This article contains images that some readers may find upsetting.

Heatwaves linked to climate change have already led to mass deaths of birds and other wildlife around the world. To stem the loss of biodiversity as the climate warms, we need to better understand how birds respond.

Our new study set out to fill this knowledge gap by examining Australian birds. Alarmingly, we found birds at our study sites died at a rate three times greater during a very hot summer compared to a mild summer.

And the news gets worse. Under a pessimistic emissions scenario, just 11% of birds at the sites would survive.

The findings have profound implications for our bird life in a warming world – and underscore the urgent need to both reduce greenhouse gas emissions, and help animals find cool places to shelter.

Feeling the heat

The study examined native birds in two parts of semi-arid New South Wales: Weddin Mountains National Park near Grenfell and Charcoal Tank Nature Reserve near West Wyalong. At both locations, citizen scientists have been catching, marking and releasing birds regularly since 1986.

This has produced data for 22,000 individual birds spanning 37 species. They include honeyeaters, thornbills, fairy-wrens, whistlers, treecreepers, finches and doves.

Data from the past 30-odd years showed cold winters led only to a relatively small drop in survival rates. But it was a far starker picture in summer.

During a mild summer with no days above 38°C, 86% of the birds survived. But in a hot summer with 30 days above 38°C, just 59% survived.

We then used these real-life findings to model future survival, to the end of the century, for birds at our study sites.

Worryingly, climate projections for the sites we studied show the number of days above 38°C will at least double by the end of the century (or the year 2104). Meanwhile, days below 0°C will disappear during this time.

These projections are broadly similar for all arid and semi-arid regions across Australia.

As winters warm, we predict bird survival in winter would increase slightly by the end of this century. But this would not offset the many more birds killed by extreme heat as summers warm.

But to what extent will populations decline? To answer this question, we considered an optimistic scenario of rapid emissions reduction – resulting in about 1°C warming compared to pre-industrial levels. Under this scenario, we predict annual survival will fall by one-third, from 63% to 43%.

Under a pessimistic scenario, involving very little emissions reduction and 3.7°C warming this century, the survival rate falls to a shocking 11%.

Other lab-based studies around the world have made similar projections for bird populations. But our projections are unusual because they’re based on actual survival rates in wild populations measured over decades.

What happens to birds in heatwaves?

Some birds do manage to survive extreme heat. We then wondered: how does a bird protect itself from soaring temperatures? And can its habitat offer life-saving shelter?

We addressed these questions in a complementary study led by zoologist Lynda Sharpe. It involved comparing the behaviour of individual birds on mild and hot days.

We chose as our subject the Jacky Winter, a small robin common across Australia. Between 2018 and 2021 we followed the fates of 40 breeding pairs living in semi-arid mallee woodland in South Australia. There, the annual number of days above 42°C has more than doubled over the past 25 years.

As heat escalated, Jacky Winters showed a broad range of behavioural responses. This included adjusting their posture, activity levels and habitat use to avoid gaining heat and to increase heat dissipation.

As air temperatures approached 35°C, birds moved to the top of the highest trees where greater wind speeds cooled their bodies. The birds also began to pant, which can lead to fatal dehydration.

Once air temperatures climbed above 40°C, exceeding the birds’ body temperature, they moved to the ground to shelter in tree-base hollows and crevices. They remained in these “thermal refuges” for as long as it took for air temperatures to drop to about 38°C – sometimes for up to eight hours. But this made foraging impossible and the birds lost body mass.

We then examined what parts of the birds’ habitat offered the coolest place to shelter on extremely hot days. Hollows in tree bases were significantly cooler than all other locations we measured. The best of these cool hollows were rare and found only in the largest eucalypt mallees.

Even with their flexible behaviour, the ability of Jacky Winters to survive heatwaves was finite – and apparently dependent on whether large trees were available. Some 29% percent of adults we studied disappeared (and were presumed dead) within 24 hours of air temperatures reaching a record-breaking 49°C in 2019.

Similarly, during two months of heatwaves in 2018, 20% of adults studied were lost, compared with only 6% in the two months prior.

Eggs and nestlings were even more susceptible to heat. All 41 egg clutches and 21 broods exposed to air temperatures above 42°C died.

We found it distressing to witness such losses among birds we had followed for months and years. And it was deeply sad to see the breeding failures after the parent birds had invested so much effort in caring for eggs and tending to young.

We need to act

Our studies show extremely high temperatures are already killing troubling numbers of birds in Australia’s arid and semi-arid regions. These regions comprise 70% of the Australian continent and 40% of the global landmass.

Such losses will only worsen as climate change escalates. This has profound implications for biodiversity in Australia and more broadly.

Obviously, humanity must urgently reduce greenhouse gas emissions to limit global warming. But we must also better manage our biodiversity as the climate changes.

Key to this is identifying and protecting thermal refuges such as tree hollows by, for example, managing fire to reduce the loss of large trees.

The authors wish to acknowledge our colleagues, especially Lynda Sharpe and Tim Bonnet, for their important contributions to the research upon which this article is based.

Janet Gardner, Adjunct Research Scientist, CSIRO and Suzanne Prober, Senior Principal Research Scientist, CSIRO

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

This week, Victoria recorded its hottest day in nearly six years. On Tuesday, the northwest towns of Walpeup and Hopetoun reached 48.9°C, and the temperature in parts of Melbourne soared over 45°C. Towns in South Australia also broke heat records.

This heatwave is not an outlier. It is a warning shot.

These weather conditions rival the extreme heat seen in the lead-up to the 2019–20 Black Summer, and they point to a future in which days like this are no longer rare, but routine.

What makes this summer so confronting is not just how hot it has been, but this: Australia already knows how to cool cities, yet we are failing to do it. Why?

Urban heat is not inevitable

Cities heat up faster and stay hotter than surrounding areas because of how they are built. Dense development, dark road surfaces, limited shade, and buildings that trap heat and rely heavily on air-conditioning create the “urban heat island” effect.

This means cities absorb vast amounts of heat during the day and release it slowly at night, preventing the city from cooling down even after sunset. During heatwaves, this trapped heat accumulates day after day and pushes temperatures well beyond what people can safely tolerate.

Future urbanisation is expected to amplify projected urban heat, irrespective of background climate conditions. Global climate change is making the urban heat island effect worse, but much of the heat we experience in cities has been built in through decades of planning and design choices.

Heat is a health and equity crisis

Heatwaves already kill more than 1,100 Australians each year, more than any other natural hazard. Extreme heat increases the risk of heart and respiratory disease, worsens chronic illness, disrupts sleep and overwhelms health services.

Poorly designed and inadequately insulated homes, particularly in rental and social housing can become heat traps. People on low incomes are least able to afford effective cooling, pushing many into energy debt or forcing them to endure dangerously high temperatures. Urban heat deepens existing inequalities. Those who contributed least to the problem often bear the greatest burden.

Australia has expertise, but not ambition

Here is the paradox. Australia is a major contributor to global research on urban heat. Australian researchers are developing national tools to measure and mitigate urban heat, and studies from cities such as Melbourne have quantified urban heat island intensity and investigated how urban design can influence heat stress.

Additionally, Australia already has the technologies to cool cities, from reflective coatings and heat-resilient pavements to advanced shading systems. Yet many of our cities remain dangerously hot. The issue isn’t a lack of solutions, but the failure to roll them out at scale.

Internationally, we are lagging behind countries where large-scale heat mitigation projects are already reducing urban temperatures, cutting energy demand and saving lives.

For example, Paris has adopted a city-wide strategy to create “cool islands”, transforming public spaces and schoolyards into shaded, cooler places that reduce heat stress during heatwaves.

In China, the Sponge City program, now implemented in cities such as Shenzhen and Wuhan, uses green infrastructure and water-sensitive design to cool urban areas and reduce heat stress.

Symbolic change can’t meet the challenge

Too often, urban heat policy stops at small, symbolic actions, a pocket park here, a tree-planting program there. These measures are important, but they are not sufficient for the scale of the challenge.

Greening cities is essential. Trees cool streets, improve thermal comfort and deliver multiple health and environmental benefits. But greenery has limits. If buildings remain poorly insulated, roads continue to absorb heat and cooling demand keeps rising, trees alone will not protect cities from extreme temperatures in the coming decades.

Urban heat is a complex systems problem. It emerges from how cities are built, and is largely shaped by construction materials, building codes, transport systems and planning decisions locked in over generations. Scientists know a great deal about how to reduce urban heat, but many responses remain piecemeal and intuitive rather than systemic.

Designing an uncomfortable future

Research suggests that even if global warming is limited to below 2°C, heatwaves in major Australian cities could approach 50°C by 2040. At those temperatures, emergency responses alone will not be enough. Beyond certain temperature thresholds, behaviour change, public warnings and cooling centres cannot fully protect people.

The choices we make now about buildings, streets, materials and energy systems will determine whether Australian cities become increasingly unliveable, or remain places where people can safely live, work and age.

The battle against urban heat will be won or lost through design, technology, innovation and political will. Cities need to deploy advanced cool materials across roofs, buildings and roads, in combination with nature-based solutions. This will only work if governments use incentives to reward heat-safe design. Heat must be planned for systematically, not treated as a cosmetic problem.

With leadership and a handful of well-designed, large-scale projects, Australia could shift from laggard to leader. We have the science. We have the industry. We have the solutions. The heat is here. The only real question is whether we act, or keep absorbing it.

A/Prof. Elmira Jamei, Associate professor, Victoria University

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

Millions of people in southeastern Australia are sweating through a record-breaking heatwave. The heat this week is likely to be one for the history books. The heat began on Saturday January 24th. On Australia Day, three sites in South Australia and two in New South Wales broke their all-time temperature records. Ceduna reached a whopping 49.5°C in the shade – just 1.2°C off the highest temperature ever recorded in Australia.

Today, temperatures have topped 49°C in northwest Victoria and South Australia for the first time on record, and many towns face days of heat over 40°C. Regions such as the Otway Ranges in Victoria are facing extreme fire danger. Renmark in South Australia has reached 49.3°C and Walpeup in Victoria has reached 48.7°C.

This is shaping up as the worst heatwave since the Black Summer of 2019-20. The intense heat that summer contributed to catastrophic bushfires which burnt 21% of the continent’s forests, an area still considered globally unprecedented.

Independent analysis found the last heatwave between January 5 to 10 was made over five times more likely by global heating. This current heatwave is substantially worse, but we’ll have to wait for attribution studies to understand how much global heating has contributed to its overall severity.

The sustained heat hitting the southeast will be widespread and prolonged. It’s likely more all-time temperature records will be broken this week, as the body of hot air stagnates over the south and southeast. People in exposed areas should heed warnings from the Bureau of Meteorology and advice from health and emergency response authorities.

What’s driving this heatwave?

The Pilbara region in northwest Western Australia is sometimes called the nation’s “heat engine”. This large, sparsely populated area is very dry. When heat hits Pilbara rocks and sands, it can quickly build up. Weather conditions are very stable, and Pilbara heatwaves can last weeks.

But that doesn’t explain how the heat gets to population centres in Australia’s south and southeast.

Over summer, there are often active monsoonal troughs (areas of low atmospheric pressure) over northern Australia. As the monsoon brings heavy rain and low pressure systems to parts of northern Australia, it pushes high pressure systems, known as heat domes, further south. This directs intense heat thousands of kilometres towards the southern, central and eastern parts of the continent.

Tropical monsoonal low-pressure systems in the north often work in tandem with slow-moving high pressure systems in the Tasman Sea or Great Australian Bight. The result is a weather pattern able to shift hot air masses thousands of kilometres to reach the southern states.

Blocking highs are strong high pressure systems which can sit in place for days or even weeks, blocking other weather systems from moving in. The blocking high pressure system responsible for the current heatwave is staying put in the atmosphere a few kilometres above New South Wales.

As winds blow from areas of high pressure to low pressure in the atmosphere, air is forced to flow down towards the surface. As the air descends, it compresses due to rising atmospheric pressure. Compression heats the air further, which can make heatwaves hotter and longer-lasting.

When conditions like this are in place, hot northerly winds often persist for days, funnelling more and more desert heat towards the coasts. This can cause temperatures to exceed 40°C in states such as South Australia, Victoria, New South Wales and southern Queensland.

During this extreme heatwave, maximum temperatures in some southern towns are approaching 50°C – the sort of temperature once restricted to famously hot towns such as Marble Bar in Western Australia.

The official Australian record for the maximum temperature in the shade is 50.7°C, recorded at Oodnadatta (South Australia) in 1960 and Onslow (Western Australia) in 2022. This shared all-time record may be broken at several southeast inland locations this week as atmospheric conditions are amplified by the steady drumbeat of global heating.

During severe, prolonged heatwaves, intense daytime heat is accompanied by hot nights. The humidity can sometimes also increase due to tropical moisture being transported south. The combination of heat and humidity (measured as heat indices) is particularly dangerous to humans, livestock and wildlife.

Should this heatwave be named?

For decades, tropical cyclones hitting Australia have been given names. Should heatwaves similarly be given names to encourage people to take them seriously? Names can make weather hazards more memorable, helping people recall warnings, share information with neighbours and prepare more effectively.

This week’s heatwave would be an excellent candidate for naming. It is severe, breaking all-time records, long-lasting and widespread. It is also threatening major metropolitan centres with high populations, as well as major regional centres and nationally important agricultural districts. To date, there’s no sign authorities plan to name it.

Responding to future heatwaves

Climate scientists now widely agree average global temperatures will permanently rise 1.5°C over pre-industrial levels by the early 2030s. They may reach 2.7°C by the 2090s if global carbon emissions do not fall sharply.

This means future heatwaves are likely to strike more often and hit harder when they arrive.

We need to adapt to the increasing threats posed by more and worse heatwaves even as we work to cut emissions. Extreme heat is a public health issue, to say nothing of the threats it poses to our wildlife and livestock who have no escape.

Correction: this article originally stated 21% of Australia burned over the Black Summer. It has been corrected as it was 21% of forested areas.

Steve Turton, Adjunct Professor of Environmental Geography, CQUniversity Australia

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

Australia has always had heatwaves. But this week’s heatwave in southeastern Australia is something else. Temperatures in some inland towns in South Australia, New South Wales and Victoria were up to 20°C above average for the time of year, which meteorologists described as “incredibly abnormal”. Victoria’s heat record toppled after Walpeup and Hopetoun hit 48.9°C. The heat is set to continue until Saturday in some areas.

As global temperatures inch upwards, summer heatwaves form against a background of higher temperatures. Heatwaves (commonly defined as three or more days of unusual heat) and extreme heat (shorter periods of intense heat) are becoming more common and more intense.

Heatwaves kill more Australians than all other natural hazards combined. In the four years to 2019, more than 1,000 people died due to heatwaves.

Heatwaves emerge from atmospheric processes which largely take place in the upper atmosphere, around 5–10 kilometres above sea level. Perhaps counterintuitively, the southeast’s record-breaking heatwave is linked to masses of moisture-laden air in Western Australia and a tropical cyclone off the northwest coast.

That’s not all. Slow-moving high pressure systems in the southeast and the southern drought have likely also made this heatwave worse. Heatwaves are complex. As Australia gets hotter, understanding these dangerous phenomena is essential.

Meanders in the jetstream

Our research has shown heatwaves hitting Australia’s southeast have a clear link to the atmospheric phenomenon known as Rossby waves. These waves manifest as disturbances in the narrow, fast-flowing jetstream that flows from west to east in the atmosphere kilometres above the surface. The waves play a major role in the weather in the southern half of Australia.

As the jetstream wobbles, it pushes aside winds to the north and south to form regions of alternating high and low pressure. As the undulations grow and deepen, they amplify the weather we experience on the ground.

Air inside a high-pressure system (or ridge) descends towards the surface and is compressed by the increasing atmospheric pressure, heating it. The end result is higher temperatures near the ground. The slower these systems move, the more delayed the welcome cool change from a summertime cold front. If these systems move slowly enough, they can turn one hot day into several, or even a heatwave.

What makes these systems bigger or slower moving?

Several things can intensify or slow down these high pressure systems.

The first is tied to Rossby waves. Cold fronts form on the western edge of high pressure systems embedded in the atmospheric wave. Moist air flows along the cold front, moving humid air polewards and upwards between the two systems. This is known as a warm conveyor belt.

Processes within the conveyor belt of warm, moist air can make high pressure ridges even stronger and more likely to persist.

This week’s heatwave was given an extra boost by Tropical Cyclone Luana, which made landfall on January 24 over the northwest coast near Derby. Luana moved inland and added even more moisture to the warm conveyor belt, bringing some rain to the Nullarbor.

Luana may have influenced the southeastern heatwave in a second way. Anticyclonic outflows from cyclones higher in the atmosphere can disturb the jet stream, amplifying the Rossby waves and strengthening the upper-level ridge, potentially lengthening the heatwave.

2009 redux?

There are clear similarities between this week’s heat and the intense, long-lasting heatwave starting in late January 2009. That heatwave broke records across the southeast of Australia and paved the way for Victoria’s devastating bushfires on February 7, now known as Black Saturday.

Both heatwaves are linked to a large-amplitude Rossby wave moving across the continent, with a persistent slow-moving high pressure ridge situated over the southeast. Both took place as a tropical cyclone hit the northwest and both have active moist airstreams intensifying the ridge.

These cyclone-heatwave events are known as compound events, where several types of extreme weather overlap in time, space or both, and can act to intensify each other. In both 2009 and 2026, ongoing drought might have been yet another compounding factor.

In 2009, southern Australia was still in the grip of the 1996-2010 Millennium Drought, which made the heatwave worse. That’s because when soil is moist, extra heat evaporates moisture in the soil first, slowing heating of the air. But if heat hits dry soil, it quickly boosts air temperatures.

Swathes of southern Australia have had periods of drought for several years. This may have intensified the current heatwave.

What’s next?

Heatwaves are often well forecast using current weather prediction models.

At least a week before the heatwave began, forecasts clearly showed extreme, prolonged heat was likely. The main culprits were visible on the charts: Rossby waves, the warm conveyor belt, the tropical cyclone and the high pressure ridge.

As people in inland towns prepare for more days over 40°C, many will wonder what the future holds.

What we know is that a hotter climate will mean heatwaves hit more often, more intensely and last longer. It will also make extremely hot days more likely. But some of these processes – particularly around how moisture and tropical cyclones affect heatwaves – are less well understood and modelled in climate projections.

In extreme weather, the details are critical. As we grapple with unprecedented heat, there’s much work to do to increase our understanding of extreme heat in the 21st century.

Tess Parker, Research Scientist in Climate Variability and Hazards, CSIRO and Michael Barnes, Research Fellow, ARC Centre of Excellence for Weather of the 21st Century, Monash University

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

The past three years have been the world’s hottest on record. In 2025, Earth was 1.44°C warmer than the long-term average, perilously close to breaching the Paris Agreement goal of 1.5°C.

This warming is fuelling Australia’s current record-breaking heatwave. Other consequences are visible globally, from Iran’s crippling drought to catastrophic wildfires and unprecedented floods in the United States to deadly cyclones hitting southern Asia.

We know what to do to tackle the climate crisis: replace fossil fuels with clean energy technologies such as solar, wind, electric vehicles and batteries. We are well on our way. Globally, the power produced by renewables overtook coal last year.

Petrostates such as Saudi Arabia and the US have made trillions from oil and gas. Now they are fighting a rearguard action to prolong fossil fuels. The US is pushing European nations to buy its gas, for instance.

But most countries have seen the writing on the wall. In November, the COP31 climate talks in Turkey are expected to deliver a global roadmap away from fossil fuels. Dozens of countries will meet in Colombia in April to fast-track the transition. The road ahead is bumpy. But the end of fossil fuels may finally be coming into view.

No holding back clean energy

There’s no one trying harder to slow the clean energy transition than US president Donald Trump. During his bid to return to the White House, Trump pressed oil executives for US$1 billion (A$1.4 bn) in campaign finance, promising a windfall in return.

In 2025, he increased subsidies for fossil fuel producers, weakened environmental laws, gutted Biden-era support for clean energy and moved to block clean energy projects, even some near completion. The US is now one of the world’s biggest exporters of liquefied natural gas (LNG) and oil.

But clean energy growth has proved difficult to kill. Despite Trump’s efforts, domestic solar generation is still expected to grow 46% in the next two years while electricity output from fossil fuel plants falls.

Trump is betting fossil fuels are the key to future American power. He made no secret of the fact the US military raid on Venezuela earlier this month was aimed at increasing oil production. He has implored US oil companies to invest billions to revive the country’s battered oil infrastructure. The response was lukewarm. ExxonMobil CEO Darren Woods said Venezuela was “uninvestable”.

Developing Venezuela’s oil reserves assumes there will be demand for decades to come. But the world now faces an oversupply of oil, even as sales of electric vehicles grow strongly in many countries. Last month, battery electric vehicles outsold petrol cars for the first time in Europe.

Electrostates rising

While the US doubles down on 20th century fossil fuels, China is betting on an electric 21st century. It is emerging as the first electrostate, dominating production and export of solar, wind, batteries and EVs. China is now the world’s biggest car exporter. Most new Chinese cars are powered by batteries, not oil.

China’s manufacturing might has driven down the price of batteries, the main cost of EVs. As EVs get cheaper, emerging economies are finding they can leapfrog fossil fuels and move straight to solar panels and EVs – even if the national power grid is limited or unreliable.

Commodity price trends show surging global demand for copper, silver and other metals needed for mass electrification. Worldwide, investment in clean energy technologies first overtook fossil fuel investment ten years ago. In 2025, clean investment was more than double the investment in coal, oil and gas. Clean energy is where the world is headed, whether Trump likes it or not.

China, India and Pakistan are rapidly making the shift to renewable power. Developing nations from Nepal to Ethiopia are taking up electric transport to slash the cost of importing fossil fuels.

A new roadmap away from fossil fuels

This week, the US formally withdrew from the Paris Agreement. But no other country has followed.

For decades, the COP talks have focused on “cutting emissions” without dealing directly with the use of coal, oil and gas. But at the 2023 talks, nearly 200 countries agreed to “transition away from fossil fuels”.

At last year’s COP30 talks, host nation Brazil proposed a roadmap to phase out fossil fuels. More than 80 countries backed the idea, including Australia, but pushback from Saudi Arabia and Russia kept it out of the final outcomes.

In response, Brazil is working to develop a roadmap for phasing out fossil fuels. This – or something similar – may be formally adopted at the next climate talks in November.

While COP31 will be held in Turkey, Australian climate minister Chris Bowen will have a key role as “President of Negotiations” and will steer global discussion ahead of the summit.

Bowen plans to lobby petrostates to support a managed shift away from fossil fuels, drawing on Australia’s experience as a major exporter of coal and LNG facing its own transition. Korea – Australia’s third largest market for thermal coal – will retire its entire coal fleet by 2040.

Government modelling suggests Australia’s coal and gas exports could plummet 50% in value in five years as global demand falls. Independent modelling suggests the decline for coal could happen even faster if countries meet their climate targets. Policymakers must plan to manage this transition.

Coalitions of the willing?

Frustrated by slow progress, a coalition of nations is separately discussing how to phase out fossil fuels. The first conference will take place in April in Colombia. Here, delegates will discuss how to wind down fossil fuels while protecting workers and financial systems. Some nations want to negotiate a standalone treaty to manage the phase-out. Conference outcomes will also feed back into the UN climate talks.

Pacific island nations aim to be the world’s first 100% renewable region. Ahead of COP31, Australia and island nations will meet to progress this.

Progress is happening

In an ideal world, nations would rapidly tackle the existential threat of climate change together. We don’t live in that world. But it may not matter.

The shift to clean electric options has its own momentum. The question is whether the shift away from coal, oil and gas will be orderly – or chaotic.

Wesley Morgan, Research Associate, Institute for Climate Risk and Response, UNSW Sydney

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

After the tragic death of Canadian backpacker Piper James on K’gari (Fraser Island) on January 19, a coroner found the 19–year–old had been bitten by dingoes while she was still alive, but the most likely cause of death was drowning.

Days later, the Queensland government announced it would cull the entire pack of ten dingoes seen near where Piper’s body was found. Most of those animals have now been killed.

Authorities justified the targeted cull on “public safety” grounds, while also signalling a strong desire to keep tourism moving. Queensland Tourism Minister Andrew Powell reassured tourism operators “the island is open” and urged people to continue to visit.

The cull took place without the knowledge or approval of the Butchulla people, the Traditional Owners of K'Gari. James’ parents also publicly opposed a cull, saying it was “the last thing” their nature-loving daughter would have wanted. There has been backlash from scientific experts, as well as the public.

So, does killing dingoes actually make K’gari safer for people?

The perfect storm

K’gari’s dingoes (called Wongari by the Butchulla) are a population of high conservation and cultural value on this World Heritage–listed sand island. Estimates put their numbers at between 70 and 200.

Huge visitor numbers (about 450,000 per year) to the roughly  1,600 square kilometre island means dingoes and humans share the same beaches and come into contact in ways they generally don’t on the mainland. Most encounters are harmless, even enjoyable. Less than 1% of visitors experience a negative interaction and many tourists visit the island specifically to see the dingoes.

Of course, risk increases when dingoes and people are in close proximity. Dingoes are often deliberately or carelessly rewarded with food scraps or find rubbish, which encourages loitering.

Most injuries caused by dingoes are minor, such as nips, bites and scratches. Serious attacks by dingoes are rare on K'gari and the mainland. Children are most vulnerable given their smaller size.

The Queensland Parks and Wildlife Service has consistently worked to reduce incidents. Their “Be dingo safe” campaign includes education, signs, fenced areas and even “dingo sticks” to deter the animals from approaching. But too often these safety warnings are not heeded. People feed dingoes or leave food in their tents or bags, come too close to dingoes and let kids roam unsupervised.

For an apex predator, dingoes are relatively small and dog-like. To many visitors, they don’t look especially dangerous, and people forget dingoes are wild predators.

Decades of lethal control

Authorities have long relied on lethal control of dingoes on K'gari. Between 2001 and 2013, 110 dingoes were killed. In 2001, after the death of nine-year-old Clinton Gage, 28 were immediately killed. In a typical year, one to two are killed.

Removing up to ten dingoes carries serious costs for a small island population. Genetically, the K’gari population has low diversity and an effective population size of about 25 (meaning only about 25 animals are effectively passing genes on, even though more dingoes exist). Studies have found inbreeding, genetic isolation and declining genetic variation in K'gari dingoes over the past two decades.

High levels of inbreeding may lead to physical deformities, reduced breeding success and an increased risk of local extinction. On an island, there is limited scope for “new” dingoes and their genes to arrive, so every avoidable death is important.

That is why our 2025 population viability analysis was sobering. We found if the number of dingo deaths stays close to natural levels, the population could remain stable. But extra deaths due to mass culls or disease outbreaks expose the animals to higher extinction risk. This makes it more likely the island’s dingoes could die out. In the highest-risk scenarios we modelled (that includes several mass culling events), the risk of extinction becomes substantial in about 50 years. Survival can fall close to zero by 100 years.

Culling rarely solves safety problems

Records of dingo incidents on K'gari offer little evidence killing dingoes delivers lasting safety. Our analysis of the “highest severity” incidents reported found the island had an average of 10.7 reports a year from 2001 to 2015. There was no clear downward trend in incidents, even though more than 110 dingoes were destroyed in that period.

What we did find was a predictable seasonal pattern. About 40% of serious incidents took place during breeding season (March to May) and 30% during whelping (June to August). These are periods when dingoes are more active and social dynamics intensify. During breeding, dingoes (especially younger males) may range more widely and test boundaries. During whelping, adults can become more vigilant and take greater foraging risks to meet the demands of pups.

The chance of serious incidents rose and fell with dingo life history and behaviour, as well as what people did around them. Incidents are not explained by visitor numbers alone.

When a dingo approaches people or loiters near them, they can be labelled as “problematic” and are more likely to be culled. But these behaviours aren’t abnormal in a wildlife tourism setting. They are predictable responses to people, food and opportunity. Younger males are often the most persistent around people, but become less exploratory as they mature or disperse.

A people problem, not a dingo problem

K’gari’s dingoes are doing what wild predators do, just as sharks and crocodiles do in Australia’s oceans and rivers.

Our safety depends on how we behave in wild places. To reduce risky encounters with wildlife, secure your food and waste, keep your kids close, don’t venture out alone, respect park guidelines and stop giving rewards such as food.

Killing dingoes won’t make K'gari safer. Changing human behaviour and attitudes will.

Bradley P. Smith, Senior Lecturer in Psychology, CQUniversity Australia and Kylie M. Cairns, Research Fellow in Canid and Wildlife Genomics, UNSW Sydney

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

For flowering plants, reproduction is a question of the birds and the bees. Attracting the right pollinator can be a matter of survival – and new research shows how flowers do it is more intriguing than anyone realised, and might even involve a little bit of magic.

In our new paper, published in Current Biology, we discuss how a single “magic” trait of some flowering plants simultaneously camouflages them from bees and makes them stand out brightly to birds.

How animals see

We humans typically have three types of light receptors in our eyes, which enable our rich sense of colours.

These are cells sensitive to blue, green or red light. From the input from these cells, the brain generates many colours including yellow via what is called colour opponent processing.

The way colour opponent processing works is that different sensed colours are processed by the brain in opposition. For example, we see some signals as red and some as green – but never a colour in between.

Many other animals also see colour and show evidence of also using opponent processing.

Bees see their world using cells that sense ultraviolet, blue and green light, while birds have a fourth type sensitive to red light as well.

The problem flowering plants face

So what do these differences in colour vision have to do with plants, genetics and magic?

Flowers need to attract pollinators of the right size, so their pollen ends up on the correct part of an animal’s body so it’s efficiently flown to another flower to enable pollination.

Accordingly, birds tend to visit larger flowers. These flowers in turn need to provide large volumes of nectar for the hungry foragers.

But when large amounts of sweet-tasting nectar are on offer, there’s a risk bees will come along to feast on it – and in the process, collect valuable pollen. And this is a problem because bees are not the right size to efficiently transfer pollen between larger flowers.

Flowers “signal” to pollinators with bright colours and patterns – but these plants need a signal that will attract birds without drawing the attention of bees.

We know bee pollination and flower signalling evolved before bird pollination. So how could plants efficiently make the change to being pollinated by birds, which enables the transfer of pollen over long distances?

Avoiding bees or attracting birds?

A walk through nature lets us see with our own eyes that most red flowers are visited by birds, rather than bees. So bird-pollinated flowers have successfully made the transition. Two different theories have been developed that may explain what we observe.

One theory is the bee avoidance hypotheses where bird pollinated flowers just use a colour that is hard for bees to see.

A second theory is that birds might prefer red.

But neither of these theories seemed complete, as inexperienced birds don’t demonstrate a preference for a stronger red hue. However, bird-pollinated flowers do have a very distinct red hue, which suggests avoiding bees can’t solely explain why consistently salient red flower colours evolved.

A magical solution

In evolutionary science, the term magic trait refers to an evolved solution where one genetic modification may yield fitness benefits in multiple ways.

Earlier this month, a team working on how this might apply to flowering plants showed that a gene that modulates UV-absorbing pigments in flower petals can indeed have multiple benefits. This is because of how bees and birds view colour signals differently.

Bee-pollinated flowers come in a diverse range of colours. Bees even pollinate some plants with red flowers. But these flowers tend to also reflect a lot of UV, which helps bees find them.

The magic gene has the effect of reducing the amount of UV light reflected from the petal, making flowers harder for bees to see. But (and this is where the magic comes in) reducing UV reflection from a petal of a red flower simultaneously makes it look redder for animals – such as birds – which are believed to have a colour opponent system.

Birds that visit these bright red flowers gain rewards – and with experience, they learn to go repeatedly to the red flowers.

One small gene change for colour signalling in the UV yields multiple beneficial outcomes by avoiding bees and displaying enhanced colours to entice multiple visits from birds.

We lucky humans are fortunate that our red perception can also see the result of this clever little trick of nature to produce beautiful red flower colours. So on your next walk on a nice day, take a minute to view one of nature’s great experiments on finding a clever solution to a complex problem.

Adrian Dyer, Associate Professor, Department of Physiology, Monash University and Klaus Lunau, Professor, Institute of Sensory Ecology, Heinrich Heine Universität Düsseldorf

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

There’s no question that being in nature is good for wellbeing. Research shows that experiencing nature and listening to natural sounds can relax us.

A key reason for these benefits may be because of the appeal of birds and their pleasant songs that we hear when in nature.

Studies show that people feel better in bird-rich environments. Even life satisfaction may be related to the richness of the bird species in an area.

My colleagues and I wanted to better study the relationship between wellbeing and birdsong. We conducted an experiment in which 233 people walked through a park – specifically the University of Tübingen’s botanical garden. The walk took about half an hour.

Participants filled out questionnaires on their psychological wellbeing both before and after their walk. We also measured blood pressure, heart rate and cortisol levels (in their saliva) to get a better understanding of the physiological effects the walk had on wellbeing. Cortisol is considered an important stress hormone that can change within just a few minutes.

In order to get a good understanding of the effect birdsong had on wellbeing, we also hung loudspeakers in the trees that played the songs of rare species of birds – such as the golden oriole, tree pipit, garden warbler or mistle thrush.

To decide which additional bird songs should be played by the loudspeakers, we looked at the results of a previous study we had conducted. In that study, volunteers listened to more than 100 different bird songs and rated them based on how pleasant they found them to be.

We used the bird songs that had been most liked by participants in that experiment. However, to avoid annoying the birds living in the garden, we only chose bird songs that did not disturb the environment. We also mapped all resident species in the area and avoided broadcasting their songs.

Participants were randomly split into five distinct groups. The first and second groups went for a walk through the garden with birdsong being played on loudspeakers. The second group was also instructed to pay attention to birdsong.

The third and fourth groups also walked through the garden, but this time they only heard natural birdsong – we did not have additional speakers playing birdsong in the area. The fourth group was also instructed to pay attention to the natural birdsong.

The fifth group was the control group. These participants went for a walk through the garden while wearing noise-cancelling headphones.

Benefits of birdsong

In all groups (even the control group), blood pressure and heart rate dropped – indicating that physiological stress was reduced after the walk. Cortisol levels also fell by an average of nearly 33%.

Self-reported mental wellbeing, as measured by the questionnaires, was also higher after the walks.

The groups who focused their attention on the birdsong saw even greater increases in wellbeing. So while a walk in nature had clear, physiological benefits for reducing stress, paying attention to birdsong further boosted these benefits.

However, the groups who went for a walk with the loudspeakers playing birdsong did not see any greater mental and physiological wellbeing improvements compared to the other groups.

This was a surprise, given previous studies have shown birdsong enriches wellbeing. Bird species diversity has also been shown to further improve restoration and relaxation.

One possible explanation for this finding may be that participants recognised the playback sounds as being fake – whether consciously or unconsciously. Another explanation could be that there might be a threshold – and having a higher number of bird species singing in an area does not improve wellbeing any further.

Appreciating birdsong

Our results show that a walk in nature is beneficial in and of itself – but the sounds of natural birdsong can further boost these wellbeing benefits, especially if you make a concerted effort to pay attention it.

You don’t even need to know a lot about birds to get these benefits, as our study showed. The positive effect was seen in everyone from casual birdwatchers through to bird nerds.

Our study’s results are a good message for everyday life. You don’t need a visit to bird-rich environments to make you happy. It seems more important to focus on the birds that are already there, listen to them and enjoy them.

The results also have implications for park design, showing that the sound of birdsong in general – rather than the number of species living there or how rare they are – is of key importance when it comes to wellbeing.

So even just a half hour walk outside while taking the time to notice birdsong could reduce your stress and improve wellbeing.

Christoph Randler, Professor, Department of Biology, University of Tübingen

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

The age of humans is increasingly an age of sameness. Across the planet, distinctive plants and animals are disappearing, replaced by species that are lucky enough to thrive alongside humans and travel with us easily. Some scientists have a word for this reshuffling of life: the Homogenocene.

Evidence for it is found in the world’s museums. Storerooms are full of animals that no longer walk among us, pickled in spirit-filled jars: coiled snakes, bloated fish, frogs, birds. Each extinct species marks the removal of a particular evolutionary path from a particular place – and these absences are increasingly being filled by the same hardy, adaptable species, again and again.

One such absence is embodied by a small bird kept in a glass jar in London’s Natural History Museum: the Fijian Bar-winged rail, not seen in the wild since the 1970s. It seems to be sleeping, its eyes closed, its wings tucked in along its back, its beak resting against the glass.

A flightless bird, it was particularly vulnerable to predators introduced by humans, including mongooses brought to Fiji in the 1800s. Its disappearance was part of a broad pattern in which island species are vanishing and a narrower set of globally successful animals thrive in their place.

It’s a phenomenon that was called the Homogenocene even before a similar term growing in popularity, the Anthropocene, was coined in 2000. If the Anthropocene describes a planet transformed by humans, the Homogenocene is one ecological consequence: fewer places with their own distinctive life.

It goes well beyond charismatic birds and mammals. Freshwater fish, for instance, are becoming more “samey”, as the natural barriers that once kept populations separate – waterfalls, river catchments, temperature limits – are effectively blurred or erased by human activity. Think of common carp deliberately stocked in lakes for anglers, or catfish released from home aquariums that now thrive in rivers thousands of miles from their native habitat.

Meanwhile, many thousands of mollusc species have disappeared over the past 500 years, with snails living on islands also severely affected: many are simply eaten by non-native predatory snails. Some invasive snails have become highly successful and widely distributed, such as the giant African snail that is now found from the Hawaiian Islands to the Americas, or South American golden apple snails rampant through east and south-east Asia since their introduction in the 1980s.

Homogeneity is just one facet of the changes wrought on the Earth’s tapestry of life by humans, a process that started in the last ice age when hunting was likely key to the disappearance of the mammoth, giant sloth and other large mammals. It continued over around 11,700 years of the recent Holocene epoch – the period following the last ice age – as forests were felled and savannahs cleared for agriculture and the growth of farms and cities.

Over the past seven decades changes to life on Earth have intensified dramatically. This is the focus of a major new volume published by the Royal Society of London: The Biosphere in the Anthropocene.

The Anthropocene has reached the ocean

Life in the oceans was relatively little changed between the last ice age and recent history, even as humans increasingly affected life on land. No longer: a feature of the Anthropocene is the rapid extension of human impacts through the oceans.

This is partly due to simple over-exploitation, as human technology post-second world war enabled more efficient and deeper trawling, and fish stocks became seriously depleted.

Partly this is also due to the increasing effects of fossil-fuelled heat and oxygen depletion spreading through the oceans. Most visibly, this is now devastating coral reefs.

Out of sight, many animals are being displaced northwards and southwards out of the tropics to escape the heat; these conditions are also affecting spawning in fish, creating “bottlenecks” where life cycle development is limited by increasing heat or a lack of oxygen. The effects are reaching through into the deep oceans, where proposals for deep sea mining of minerals threaten to damage marine life that is barely known to science.

And as on land and in rivers, these changes are not just reducing life in the oceans – they’re redistributing species and blurring long-standing biological boundaries.

Local biodiversity, global sameness

Not all the changes to life made by humans are calamitous. In some places, incoming non-native species have blended seamlessly into existing environments to actually enhance local biodiversity.

In other contexts, both historical and contemporary, humans have been decisive in fostering wildlife, increasing the diversity of animals and plants in ecosystems by cutting or burning back the dominant vegetation and thereby allowing a greater range of animals and plants to flourish.

In our near-future world there are opportunities to support wildlife, for instance by changing patterns of agriculture to use less land to grow more food. With such freeing-up of space for nature, coupled with changes to farming and fishing that actively protect biodiversity, there is still a chance that we can avoid the worst predictions of a future biodiversity crash.

But this is by no means certain. Avoiding yet more rows of pickled corpses in museum jars will require a concerted effort to protect nature, one that must aim to help future generations of humans live in a biodiverse world.

Mark Williams, Professor of Palaeobiology, University of Leicester and Jan Zalasiewicz, Professor of Palaeobiology, University of Leicester

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

Ditches and canals are the underdog of the freshwater world. These human-made waterways are often forgotten, devalued and perceived negatively – think “dull as ditchwater”. But these unsung heroes have a hidden potential for climate change mitigation, if they’re managed correctly.

We know that ditches and canals have a large global extent, covering at least 5.3 million hectares — about 22% of the UK’s total land area. However, no one has yet mapped all global ditch and canal networks robustly, so it’s potentially more.

These waterways are also hotspots of greenhouse gas emissions, which contribute to climate change. We have previously calculated that ditches emit 333 teragrams of carbon dioxide equivalents (a common unit to express the climate impact of all greenhouse gases), which is nearly comparable to the UK’s total greenhouse gas emissions in 2023.

Ditches often contain stagnant waters and are commonly found running through farmland or cities, where they receive high amounts of nutrients from fertilisers, manure and stormwater run-off. This creates the low-oxygen, high-nutrient conditions that are ideal for the production of potent greenhouse gases methane and nitrous oxide – both of which warm the atmosphere considerably more than CO₂.

However, ditches and their surrounding landscape can be managed (by farmers and landowners, for example) in ways that reduce nutrient inputs and therefore lower their greenhouse gas emissions. This makes them an untapped solution for reducing the effects of climate change.

Many nature restoration solutions focus on storing atmospheric carbon – by planting trees or mangroves, for example. But there are also immediate wins to be made simply by reducing greenhouse gas emissions. The importance of methane reduction has now been recognised by more than 160 countries, all of which signed the global methane pledge to cut human-caused methane emissions by at least 30% from 2020 levels by the end of the decade.

Our new study outlines the steps needed to reduce emissions from global ditches and canals. First, we need to better understand these systems by mapping their global extent. We also need to collect more measurements of greenhouse gas emissions from underrepresented regions like South America and Africa. Emissions from irrigation ditches in these understudied places could be large.

We also need to improve our understanding of how the potent greenhouse gas methane escapes the sediments in bubbles. This involves using sensors that monitor methane concentrations continuously, in order to capture “hot moments” when weather or human activity (such as fertiliser use on farmland) cause sudden pulses of emissions.

All of these strategies will improve estimates of global greenhouse gas emissions from ditches. From that new baseline, any progress in reducing emissions can be more accurately measured.

New directions for ditches

There are several ways to reduce greenhouse gas emissions from ditches and canals. These include reducing fertiliser application rates on farmland, excluding livestock from areas beside ditches to reduce the amount of manure that ends up in waterways (which has already been shown to be effective for ponds), and managing pollution sources like wastewater treatment plants.

In the Netherlands, researchers have tested the effects of dredging agricultural ditches to remove the nutrient- and organic matter-rich sediments that release greenhouse gases.

They found that dredging resulted in a 35% decline in ditch emissions after one year. However, this method isn’t perfect, as the emissions from the removed sediments still need to be accounted for at a later stage, and dredging disturbs aquatic habitats and organisms.

Planting vegetation alongside ditches helps intercept nutrients and sediments before they reach the ditch. This vegetation also provides shading, which reduces water temperature and rates of greenhouse gas emissions. A study across Denmark, Great Britain and Sweden found that riverside vegetation helped to considerably reduce nutrient inputs to rivers and streams, and improved habitats for stream organisms like bugs and frogs.

Introducing floating vegetation can also trap methane and create the conditions for its removal before it is released into the atmosphere. Current trials in the UK are looking at introducing Sphagnum moss to peatland ditches. Once a floating mat of this moss has been established, it can trap bubbles of methane in an oxygen-rich environment created by the photosynthesising moss.

When methane and oxygen are present together, methane-eating bacteria can convert methane to carbon dioxide, which has a much lower impact on the climate. Initial results showed a decrease in methane of approximately 40% when Sphagnum was present.

Some of these techniques might be too expensive to scale, and many are still at the early stages of research into their use in ditches. Nevertheless, ditches and canals can in future be climate heroes – we just need to give them the chance by managing them in smart and sustainable ways.

Teresa Silverthorn, Postdoctoral Research Associate, University of Liverpool; Jonathan Ritson, Research Fellow, Geography, University of Manchester, and Mike Peacock, Lecturer in Biogeochemical Cycles, School of Environmental Sciences, University of Liverpool

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

No matter where you live in the United States, you have likely seen headlines about PFAS being detected in everything from drinking water to fish to milk to human bodies.

PFAS, or per- and polyfluoroalkyl substances, are a group of over 10,000 synthetic chemicals. They have been used for decades to make products waterproof and stain- and heat-resistant – picture food wrappers, stain-resistant carpet, rain jackets and firefighting foam.

These chemicals are a growing concern because some PFAS are toxic even at very low levels and associated with health risks like thyroid issues and cancer. And some of the most common PFAS don’t naturally break down, which is why they are often referred to as “forever chemicals.”

Now, PFAS are posing a threat to the Great Lakes, one of America’s most vital water resources.

The five Great Lakes are massive, with over 10,000 miles of coastline (16,000 kilometers) across two countries and containing 21% of the world’s fresh surface water. They provide drinking water to over 30 million people and are home to a robust commercial and recreational fishing industry.

My colleagues at the University of Wisconsin-Madison and I study how chemicals like PFAS are affecting water systems. Here’s what we’re learning about how PFAS are getting into the Great Lakes, the risks they’re posing and how to reduce those risks in the future.

PFAS’ many pathways into the Great Lakes

Hundreds of rivers flow into the lakes, and each can be contaminated with PFAS from sources such as industrial sites, military operations and wastewater treatment plants in their watersheds. Some pesticides also contain PFAS, which can wash off farm fields and into creeks, rivers and lakes.

The concentration of PFAS in rivers can vary widely depending on these upstream impacts. For example, we found concentrations of over 1,700 parts-per-trillion in Great Lakes tributaries in Wisconsin near where firefighting foam has regularly been used. That’s more than 400 times higher than federal drinking water regulations for PFOS and PFOA, both 4 parts-per-trillion.

However, concentration alone does not tell the whole story. We also found that large rivers with relatively low amounts of PFAS can put more of these chemicals into the lakes each day compared with smaller rivers with high amounts of PFAS. This means that any effort to limit the amount of PFAS in the Great Lakes should consider both high-concentration hot spots and large rivers.

Groundwater is another key route carrying PFAS into the Great Lakes. Groundwater is a drinking water source for more than one-third of people in the U.S., and it can become contaminated when PFAS in firefighting foam and other PFAS sources seep into soil.

When these contaminated plumes enter the Great Lakes, they carry PFAS with them. We detected PFAS concentrations of over 260 parts-per-trillion in the bay of Green Bay in Lake Michigan. The chemicals we found were associated with firefighting foam, and we were able to trace them back to a contaminated groundwater plume.

PFAS can also enter the Great Lakes in unexpected ways, such as in rain and snowfall. PFAS can get into the atmosphere from industrial processes and waste incineration. The chemicals have been detected in rain across the world, including in states surrounding the Great Lakes.

Although PFAS concentrations in precipitation are typically lower than in rivers or groundwater, this is still an important contamination source. Scientists estimate that precipitation is a major source of PFAS to Lake Superior, which receives about half of its water through precipitation.

Where PFAS end up determines the risk

Much of the PFAS that enter Lake Superior will eventually make their way to the downstream lakes of Michigan, Huron, Erie and Ontario.

These chemicals’ ability to travel with water is one reason why PFAS are such a concern for drinking water systems. Many communities get their drinking water from the Great Lakes.

PFAS can also contaminate other parts of the environment.

The chemicals have been detected in sediments at the bottom of all the Great Lakes. Contaminated sediment can release PFAS back into the overlying water, where fish and aquatic birds can ingest it. So, future remediation efforts to remove PFAS from the lakes are about more than just the water – they involve the sediment as well.

PFAS can also accumulate in foams that form on lake shorelines during turbulent conditions. Concentrations of PFAS can be up to 7,000 times higher in natural foams compared with the water because PFAS are surfactants and build up where air and water meet, like bubbles in foam. As a result, state agencies recommend washing skin that comes in contact with foam and preventing pets from playing in foam.

Some PFAS bioaccumulate, or build up, within fish and wildlife. Elevated levels of PFAS have been detected in Great Lakes fish, raising concerns for fisheries.

High PFAS concentrations in fish in coastal areas and inland waters have led to advisories recommending people limit how much they fish they eat.

Looking ahead

Water cycles through the Great Lakes, but the process can take many years, from 2.6 years in Lake Erie to nearly 200 years in Lake Superior.

This means that PFAS that enter the lakes will be there for a very long time.

Since it is not possible to clean up the over 6 quadrillion gallons of water in the Great Lakes after they have been contaminated, preventing further contamination is key to protecting the lakes for the future.

That starts with identifying contaminated groundwater and rivers that are adding PFAS to the lakes. The Sea Grant College Program and the National Institutes of Water Resources, including the Wisconsin programs that I direct, have been supporting research to map these sources, as well as helping translate that knowledge into actions that policymakers and resource managers can take.

PFAS contamination is an issue beyond the Great Lakes and is something everyone can work to address.

• Drinking water. If you are one of the millions of people who drink water from the Great Lakes, find out the PFAS concentrations in your drinking water. This data is increasingly available from local drinking water utilities.

• Fish. Eating fish can provide great health benefits, but be aware of health advisories about fish caught in the Great Lakes and in inland waters so you can balance the risks. Other chemicals, such as mercury and PCBs, can also lead to fish advisories.

• Personal choice. Scientists have proposed that PFAS only be used when they have vital functions and there are no alternatives. Consumer demand for PFAS-free products is helping reduce PFAS use in some products. Several states have also introduced legislation to ban PFAS use in some applications.

Decreasing use of PFAS will ultimately prevent downstream contamination in the Great Lakes and around the U.S.

Christy Remucal, Professor of Civil and Environmental Engineering, University of Wisconsin-Madison

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

Cold spray whipped off the ropes as a diesel engine throbbed in the background. One by one, empty shellfish pots came over the side of the fishing boat, occasionally containing the remnants of crab and lobster claws and carapaces. Something strange was going on.

Then the culprit revealed itself – a squirming orange body surrounded by a writhing tangle of tentacles. A few minutes later, three more of these denizens of the deep came up in a single pot, and then, incredibly, a final pot rose from the water completely rammed full of them, more than a dozen together in a squirming mass.

This was a familiar scene off the south coasts of Devon and Cornwall early last year, as a bloom of the common octopus (Octopus vulgaris) emerged, the first time anything like this had been seen for 75 years. In fact, commercial catches of common octopus in 2025 were almost 65 times higher than the recent annual average. A new report now sheds light on these blooms: their history, the causes and the consequences.

The common octopus, despite the name, is not normally common in British waters. Instead, it favours the warmer climes of southern Europe, the Mediterranean and north Africa. But, occasionally, such as in 1900, 1950 and now 2025, numbers explode off the south-west coast of England, changing marine food chains and disrupting the local fishing industry.

Common octopuses take the ultimate “live fast, die young” approach to life. Despite the large size they can attain, they generally only live for less than two years, with females dying after their eggs hatch. The males also die after breeding. This means octopus populations are highly affected by changes in environmental conditions.

Octopus blooms have previously been rare in the UK, but emerging evidence from long-term marine monitoring of the western Channel suggests that these episodes coincide with sustained periods of unusual warmth in both the ocean and atmosphere.

These “marine heatwaves” can stimulate rapid population growth, whether the octopus are locally established or newly arrived from the south. These warm conditions are often accompanied by unusually low salinity in coastal waters, a signal that points to fresher water entering the region. While salinity itself is unlikely to drive the outbreaks, it serves as a valuable tracer of the water’s origin.

The fresher conditions may stem from high river flow from major French Atlantic rivers such as the Loire, or from prolonged easterly winds over the Channel during the cooler months (October to March). These processes could help transport octopus larvae across the Channel from northern France and the Channel Islands.

Taken together, the combination of warmth, altered circulation and low-salinity signatures suggests that climate-driven shifts in ocean and atmospheric dynamics underpin these outbreaks.

From crisis to opportunity?

Those early scenes of octopus consuming catches in crab and lobster pots continued as 2025 rolled on. But they didn’t just stop at crustaceans. Piles of empty scallop shells were found in many pots, sometimes with remnants of flesh still attached.

Scallops don’t normally go into crab and lobster pots (unless they have lights in them, which these ones didn’t), so the only explanation is that octopus were actively putting scallops in pots to stock up their larder, consuming them at leisure later.

However, fishers are nothing if not adaptable. They soon realised that there was a lucrative export market for octopus and began targeting them. One boat fishing out from Newlyn in Cornwall brought home over 20 tonnes of octopus, worth £142,000, from just three days fishing.

Between £6.7 million and £9.4 million worth of common octopus was landed on the south coast of the UK from January to August 2025. However, not all fishers benefited, and for most boats, octopus catches suddenly dropped off in August. With other shellfish fisheries also declining dramatically last year – lobsters by 30% and brown crabs and scallops by over 50% – many fishers worry about a future in which there is nothing left to catch.

So, what does the future hold? Given the link with climate change, the extensive reports of octopus breeding and a recent appearance of juvenile octopuses in UK waters, the continued presence of the common octopus seems likely.

If a bloom the size of last year’s occurs again soon, future fisheries should be guided by sustainable and ethical principles that help diversify opportunities for fishing fleets, while leaving enough octopus in the sea to be enjoyed by the hundreds of divers and snorkellers who loved watching these amazing creatures last year.

Don’t have time to read about climate change as much as you’d like?
Get a weekly roundup in your inbox instead. Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. Join the 47,000+ readers who’ve subscribed so far.

Bryce Stewart, Associate Professor, Marine Ecology and Fisheries Biology, University of Plymouth; Marine Biological Association; Emma Sheehan, Associate Professor of Marine Ecology, University of Plymouth, and Tim Smyth, Head of Group: Marine Processes and Observations, Plymouth Marine Laboratory

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