Climate change is causing fish to move to cooler water. But what if their escape route is blocked?

by bpckle | Jun 12, 2026 | In the Media

Around the world, ocean warming is causing fish to move polewards in search of cooler water.

But what if you’re a tiny prawn, barramundi or rare sawfish in a northern Australian gulf and your exit southwards is blocked by land? To date, there’s been a global gap in understanding how shallow tropical gulfs and bays are responding to climate change.

These marine environments are vital for nature, fisheries and coastal communities. However, their conditions are becoming more extreme and variable due to cumulative climate change. Species are riding an environmental roller coaster, with the rapid changes hindering their recovery.

Some of the world’s most populous countries – and unique species – are in the tropics. Lessons from remote northern Australia can prove insightful.

Our new research focuses on these unique Australian ecosystems and highlights their importance and complexity. It takes into account land barriers, the monsoonal climate, influence of cyclones and massive variability in sea levels.

Northern Australian seas are unique

To help unravel the complex dynamics of these systems, our team drew on the CSIRO’s 50-year history of research in northern Australia, focused on the Gulf of Carpentaria, Joseph Bonaparte Gulf and Torres Strait. Northern Australia has many seagrasses and mangroves, and is a stronghold for threatened species such as sawfish, dugongs, turtles and the snubfin dolphin.

We analysed climate influences on popular fishing species, such barramundi, mud crabs and lobsters, as well as Australia’s largest and most valuable prawn fishery, the Northern Prawn Fishery. And we discovered ocean temperature isn’t the only important indicator of climate change.

Our research showed these marine systems are influenced by compounding climate events in complex ways, which can be simplified into four primary factors to explain how, why and when species are affected.

We found combinations of extreme temperatures, exposure to dehydration, cloudiness in the water (turbidity) and hydrologic disconnection – the restriction or changes to the natural movement of water – combined to bolster some populations while devastating others. These patterns of change are largely influenced by El Niño or La Niña weather events.

Species are riding more extreme climate rollercoasters, with steeper and larger changes in the marine environment hindering their recovery. A good example is the brown tiger prawn.

The Goldilocks prawn

The original impetus for our research was to understand why present-day brown tiger prawn populations in northern Australia had not bounced back to levels seen before the turn of the century, despite reduced fishing. This region is the only place they exist.

We called them the “Goldilocks” prawns because they like ocean conditions that are just right – not too hot or too cold. Furthermore, earlier research showed juvenile brown tiger prawns are very fussy about the kinds of seagrass they use for shelter and food.

Our research found strong evidence of a major step-change in physical conditions around 1998 or 1999. Specifically, there were more La Niñas over the past two decades, higher than average freshwater flows, including from the Roper River, and increased cyclone intensity.

Cyclones cause massive seagrass damage, while sediment from flooding rivers limits seagrass growth. This means reduced nursery habitat for the brown tiger prawn already under pressure from rising temperatures. Our modelling found a sustained decrease in brown tiger prawns connected to a shift in climate patterns.

By contrast, the more robust grooved tiger prawns were not similarly affected, and common and redleg banana prawns thrived in response to good river flows. In fact, Redleg banana prawns, sawfish and mangroves are at risk during El Niño periods, when dry weather and lowered sea levels disrupt the river-ocean connections they rely on.

Why this matters

Climate change is playing out differently in northern Australia to the rest of the country. This new research will help us anticipate, prepare for and respond to compound climate events – when multiple weather or climate conditions interact with severe environmental consequences.

For example, fisheries could switch between tiger and banana prawns depending on environmental conditions. Conservation teams could benefit from knowing in advance how extreme climate events threaten species such as the endangered largetooth sawfish.

Globally, better waterway management is needed, because taking too much water out of river systems threatens downstream ecosystems and marine livelihoods.

An extreme El Niño is forecast for later this year. Our work offers insights into its potential impacts across these marine environments and helps ecosystem and fisheries managers prepare.

Éva Plagányi works for CSIRO which receives funding from several sources, including the Fisheries Research and Development Corporation (FRDC) and the Australian Fisheries Management Authority (AFMA). She is a scientific member of the Northern Prawn Fishery (NPF) Resource Assessment Group. Éva acknowledges NPF stakeholders as well as Torres Strait Traditional Owners who depend on these natural resources, and she acknowledges and pays respect to the Traditional Owners on whose country this research was conducted. She is an editorial board member for Fisheries Research and an Associate Editor-in-Chief of Ecological Applications.

Laura Blamey works for CSIRO which receives funding from several sources, including the Fisheries Research and Development Corporation (FRDC) and the Australian Fisheries Management Authority (AFMA). Laura is a scientific member of the Torres Strait Tropical Rock Lobster Resource Assessment Group and Working Group. Laura acknowledges stakeholders from the Northern Prawn Fishery as well as Torres Strait Traditional Owners who depend on these natural resources, and she acknowledges and pays respect to the Traditional Owners on whose country this research was conducted. Laura is an assistant editor at the Journal of Fish Biology.

Good news for renewables: southern Australia’s offshore winds will stay strong even as the climate changes

by bpckle | Jun 11, 2026 | In the Media

If you’ve ever stood on a Victorian beach and felt the wind from the Southern Ocean, you’ll know this is not a gentle force. Whipped up across thousands of kilometres of cold ocean, these winds are relentless and powerful.

More than that – they’re one of Australia’s most valuable untapped sources of energy. Australia has many windfarms, but all of them have been built on land.

The stronger, more reliable winds blowing over oceans now turn truly enormous turbines in nations from Denmark to China. Offshore wind would work particularly well in Victoria. The state government wants large windfarms built out at sea to replace the remaining coal plants.

But will these strong winds keep blowing as reliably under climate change? Our recent research is reassuring. Despite small drops in wind strength, the winds will remain strong and reliable over the next 30-50 years.

What’s so good about offshore wind?

Offshore wind farms produce power more reliably than onshore wind or solar. They can produce a great deal of power and require minimal land. This is why offshore wind has been seen as a good fit for Australia.

Coupled with big batteries and transmission lines, offshore wind could contribute significantly to the energy transition.

Victoria has most at stake. For decades it has relied on brown coal and gas. But its gas supplies are depleting fast and ageing coal plants in the Gippsland region will not be replaced with more coal. Instead, the state wants to tap Gippsland’s offshore wind resources, which rank among the world’s best.

Despite the interest, the offshore wind sector has been slow to start. Political and economic headwinds have led some projects to be cancelled. But the sector looks set to finally begin in August, when Victoria will host the nation’s first offshore auction with a goal of securing 2 gigawatts of capacity.

Victoria is not alone. Offshore wind zones have been declared along Australia’s entire southern and western coastline, including Victoria, South Australia, Tasmania and parts of New South Wales and Western Australia.

Will the winds stay strong?

As the climate changes, wind patterns are likely to change too.

The powerful westerly winds of the Southern Ocean are forecast to be gradually pushed closer to Antarctica. Wind speeds across southern mainland Australia could drop by up to 5% by the end of the century.

If wind speeds drop too much, it could pose a problem for offshore wind. Weaker winds would mean less electricity can be generated, potentially making projects less viable and slowing the energy transition.

An offshore windfarm commissioned today will operate for 25–30 years. That means it will still be operating mid-century, when climate change is likely to have intensified.

To find out what climate change will mean for offshore wind, we worked with climate scientists and offshore wind researchers to simulate winds 30-50 years from now using seven high-resolution regional climate models.

We projected future wind speeds at the ocean surface and offshore wind energy production across Australia’s existing offshore wind zones under two scenarios – ambitious climate action limiting global warming to around 1.8°C and continued fossil fuel dependence driving warming to roughly 3.6°C by 2100.

We validated our projections against the best available records of historical wind speeds, which date back several decades. This is because it’s not just about whether wind speeds change, but whether they will change more than the natural variability offshore wind farms can already cope with.

What we found was broadly reassuring. Yes, the winds are likely to weaken over the next 30 to 50 years. But the changes are minor, falling 0.1% to 2.6% on average. That’s within the bounds of natural variability. Unlike projections of future rainfall or temperature, our findings hold across both emissions scenarios. This suggests offshore winds will remain strong and reliable overall.

While reassuring, one area is likely to see a larger drop. Under the high emissions scenario, wind speeds are likely to fall up to 20% over winter in Western Australia’s offshore wind zones near Bunbury.

Good news for offshore wind?

It’s good news that average wind speeds across Australia’s offshore wind zones are not likely to change significantly.

Our research is not the whole story, however. We didn’t model whether extreme winds or strong swell conditions will become more likely. These events can stop windfarms from operating, damage infrastructure and shorten the window of time when turbines can be installed and maintained.

To give offshore wind developers full certainty, it will be important to study what climate change will do to these extreme events.

Shiaohuey Chow receives funding from the Australian Research Council.

Alberto Meucci and Guisela Grossmann-Matheson do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.