Environment - Mangrove swamps are improving despite climate change

 

The world’s mangrove forests are bouncing back. That’s good news for our coasts and climate

talented young photographer/Getty

Catherine Lovelock, The University of Queensland

Mangroves are perplexing plants.

They breathe through their roots, appear to stand on stilts and grow best in hot, salty seawater drawn in and out by the tide.

Historically, mangrove forests have been dismissed as inhospitable places to avoid and have been extensively cleared. But these fascinating trees are now gaining attention for how they support biodiversity, store carbon and buffer the effects of storms, cyclones and tsunamis.

Since 1984, scientists have been monitoring the growth and geographical reach of mangrove forests using satellites. And for the first time, these unique ecosystems are expanding at a faster rate than they are declining.

So what’s driving this? And could it help curb climate change?

Mangroves thrive in coastal environments, where the tide comes in and out. Vicki Smith

Why mangroves matter

Mangrove forests were long viewed as largely expendable places. Research shows people were quick to convert them into rice paddies, oil palm plantations and aquaculture operations. Some were even used as rubbish tips.

However, mangrove forests are now recognised as a vital part of our coastal environments. They provide habitat for a wealth of plants and animals including fish such as barramundi and giant shovelnose rays, reptiles such as seasnakes and even mammals such as the proboscis monkey and water mouse. They are crucial carbon stores, locking up roughly four times more carbon than other land-based forests. Mangroves can also shelter coastal communities and ecosystems from natural disasters by reducing the risk of flooding and erosion.

From an economic perspective, mangrove forests allow millions of fishers to earn a living as well as supporting commercial fisheries. These forests are also of immense cultural value to First Nations communities, many of which associate mangroves with certain religious gods or cultural practices.

Mangrove seedlings growing in the tidal flats of the Narrawallee estuary in NSW. lynnebeclu/Getty

Mangroves are bouncing back

For decades, mangrove forests have been systematically cleared and destroyed. Between the 1980s and 2010, we lost more than 12,000 square kilometres – an area the size of Jamaica – of mangroves worldwide. That means there are far fewer mangroves that can trap harmful greenhouse gas emissions and slow the effects of climate change.

However, this trend may be reversing. A recent study analysed four decades of global data documenting the reach and growth of mangroves. It had three key – and somewhat surprising – findings.

Mangroves are rebounding despite climate change

Human-induced climate change is putting immense pressure on our mangrove forests. It is driving more severe and frequent droughts and storms that can damage or kill mangroves. It is also accelerating sea level rise, potentially drowning mangroves.

This study shows the world’s mangrove forests are rebounding, even as our planet rapidly warms. Since 2010, they have expanded by more than 2,000 square kilometres.

Importantly, the reasons for this vary between regions. Before 2010, Myanmar and Indonesia were hot-spots of mangrove loss. But this trend has now stabilised, with policymakers strengthening the laws around mangrove protection following the catastrophic 2004 Indian Ocean tsunami and 2008 cyclone Nargis.

Australia’s mangrove forests are also expanding. However, research suggests this is because mangroves are increasingly growing on floodplains. Rising sea levels allow tides to reach further inland, creating the salty conditions in which mangroves thrive.

In some places – such as where mangroves regenerate in unused aquaculture ponds – this shift inland is positive. In northern Australia, however, it threatens to degrade freshwater ecosystems and is an urgent concern for Traditional Owners.

Mangroves are shifting closer to the sea

This new study suggests mangroves are increasingly growing on newly formed mud flats.

This is counter intuitive because rising sea levels should, in theory, restrict mangrove growth. It may be happening because rivers are carrying soil and sand from deforested areas to the coast, creating new habitat for mangroves.

This demonstrates the resilience of mangrove ecosystems. However, it seems mangroves aren’t regenerating rapidly in the coastal regions where they once thrived – an indicator of successful restoration.

Mangroves are expanding and retreating at the same time

The authors of this study also examined trends in mangrove degradation.

Degradation occurs when mangrove canopies become less dense – a sign they are not as healthy as before. The researchers point to human activities, such as harvesting or pollution, and extreme weather as the main factors driving mangrove degradation.

However, exact causes will differ between regions.

Mangroves have very recognisable roots. Dulyanut Swdp/Getty

More work needed

The expansion of the world’s mangrove forests is promising – and perhaps unexpected – news. However, we can’t be complacent. Current evidence suggests mangrove forests are still thinning overall, putting coastal ecosystems and climate action efforts at risk.

To combat this trend of mangrove degradation, we should support policies that strengthen mangrove protection and restoration.

Organisations such as the Global Mangrove Alliance and Mangrove Breakthrough are also raising the profile of these fascinating ecosystems.

Further research is needed to monitor the varying impacts of climate change on mangroves.

Mangroves at Cullendulla Creek Nature Reserve, New South Wales at low tide. Simon McGill/Getty

Catherine Lovelock, Professor of Biology, The University of Queensland

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

Environment - H5N1 bird flu - survival insights needed

 

We don’t know how well threatened species fight off bird flu – but we need to

Katherine Belov, University of Sydney and Carolyn Hogg, University of Sydney

Lethal bird flu is now spreading in Australia. This is bad news for many native species.

New federal government analysis suggests close to one in five Australian bird and mammal species is at high, very high or extreme risk. But this risk assessment omits something vital – how genetically well-equipped the species is to fight the virus.

While species such as black swans are likely to be very hard-hit, others such as wild ducks are expected to be less affected. One reason for this is different immune systems – some are more or less able to fight the virus. But there’s a more significant factor – how much variation there is in key immune system genes across populations.

Right now, we don’t have an overview of which threatened species are at highest risk based on this. If we urgently create a national immune-risk map for species at risk, we can act to protect those in most danger.

Black swans are likely to be hard hit by bird flu, unlike wild duck species. The difference lies in their immune systems. irmaferreira/Getty

Why immune gene variations matter

When a virus enters an animal’s body, its immune system must first detect it, then respond. Key immune genes help determine if an animal fights off infection, becomes seriously ill or dies.

Different individuals will have slightly different immune responses based on variations at different immune genes. Some variants will allow an individual to survive the virus, and others won’t. This is why diversity in these genes is critical across the species.

Large wildlife populations often have a wide array of variants at each immune gene. This acts as biological insurance – when a new disease arrives, some individuals will be more able to survive. But if a species becomes threatened and its population falls, it’s likely to lose much of this protective diversity.

If the remaining individuals share similar vulnerabilities, a lethal disease such as H5N1 bird flu could be enough to push the species closer to extinction.

Threatened species are often immunologically fragile

Australia’s wildlife faces threats such as habitat loss, climate change, invasive species, pollution and disease. These threats not only reduce population size – they erode genetic diversity.

Small, fragmented populations may have enough genetic diversity to look viable in the short term. But when a new disease arrives, they may lack the breadth of variation at the immune genes needed to survive the new disease. This is a large, hidden vulnerability.

The orange-bellied parrot is a species that worries us deeply. The small, migratory parrot is one of Australia’s most endangered birds. Just 86 birds are left in the wild, with a few hundred more in captive breeding populations.

Our previous research found the parrot has suffered a dramatic loss of genome-wide diversity over the past century – including variation in immune genes.

If H5N1 infects these parrots, they may lack the immune gene variants needed to buffer the species against severe disease.

Many orange-bellied parrots are being reared in captive breeding programs. Outback to Coast/Getty

Tasmanian devils are similarly at risk. These iconic marsupials have critically low immune gene diversity due to population bottlenecks over the past 5,000 years. This left them vulnerable to the contagious devil facial tumour disease, which saw populations plummet with local declines of 95%, and an estimated 80% decline across Tasmania since the disease arose in the 1990s. Our preprint research shows facial tumour disease is still eroding immune gene diversity.

These scavengers are likely to be exposed to bird flu by eating carcasses, and we know which devil populations eat seabirds. The question will be whether devils have enough immune variation to respond to H5N1.

How a national immune-risk map could help

While we know how some species are likely to respond to the virus, the picture is far from complete.

We could fill in the blanks quickly, using DNA samples held in museums or from animals in zoos to generate genomic data on many more species.

We could then analyse immune gene variation across different populations of each species to measure how diverse they are. This approach could reveal populations that have lost important immune variants and may be particularly vulnerable to bird flu.

The Threatened Species Initiative, has collected this data for more than 125 threatened species. But there are hundreds more threatened animal species for which we have no data and no samples.

If we worked quickly to create a national immune-risk map, wildlife managers could focus surveillance, vaccination and protection efforts on the populations likely to be at most risk.

Importantly, they could establish new captive populations before the virus arrives, using breeding programs to maximise immune fitness and keep inbreeding to a minimum.

This is not science fiction. We led immune-guided conservation work in Tasmanian devils, where data on immune genes shape decisions around breeding. The end result: devil joeys with stronger immune systems.

If we use this approach for more at-risk species, we could better protect wildlife from bird flu and future diseases.

No time to waste

Responses to wildlife diseases are often reactive. Animals start dying in large numbers and then we investigate. This approach will be much too slow to respond to the fast-moving H5N1 strain.

Australia has world-leading wildlife genomics expertise, valuable museum and zoo collections, threatened species recovery programs and growing genome resources.

What’s missing is a coordinated way to translate immune gene data into practical action.

It’s not too late. But we have to act fast to identify species and populations with low immune diversity and roll out measures before irreversible losses occur.

Katherine Belov, Professor of Comparative Genomics, University of Sydney and Carolyn Hogg, Professor of Biodiversity & Conservation and Co-Lead, Australasian Wildlife Genomics Group, University of Sydney

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

Environment - Bird Flu H5N1 - managing the threat

 

Powerless against bird flu? Not entirely. Here are 8 ways to help protect Australia’s birds and mammals

Philip Thurston/Getty, CC BY

John Woinarski, Charles Darwin University; Euan Ritchie, Deakin University, and Stephen Garnett, Charles Darwin University

The deadly H5N1 strain of bird flu has now spread from migratory birds to infect resident Australian birds. Clusters of dead birds have been found in several locations. The virus will inevitably infect other wildlife, most notably mammals.

Death rates range from 75-100% in poultry and some wild bird species. There’s great uncertainty about how big the death toll will be over both the short and long-term. Native species such as the black swan are highly vulnerable, while others may prove more resilient.

Based on overseas experience, we can expect many thousands, if not millions, of Australian birds, and large numbers of mammals, to perish. Poultry will likely become infected, while some beloved pets may die.

Overall, the populations of many Australian species will likely plummet. Some threatened species will move closer to extinction, and relatively safe species could become threatened. As the virus spreads through widespread species such as silver gulls, white ibis, pigeons, ducks and crows, many of us will be confronted by wildlife deaths close to home.

Facing a threat like this can make us feel powerless. But there are actions we can take.

Blow after blow for wildlife

Over the 2019-20 summer, megafires incinerated forests and wildlife. In 2025, the lethal South Australian algal bloom denuded large marine areas.

The prospect of yet another hammer blow to wildlife is haunting and emotionally triggering for conservationists, wildlife carers and people who love nature.

To date, the official messaging asks us to watch for, report and record sick birds and mammals. This is important, but it risks leaving the community feeling disempowered witnesses to catastrophe. The situation is far from hopeless. Now is the time to act.

What can be done?

Following overseas work on ways to reduce the toll, we have come up with eight actions.

1. Tackle other threats to give species a fighting chance

While federal, state and territory response plans are not public, what we do know suggests a focus on controlling threats other than bird flu, especially for species that are threatened.

For example, locally eradicating predators such as cats and foxes could give more individuals a chance to get through the first wave of bird flu. Banning duck hunting could also reduce one threat to wildlife.

Working to reduce other threats such as feral cats will boost resilience to the virus at a species level. Pictured: a cat stalking a red-tailed tropic-bird chick on Christmas Island. Janos Hennicke, CC BY

2. Secure insurance populations

Threatened birds and mammals with populations in captivity provide some security. We can boost these insurance populations by increasing their genetic diversity and the number of individuals kept.

For at-risk species without these populations, we may have to collect wild animals before infection reaches them (where practical). Zoos may offer the most protection, but there’s scope to translocate species (such as northern quolls) to safer wild places.

3. Vaccinate species at risk

New Zealand authorities are already giving vaccines to birds at risk. To date, Australia is not doing so, though policymakers are exploring the option. Limited trials in mammals have been undertaken in the United States.

Wild animals have to be caught, given the vaccine, and recaptured for a booster 4-6 weeks later. This is challenging but often feasible. In the US, authorities captured and vaccinated endangered Californian condors, then released them back to the wild.

We need to explore new vaccines, especially for mammals.

4. Widen monitoring

We need good monitoring to track the spread, understand whether our efforts have helped and plan future actions. Monitoring will show what the virus has done to species, track viral mutations and assess survival rates.

For many seabirds and waterbirds, existing programs give us good estimates of current population size. This will let us estimate declines and any recoveries. But we don’t have robust estimates for other at-risk bird and mammal species. This gap needs to be rapidly filled with funding for targeted monitoring. Citizen scientists can also help.

Citizen scientists can play a key role in monitoring population declines and – hopefully – recovery through platforms such as iNaturalist and Birdata. Renee Mead, CC BY

5. Expand research

Much Australian fauna is very distinct from species overseas, meaning lessons learned elsewhere won’t necessarily apply. We need to know which species are most vulnerable, which species spread the virus most effectively, whether survivors have compromised immune systems and how much genetic diversity has been lost.

6. Slow the spread

The virus spreads rapidly in contaminated water and through the movements of infected birds and mammals. Even so, we can slow the spread. In some situations, authorities can remove sick or dead animals to reduce the chance of scavenging birds and animals eating them and contracting then spreading the virus.

Some areas may need to be closed to the public to reduce infection risks through disturbance or contamination. It may be necessary to shut down some water sources or make them less attractive to waterfowl, who are often good carriers of the virus. Poultry farmers will need to control water sources too, to avoid attracting infected birds.

7. Involve interested groups

Authorities must ensure community members, land-owners, First Nations groups and conservationists are involved in creating response plans. Bird flu is a shared problem. Governments cannot respond alone.

8. Look for some silver linings

This virus will likely have dire consequences for many species. But it could also kill introduced predators and scavengers such as feral pigs, cats, foxes and common mynahs.

Time to act

The damage this virus will do isn’t set. We can shape some outcomes. We believe this package of actions could help avert the worst future for Australian birds and mammals – and encourage their recovery.

Acknowledgements: Ecologist Tanya Loos provided helpful feedback.

John Woinarski, Professor of Conservation Biology, Charles Darwin University; Euan Ritchie, Professor in Wildlife Ecology and Conservation, School of Life & Environmental Sciences, Deakin University, and Stephen Garnett, Professor of Conservation and Sustainable Livelihoods, Charles Darwin University

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

Health - Less than 10,000 steps a day is optimum for good health

 

In recent years increasing attention has been paid to the value of walking and 'step counts' with varying numbers quoted as to the number of steps per day that is optimum for health. This blog has previously published recent research on this subject that can be found at these links:

• Recommended steps by age group

• Exercise and walking to avoid Alzheimers disease

Further insights are provided in this article -

Do we really need 10,000 steps a day?

Canva, Ono Kosuki/Pexels, Billion Photos/Canva, Josh Blake/Canva, The Conversation

Hunter Bennett, Adelaide University

You’ve probably heard that hitting 10,000 steps a day is the key to health and longevity.

This magic number feels like a medical rule, handed down by doctors across the globe.

But where did it come from? And is it even true?

Let’s step back to Japan in 1964

Believe it or not, but the infamous 10,000 steps a day recommendation didn’t come from a research laboratory.

In fact, it is not scientific at all.

It came from a Japanese pedometer called the manpo-kei which translates to “10,000-step meter”.

This pedometer went on sale just after the 1964 Tokyo Olympics, at a time when there was a growing worry people in Japan weren’t moving enough.

The number was mainly chosen was because it was catchy and easy to remember. The Japanese kanji character for 10,000 – 万 – even looks a little like a walking person, which may have played a role in deciding on the number.

So 10,000 was a slogan to sell a step-counter, not an evidence-based recommendation.

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So many ideas about what makes us sick, or keeps us well, sound plausible. Early studies might sound promising. But then something gets twisted. In this series, we investigate how a grain of truth ends up as a common health myth. And we untangle what went wrong along the way.

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So what does the research say?

Getting 10,000 steps a day can be a useful goal, and it will have a positive impact on your health. But you can reap health benefits from even less.

A recently published systematic review combined the results of 57 studies and more than 160,000 adults to examine the relationship between daily steps and health. Interestingly, they found 7,000 steps a day was where health benefits were maximised.

Reaching 7,000 steps a day was linked to a 47% lower risk of dying early, a 25% lower risk of cardiovascular disease (heart disease and stroke), a 14% lower risk of type 2 diabetes, a 38% lower risk of dementia, a 22% lower some of depression and a 28% lower risk of falls.

Some health benefits started well before 7,000 steps.

The researchers found going from about 2,000 to 4,000 steps a day makes a real difference. These health benefits then increase again slightly from 4,000 to 7,000 steps a day, after which the benefits start to plateau.

These results align closely with other research looking at all types of physical activity, where going from being inactive to moderately active yields the largest health improvements. Moving from a moderate to high level of activity does provide additional benefits, but these are much smaller in magnitude.

Why walking is good for you

Walking is a form of “aerobic” exercise. It raises your heart rate and places stress on your respiratory, muscular and cardiovascular systems.

If you do it regularly, it can improve your heart and metabolic health, and reduce your bodyweight.

Walking can also reduce stress and improve mental health, possibly due improvements in feelings of self-esteem and self-efficacy that comes with regular movement.

Steps versus minutes

There is some additional nuance that needs to be considered when discussing how far you walk each day: how hard you walk.

Most people choose a walking pace that pushes them into the realm of “moderate intensity” exercise. However, the health benefits of exercise scale up with exercise intensity: you get more bang for your buck from more intense exercise.

So, if you pick up the pace and move towards a vigorous exercise intensity (where it’s hard to maintain a conversation), you will get larger health benefits in less time. This is why official exercise guidelines treat 75 minutes of vigorous activity as roughly equal to 150 minutes of moderate activity.

With this in mind, rather than focusing on steps, you might be better off focusing on the number of minutes you accumulate each week.

Recent research even suggests short bursts of high-intensity exercise spread across the day can have surprising health benefits.

So, if you’re short on time, walking faster is one of the simplest ways to get more out of that same walk.

But walking alone isn’t enough

Walking covers the “aerobic” side of fitness well. However, it doesn’t really address the “anaerobic” side.

Anaerobic fitness refers to your muscle mass, muscle strength, and power. Having higher anaerobic fitness is linked to having a better quality of life and lower risk of mortality as you get older.

This is why most health authorities recommend muscle-strengthening activities (such as lifting weights) at least two days a week.

This will also help reduce your risk of type 2 diabetes, while also helping you avoid falls and stay independent for longer as you get older.

If you can aim to hit 7,000 steps each day, and add in weight training twice per week, you’re going to have most of your bases covered from a health perspective.

Hunter Bennett, Lecturer in Exercise Science, Adelaide University

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

Climate change - fires intensify after flash droughts

 

Flash droughts pull ‘alarming’ amounts of moisture from the landscape and intensify wildfires: new research

Abhirup Dikshit, UNSW and Jason Evans, UNSW

When catastrophic wildfires capture global headlines, such as the unprecedented blazes sweeping through southern Europe this summer or the devastating 2019–20 “Black Summer” in Australia, they are almost always preceded by severe drought. Dry vegetation and parched landscapes are necessary ingredients for infernos.

But not all droughts are created equal – the way a drought evolves can drastically alter how a fire behaves once it ignites. As global temperatures rise, a new and dangerous phenomenon is becoming increasingly common: the “flash drought”.

Unlike standard droughts, which take place over months or years, flash droughts are rapidly occurring dry spells, driven by intense heat and unusually low humidity. They suck moisture out of the landscape at an alarming rate.

While scientists know standard droughts increase fire risks, a critical question has remained unanswered: do flash droughts further increase this risk, and what happens when these two drought types collide?

Our latest research mapped two decades of global satellite data to answer this question. We found when landscapes transition from a prolonged standard drought into a rapid flash drought – or when the two overlap – they create a “hyper-flammable” state. This acts as a massive fire accelerant; they spread faster, last longer and grow significantly larger than other wildfires.

How hyper-flammability works

To understand why this happens, we have to look at how different droughts affect the environment. The major difference is the speed at which they occur.

A standard drought acts like a slow, relentless oven. Over months, it gradually dries out vegetation and severely reduces soil moisture, leaving a dry environment primed to burn.

A flash drought, on the other hand, is like hitting the landscape with a high-powered hairdryer. The atmospheric dryness rapidly increases, characterised by extreme heat and low humidity, and quickly depletes remaining soil moisture.

When a standard drought turns into a flash drought, the effects don’t just add up; they multiply. Combined, they cause the fire danger to skyrocket, setting the perfect stage for fast-spreading and intense wildfires. Short-lived weather anomalies such as flash droughts generate disproportionately severe and extreme fires.

Tracking two decades of global fires

To uncover this pattern, we analysed global drought and satellite-based fire data sets from 2002 to 2021. Global wildfires were categorised into four distinct groups: fires occurring under normal (no drought) conditions; fires occurring during flash droughts; fires occurring during isolated standard droughts; and fires occurring where the two drought types overlapped or followed one another.

Across every single fire metric we measured, including speed, size, duration and spread, fires burning under combined drought conditions were the most extreme. The median size of these fires was 65% larger than fires in normal conditions, and 21% larger than those occurring during standard droughts alone. They spread 35% faster and burned 19% longer.

We also discovered that regions experiencing combined drought conditions endured significantly longer dry spells before a fire actually started. On average, 72 days passed between the onset of a combined drought and the start of a fire. This compared with only 17 days for flash droughts and 56 days for standard droughts. This prolonged period allows severe dryness to develop before fires start.

Global fire hotspots

While fires that follow standard droughts are widespread across the globe’s arid and semi-arid zones, we found fires following flash droughts and, particularly, combined droughts, clustered in distinct geographic hotspots.

The most extreme are heavily concentrated in highly vulnerable communities of plants and animals, including the savannas of South America and Africa, northern Australia, and the western United States.

These regions are highly susceptible to rapid-onset heat and moisture stress, making them ground zero for compounding climate extremes. The presence of both slow-moving and flash droughts causes the most extreme fire behaviour, thus amplifying the fire’s intensity.

Rethinking wildfire preparation

As the climate continues to heat up, the rate of evaporation increases worldwide. This means the frequency and extent of combined droughts are likely to increase across fire-prone regions around the world.

Crucially, we must stop viewing droughts simply as a static state of reduced moisture. Instead, we must recognise them as evolving processes, in which the shift from one type of drought to another can fundamentally change wildfire severity.

Unfortunately, many current global drought and fire monitoring systems emphasise real-time conditions, or look at drought severity as an aggregated whole. To better protect communities and nature, these systems urgently need to integrate information on how droughts evolve. This would enable us to better detect emerging hyper-flammable landscapes before the first spark.

Abhirup Dikshit, ARC DECRA Fellow, Climate Change Research Centre, UNSW and Jason Evans, Professor, Climate Change Research Centre, UNSW

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

Satellites in orbit and many more to come

 

There are already 16,000 satellites in Earth’s orbit. How will we manage the next 100,000?

Visualisation of objects in Earth’s orbit. LeoLabs

Tony Jan, Torrens University Australia

Earth’s orbit is getting crowded.

About 16,000 satellites currently circle our planet, supporting everything from GPS navigation and weather forecasting to banking, emergency services and internet communications.

Dozens more are launched every few weeks. Some estimates suggest the total number of satellites could exceed 100,000 within this decade, with more conservative estimates landing on up to 60,000 satellites by 2030 – still a staggering amount.

This rapid growth is creating an important challenge. How do we safely manage an increasingly crowded orbital environment while ensuring the satellites we depend on continue to work reliably?

The risks are not difficult to imagine. Large satellite constellations increase light pollution and other disruptions to astronomy and the night sky. More satellites mean more traffic, a greater chance of collisions and an increasing amount of space debris.

In a worst-case scenario, space debris can cause a runaway chain reaction known as Kessler syndrome, which would ensconce Earth in a cloud of debris and render its orbit unusable, without the ability to launch satellites or any other space missions.

Even short of this, ageing or damaged satellites can become hazards if they stop working, collide with other objects, or eventually make uncontrolled re-entries through the atmosphere.

This raises a practical question – satellites can’t simply be brought home for repairs. So how do we maintain tens of thousands of machines that are hundreds of kilometres above Earth?

The Conversation, CC BY-SA

Satellites don’t last forever

The challenge of satellite maintenance became more visible in March this year when a large NASA satellite made an uncontrolled re-entry into Earth’s atmosphere.

The US Space Force confirmed the spacecraft re-entered over the eastern Pacific Ocean, and NASA expected most of it to burn up, though some components may have survived. The event attracted worldwide attention as experts tracked its descent and estimated where debris might land, including the possibility that large debris could one day cause damage in populated areas.

The incident was a reminder that satellites don’t last forever. Like any machine, they age. Batteries degrade, electronic components wear out and harsh space conditions gradually take their toll.

Unlike aircraft or cars, however, we can’t easily take satellites to a repair workshop.

Once launched, they must continue operating in an environment of intense radiation, extreme temperature changes and constant mechanical stress. Servicing missions are technically possible, but remain expensive and relatively uncommon.

How do we keep satellites ‘healthy’?

Today, satellite health is monitored largely from the ground.

Engineers receive streams of telemetry data showing battery performance, temperatures, power consumption and the status of onboard systems. They analyse this information and look for warning signs that something may be going wrong.

This approach has worked well for decades. But it may become increasingly difficult as satellite constellations grow from dozens of spacecraft to hundreds or even thousands. Human operators can only monitor so much information at once.

This is where recent advances in artificial intelligence (AI) may help. Researchers have been investigating how AI can identify early signs of satellite degradation before they become mission-threatening failures.

One important example involves batteries. Satellite batteries gradually lose performance over time, much like the battery in a smartphone or electric vehicle.

If this degradation can be detected early, operators may be able to adjust how a satellite is used, extend its operational life or avoid unexpected failures. They could do this by sending new instructions to the satellite, such as reducing power-hungry activities, changing when data are processed or transmitted, or placing non-essential systems into standby.

Our recent research used publicly available NASA satellite battery data to explore how machine learning (a type of artificial intelligence) can recognise patterns associated with battery ageing and predict future performance.

The goal is similar to predictive maintenance systems already used in modern aircraft, wind farms and manufacturing plants. Rather than waiting for equipment to fail, AI looks for subtle changes that suggest problems may be developing.

Satellites can learn from each other

In our approach, we also considered federated learning.

Normally, enormous amounts of satellite data would need to be transmitted back to Earth for analysis. This requires time, bandwidth and energy. Federated learning offers a different approach. Individual satellites can “learn” from their own experience and share useful insights with other satellites or ground systems without constantly sending every piece of raw data.

In simple terms, satellites could help each other become better at recognising potential faults. Over time, this could support continuous self-monitoring across large satellite networks.

There are, however, important limitations.

AI can’t prevent every satellite failure. It can’t eliminate space debris or solve orbital congestion on its own. Predictive models require extensive testing, such as checking them against historical satellite data, simulated faults and laboratory battery experiments before they are trusted in orbit. And any autonomous decision-making systems must be reliable enough for safety-critical applications while remaining under human oversight.

The next great challenge of the new space age may not simply be launching another 100,000 satellites. It may be ensuring those satellites are intelligent enough to monitor their own condition, detect problems early and help keep the space services we rely on running safely and reliably.

Tony Jan, Professor of Information Technology and Director of Artificial Intelligence Research and Optimization (AIRO) Centre, Torrens University Australia

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

Climate change and pollinators - the risk of CO2 emissions for bees

 

Big bees have the most to lose as global CO₂ levels rise: new research

Xylocopa (Koptortosoma) sp. female. Kit Prendergast

Kit Prendergast, University of Southern Queensland; Curtin University

Pollinators – including bees, flies, wasps, moths, butterflies and some nectar-loving birds – are a cornerstone of our natural environment.

By helping plants reproduce, they keep our ecosystems healthy and ensure we can grow vital food crops.

But climate change threatens the very survival of these hard-working animals.

Previous research has focused on how temperature changes affect bees, finding that certain groups are more vulnerable to hotter temperatures.

But our new study shows rising carbon dioxide (CO₂) levels may also be putting pollinators – such as bees and hoverflies – at risk.

Larger bees are the most vulnerable. We found populations of big bees – including Bombus asiaticus and Xylocopa pubescens – were smaller and less genetically diverse in areas with high CO₂. Small-bodied pollinators, however, may actually do better in higher-CO₂ environments.

A dire situation

In Australia and around the world, we are facing a pollinator crisis. There are several reasons for this, including the loss and degradation of wild pollinator habitat, the introduction of the European honey bee and other invasive species, and the use of broad-spectrum pesticides.

But climate change – driven by human-made greenhouse gases including CO₂ emissions – is another key factor. Australia contributes to higher CO₂ levels as the second-largest fossil fuel exporter in the world.

Elevated CO₂ levels can affect pollinators by reducing how much protein is in flower pollen. Having more CO₂ in our atmosphere may also change the chemical make-up of nectar, for example reducing how much sugar it contains. Both factors influence how pollinators develop and survive.

Other research suggests higher CO₂ concentrations could impact how pollinators’ bodies function, for example by accelerating how quickly they break down fats.

What we studied

In our latest study, we examined how bees and hoverflies coped with different levels of CO₂ across 25 sites. This is the first time researchers have investigated how natural changes in CO₂ levels affect pollinators.

While our study was conducted in Pakistan, it is relevant to pollinator networks in Australia and around the world, given that CO₂ levels are rising globally. Importantly, we controlled for other factors that may affect the number and distribution of bees and hoverflies, including altitude, temperature, humidity and rainfall.

Our results suggest pollinators respond to variations in CO₂ in different ways. Specifically, smaller pollinators may actually do better in higher-CO₂ environments. In contrast, larger-bodied pollinators were less abundant in areas with more CO₂.

We identified Xylocopa and Amegilla bees, two genera found in Australia, as being particularly vulnerable to increased CO₂ levels. Ceratina and Lasioglossum bees are two examples of smaller-bodied Australian genera that did well in higher-CO₂ environments.

The pubescent carpenter bee is a larger-bodied species that is vulnerable to rising CO₂ levels. Waseem Akram

Why big bees matter

These findings are concerning for several reasons.

Existing evidence shows larger-bodied bees such as Bombus are already more vulnerable to climate change. This is because they tend to retain more heat and don’t cope as well in dry conditions. Big bees also have higher metabolic demands than smaller pollinators, meaning they need more resources to keep their bodies functioning.

Large bees are among our most effective pollinators. They typically carry and deposit more pollen than smaller-bodied pollinator species. They also fly longer distances, meaning they can transport seeds and pollen to help plants reproduce and spread their genes to new places.

Other research suggests flowers have even evolved to match pollinators with particular body sizes. We see this in Australia with Melastoma. This plant’s impressive flowers are most effectively pollinated by large pollinators such as Xylocopa bees, which use vibrations to release pollen from flowers.

So, what can we do?

Here are four practical ways we can help our larger pollinators thrive in a warming world.

• protect their habitat by preventing further land clearing, for example to make room for more livestock farms

• ensure pollinators have access to wildlife corridors to help them move to areas that are naturally lower in CO₂, such as dense forests

• plant more bee-friendly trees, with some Australian examples being Eucalyptus, Corymbia, Angophora, Melaleuca, Banksia and Brachychiton

• maintain populations of larger-bodied bees by reducing other threats such as competition from introduced honey bees, to ensure they have the genetic diversity to adapt to rising CO₂ levels.

To protect our pollinators in a rapidly changing climate, we must act now. Ensuring their habitat remains intact and curbing our greenhouse gas emissions are vital first steps.

Kit Prendergast, Postdoctoral Researcher, Pollination Ecology, University of Southern Queensland; Curtin University

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

South Australian algae bloom and implications for other parts of the world

 

The tiny microalgae behind South Australia’s harmful algal bloom is among the most toxic ever tested

Mark Piovesan/Getty

Shauna Murray, University of Technology Sydney; Cheong Xin Chan, The University of Queensland; Craig Styan, University of Adelaide; Greta Gaiani, University of Technology Sydney, and Gustaaf Hallegraeff, University of Tasmania

Over the past 15 months, one of the country’s worst marine environmental disasters has been unfolding in South Australia.

A harmful algal bloom expanded in many coastal seas, killing thousands of fish, birds, shellfish and marine mammals. Even iconic species such as giant cuttlefish and seadragons have washed up dead on beaches.

These blooms happen when particular species of microscopic algae accumulate in a body of water. Several hundred species of microalgae produce toxins that, in high concentrations, can be harmful to humans and deadly to marine creatures.

Our new research shows Karenia cristata, the rare microalgal species behind this catastrophic bloom, is among the most toxic species to marine life ever studied. It’s capable of killing zooplankton, a type of small marine animal, in concentrations of just five cells per millilitre of seawater.

A marine disaster

In March 2025, dozens of surfers and swimmers fell ill after being exposed to water or seafoam on the Fleurieu Peninsula, south of Adelaide.

Local residents and tourists reported respiratory symptoms such as coughing and shortness of breath, as well as skin and eye irritation.

Reports of dead or dying marine creatures followed. And water testing by authorities found the first signs of an algal bloom.

In the following months, the algal bloom spread across SA’s two main gulfs, the Gulf St Vincent and Spencer Gulf. It has proved devastating for the state’s marine ecosystems, aquaculture industries and coastal communities.

The detection of brevetoxins in shellfish forced local oyster and mussel farmers to stop harvesting for up to eight months. Hundreds of coastal businesses, such as recreational fishing charters and wildlife tour operators, lost significant income.

What is Karenia cristata?

K. cristata is an extremely rare microalgal species. Before this bloom, it has only ever been found in two locations: South Africa and an island off the coast of Newfoundland.

There are many different species of Karenia. But they’re often hard to distinguish as their cells have a similar size and shape. This is a problem because Karenia species that look similar can produce completely different toxins, or no toxins at all.

In our new study, we used a method called scanning electron microscopy to get an extremely close-up view of K. cristata cells. This allowed us to compare them with the cells of other types of Karenia.

We also developed several new molecular genetic methods to measure the number and distribution of Karenia during the SA bloom. These genetic methods allowed us to easily distinguish between different Karenia species.

We found the only other Karenia species known to produce brevetoxins, K. brevis, was not in the SA bloom. We also found both K. cristata and K. brevis produced similar concentrations of brevetoxins, but with a different chemical makeup.

We found K. cristata was the dominant Karenia species. It was in 90% of the samples we tested, and remained in high concentrations over time. We also identified four other Karenia species in our samples.

Why is this algae so lethal?

Our latest research suggests the microalgae that caused SA algal bloom is among the deadliest species of its kind, in terms of impact on marine life.

Our team of 25 scientists took a closer look at laboratory-grown strains of K. cristata. To do this, we hand-picked individual cells of microalgae from seawater using ultrafine glass pipettes. We then grew them in bacteria-free, nutrient-rich seawater and made sure the temperature and amount of light stayed the same.

Using these lab-grown cells, we conducted three different experiments to observe how Karenia toxins affect the cells of fish and invertebrates – tiny marine animals that don’t have a backbone such as rotifers, a type of small zooplankton, and larval crustaceans.

The results were startling. K. cristata killed half the invertebrates we studied, even in extremely low concentrations of only five cells per millilitre – or 5,000 cells per litre – of seawater. This makes it more deadly to invertebrates than any other species of toxin-producing algae tested using this same method. The algae had a similar affect on lab-grown fish gill cells.

Compared with our experiments, K. cristata was present in higher concentrations in the waters around SA during the latest algal bloom. In August and September 2025, we routinely recorded concentrations higher than one million cells per litre of seawater off the coast of Adelaide.

This may explain why this bloom was so catastrophic.

Where to from here?

Until now, we thought an algal bloom of this scale could only develop in the warm waters off the southeastern United States. There, harmful algal blooms caused by the K. brevis microalgae are fairly common.

But our research shows other coastal areas around the world could also be at risk – including those with cooler waters.

We urgently need more research to understand the conditions that allow K. cristata to thrive and produce toxins in such high concentrations.

This will allow us to develop monitoring programs that not only detect harmful algae, but also identify which species may be most deadly. Only then can we protect our coastal ecosystems, industries and communities from another marine disaster.

Shauna Murray, Professor; Faculty of Science, University of Technology Sydney; Cheong Xin Chan, Associate Professor, School of Chemistry and Molecular Biosciences, The University of Queensland; Craig Styan, Associate Professor, School of Physics, Chemistry and Earth Sciences, University of Adelaide; Greta Gaiani, Chancellor's Postdoctoral Research Fellow, School of Life Sciences, University of Technology Sydney, and Gustaaf Hallegraeff, Adjunct Senior Researcher, Ecology and Biodiversity, University of Tasmania

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