of Australia humpback whales frequently move between populations and during a census may not be attributed to their original population.

What’s more, conditions prior to whaling are not comparable with today’s conditions. Krill is a major food source for whales, and widespread whaling in the Southern Hemisphere caused krill numbers to increase. Research from 2019 suggests humpback whales’ fast recovery after whaling ceased may have been due to widely available krill.

But krill numbers have declined or their availability has shortened in recent years due to threats such as climate change and industrial fishing.

Aerial view of humpback under icy water . — Every year humpback whales migrate from Antarctica where they feed, to breed in Australia.
Shutterstock

Proceed with caution

Humpback whales off Australia’s coast will continue to have some protection under the Environment Protection and Biodiversity Conservation Act, even if they’re taken off the threatened species list.

Generally, all marine mammals are protected in Australian waters. But getting delisted means fewer resources devoted to their protection.

Forecasting the complex interactions of today’s threats, in order to predict tomorrow’s humpback whale populations, is challenging. A cautionary approach should therefore be taken.

In 2016, the US delisted some humpback whale populations. But before doing so, it established a ten-year monitoring plan to track population changes, threats and species abundance.

If Australia proceeds with the delisting, it should follow the US’ lead. Humpback whales should remain listed for another five years so a monitoring plan can be developed. Federal and state governments must invest resources into this process, and react swiftly if changes are detected.

A number of whale researchers and organisations concerned about the humpback whale delisting, including the author, prepared a detailed response to the proposal here.

Olaf Meynecke, Research Fellow in Marine Science, Griffith University

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

Marine life is fleeing the equator to cooler waters. History tells us this could trigger a mass extinction event

Anthony Richardson, The University of Queensland; Chhaya Chaudhary, University of Auckland; David Schoeman, University of the Sunshine Coast, and Mark John Costello, University of AucklandThe tropical water at the equator is renowned for having the richest diversity of marine life on Earth, with vibrant coral reefs and large aggregations of tunas, sea turtles, manta rays and whale sharks. The number of marine species naturally tapers off as you head towards the poles.

Ecologists have assumed this global pattern has remained stable over recent centuries — until now. Our recent study found the ocean around the equator has already become too hot for many species to survive, and that global warming is responsible.

In other words, the global pattern is rapidly changing. And as species flee to cooler water towards the poles, it’s likely to have profound implications for marine ecosystems and human livelihoods. When the same thing happened 252 million years ago, 90% of all marine species died.

The bell curve is warping dangerously

This global pattern — where the number of species starts lower at the poles and peaks at the equator — results in a bell-shaped gradient of species richness. We looked at distribution records for nearly 50,000 marine species collected since 1955 and found a growing dip over time in this bell shape.

A chart with three overlapping lines, each representing different decades. It shows that between 1955 and 1974, the bell curve is almost flat at the top. For the lines 1975-1994 and 1995-2015, the dip gets progressively deeper, with peaks either side of the centre. — If you look at each line in this chart, you can see a slight dip in total species richness between 1955 and 1974. This deepens substantially in the following decades.
Anthony Richardson, Author provided

So, as our oceans warm, species have tracked their preferred temperatures by moving towards the poles. Although the warming at the equator of 0.6℃ over the past 50 years is relatively modest compared with warming at higher latitudes, tropical species have to move further to remain in their thermal niche compared with species elsewhere.

As ocean warming has accelerated over recent decades due to climate change, the dip around at the equator has deepened.

We predicted such a change five years ago using a modelling approach, and now we have observational evidence.

For each of the 10 major groups of species we studied (including pelagic fish, reef fish and molluscs) that live in the water or on the seafloor, their richness either plateaued or declined slightly at latitudes with mean annual sea-surface temperatures above 20℃.

Today, species richness is greatest in the northern hemisphere in latitudes around 30°N (off southern China and Mexico) and in the south around 20°S (off northern Australia and southern Brazil).

school of tuna fish — The tropical water at the equator is renowned for having the richest diversity of marine life, including large aggregations of tuna fish.
Shutterstock

This has happened before

We shouldn’t be surprised global biodiversity has responded so rapidly to global warming. This has happened before, and with dramatic consequences.

252 million years ago…

At the end of the Permian geological period about 252 million years ago, global temperatures warmed by 10℃ over 30,000-60,000 years as a result of greenhouse gas emissions from volcano eruptions in Siberia.

A 2020 study of the fossils from that time shows the pronounced peak in biodiversity at the equator flattened and spread. During this mammoth rearranging of global biodiversity, 90% of all marine species were killed.

125,000 years ago…

A 2012 study showed that more recently, during the rapid warming around 125,000 years ago, there was a similar swift movement of reef corals away from the tropics, as documented in the fossil record. The result was a pattern similar to the one we describe, although there was no associated mass extinction.

Authors of the study suggested their results might foreshadow the effects of our current global warming, ominously warning there could be mass extinctions in the near future as species move into the subtropics, where they might struggle to compete and adapt.

Today…

During the last ice age, which ended around 15,000 years ago, the richness of forams (a type of hard-shelled, single-celled plankton) peaked at the equator and has been dropping there ever since. This is significant as plankton is a keystone species in the foodweb.

Our study shows that decline has accelerated in recent decades due to human-driven climate change.

The profound implications

Losing species in tropical ecosystems means ecological resilience to environmental changes is reduced, potentially compromising ecosystem persistence.

In subtropical ecosystems, species richness is increasing. This means there’ll be species invaders, novel predator-prey interactions, and new competitive relationships. For example, tropical fish moving into Sydney Harbour compete with temperate species for food and habitat.

This could result in ecosystem collapse — as was seen at the boundary between the Permian and Triassic periods — in which species go extinct and ecosystem services (such as food supplies) are permanently altered.

The changes we describe will also have profound implications for human livelihoods. For example, many tropical island nations depend on the revenue from tuna fishing fleets through the selling of licenses in their territorial waters. Highly mobile tuna species are likely to move rapidly toward the subtropics, potentially beyond sovereign waters of island nations.

Similarly, many reef species important for artisanal fishers — and highly mobile megafauna such as whale sharks, manta rays and sea turtles that support tourism — are also likely to move toward the subtropics.

The movement of commercial and artisanal fish and marine megafauna could compromise the ability of tropical nations to meet the Sustainable Development Goals concerning zero hunger and marine life.

Is there anything we can do?

One pathway is laid out in the Paris Climate Accords and involves aggressively reducing our emissions. Other opportunities are also emerging that could help safeguard biodiversity and hopefully minimise the worst impacts of it shifting away from the equator.

Currently 2.7% of the ocean is conserved in fully or highly protected reserves. This is well short of the 10% target by 2020 under the UN Convention on Biological Diversity.

Manta ray with other fish — Manta rays and other marine megafauna leaving the equator will have a huge impact on tourism.
Shutterstock

But a group of 41 nations is pushing to set a new target of protecting 30% of the ocean by 2030.

This “30 by 30” target could ban seafloor mining and remove fishing in reserves that can destroy habitats and release as much carbon dioxide as global aviation. These measures would remove pressures on biodiversity and promote ecological resilience.

Designing climate-smart reserves could further protect biodiversity from future changes. For example, reserves for marine life could be placed in refugia where the climate will be stable over the foreseeable future.

We now have evidence that climate change is impacting the best-known and strongest global pattern in ecology. We should not delay actions to try to mitigate this.

This story is part of Oceans 21

Our series on the global ocean opened with five in-depth profiles. Look out for new articles on the state of our oceans in the lead-up to the UN’s next climate conference, COP26. The series is brought to you by The Conversation’s international network.

Anthony Richardson, Professor, The University of Queensland; Chhaya Chaudhary, , University of Auckland; David Schoeman, Professor of Global-Change Ecology, University of the Sunshine Coast, and Mark John Costello, Professor, University of Auckland

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

Small breaks in habitat can have big impacts

Disastrous clearing laws

The code should be amended

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The 26 most imperilled frogs

What are we up against?

So what can we do about it?

Finding and creating wild refuges

No time to lose

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Sobering findings

A broader extinction crisis?

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How did the strategy perform?

Falling short on feral cats

Priority species: how did we do?

What must change

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Back from the dead

Not safe yet

Other eye-opening revelations

There’s a clear lesson in all this

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Why we need to look at species more closely

Taxonomists at work

Australia’s lizards and snakes

A race against extinction

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Lilac underwater gardens

An alarming decline

Then the floods hit

Urgent work required

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What’s driving the loss?

On the brink

So how can we protect them?

Now we need the political will

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A host of threats

The humpback whales’ plight

The problem with counting whales

Proceed with caution

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The bell curve is warping dangerously

This has happened before

The profound implications

Is there anything we can do?

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