Cate Macinnis-Ng, University of Auckland and Angus Mcintosh, University of CanterburyIslands are biodiversity hotspots. They are home to 20% of the world’s plants and animals yet cover only 5% of the global landmass. But island ecosystems are highly vulnerable, threatened by habitat fragmentation and introduced invasive weeds and predators.
Climate change adds to all these stresses. In our recent paper, we use Aotearoa New Zealand as a case study to show how climate change accelerates biodiversity decline on islands by exacerbating existing conservation threats.
Aotearoa is one of the world’s biodiversity hotspots, with 80% of vascular plants, 81% of arthropods and 60% of land vertebrate animals found nowhere else.
Conservation efforts have rightly concentrated on the eradication of introduced predators, with world-leading success in the eradication of rats in particular.
Potential climate change impacts have been mostly ignored. Successive assessments by the Intergovernmental Panel on Climate Change (IPCC) highlight the lack of information for Aotearoa. This could be due to insufficient research, system complexity or a lack of impacts.
In the past, some researchers even dismissed climate change as an issue for biodiversity in Aotearoa. Our maritime climate is comparatively mild and already variable. As a result, organisms are expected to be well adapted to changing conditions.
Palaeo-ecological records suggest few species extinctions despite abrupt environmental change during the Quaternary period (from 2.5 million years ago to present). But past climate change provides an incomplete picture of contemporary change because it did not include human-induced threats.
Habitat loss and fragmentation, land‐use change and complex interactions between native species and introduced predators or invasive weeds all contribute to these threats.
Species respond to climate change by evolving physiological adjustments, moving to new habitats or, in the worst cases, becoming extinct. These responses then change ecosystem processes, including species interactions and ecosystem functions (such as carbon uptake and storage).
Methods for identifying climate change impacts are either empirical and observational (field studies and manipulative experiments) or mechanistic (ecophysiological models). Mechanistic approaches allow predictions of impacts under future climate scenarios. But linking species and ecosystem change directly to climate can be challenging in a complex world where multiple stressors are at play.
There are several well-known examples of climate change impacts on species endemic to Aotearoa. First, warming of tuatara eggs changes the sex ratio of hatchlings. Hotter conditions produce more males, potentially threatening long-term survival of small, isolated populations.
Second, mast seeding (years of unusually high production of seed) is highly responsive to temperature and mast events are likely to increase under future climate change. During mast years, the seeds provide more food for invasive species like rats or mice, their populations explode in response to the abundant food and then, when the seed resource is used up, they turn to other food sources such as invertebrates and bird eggs. This has major impacts on native ecosystems.
How masting plants respond to climate change is complex and depends on the species. The full influence of climate is still emerging.
We identified a range of known and potential complex impacts of climate change in several ecosystems. The alpine zone is particularly vulnerable. Warming experiments showed rising temperatures extend the overlap between the flowering seasons of native alpine plants and invasive plants. This potentially increases competition for pollinators and could result in lower seed production.
Some large alpine birds, including the alpine parrot kea, will have fewer cool places to take refuge from invasive predators. This will cause
local extinctions in a process know as “thermal squeeze”.
Small alpine lakes, known as tarns, are not well understood but are also likely to suffer from thermal squeeze and increased drought periods. Warmer temperatures may also allow Australian brown tree frogs to invade further into these sensitive systems.
Climate change disproportionately affects Indigenous people worldwide. In Aotearoa, culturally significant species such as tītī (sooty shearwater) and harakeke (flax) will be influenced by climate change.
The breeding success of tītī, which are harvested traditionally, is strongly influenced by the El Niño Southern Oscillation (ENSO) cycle. As ENSO intensifies under climate change, numbers of young surviving are decreasing. For harakeke, future climate projections predict changes in plant distribution, potentially making weaving materials unavailable to some hapū (subtribes).
Mātauranga, the Indigenous knowledge of Māori, provides insights on climate change that haven’t been captured in western science. For instance, the Māori calendar, maramataka, has been developed over centuries of observations.
Maramataka for each hāpu (subtribe) provide guidance for the timing of gathering mahinga kai (traditional food sources). This includes the gathering of fish and other seafood, planting of crops and harvesting food. Because this calendar is based on knowledge that has accrued over generations, some changes in timing and distributions due to environmental or climate change may be captured in these oral histories.
Much of the focus of climate change research has been in agricultural and other human landscapes but we need more effort to quantify the threat for our endemic systems.
On islands across the world, rising sea levels and more severe extreme weather events are threatening the survival of endemic species and ecosystems. We need to understand the complicated processes through which climate change interacts with other threats to ensure the success of conservation projects.
While we focused on terrestrial and freshwater systems, marine and near-shore ecosystems are also suffering because of ocean acidification, rising sea levels and marine heatwaves. These processes threaten marine productivity, fisheries and mahinga kai resources.
And for long-term conservation success, we need to consider both direct and indirect impacts of climate change on our unique species and ecosystems.
Mark Lintermans, University of Canberra; Hayley Geyle, Charles Darwin University; Jaana Dielenberg, The University of Queensland; John Woinarski, Charles Darwin University; Stephen Beatty, Murdoch University, and Stephen Garnett, Charles Darwin University
Many species have declined sharply in recent decades, and as many as 90 of Australia’s 315 freshwater fish species may now meet international criteria as threatened.
No Australian fish species is yet listed officially as extinct, but some have almost certainly been lost before scientists even knew they existed. With so many species at risk, understanding which are in greatest peril is a vital first step in preventing extinctions.
This is what our new research has done. We’ve identified 20 freshwater fish species with a 50% or greater probability of extinction within the next two decades, and a further two with a 40-50% chance – unless there’s new targeted conservation action.
Many small-bodied species, including Australia’s smallest fish the red-finned blue-eye, look likely to be lost within a single human generation. These fish have evolved over millions of years.
Twelve of the species identified have only been formally described in the past decade, and seven are still awaiting description.
This highlights the urgent need to act before species are listed under the national legislation that gives fishes their conservation status, and even before they’re formally described.
These processes can take many years, at which point it may be too late for some species.
More than half the species on our list are galaxiids – small, scaleless fish, that live in cooler, upland streams and lakes. Trout, an introduced, predatory species, also favour these habitats, and the trout have taken a heavy toll on galaxiids and many other small species in southern Australia.
For example, the Victorian Shaw galaxias has been eaten out of much of its former range. Now just 80 individuals survive, protected by a waterfall from the trout below. We estimate the Shaw galaxias has an 80% chance or more of extinction within the next 20 years.
Many galaxiids do not thrive or readily breed in captivity, so suitable trout-free streams are essential for their survival.
Improving trout management requires an urgent, sustained conservation effort, including collaborations with recreational fishers, increased awareness and changing values among government and key sectors of society.
Without this, trout will almost certainly cause many native galaxiids to go extinct.
Native fish out of their natural place can also be a problem. For example, sooty and khaki grunters – native fishing species people in northern Australia have widely moved – threatening the ancient Bloomfield River cod.
All of the most imperilled species are now highly localised, which means they’re restricted to very small areas. Their distributions range from only four to 44 square kilometres.
A single catastrophic event could completely wipe out these species, such as a large bushfire that fills their streams with ash and robs them of oxygen.
For example, until 2019 the Yalmy galaxias had survived in the cool creeks of the Snowy River National Park. But after the devastating Black Summer fires, just two individuals survived, one male and one female, in separate areas.
Millions of years of evolution could be lost if a planned reunion is too late.
One of the key steps to reduce this risk is moving fish to new safe locations so there are more populations. Researchers choose these new locations carefully to make sure they’re suitable for different species.
Climate change is another threat to all identified species, as it’s likely to reduce flows and water quality, or increase fires, storms and flooding. Many species have been forced to the edge of their range and a prolonged drought could dry their remaining habitat.
The short-tail galaxias existed in two small separated populations in creeks of the upper Tuross River Catchment, in the south coast of NSW. One stream dried in the recent drought, and the other was burnt in the subsequent fires.
Luckily the species is still hanging on in the burnt catchment, but only a single individual has been found in the drought-affected creek.
Only three of the highly imperilled fish species are currently listed as threatened under national environmental legislation: the red-finned blue-eye, Swan galaxias and little pygmy perch.
Listing species is vital to provide protection to survivors and can prompt recovery action. Given our research, 19 fish species should urgently be added to the national threatened species list, but conservation action should start now.
Small native freshwater fishes are worth saving. They play a vital role in our aquatic ecosystems, such as predating on pest insect larvae, and are part of our natural heritage.
By identifying and drawing attention to their plight, we are aiming to change their fates. We cannot continue with business as usual if we want to prevent their extinctions.
Mark Lintermans, Associate professor, University of Canberra; Hayley Geyle, Research Assistant, Charles Darwin University; Jaana Dielenberg, Science Communication Manager, The University of Queensland; John Woinarski, Professor (conservation biology), Charles Darwin University; Stephen Beatty, Research Leader (Catchments to Coast), Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, and Stephen Garnett, Professor of Conservation and Sustainable Livelihoods, Charles Darwin University
Seventy-five years of Australian research into how houses respond to bushfire has identified 21 main weak points in houses and the area immediately surrounding them.
In recent decades this knowledge has been used to inform new building construction. But older houses are generally not built to the same standard, unless they have been significantly renovated.
Older homes make up the majority of buildings in bushfire prone-areas. There are some simple things that can improve the performance of an older house in a bushfire. Here are 12 suggestions: six simple projects that could be done over a weekend or two, and six low-cost things you could do in a single afternoon.
This is particularly true for garden beds near timber-framed windows and doors. For timber and fibro homes, garden beds adjacent to the house should be avoided entirely. At the very least prune dense bushes close to timber-framed windows back hard.
Over time, paint peels and cracks appear in the exposed and weathered timber. During a bushfire, embers can lodge in these cracks and ignite.
Flammable items are often stored underneath the house. If this area is not enclosed these items will catch, often due to ember attack, and pose a threat to every room in the house. The exposed underside of timber floors can be protected with a lightweight, non-combustible layer.
Curious Kids: how do bushfires start?
Just as embers can land in cracks in door and window frames, the same can also happen to weathered timber decking. Most decks are right next to the house and if they go up fire easily spreads to the home.
Think of it as an additional protective defence area. You could use gravel, paving tiles, bricks, concrete, or ground rock such as scoria.
Roofs gradually weaken and require maintenance. A professional roof repairer can check that tiles are in place, repair damaged ridge tiles, and ensure that skylights, air vents, evaporative coolers, and solar panels are in good order and are free from gaps where embers could enter.
The product specifications for timber door and window frames, metal mesh, and decking materials can be found in the relevant Australian Standard and steel construction standard. Actual requirements for houses vary according to the bushfire attack level associated with a specific block of land.
While they appear harmless, natural organic doormats can cause a fire to grow if they ignite. Due to their density they burn for a long time, and can spread flames to timber door frames. A synthetic mat will only flare up for a short time.
Burning embers can easily ignite dried-out organic mulch, setting fire to surrounding plants. If garden beds are near the house, particularly timber door and window frames, the danger is increased. Either remove mulch in garden beds next to the house or – if the mulch is suitable – dig it in deeply.
It is best to store wood well away from the house, but no one wants to walk metres in cold winters to get that wood. So some firewood is often stored close to the house on a burnable deck, and often it’s left there over summer. Putting it into a large metal container can remove that fire risk.
When embers enter the roof cavity and underneath the house, flames can rapidly spread to every room. It is vital to keep these areas clear of flammable materials.
A timber bench on a timber deck next to a timber house is an unnecessary risk, similar to having a wood pile on a timber deck.
Both the 2003 Canberra and the 2016 Wye River bushfires showed the danger of having gas bottle valves facing the house. In both fires, houses were destroyed when either the gas plume flamed or gas bottles exploded.
While these projects will improve the bushfire protection of your home, they can’t guarantee your home will survive a bushfire, especially during catastrophic bushfire conditions. It is also crucial to upgrade your home insurance so you can meet the higher costs of new building standards, in the event you have to rebuild. And in all cases, act on warnings given by your state or territory fire authority.
The advice given in this article is general and may not suit every circumstance.
A recent update on the state of New Zealand’s environment paints a particularly bleak picture about the loss of native ecosystems and the plants and animals within them.
Almost two-thirds of rare ecosystems are threatened by collapse, according to Environment Aotearoa 2019, and thousands of species are either threatened or at risk of extinction. Nowhere is the loss of biodiversity more pronounced than in Aotearoa New Zealand: we have the highest proportion of threatened indigenous species in the world.
This includes 90% of all seabirds, 84% of reptiles, 76% of freshwater fish and 74% of terrestrial birds. And this may well be an underestimate. An additional one-third of named species are listed as “data deficient”. It is likely many more would be on the threatened list had they been assessed. Then there are the species that have not been named and we have no idea about.
Biodiversity is a word that means different things to different people. Its use has exploded recently as more people appreciate the magnitude of its decline and its importance to people’s future.
Popularly biodiversity is understood as the number of species in a given country or ecosystem. For scientists, the concept is deeper. It includes genetic and ecosystem diversity and has crucial components such as endemicity (species found nowhere else), native diversity (the proportion of native species) and keystone species (species that are crucial to ecosystem function).
Globally, biodiversity in all its guises is undergoing an unprecedented decline. Estimates are that we are now losing species at more than 1,000 times the background or natural rate. People are also moving species outside their native ranges, and this results in a global biological homogenisation and has helped a small number of species to thrive in human-dominated habitats across the world.
The classification of threat status, globally and in New Zealand, is complex. There are multiple levels, ranging from “nationally critical” to “at risk”. When describing levels of biodiversity decline, it is simpler to look at the proportion of species listed as “not threatened”.
In New Zealand, only around 18% of beetles, 26% of freshwater fish, 38% of marine mammals, 12% lizards, 5% of snails and 50% of plants are listed as not threatened or not at risk. This is a rather dire situation, especially given the 100%-pure slogan used to market Aotearoa New Zealand overseas.
Another important facet of biodiversity decline is that New Zealand has many endemic species, with around 40% of plants, 90% of fungi, 70% of animals and 80% of freshwater fish found nowhere else. If they are lost here they are lost entirely.
In a recent report to the UN Convention on Biological Diversity, the Department of Conservation could not say whether New Zealand’s biodiversity is declining or not. One quarter of the nearly 4,000 species currently classified as threatened or at risk have only been assessed once and there is no way to know whether their conservation status has changed. Of the remaining roughly 3,000 threatened or at risk species, 10% had worsened to a more threatened ranking. Only 3% had improved.
The numbers above show the failure of legislation intended to protect biodiversity in Aotearoa New Zealand. The Wildlife Act (1953) purportedly gives absolute protection to all wildlife. But it is not enforced in any meaningful way, and therefore has had no impact on biodiversity conservation.
The Native Plants Protection Act (1934) stipulates that native plants have protection on conservation land but makes no mention of protection outside that and, in any case, is not enforced. Native fish are not covered by the Wildlife Act and the Freshwater Fisheries Act affords them no protection either.
Apart from ineffective species protection, another factor is the loss of habitat and ecosystems through land-use change for agricultural and urban intensification. The first changes happened with Polynesian arrival, and then again after European colonisation, including massive forest clearance and wetland drainage. More recently, the expansion of dairy farms has contributed to significant biodiversity losses.
Freshwater fish are a good example. The increase in the proportion of threatened species has gone from around one-quarter in the early 1990s to three-quarters now. This recent loss reveals the failure of successive governments to protect biota, their habitats and ecosystems. Lowland coastal forests and wetlands in particular continue to be degraded by human activity.
Indigenous terrestrial vegetation cover is now less than 30%, down from approximately 90% in pre-human times. One-third of the country is covered in exotic grasslands.
About one-third of the country is putatively protected by being within the conservation estate. This sounds impressive, but it obscures the true state of protected areas. The ecosystem types in the estate are far from a representative selection. It mostly contains areas that are too steep to farm and too inhospitable to live in.
The failure to protect habitats is reflected in the reduction in ecosystem diversity: 62% of the ecosystems classified as rare are now listed as threatened, and more than 90% of wetlands have been destroyed. This loss is not confined to the past. Estimates are that 214 wetlands (1,250 ha) were lost between 2001 and 2016, and a further 746 wetlands declined in size.
Protection levels of marine habitats are even worse. New Zealand’s marine area is 15 times larger than its land area, but marine biodiversity is poorly regulated. Only 0.4% is covered by “no-take” marine reserves.
As a signatory to the UN Sustainable Development Goals (SDGs), New Zealand is obligated to reduce biodiversity loss. We have committed to achieving SDG 14 (life under water) and SDG 15 (life on land). The former stipulates that we “conserve and sustainably use the oceans, seas and marine resources for sustainable development”. The latter that we “protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss”.
There is no sign of any real achievement in reducing biodiversity loss. While New Zealand produced a national biodiversity strategy in 2000, it has been largely ineffective at improving the state of biodiversity. As the OECD noted, the strategy and plan lack clarity and clear implementation pathways.
We have tried writing plans with no teeth. Now it is time for action from all levels of society. Cities and regions need to ensure parks and protected areas are adequately managed. Government must work to update ineffective legislation and commit to enforcing the law.
Michael (Mike) Joy, Senior Researcher; Institute for Governance and Policy Studies, Victoria University of Wellington and Sylvie McLean, Masters Student in Environmental Studies, Victoria University of Wellington
Several new species of trapdoor spiders found in Queensland are finally described in an article published this month in Invertebrate Systematics.
But each of the new species occurs in only its own single, isolated patch of rainforest in southeastern Queensland, and nowhere else.
Because these species have such tiny natural distributions, they are especially vulnerable to extinction.
These newly described spiders have been given the common name palisade trapdoor spiders because of the strange and unique burrows they construct. The entrance to the burrow projects out from the surrounding soil like a miniature turret.
Not only that, but each of the four new palisade trapdoor spider species constructs its own unique type of burrow.
One species, found in national parkland near Gympie and known scientifically as Euoplos crenatus, constructs a particularly elaborate burrow. The hinged door that covers the burrow entrance is adorned with several rounded lobes which project from the door’s circumference.
This marvel of natural architecture is constructed by the spider using silk and soil. No other spider species in the world constructs something similar.
This species was originally discovered by local naturalists Kelvin and Amelia Nielsen in 1999, who then guided researchers back to the discovery location in 2016 to collect specimens so the species could be formally named.
Another species, Euoplos thynnearum, constructs a burrow entrance with a thick lip within which the burrow door sits. It’s found in the Mary Cairncross Scenic Reserve, a 55-hectare patch of subtropical rainforest popular with visitors to the Sunshine Coast hinterland.
This species is named after Elizabeth, Mabel and Mary Thynne, who originally donated the reserve land to the local council in 1941 to honour their mother Mary Thynne (née Cairncross). Currently, this species is known to occur only within the reserve and in other rainforest patches in the immediate vicinity.
Species that only only occur in a very small area, like these new palisade trapdoor spider species, are known as short-range endemic species.
Although scientists are naming new species at a faster rate than ever before, estimates of the total number of species on Earth still suggest that most animal species have not been formally named. With so much work still to do, some scientists have chosen to prioritise work on particular types of animals that are especially vulnerable to extinction.
In 2002, Mark Harvey, an arachnologist from the Western Australian Museum, proposed that scientists should prioritise the discovery and description of short-range endemic species.
He reasoned that the small ranges of these species make them inherently vulnerable to extinction, and that identifying, naming and studying them is the first step to protecting them.
For trapdoor spiders, short-range endemism is the rule, not the exception. These spiders live their entire lives in a burrow. Juvenile spiders walk only short distances from their mother’s burrow, before constructing a burrow of their own.
Usually, these spiders will then remain in the same burrow for the remainder of their lives, enlarging it as they grow.
Adult male trapdoor spiders will also leave their burrow to breed, but will only travel relatively short distances. Over time, this extremely limited dispersal ability has led to the evolution of many different trapdoor spider species, each of which occurs in only a very small area.
Since 2012, a research team, led by Queensland Museum researcher Michael Rix, has been trying to discover and name all species of spiny trapdoor spider – this group includes the palisade trapdoor spiders, as well as other strange trapdoor spider species such as the shield-backed trapdoor spiders of Western Australia.
So far, this project has led to the description of more than 100 new species from throughout Australia, some of which are already classified as threatened by federal and state governments.
The most iconic of these is Idiosoma nigrum (also a shield-backed trapdoor spider), which is a listed threatened species.
The discovery of all these weird and wonderful spider species should remind us that Australia has some of the most remarkable invertebrate species in the world, and new species are waiting to be discovered in the national parks and reserves which occur around, and even within, our towns and cities – under our noses.
Next time you visit a national park, or drive past a patch of forest while commuting along Australia’s east coast, think to yourself, what might be living in there? Do those species occur anywhere else? And above all, if we lose that forest remnant, what unique species might disappear along with it?
Martine Maron, The University of Queensland; Andrea Griffin, University of Newcastle; April Reside, The University of Queensland; Bill Laurance, James Cook University; Don Driscoll, Deakin University; Euan Ritchie, Deakin University, and Steve Turton, CQUniversity Australia
Australia’s high rates of forest loss and weakening land clearing laws are increasing bushfire risk, and undermining our ability to meet national targets aimed at curbing climate change.
This dire situation is why we are among the more than 300 scientists and practitioners who have signed a declaration calling for governments to restore, or better strengthen regulations to protect native vegetation.
Land clearing laws have been contentious in several states for years. New South Wales relaxed its land clearing controls in 2017, triggering concerns over irreversible environmental damage. Although it is too early to know the impact of those changes, a recent analysis found that land clearing has increased sharply in some areas since the laws changed.
The Queensland Labor government’s 2018 strengthening of land clearing laws came after years of systematic weakening of these protections. Yet the issue has remained politically divisive. While discussing a federal inquiry into the impact of these policies on farmers, federal agriculture minister David Littleproud suggested that the strenthening of regulations may have worsened Queensland’s December bushfires.
We argue such an assertion is at odds with scientific evidence. And, while the conservation issues associated with widespread land clearing are generally well understood by the public, the consequences for farmers and fire risks are much less so.
During December’s heatwave in northern Queensland, some regions were at “catastrophic” bushfire risk for the first time since ratings began. Even normally wet rainforests, such as at Eungella National Park inland from Mackay, sustained burns in some areas during “unprecedented” fire conditions.
There is no evidence to support the suggestion that 2018’s land clearing law changes contributed to the fires. No changes were made to how vegetation can be managed to reduce fire risk. This is governed under separate laws, which remained unaltered.
In fact, shortly after the fires, Queensland’s land clearing figures were released. They showed that in the three years to June 2018, an area equivalent to roughly 570,000 Melbourne Cricket Grounds (1,138,000 hectares) of bushland was cleared, including 284,000 hectares of remnant (old-growth) ecosystems.
Tree clearing can worsen fire risk in several ways. It can affect the regional climate. In parts of eastern Australia, tree cover reductions are estimated to have increased summer surface temperatures by up to 2℃ and southwest Western Australia by 0.4–0.8℃, reduced rainfall in southeast Australia, and made droughts hotter and longer.
Removing forest vegetation depletes soil moisture. Large, intact areas of forest typically have cooler, wetter microclimates buffered from extreme temperatures. Over time, some forest types can even become fire-resistant, but smaller patches of trees are typically drier and more flammable.
Trees also form a natural windbreak that can slow the spread of bushfires. An analysis of the 2005 Wangary fire in South Australia found that fires spread most rapidly through paddocks, rather than through areas lined with native trees.
Extensive tree clearing also leads to problems for farmers, including rising salinity, reduced water quality, and soil erosion. Governments and rural communities spend significant money and labour redressing the aftermath of excessive clearing.
Sensible regulation of native vegetation removal does not restrict existing agriculture, but rather seeks to support sustainable production. Retained trees can help deal with many environmental risks that hamper agricultural productivity, including animal health, long-term pasture productivity, risks to the water cycle, pest control, and human well-being.
Rampant tree clearing is undoing climate policy too. Much of the federal government’s A$2.55 billion Emissions Reduction Fund has gone towards tree planting. But it would take almost this entire sum just to replace the trees cleared in Queensland since 2012.
In 2019, Australians might reasonably expect that our relatively wealthy and well-educated country has moved beyond a frontier-style reliance on continued deforestation, and we would do well to better acknowledge and learn lessons from Indigenous Australians with respect to their land management practices.
Yet the periodic weakening of land clearing laws in many parts of Australia has accelerated the problem. The negative impacts on industry, society and wildlife are numerous and well established. They should not be ignored.
Martine Maron, ARC Future Fellow and Associate Professor of Environmental Management, The University of Queensland; Andrea Griffin, Senior Lecturer, School of Psychology, University of Newcastle; April Reside, Researcher, Centre for Biodiversity and Conservation Science, The University of Queensland; Bill Laurance, Distinguished Research Professor and Australian Laureate, James Cook University; Don Driscoll, Professor in Terrestrial Ecology, Deakin University; Euan Ritchie, Associate Professor in Wildlife Ecology and Conservation, Centre for Integrative Ecology, School of Life & Environmental Sciences, Deakin University, and Steve Turton, Adjunct Professor of Environmental Geography, CQUniversity Australia
Matthew Fraser, University of Western Australia; Ana Sequeira, University of Western Australia; Brendan Paul Burns, UNSW; Diana Walker, University of Western Australia; Jon C. Day, James Cook University, and Scott Heron, James Cook University
The devastating bleaching on the Great Barrier Reef in 2016 and 2017 rightly captured the world’s attention. But what’s less widely known is that another World Heritage-listed marine ecosystem in Australia, Shark Bay, was also recently devastated by extreme temperatures, when a brutal marine heatwave struck off Western Australia in 2011.
A 2018 workshop convened by the Shark Bay World Heritage Advisory Committee classified Shark Bay as being in the highest category of vulnerability to future climate change. And yet relatively little media attention and research funding has been paid to this World Heritage Site that is on the precipice.
Shark Bay, in WA’s Gascoyne region, is one of 49 marine World Heritage Sites globally, but one of only four of these sites that meets all four natural criteria for World Heritage listing. The marine ecosystem supports the local economy through tourism and fisheries benefits.
Around 100,000 tourists visit Shark Bay each year to interact with turtles, dugongs and dolphins, or to visit the world’s most extensive population of stromatolites – stump-shaped colonies of microbes that date back billions of years, almost to the dawn of life on Earth.
Commercial and recreational fishing is also extremely important for the local economy. The combined Shark Bay invertebrate fishery (crabs, prawns and scallops) is the second most valuable commercial fishery in Western Australia.
However, this iconic and valuable marine ecosystem is under serious threat. Shark Bay is especially vulnerable to future climate change, given that the temperate seagrass that underpins the entire ecosystem is already living at the upper edge of its tolerable temperature range. These seagrasses provide vital habitat for fish and marine mammals, and help the stromatolites survive by regulating the water salinity.
Shark Bay received the highest rating of vulnerability using the recently developed Climate Change Vulnerability Index, created to provide a method for assessing climate change impacts across all World Heritage Sites.
In particular, extreme marine heat events were classified as very likely and predicted to have catastrophic consequences in Shark Bay. By contrast, the capacity to adapt to marine heat events was rated very low, showing the challenges Shark Bay faces in the coming decades.
The region is also threatened by increasingly frequent and intense storms, and warming air temperatures.
To understand the potential impacts of climatic change on Shark Bay, we can look back to the effects of the most recent marine heatwave in the area. In 2011 Shark Bay was hit by a catastrophic marine heatwave that destroyed 900 square kilometres of seagrass – 36% of the total coverage.
This in turn harmed endangered species such as turtles, contributed to the temporary closure of the commercial crab and scallop fisheries, and released between 2 million and 9 million tonnes of carbon dioxide – equivalent to the annual emissions from 800,000 homes.
Some aspects of Shark Bay’s ecosystem have never been the same since. Many areas previously covered with large, temperate seagrasses are now bare, or have been colonised by small, tropical seagrasses, which do not provide the same habitat for animals. This mirrors the transition seen on bleached coral reefs, which are taken over by turf algae. We may be witnessing the beginning of Shark Bay’s transition from a sub-tropical to a tropical marine ecosystem.
This shift would jeopardise Shark Bay’s World Heritage values. Although stromatolites have survived for almost the entire history of life on Earth, they are still vulnerable to rapid environmental change. Monitoring changes in the microbial makeup of these communities could even serve as a canary in the coalmine for global ecosystem changes.
Despite Shark Bay’s significance, and the seriousness of the threats it faces, it has received less media and funding attention than many other high-profile Australian ecosystems. Since 2011, the Australian Research Council has funded 115 research projects on the Great Barrier Reef, and just nine for Shark Bay.
The World Heritage Committee has recognised that local efforts alone are no longer enough to save coral reefs, but this logic can be extended to other vulnerable marine ecosystems – including the World Heritage values of Shark Bay.
Safeguarding Shark Bay from climate change requires a coordinated research and management effort from government, local industry, academic institutions, not-for-profits and local Indigenous groups – before any irreversible ecosystem tipping points are reached. The need for such a strategic effort was obvious as long ago as the 2011 heatwave, but it hasn’t happened yet.
Due to the significant Aboriginal heritage in Shark Bay, including three language groups (Malgana, Nhanda and Yingkarta), it will be vital to incorporate Indigenous knowledge, so as to understand the potential social impacts.
And of course, any on-the-ground actions to protect Shark Bay need to be accompanied by dramatic reductions in greenhouse emissions. Without this, Shark Bay will be one of the many marine ecosystems to fundamentally change within our lifetimes.
Matthew Fraser, Postdoctoral Research Fellow, University of Western Australia; Ana Sequeira, ARC DECRA Fellow, University of Western Australia; Brendan Paul Burns, Senior Lecturer, UNSW; Diana Walker, Emeritus Professor, University of Western Australia; Jon C. Day, PSM, Post-career PhD candidate, ARC Centre of Excellence for Coral Reef Studies, James Cook University, and Scott Heron, Senior Lecturer, James Cook University
The directors of most Australian companies are well aware of the impact of carbon emissions, not only on the environment but also on their own firms as emissions-intensive industries get lumbered with taxes and regulations designed to change their behaviour.
Many are getting out of emissions-intensive activities ahead of time.
But, with honourable exceptions, Australia’s tourism industry (and the Australian authorities that support it) is rolling on as if it’s business as usual.
This could be because tourism isn’t a single industry – it is a composite, made up of many industries that together create an experience, none of which take responsibility for the whole thing.
But tourism is a huge contributor to emissions, accounting for 8% of emissions worldwide and climbing as tourism grows faster than the economies it contributes to.
Tourism operators are aiming for even faster growth, most of them apparently oblivious to clear evidence about what their industry is doing and the risks it is buying more heavily into.
If Australian tourist destinations were companies they would be likely to discuss the risks to their operating models from higher taxes, higher oil prices, extra regulation, and changes in consumer preferences.
Aviation is one of the biggest tourism-related emitters, with the regions that depend on air travel heavily exposed.
But at present the destination-specific carbon footprints from aviation are not recorded, making it difficult for destinations to assess the risks.
A recent paper published in Tourism Management has attempted to fill the gap, publishing nine indicators for every airport in the world.
The biggest emitter in terms of departing passengers is Los Angeles International Airport, producing 765 kilo-tonnes of CO₂ in just one month; January 2017.
When taking into account passenger volumes, one of the airports with the highest emissions per traveller is Buenos Aires. The average person departing that airport emits 391 kilograms of CO₂ and travels a distance of 5,651 km.
The analysis used Brisbane as one of four case studies.
Brisbane’s share of itineraries under 400 km is very low at 0.7% (compared with destinations such as Copenhagen which has 9.1%). That indicates a relatively low potential to survive carbon risk by pivoting to public transport or electric planes, as Norway is planning to.
The average distance travelled from Brisbane is 2,852 km, a span exceeded by Auckland (4,561 km) but few other places.
As it happens, Brisbane Airport is working hard to minimise its on-the-ground environmental impact, but that’s not where its greatest threats come from.
The indicators suggest that the destinations at most risk are islands, and those “off the beaten track” – the kind of destinations that tourism operators are increasingly keen to develop.
Queensland’s Outback Tourism Infrastructure Fund was established to do exactly that. It would be well advised to shift its focus to products that will survive even under scenarios of extreme decarbonisation.
They could include low-carbon transport systems and infrastructure, and a switch to domestic rather than international tourists.
Experience-based travel, slow travel and staycations are likely to become the future of tourism as holidaymakers continue to enjoy the things that tourism has always delivered, but without travelling as much and without burning as much carbon to do it.
An industry concerned about its future would start transforming now.
Large parts of Australia are facing a hotter and drier summer than average, according to the Bureau of Meteorology’s summer outlook.
Drier than average conditions are likely for much of northern Australia. Most of the country has at least an 80% chance of experiencing warmer than average day and night-time temperatures.
The threat of bushfire will remain high, with few signs of the sustained rain needed to reduce fire risk or make a significant dent in the ongoing drought.
Large parts of Western Australia, most of Queensland and the Top End of the Northern Territory are expected to be drier than usual. Further south, the rest of the country shows no strong push towards a wetter or drier than average summer, which is a change for parts of the southeast compared to recent months.
Queensland has already seen some extraordinary record-breaking heat in recent days, with summer yet to truly begin. With the summer outlook predicting warmer days and nights, combined with recent dry conditions and our long-term trend of increasing temperatures, some extreme highs are likely this summer.
All of this means above-normal bushfire potential in eastern Australia, across New South Wales, Victoria and Queensland. The bushfire outlook, also released today, notes that rain in areas of eastern Australia during spring, while welcome, was not enough to recover from the long-term dry conditions. The current wet conditions across parts of coastal New South Wales will help, but it will not take long once hot and dry conditions return for vegetation to dry out.
The Bureau is currently at El Niño ALERT, which means a roughly 70% chance of El Niño developing this season.
However, not all the ducks are lined up. While ocean temperatures have already warmed to El Niño levels, to declare a proper “event” there must also be a corresponding response in the atmosphere to reinforce the ocean – this hasn’t happened yet.
That said, climate models expect this event to arrive in the coming months. The outlook has factored in that chance, and the conditions predicted are largely consistent with what we would expect during El Niño. In summer, this includes drier weather in parts of northern Australia, and warmer summer days.
Once an El Niño is in place, weather systems across southern Australia tend to be more mobile. This can mean shorter but more intense heatwaves in Victoria and southern South Australia. However, in New South Wales and Queensland, El Niño is associated with both longer and more intense heat waves.
The exact reason why the states are affected differently is complicated, but relates to the fast-moving cold fronts and troughs that sweep through Victoria and South Australia in the summertime, creating cool changes. These weather systems don’t influence areas further north so when hot air arrives, it takes longer to clear.
The heavy rains seen in parts of eastern Australia in October and November have provided some welcome short-term relief to drought-stricken farmers, but longer-term rainfall relief has not arrived yet. If El Niño arrives, this widespread relief may only be on the cards in autumn.