Cyclone Seroja just demolished parts of WA – and our warming world will bring more of the same


Bureau of Meteorology

Jonathan Nott, James Cook UniversityTropical Cyclone Seroja battered parts of Western Australia’s coast on Sunday night, badly damaging buildings and leaving thousands of people without power. While the full extent of the damage caused by the Category 3 system is not yet known, the event was unusual.

I specialise in reconstructing long-term natural records of extreme events, and my historic and prehistoric data show cyclones of this intensity rarely travel as far south as this one did. In fact, it has happened only 26 times in the past 5,000 years.

Severe wind gusts hit the towns of Geraldton and Kalbarri – towns not built to withstand such conditions.

Unfortunately, climate change is likely to mean disasters such as Cyclone Seroja will become more intense, and will be seen further south in Australia more often. In this regard, Seroja may be a timely wake-up call.

Seroja: bucking the cyclone trend

Cyclone Seroja initially piqued interest because as it developed off WA, it interacted with another tropical low, Cyclone Odette. This rare phenomenon is known as the Fujiwhara Effect.

Cyclone Seroja hit the WA coast between the towns of Kalbarri and Gregory at about 8pm local time on Sunday. According to the Bureau of Meteorology it produced wind gusts up to 170 km/hour.

Seroja then moved inland north of Geraldton, weakening to a category 2 system with wind gusts up to 120 km/hour. It then tracked further east and has since been downgraded to a tropical low.

The cyclone’s southward track was historically unusual. For Geraldton, it was the first Category 2 cyclone impact since 1956. Cyclones that make landfall so far south on the WA coast are usually less intense, for several reasons.

First, intense cyclones draw their energy from warm sea surface temperatures. These temperatures typically become cooler the further south of the tropics you go, depleting a cyclone of its power.

Second, cyclones need relatively low speed winds in the middle to upper troposphere – the part of the atmosphere closest to Earth, where the weather occurs. Higher-speed winds there cause the cyclone to tilt and weaken. In the Australian region, these higher wind speeds are more likely the further south a cyclone travels.

Third, most cyclones make landfall in the northern half of WA where the coast protrudes far into the Indian Ocean. Cyclones here typically form in the Timor Sea and move southward or south-west away from WA before curving southeast, towards the landmass.

For a cyclone to cross the coast south of about Carnarvon, it must travel a considerable distance towards the south-west into the Indian Ocean. This was the case with Seroja – winds steered it away from the WA coast before they weakened, allowing the cyclone to curve back towards land.

Reading the ridges

My colleagues and I have devised a method to estimate how often and where cyclones make landfall in Australia.

As cyclones approach the coast, they generate storm surge – abnormal sea level rise – and large waves. The surge and waves pick up sand and shells from the beaches and transport them inland, sometimes for several hundred metres.

These materials are deposited into ridges which stand many metres above sea level. By examining these ridges and geologically dating the materials within them, we can determine how often and intense the cyclones have been over thousands of years.




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At Shark Bay, just north of where Seroja hit the coast, a series of 26 ridges form a “ridge plain” made entirely of one species of a marine cockle shell (Fragum eragatum). The sand at beaches near the plain are also made entirely of this shell.

The ridge record shows over the past 5,000 years, cyclones of Seroja’s intensity, or higher, have crossed the coast in this region about every 190 years – so about 26 times. Some 14 of these cyclones were more intense than Seroja.

The record shows no Category 5 cyclones have made landfall here over this time. The ridge record prevents us from knowing the frequency of less intense storms. But Bureau of Meteorology cyclone records since the early 1970s shows only a few crossed the coast in this region, and all appear weaker than Seroja.

Emergency services crews in the WA town of Geraldton, preparing ahead of the arrival of Tropical Cyclone Seroja
Emergency services crews in the WA town of Geraldton, preparing ahead of the arrival of Tropical Cyclone Seroja – an event rarely seen this far south.
Department of Fire and Emergency Services WA

Cyclones under climate change

So why does all this matter? Cyclones can kill and injure people, damage homes and infrastructure, cause power and communication outages, contaminate water supplies and more. Often, the most disadvantaged populations are worst affected. It’s important to understand past and future cyclone behaviour, so communities can prepare.

Climate change is expected to alter cyclone patterns. The overall number of tropical cyclones in the Australian region is expected to decrease. But their intensity will likely increase, bringing stronger wind and heavier rain. And they may form further south as the Earth warms and the tropical zone expands poleward.

This may mean cyclones of Seroja’s intensity are likely to become frequent, and communities further south on the WA coast may become more prone to cyclone damage. This has big implications for coastal planning, engineering and disaster management planning.

In particular, it may mean homes further south must be built to cope with stronger winds. Storm surge may also worsen, inundating low-lying coastal land.

Global climate models are developing all the time. As they improve, we will gain a more certain picture of how tropical cyclones will change as the planet warms. But for now, Seroja may be a sign of things to come.




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This article is part of Conversation series on the nexus between disaster, disadvantage and resilience. Read the rest of the stories here.The Conversation

Jonathan Nott, Professor of Physical Geography, James Cook University

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

We tested tiger snake scales to measure wetland pollution in Perth. The news is worse than expected


Shutterstock

Damian Lettoof, Curtin University; Kai Rankenburg, Curtin University; Monique Gagnon, Curtin University, and Noreen Evans, Curtin University

Australia’s wetlands are home to a huge range of stunning flora and fauna, with large snakes often at the top of the food chain.

Many wetlands are located near urban areas. This makes them particularly susceptible to contamination as stormwater, urban drainage and groundwater can wash metals — such as arsenic, cadmium, lead and mercury — into the delicate ecosystem.

We know many metals can travel up the food chain when they’re present in the environment. So to assess contamination levels, we caught highly venomous tiger snakes across wetlands in Perth, and repurposed laser technology to measure the metals they accumulated.

In our new paper, we show metal contamination in wild wetland tiger snakes is chronic, and highest in human-disturbed wetlands. This suggests all other plants and animals in these wetlands are likely contaminated as well.

34 times more arsenic in wild wetland snakes than captive snakes

Urban growth and landscape modification often introduces metals into the surrounding environment, such as mining, landfill and waste dumps, vehicles and roadworks, and agriculture.

When they reach wetlands, sediments collect and store these metals for hundreds of years. And if a wetland’s natural water levels are lowered, from agricultural draining for example, sediments can become exposed and erode. This releases the metals they’ve been storing into the ecosystem.

A reflective lake, with green vegetation surrounding it
The wetland in Yanchep National Park, Perth, was supposed to be our ‘clean’ comparison site. Its levels of metal contamination was unprecedented.
Shutterstock

This is what we suspect happened in Yanchep National Park’s wetland, which was supposed to be our “clean” comparison site to more urban wetlands. But in a 2020 study looking at sediment contamination, we found this wetland had higher levels of selenium, mercury, chromium and cadmium compared to urban wetlands we tested.

And at Herdsman Lake, our most urban wetland five minutes from the Perth city centre, we found concentrations of arsenic, lead, copper and zinc in sediment up to four times higher than government guidelines.




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In our new study on tiger snake scales, we compared the metal concentrations in wild wetland tiger snakes to the concentrations that naturally occurs in captive-bred tiger snakes, and to the sediment in the previous study.

We found arsenic was 20-34 times higher in wild snakes from Herdsman Lake and Yanchep National Park’s wetland. And snakes from Herdsman Lake had, on average, eight times the amount of uranium in their scales compared to their captive-bred counterparts.

Tiger snake on the ground, near rubbish.
Our research confirmed snake scales are a good indicator of environmental contamination.
Damian Lettoof, Author provided

Tiger snakes usually prey on frogs, so our results suggest frogs at these lakes are equally as contaminated.

We know for many organisms, exposure to a high concentration of metals is fatally toxic. And when contamination is chronic, it can be “neurotoxic”. This can, for example, change an organism’s behaviour so they eat less, or don’t want to breed. It can also interfere with their normal cellular function, compromising immune systems, DNA repair or reproductive processes, to name a few.

Snakes in general appear relatively resistant to the toxic effects of metal contamination, but we’re currently investigating what these levels of contamination are doing to tiger snakes’ health and well-being.

Our method keeps snakes alive

Snakes can be a great indicator of environmental contamination because they generally live for a long time (over 10 years) and don’t travel too far from home. So by measuring metals in older snakes, we can assess the contamination history of the area they were collected from.

Typically, scientists use liver tissue to measure biological contamination since it acts like a filter and retains a substantial amount of the contaminants an animal is exposed to.

But a big problem with testing the liver is the animal usually has to be sacrificed. This is often not possible when studying threatened species, monitoring populations or working with top predators.

Two black swans in a lake, near cut grass
Sediment in Herdsman Lake had four times higher heavy metal levels than what government guidelines allow.
Shutterstock

In more recent years, studies have taken to measuring metals in external “keratin” tissues instead, which include bird feathers, mammal hair and nails, and reptile scales. As it grows, keratin can accumulate metals from inside the body, and scientists can measure this without needing to kill the animal.

Our research used “laser ablation” analysis, which involves firing a focused laser beam at a solid sample to create a small crater or trench. Material is excavated from the crater and sent to a mass spectrometer (analytical machine) where all the elements are measured.

This technology was originally designed for geologists to analyse rocks, but we’re among the first researchers applying it to snake scales.

Laser ablation atomises the keratin of snake scales, and allowed us to accurately measure 19 contaminants from each tiger snake caught over three years around different wetlands.

Wild tiger snake
Snakes generally appear resistant to the toxic effects of heavy metals.
Kristian Bell/Shutterstock

We need to minimise pollution

Our research has confirmed snake scales are a good indicator of environmental contamination, but this is only the first step.

Further research could allow us to better use laser ablation as a cost-effective technology to measure a larger suite of metals in different parts of the ecosystem, such as in different animals at varying levels in the food chain.

This could map how metals move throughout the ecosystem and help determine whether the health of snakes (and other top predators) is actually at risk by these metal levels, or if they just passively record the metal concentrations in their environment.




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It’s difficult to prevent contaminants from washing into urban wetlands, but there are a number of things that can help minimise pollution.

This includes industries developing strict spill management requirements, and local and state governments deploying storm-water filters to catch urban waste. Likewise, thick vegetation buffer zones around the wetlands can filter incoming water.The Conversation

Damian Lettoof, PhD Candidate, Curtin University; Kai Rankenburg, Researcher, Curtin University; Monique Gagnon, Researcher, Curtin University, and Noreen Evans, Professor, Curtin University

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

Enjoy them while you can? The ecotourism challenge facing Australia’s favourite islands



Remarkable Rocks, Kangaroo Island, South Australia.
Greg Brave/Shutterstock

Freya Higgins-Desbiolles, University of South Australia

I fell for Kangaroo Island from my first visit. I recall standing on a headland on the island’s southern coast, near Remarkable Rocks (a popular tourist site), and being awestruck by the Southern Ocean.

The island (Australia’s third-largest after Tasmania and Melville Island) is one of 16 designated National Landscapes and arguably South Australia’s greatest tourism treasure. Its protected areas (notably Flinders Chase National Park) are home to rare and endangered marsupials and birds.

A year ago, in Australia’s “Black Summer”, bushfires ravaged more than half the island (about 211,000 hectares). Those fires underscored the threat to this and other iconic island destinations.

Both directly and indirectly, humans are endangering these fragile ecosystems through unsustainable development and human-caused climate change.

The most ironic threat is from unsustainable tourism. These islands attract millions of visitors a year keen to experience their natural wonders. Yet often this very “ecotourism” is contributing to their degradation.

How to do better?

Last October I took part in a workshop at which Kangaroo Island’s tourism operators discussed how to do so. 2020 was a difficult year for them, first with the fires, then with the COVID-19 pandemic. But in that adversity they also saw the opportunity to reset “business as usual” and come back better, creating an industry not harming its core asset.




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A range of ideas came out of our talks applicable to all our island destinations. But there was one key point. Ecotourism should be more than fleeting feel-good experiences. It should not be a “value extraction” but a “values education”, inspiring visitors to go home and live more eco-consciously.

Macquarie island

The paradox of ecotourism is perhaps best exemplified by Australia’s least visited island destination – Macquarie Island, about 1,500 km south-east of Hobart, halfway between New Zealand and the Antarctica.

Just 1,500 tourists a year, rather than hundreds of thousands, are permitted by the Tasmania Parks and Wildlife Service to visit. The island has no hotels, restaurants or souvenir shops. The only buildings are those of the Macquarie Island Station research base and a few isolated field huts for scientists.

The Macquarie Island Research Base.
The Macquarie Island Research Base.
Dale Lorna Jacobsen/Shutterstock

Tourists must be content with coming ashore for the day from the 18 small cruise ships that ply these waters in summer. The only hospitality is the traditional station offering of tea and scones.

But what tourists do get is a unique experience. Macquarie is World Heritage listed as the only island made entirely from the earth’s mantle. It also teems with wildlife – multiple species of penguins and seals in their tens of thousands, and birds in their millions.

Royal Penguins and Southern Elephant Seals at Sandy Bay, Macquarie Island.
Royal Penguins and Southern Elephant Seals at Sandy Bay, Macquarie Island.
Janelle Lugge/Shutterstock

It’s about as pure an ecotourism experience you can have (if you can afford it). Even so, it still takes resources to get there, including the burning of fossil fuels, contributing to the global warming that is the greatest threat to the environmental integrity of Macquarie Island (and other island ecosystems).

However, the Tasmania Parks and Wildlife Service does at least expect cruise ship operators to “demonstrate their capacity to deliver desirable outcomes” on criteria including minimisation of environmental impacts and communicating to tourists “messages about the natural and cultural values of the island”, including the role they play in its preservation.




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K’gari (Fraser island)

Communicating such messages is something that certainly needs improvement on another World Heritage listed island – K’gari (commonly known as Fraser island), the world’s largest sand island.

About 250 km north of Brisbane, at the southern end of the Great Barrier Reef, the island draws many hundreds of thousands of visitors a year to its beaches, woodlands and rainforests. (There are no recent public statistics on island visitor numbers but in 2017-18 the Fraser Coast region attracted 1,515,000 visitors.)

Rainforest on K'gari.
Rainforest on K’gari.
Marco Saracco/Shutterstock

Once the island’s resources were mined and logged. Tourism was meant to be much less exploitative. But a range of organisations including the International Union for Conservation of Nature have highlighted the pressure tourist numbers (along with their vehicles and infrastructure) are placing on K’gari’s landscapes and wildlife.

Communicating to all those visitors the role they play in the island’s preservation appears to be failing. The bushfires that burnt half the island (about 165,500 hectares) over nine weeks between October and December last year allegedly resulted from an illegal camp fire.

Headline-grabbing attacks by the island’s residents dingos – such as in April 2019 when a toddler was dragged from a campervan – have also been credited to rampant irresponsible tourist behaviour (feeding dingoes to get better photos, for example).

Indigenous elders, conservationists and scientists have all pointed to the problem of a mass-tourism model that doesn’t put enough emphasis on educating visitors about the environment and their responsibilities.




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Rottnest Island

One of our proposals for Kangaroo Island is to reduce the impact of motor vehicles through encouraging more extended walking and cycling experiences.

The value of sustainable transport as the foundation for ecotourism is demonstrated by Rottnest Island, 20 km off the coast of Perth.

The entire island is managed as an A-Class Nature Reserve. Apart from service vehicles and shuttle buses, it is car-free. You can hire a bike or bring your own to get around the island (11 km long and 4.5 km wide). Or simply walk.

The absence of traffic makes a Rottnest holiday a distinctly more relaxed experience. It’s a fair example of slow tourism; and, of course, it is also good for the island’s world famous quokkas, which co-exist with close to 800,000 visitors a year.

Rottnest island has the world’s only sizeable population of quokkas. There are 10,000 to 12,000 quokkas on the island.
Grakhantsev Nikolai/Shutterstock



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Before they are gone

Given a little space, nature is resilient.

After Kangaroo Island’s bushfires a year ago, for example, it was feared a number of endangered species had finally been driven to extinction.

But in two of 2020’s few good news stories, scientists found critically endangered Kangaroo Island dunnarts and little pygmy possums – the world’s smallest marsupial – had survived.

Kangaroo Island pygmy possum.
Kangaroo Island pygmy possum.
Ashlee Benc/Kangaroo Island Land for Wildlife, CC BY

But we can’t take that resilience for granted if we keep putting pressure on these fragile ecosystems. We need a better approach to ensure ecotourism isn’t about enjoying these natural wonders before they are gone.The Conversation

Freya Higgins-Desbiolles, Senior Lecturer in Tourism Management, University of South Australia

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

Can a mining state be pro-heritage? Vital steps to avoid another Juukan Gorge



Participants in the Wintawari Guruma Rock Art Research Project record rock art near Tom Price in the Pilbara region.
Jo McDonald, CRAR+M Database, Photo reproduced with permission WGAC, Author provided

Jo McDonald, University of Western Australia

The destruction of 46,000-year-old Juukan Gorge sites in the Pilbara has created great distress for their traditional owners, seismic shockwaves for heritage professionals and appalled the general public.

The fallout for Rio Tinto has been profound as has the groundswell of criticism of Western Australia’s outdated heritage laws. A path forward must ensure a pivotal role for Indigenous communities and secure Keeping Places for heritage items. More broadly, we need more Indigenous places added to the National Heritage List, ensuring them the highest form of heritage protection.

In a state heavily dependent on mining, the model for this could follow the successful seven-year heritage collaboration I have been part of on-country with Murujuga Aboriginal Corporation (MAC) and Rio Tinto in the Dampier Archipelago (Murujuga).

As Director of the Centre for Rock Art Research and Management at the University of Western Australia, I am funded to undertake research supported by Rio Tinto’s conservation agreement with the Commonwealth.

This Rio Tinto funding enables research documenting the significant scientific and community values of the archipelago, feeding into the management of this estate by MAC, who represent the local coastal Pilbara groups. It also resources Indigenous rangers and trains undergraduate students.

The Murujuga conservation agreements, made between the Commonwealth and both Rio Tinto and Woodside, were negotiated when the archipelago’s one million-plus engravings and stone features were added to Australia’s National Heritage List in 2007.




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Murujuga is one of only seven Indigenous rock art places on the National Heritage List. There are 118 listings in total in Australia (only 20 of them Indigenous). Murujuga is the only listed Indigenous site here with a conservation agreement requiring industry to fund heritage protection.

Rio Tinto does not have a similar agreement with the traditional owners of Juukan Gorge, the Puutu Kunti Kurruma Pinikuru (PKKP) peoples — nor do any of the other Pilbara resource extraction companies with their host native title communities. These mining tenements are managed by a range of royalty agreements, which recognise native title rights but are flexible and require transparency.

Despite working closely with Rio Tinto, I have been dismayed by the Juukan incident and the fault lines it has revealed in Rio Tinto’s historically significant investment in heritage management and agreement-making with Aboriginal people.

PKKP this week expressed their distress at the company’s behavior. Clearly, there is much for Rio Tinto to improve. But similarly, the regulation process is seriously flawed.

A screenshot of a supplied video taken in 2015 showing one of the Juukan Gorge rock shelters in Western Australia before they were destroyed by Rio Tinto in May 2020.
PKKP AND PKKP Aboriginal Corporation.



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Conserving Aboriginal heritage

Many of the changes in the WA Government’s new Aboriginal Cultural Heritage Bill 2020 are welcome: in particular, the recognition of native title, allowing “stop work orders” if an Indigenous community says mining work was begun without their permission, and increased penalties for damaging heritage.

But Aboriginal groups, including many in the Kimberley and south-west WA, fear the onus for this regulatory process will be passed onto them and — despite being the appropriate people to manage their own heritage — they will not be adequately resourced to do so.

The number of heritage sites likely to be at risk in the future will number in the thousands, given the current footprint of mining is a mere 1% of the planned expansion over the next century. A new paradigm is needed in managing heritage. There needs to be a process of identifying regionally significant landscapes and earmarking them for conservation before future development footprints are determined.

And there need to be more conservation agreements like the Murujuga one, with industry-funding heritage and conservation rather than just mining clearance work.

In the Pilbara, for instance, there are three national parks, Karajini, Millstream-Chichester and Murujuga, where mining cannot occur. But more are needed in other native title areas. They need to be resourced so Aboriginal heritage rangers can manage them, with appropriate facilities for tourists.

Members of the Wintawari Guruma Rock Art Project recording contemporary values with traditional custodians, university researchers and Rio Tinto heritage personnel.
Jo McDonald CRAR+M Database reproduced with permission of Wintawari Guruma Aboriginal Corporation

Mining compliance surveys, which “manage harm” to heritage are a significant economy for many Aboriginal communities.

But a number of Pilbara Aboriginal Corporations, including Wintawari Gurama, with whom I have developed a rock art research project, don’t want to just participate in the mining economy, which is tantamount to destroying their heritage.

They want to train local rangers, and document, record and manage their own heritage estates, enabling elders and young people to earn a living on country.

A Murujuga Ranger recording rock art.
Jo McDonald CRAR+M Database reproduced with permission of Murujuga Aboriginal Corporation

This approach is equally required in places like the Kimberley, where fracking could be the next resources “boom”.

Aboriginal communities need Keeping Places.

Across the Pilbara, items such as the 7,000 heritage items salvaged from Juukan Gorge, are being housed in locked shipping containers. Secure air-conditioned Keeping Places are an urgent requirement.




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These, too, could be funded by industry, becoming the focus of heritage tourism and ranger training, and hosting collaborative research on heritage, biodiversity and conservation.

Murujuga, which has been added to the World Heritage Tentative List, has a tourism management plan. A Living Knowledge Centre is planned, and additional interpretation facilities.

Ngajarli (Deep Gorge) bird track panel on Murujuga with evidence of industry visible in the background.
Jo McDonald CRAR+M Database reproduced with permission of Murujuga Aboriginal Corporation

The state government and industry stakeholders are funding the Murujuga Rock Art Strategy, which will monitor and assess emissions from nearby industry. There are, however, concerning plans to introduce new industry in the adjacent Burrup Industrial Estate. This is an issue, too, for the federal government, which has ultimate oversight of heritage on the national list.

In WA, the state government asserts that heritage can co-exist with industry. But this will only be possible if the state recognises heritage is non-renewable — just like the mineral wealth of this country.The Conversation

Jo McDonald, Director, Centre for Rock Art Research + Management, University of Western Australia

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

With no work in lockdown, tour operators helped find coral bleaching on Western Australia’s remote reefs



Jeremy Tucker, Author provided

James Paton Gilmour, Australian Institute of Marine Science

Significant coral bleaching at one of Western Australia’s healthiest coral reefs was found during a survey carried out in April and May.

The survey took a combined effort of several organisations, together with tour operators more used to taking tourists, but with time spare during the coronavirus lockdown.

WA’s arid and remote setting means many reefs there have escaped some of the pressures affecting parts of the east coast’s Great Barrier Reef), such as degraded water quality and outbreaks of crown of thorns starfish.

The lack of these local pressures reflects, in part, a sound investment by governments and communities into reef management. But climate change is now overwhelming these efforts on even our most remote coral reefs.

Significant coral bleaching has been identified at WA reefs.
Nick Thake, Author provided

When the oceans warmed

This year, we’ve seen reefs impacted by the relentless spread of heat stress across the world’s oceans.

As the 2020 mass bleaching unfolded across the Great Barrier Reef, a vast area of the WA coastline was bathed in hot water through summer and autumn. Heat stress at many WA reefs hovered around bleaching thresholds for weeks, but those in the far northwest were worst affected.

The remoteness of the region and shutdowns due to COVID-19 made it difficult to confirm which reefs had bleached, and how badly. But through these extraordinary times, a regional network of collaborators managed to access even our most remote coral reefs to provide some answers.




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Australia’s Bureau of Meteorology provided regional estimates of heat stress, from which coral bleaching was predicted and surveys targeted.

At reefs along the Kimberley coastline, bleaching was confirmed by WA’s Department of Biodiversity, Conservation and Attractions (DBCA), Bardi Jawi Indigenous rangers, the Kimberley Marine Research Centre and tourist operators.

At remote oceanic reefs hundreds of kilometres from the coastline, bleaching was confirmed in aerial footage provided by Australian Border Force.

Subsequent surveys were conducted by local tourist operators, with no tourists through COVID-19 shutdown and eager to check the condition of reefs they’ve been visiting for many years.

The first confirmation of bleaching on remote coral atolls at Ashmore Reef and the Rowley Shoals was provided in aerial images captured by Australian Border Force.
Australian Border Force, Author provided

The Rowley Shoals

Within just a few days, a tourist vessel chartered by the North West Shoals to Shore Research Program, with local operators and a DBCA officer, departed from Broome for the Rowley Shoals. These three reef atolls span 100km near the edge of the continental shelf, about 260km west-north-west offshore.

One of only two reef systems in WA with high and stable coral cover in the last decade, the Rowley Shoals is a reminder of beauty and value of healthy, well managed coral reefs.

But the in-water surveys and resulting footage confirmed the Rowley Shoals has experienced its worst bleaching event on record.

The most recent heatwave has caused widespread bleaching at the Rowley Shoals, which had previously escaped the worst of the regional heat stress.
Jeremy Tucker, Author provided

All parts of the reef and groups of corals were affected; most sites had between 10% and 30% of their corals bleached. Some sites had more than 60% bleaching and others less than 10%.

The heat stress also caused bleaching at Ashmore Reef, Scott Reef and some parts of the inshore Kimberley and Pilbara regions, all of which were badly affected during the 2016/17 global bleaching event.

This most recent event (2019/20) is significant because of the extent and duration of heat stress. It’s also notable because it occurred outside the extreme El Niño–Southern Oscillation phases – warming or cooling of the ocean’s surface that has damaged the northern and southern reefs in the past.

A reef crisis

The impacts from climate change are not restricted to WA or the Great Barrier Reef – a similar scenario is playing out on reefs around the world, including those already degraded by local pressures.

By global standards, WA still has healthy coral reefs. They provide a critical reminder of what reefs offer in terms of natural beauty, jobs and income from fisheries and tourism.

Despite the most recent bleaching, the Rowley Shoals remains a relatively healthy reef system by global standards. But like all reefs, its future is uncertain under climate change.
James Gilmour, Author provided

But we’ve spent two decades following the trajectories of some of WA’s most remote coral reefs. We’ve seen how climate change and coral bleaching can devastate entire reef systems, killing most corals and dramatically altering associated communities of plants and animals.

And we’ve seen the same reefs recover over just one or two decades, only to again be devastated by mass bleaching – this time with little chance of a full recovery in the future climate.

Ongoing climate change will bring more severe cyclones and mass bleaching, the two most significant disturbances to our coral reefs, plus additional pressures such as ocean acidification.

Reducing greenhouse gas emissions is the only way to alleviate these pressures. In the meantime, scientists will work to slow the rate of coral reef degradation though new collaborations, and innovative, rigorous approaches to reef management.The Conversation

James Paton Gilmour, Research Scientist: Coral Ecology, Australian Institute of Marine Science

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

The showy everlasting is endangered, but a primary school is helping out



The showy everlasting is being grown at Woodlupine Primary School.
Andrew Crawford, Author provided

Leonie Monks, Murdoch University; Alanna Chant, and Andrew Crawford

Western Australia boasts seemingly endless fields of pink, white and yellow everlasting daisies. But while there might seem to be an infinite number, one species in particular is actually endangered. The showy everlasting (or Schoenia filifolia subsp. subulifolia) once grew in the Mid West of WA. Now it is found in just a few spots around the tiny inland town of Mingenew.

But a WA primary school is helping my colleagues and me save the beautiful showy everlasting. With new seed banks, a genetic project and a whole lot of digging, we’re hopeful we can keep this gorgeous native daisy around for the next generation.




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A grower and a shower

The first European to collect the showy everlasting was eminent botanist James Drummond, most likely in the mid-1800s. Initially the species was placed in the Helichrysum family (a group of plants also known as everlastings), but in 1992 botanist Paul Wilson formally described the species based on a specimen collected from Geraldton.

The genus name Schoenia is in honour of the 19th-century eye specialist and botanical illustrator Johannes Schoen, and the species name filifolia refers to its long, slender leaves.

Showy everlastings retain their colour long after they’re picked and dried.
Andrew Crawford, Author provided

Everlastings get their name from the fact that that the flowers hold their colour long after they have been picked and dried. The species is known as the showy everlasting because its large, brightly coloured flowers put on a spectacular show when in bloom.

The showy everlasting is an annual plant, growing around 30cm high, with long narrow leaves. Its bright yellow flowers bloom from August to October. The showy everlasting has two closely related sister species: the more common Schoenia filifolia subsp. filifolia, found throughout the WA Wheatbelt, and Schoenia filifolia subsp. arenicola, which grows around Carnarvon but hasn’t been collected for decades. The main differences between the showy everlasting and its sister species are the much larger flowers and the shape of the base of the flower, which is hemispherical rather than vase-shaped.




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Collections of the showy everlasting housed in the Western Australian Herbarium indicate the species was once more widespread. It’s likely land clearing for farms and infrastructure led to the disappearance of the species from much of its known range.

It was listed as endangered in 2003. At that time the species was found in just three locations. At each of these sites, threats such as chemical drift from nearby agricultural land, grazing by animals, competition from weeds, and increasing soil salinity were all jeopardising the survival of the species.

Unfortunately, by the late 2000s two of these three populations had succumbed to these threats and were lost. However, continued search efforts since then have uncovered two new populations. The showy everlasting is hanging on, but a concerted conservation effort is needed to ensure its survival in the wild.

New populations needed

To ensure the long-term survival of the showy everlasting, we need to establish new populations – a process called translocation.

As an insurance policy, in 2007 seeds were collected and frozen in the Threatened Flora Seed Vault at the Western Australia Seed Centre. In 2015 my colleagues and I used some of these seeds in small-scale translocation trials, successfully getting new plants to grow, flower and seed in three small populations.

Despite this success, we knew the populations would need to be much, much larger and we would need many more populations to ensure persistence of the species. And for that we needed more information about the showy everlasting’s biology, and larger amounts of seed.

Currently a genetic study is underway to look at the difference between the showy everlasting in different locations and its sister species. As part of my PhD study with Murdoch University, I am running a glasshouse experiment to see whether different populations of the showy everlasting can cross and produce viable seed, and whether there are benefits or risks to such crosses.

The initial translocation trials have proved we can successfully establish new populations, but we’re currently limited by the amount of available seed. This is because our trials showed the most efficient way to establish the showy everlasting is by planting seeds directly into the ground. However, this process uses a lot of seeds – more than we have stored in the Seed Vault. Rather than denude the wild populations, we needed a new source.

Fortunately, at this time Andrew Crawford, manager of the Threatened Flora Seed Vault at the Western Australian Seed Centre, was approached by the principal of the Woodlupine Primary School, Trevor Phoebe. He was looking for a meaningful way to involve his students with plant conservation. This led to the establishment of a seed production area at the school which aims to grow and harvest seed of the showy everlasting. The students at the school are involved with planting, monitoring and taking care of the plants, and will help collect the seed when they ripen.




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It is still early days for this project, however early signs are promising. Seedlings have established well and have begun flowering. Seed collection is planned for later in the year.

The seed harvested will be used in the future to boost plant numbers in the existing populations, and to establish new sites, hopefully securing this beautiful species in the wild so that everyone can enjoy the showy everlasting for decades to come.


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Leonie Monks, Research scientist, Murdoch University; Alanna Chant, Invited User, and Andrew Crawford, Research scientist

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

The Albany pitcher plant will straight up eat you (if you’re an ant)



FEED me, Seymour!
Adam Cross, Author provided

Adam Cross, Curtin University

Sign up to the Beating Around the Bush newsletter here, and suggest a plant we should cover at batb@theconversation.edu.au.


On a warm evening in early 1802, Robert Brown sat aboard the HMS Investigator describing several plant specimens collected that day. Brown was the botanist on Captain Matthew Flinders’ expedition, and they had been anchored in King George Sound for nearly a month documenting the remarkable flora of the area.

He keenly awaited the return of their gardener, Peter Good, who had left earlier in search of a curious “pitcher plant” discovered the previous morning by botanical artist Ferdinand Bauer and landscape artist William Westall.




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Death traps: how carnivorous plants catch their prey


Unbeknownst to him, in minutes he would be gazing upon a uniquely wondrous plant: Cephalotus follicularis, the Albany pitcher plant.

Named after the southwestern Australian port city around which it occurs, the Albany pitcher plant stands out as an oddity even by the standards of carnivorous plants. The species is instantly recognisable, as it produces distinctive insect-trapping pitcher leaves that sit on the ground almost expectantly waiting for prey.



The Conversation

The toothed mouth and overarching lid of these pitchers look superficially similar to those of the tropical pitcher plants (Nepenthes) and North American pitcher plants (Sarracenia). However, these plants are not related; this similarity is a remarkable example of convergent evolution. The Albany pitcher plant is unique.

C. follicularis is the only species in the genus Cephalotus, which is the only genus within the family Cephalotaceae. Its nearest living relatives are rainforest trees from tropical South America, from which it is separated by some 50 million years. Indeed, it is the only carnivorous plant among the 70,000 species, a quarter of all flowering plants, that make up one of the largest evolutionary plant groups, the rosid clade.




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The Albany pitcher plant is more closely related to cabbages, roses and pumpkins than it is to other pitcher plants.

The Albany pitcher plant only grows in a very small area of Western Australia, and is thought to be an ancient Gondwanan relict from a period when this region was almost tropical. It grows in nutrient-poor soils of coastal swamps and lowlands, where it survives by luring insects into its traps to be digested in a pool of enzymes at the base of each pitcher. Each pitcher bears a lid to prevent rain from diluting the pool of enzymes, with translucent windows to disorient trapped prey and prevent escape.

Interestingly, one species of insect not only survives inside the fluid of the pitchers, but relies on it for survival. The wingless stilt fly Badisis ambulans lays its eggs in the pitchers, and the larvae develop in the pool of pitcher fluid, feeding on captured prey.

The wingless stilt fly lives inside the Albany pitcher plant.
Tony D/Wikimedia, CC BY

These stilt flies live only in the dense vegetation of the swamps inhabited by the Albany pitcher plant. They look more like an ant than a fly, which is probably a deliberate mimicry of the ant Iridomyrmex conifer, the primary prey of the pitcher plant. It is likely that these three species – plant, fly and ant – have co-evolved together over millions of years.

The Albany pitcher plant was probably widespread in the southwest corner of WA before European settlement, and almost 150 populations have been recorded throughout this region. However, the species has declined dramatically over the past century as extensive land has been cleared throughout the southwest for agriculture and urban development.

The Albany pitcher plant now occurs only as small, isolated populations in remnant habitat patches. It is thought that less than 3,000 hectares of habitat suitable for the species now remains in the greater Albany region. Recent survey efforts suggest that fewer than 20 populations of the Albany pitcher plant still exist, and fewer than 5,000 plants remain.

Despite the perilous state of the Albany pitcher plant, it still has no formal conservation status. Indeed, swamps containing the species have been bulldozed for housing development in the past 12 months. But habitat loss and changes to bushfire frequency and water flow are not the only threats to this amazing species. Current projections of a drying climate in the southwest of Western Australia may see the species pushed towards extinction in the coming decades.

Incredibly, the Albany pitcher plant is also at risk from poaching. The species is prized for its horticultural novelty, and unscrupulous individuals dig up plants from the wild either to grow or sell. At one accessible location where the species was known to grow in abundance, every single plant within reach has been removed. At other sites, entire populations have been dug up.




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Without improved conservation measures, and tough penalties for removing this incredible species from its natural habitat, the Albany pitcher plant and its complex web of insect relationships face a potentially dire future.


Sign up to Beating Around the Bush, a series that profiles native plants: part gardening column, part dispatches from country, entirely Australian.The Conversation

Adam Cross, Research Fellow, Curtin University

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

Built like buildings, boab trees are life-savers with a chequered past



A boab tree in the Kimberley. Boab trees can live for thousands of years and their trunks hollow out as they get older.
Shutterstock

Gregory Moore, University of Melbourne

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When you are in the northern part of Western Australia, one of nature’s joys is seeing a large boab tree close up, perhaps for the first time.

The boab (Adansonia gregorii) is a native to this part of Australia, but is related to the broader group of species called boababs that live in Madagascar and Africa – but more on that connection later.

Boabs are also called bottle trees, the tree of life, boababs and Australian boababs. Some of the indigenous Australian names include gadawon and larrgadi.

From their iconic swollen trunks, to living up to 2,000 years and the many uses for their “superfood” fruits, here’s what makes boab trees so fascinating.



The Conversation

The ‘upside-down tree’: trunks that save lives and lock up prisoners

While the boab in Australia is not quite as well-documented as the African species, specimens have been recorded at over 1,000 years of age. Some living trees have been estimated to be nearer to 2,000 years old.

And while it’s difficult to age the trees, several specimens of the African species have been dated at 2,000 or more years old.

Australian boabs can grow up to 15 metres tall at maturity and have swollen, attention-grabbing trunks called a caudex, which may be up to five metres in diameter.

The African boab species, A. digitata, can be much taller, at 25 metres high and with a diameter of up to 15 metres.




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In such dry continents, the caudex is a life-saver, often containing water, which was tapped by Indigenous folk. It has been estimated that some of these huge old trees can hold more than 100,000 litres of water in their trunks.

In Africa, these massive trunks have been used as shelters, homes, farm sheds and, more recently, even shops and bars.

Sadly in Australia, legend has it the huge trunks were used to make lock-ups for Indigenous people and other prisoners.

The infamous Boab Prison Tree, just south of Derby in Western Australia, was said to have once held Indigenous prisoners.
Shutterstock

It’s not just the trunk that can stop you in your tracks. The boab has a unique branching structure, one that looks more like a root system than a canopy.

Some locals in Africa will tell you the tree was dropped from heaven to earth and landed upside down. So the African species of boab is sometimes called the upside-down tree.

Boab fruits are ‘superfoods’ and its shell has many uses

A. gregorii, the Australian boab species, has large, attractive white flowers up to 75 millimetres in length. Its round fruits are edible and sought after by birds, mammals and humans. The fruit gives rise to some of the common names for the tree, such as monkey bread tree and dead rat tree. The latter comes from the appearance of older fruits in the canopy looking a bit like … well, dead rats?




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In fact, there’s great interest in fruits from the African species, A. digitata, which are considered a “superfood” because of their high levels of antioxidants, calcium, potassium, magnesium, fibre and vitamin C. It’s assumed many of these traits will be shared by the Australian boab, but there is little research as yet to prove it.

Fruit of the African boab tree fruit are initially covered in velvety fur.
Ton Rulkens/Wikimedia, CC BY-SA

The soft part of the fruit is surrounded by a hard, coconut-like shell that’s initially covered in a velvety fur. The hard shell has been used for cups and bowls, but has also been intricately carved and decorated by Aboriginal artists in Africa and Australia. If the seeds are left inside the fruit as it dries, they can be used for toys like rattles.

On both continents, Aboriginal people have eaten the white powder that surrounds the seeds. The leaves are rich in iron and the pulp from the fruits tastes like cream of tartar.

The Indigenous people of both continents were also well aware of the medicinal uses of the fruits. The bark and leaves of the trees also treat various ailments, but particularly those associated with digestive disorders.




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But at present there is very little modern research on the medicinal and dietary aspects of either the baobab or boab.

How the boab tree got to Australia

One of the mysteries surrounding the boab is how it got to Australia – the Australian species has clear affinities with related species in continental Africa and Madagascar.

A baobab tree, Adansonia digitata, in Tarangire National Park, Tanzania. Its journey from Africa to Australia remains a mystery.
Yoki/Wikimedia, CC BY-SA

There are three intriguing theories.

The first is that all of the boababs originate from the super-continent Gondwana – consisting of Africa, South America, Antarctica, Australia, India and Madagascar – before it fragmented almost 80 million years ago. But A. Gregorii and A. digitata are so similar genetically that, given the millions of years that have elapsed, this theory is now in question.

The second theory comes from recent DNA analysis of the species. It suggests they separated more recently, perhaps only 70,000 years ago, which raises the question, were humans involved in their journey? But did they come to Australia from Africa, or from Australia to Africa? The latter is a less likely scenario given the direction of ocean currents.

And the third theory is that fruits arrived on the Australian shore after an epic ocean voyage from Africa.




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Boabs are usually found in the remote outback of Australia, but in 2008, a large 750-year-old boab was transported from Warmun in the Kimberley to Perth and transplanted in Kings Park.

Transplanting such a large tree is both daunting and fraught, with a high chance of failure, but the deciduousness and growth habit of the boab gave some cause for optimism about a successful outcome. For the reward of having a large old boab growing in Perth, it would be worth it.

After a period of stress, the tree appears to be coming good, reflecting the toughness of the species.

A large, mature boab is a splendid tree of arid Australia that inspires awe in all who experience them close up. They really are a beauty and a bottler of a tree!


Sign up to Beating Around the Bush, a series that profiles native plants: part gardening column, part dispatches from country, entirely Australian.The Conversation

Gregory Moore, Doctor of Botany, University of Melbourne

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

How we’re helping the western ground parrot survive climate change



A western ground parrot being released with a GPS tracker fitted.
Alan Danks

Shaun Molloy, Edith Cowan University and Robert Davis, Edith Cowan University

When a threatened species is found only in one small area, conservationists often move some individuals to another suitable habitat. This practice, called “translocation”, makes the whole species less vulnerable to threats.

In the past, this approach has worked really well for some species, but climate change is creating new problems. Will the climate change at that location in the future, and will it remain suitable for the species of interest? On the other hand, some regions might become appropriate for a threatened species.

This fundamental question is important in a rapidly changing climate, yet it has seldom featured when picking new areas for translocations.

Western ground parrots live and nest on the ground, making them very vulnerable to foxes and cats.
Alan Danks/DBCA

Saving the western ground parrot

Our recent research applied climate change modelling to translocation decisions for the critically endangered western ground parrot. This species is now restricted to a single population, with probably fewer than 150 birds, on the south coast of Western Australia.

It is enigmatic, in that it lives and nests entirely on the ground, unlike almost all other parrots except the closely related night parrot. And it is one of the many unique animals that make Australia so distinctive from all other parts of the world. But living on the ground has its drawbacks, as the parrot is very vulnerable to foxes and cats.

Its home near the south coast is particularly vulnerable to the effects of climate change. As southwestern Australia becomes warmer and drier, the risk of fire to the parrot increases.

Understanding potential climate change impacts is essential when selecting reintroduction sites. We developed high-precision species distribution models and used these to investigate the effect of climate change on current and historical distributions, and identify locations that will remain, or become, suitable habitat in the future.

Our findings predict that some of the western ground parrot’s former south coast range will become increasingly unsuitable in the future, so reintroductions there may not be a good idea. Four out of 13 potential release sites are likely to become inhospitable to these threatened birds.

On the other hand, many of the former or future sites are likely to become important refuge habitats as the climate continues to warm, and would make an excellent choice for any translocations or reintroductions.

We have given this information to an expert panel, who will use these predictions identify and prioritise areas for management and translocation.

Researchers have radio tracked a small number of birds to learn more about habitat use and movement patterns.
Allan Burbidge

The parrot in the coal mine

Fire is already a significant threat which, combined with predation by feral cats, may have led to the loss of this species from its former home at Fitzgerald River National Park. Many of these threats act together, so they must all be considered and managed alongside climate change.

What’s more, the western ground parrot may be an important indicator for the fate of many other species it currently (or formerly) shares its range with. These include the western whipbird, noisy scrub-bird, and a carnivorous marsupial, the dibbler.

These species are all likely to face the same threats and may be equally affected by the changing climate. Future studies will attempt to model these species and to assess whether all will benefit from similar management.

Many challenges remain for the western ground parrot, including the possible negative genetic impacts of the current small population size, and the increasing risk of damaging fires in a drying and warming climate.

But locating “future-proofed” sites is giving us some hope we can ensure the long term persistence of this enigmatic species, and the myriad other unusual species that occur in the biodiversity hotspot of southwestern Australia.


The authors would like to thank Allan Burbidge and Sarah Comer from the WA Department of Biodiversity Conservation and Attractions for their invaluable help and guidance in putting together this article.The Conversation

Shaun Molloy, Associate research scientist (Ecology), Edith Cowan University and Robert Davis, Senior Lecturer in Vertebrate Biology, Edith Cowan University

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