The Silent Invasion: Reading the Ocean’s Genetic Fingerprints to Track a World on the Move

Abstract

Climate change is forcing a global redistribution of marine life, yet tracking the vanguard of this migration is challenging with traditional visual surveys that often miss rare or cryptic first arrivals. This article explores a forensic-inspired approach using environmental DNA (eDNA) to detect the genetic “fingerprints” of species in seawater. A pioneering study along Australia’s east coast, a global warming hotspot, reveals how eDNA successfully identified tropical fish in temperate kelp forests where they had never been seen before. This “tropicalization” has profound ecological consequences, as voracious new herbivores threaten to decimate kelp forests, triggering a phase shift in the entire ecosystem. By integrating the sensitivity of eDNA with the established value of visual surveys, scientists are gaining their clearest view yet of how climate change is reshaping our oceans, forcing a new paradigm for conservation in a world of novel ecosystems and constant flu

Audio summary

The Unseen Frontier

Beneath the rhythmic swell of the Tasman Sea, off the coast of New South Wales, lies a world of vertical forests. Here, great stands of kelp, the sequoias of the ocean, sway in the currents, their fronds forming dense canopies that shelter a bustling metropolis of marine life. This is the temperate heart of Australia’s marine domain, a complex ecosystem built on cool, nutrient-rich waters. For decades, scientists have patrolled these underwater forests, their transect lines and clipboards the trusted tools of their trade, meticulously counting the familiar residents: the silvery schools of Australian Mado, the cryptic morwongs, the valuable rock lobsters that hide in rocky crevices.

Yet, for years, there has been a growing sense of unease, a feeling that the familiar roll call of species was becoming incomplete. The ocean itself was changing. Waters were warming at an alarming rate, and with the heat came whispers of new arrivals from the tropics. Professor David Booth, a marine ecologist at the University of Technology Sydney, has witnessed this firsthand. “New coral and fish species arrive in Sydney’s oceans every year,” he observes, “and this is expected to increase with future climate change”.¹ The great biotic boundaries of the ocean were dissolving, and a silent invasion was underway.

The problem, however, was one of visibility. The vanguards of this great ecological shift were proving to be ghosts. The first arrivals, the pioneers venturing into new, cooler territories, are often small, rare, or masters of camouflage. “Many of the early-arrival species are small, rare, or cryptic, so they can be easily missed,” explains Dr. Angus Mitchell from the University of Adelaide.¹ “As a result, we may be underestimating the true rate of species on the move.” Traditional visual surveys, the bedrock of marine monitoring, were like trying to spot a handful of foreign spies in a crowded city; the odds of an encounter were slim. The scientific community was faced with a profound challenge: how do you track an invasion when the invaders remain unseen? How do you quantify a transformation that is happening in the margins, in the shadows of the kelp, and under the cover of night? The answer, it turned out, would not come from looking harder, but from learning to see the invisible.

Section 1: The Ghost Fish of the Kelp Forest

The breakthrough came from a young researcher at the University of Adelaide who decided to stop looking for the fish and start looking for their fingerprints. Dr. Chloe Hayes, a marine ecologist, took a page from a different field entirely. “We took off our marine ecologist hats and became forensic scientists, searching the water for clues about species on the move,” she explains.³ Her inspiration was the fundamental principle of forensic science: every contact leaves a trace. In the ocean, this principle holds true on a vast and constant scale.

The Forensic Inspiration

An ocean teeming with life is also an ocean saturated with genetic information. “Every organism leaves behind traces of itself in its environment,” says Dr. Hayes. “Fish shed mucus, scales and waste, all of which contain DNA”.¹ This free-floating genetic material is known as environmental DNA, or eDNA. For decades, the idea of using eDNA was confined to studying microbes in soil and water.³ But by the early 2000s, scientists realized this genetic soup could reveal the presence of much larger animals. The concept is elegantly simple. Just as a detective can solve a crime by analyzing a stray hair left at the scene, an ecologist can build a detailed picture of marine life by analyzing the genetic fingerprints floating invisibly in the water.¹

This technique, known as eDNA metabarcoding, involves collecting a sample of seawater, filtering it to capture the fragments of DNA, and then using high-throughput sequencing to identify which species those fragments belong to. It offers a non-invasive, powerful snapshot of the biodiversity in a given area. For Dr. Hayes and her team, it was the perfect tool to hunt for the ghosts of the kelp forest.

The 2,000km Experiment

To test the power of eDNA to reveal species on the move, the research team embarked on an ambitious survey along 2,000 kilometres of Australia’s east coast.¹ Their study sites spanned the entire climatic gradient of the region, from the vibrant tropical coral reefs of the Great Barrier Reef, through the subtropical transition zones, and down into the cool, temperate kelp forests of New South Wales.

At each location, they conducted a meticulous, two-pronged investigation. First, they used the gold standard of marine monitoring: underwater visual census (UVC). Divers swam along defined transects, recording every fish they saw.³ This method has built decades of invaluable data and remains crucial for understanding fish populations. Immediately alongside these surveys, the team collected bottles of seawater. “A few litres of water might not look like much,” the researchers note, “but it holds invisible genetic fingerprints of hundreds of species”.³ Back in the lab, this water was filtered, the captured DNA was extracted and sequenced, and the genetic roll call was compared to the visual one.

The Revelation: Detecting the Unseen

“When we compared traditional visual surveys with eDNA water samples, the results were interesting,” Dr. Hayes reports. “Each method revealed a somewhat different fish community, but together they gave us a more complete picture than either method could on its own”.¹ The most striking results came from the temperate zones. The eDNA analysis detected a suite of tropical species in these cooler ecosystems that had never been recorded there before by visual surveys.¹ The ghosts had been found.

Among the new arrivals were several species of herbivorous fish, a group with profound implications for kelp forest health. The genetic evidence confirmed the presence of the lined surgeonfish (Acanthurus lineatus), the striated surgeonfish (Ctenochaetus striatus), and the common parrotfish (Scarus psittacus) far south of their typical ranges.⁴

The technique also excelled at finding cryptic species, the masters of hiding that divers almost always overlook. The DNA of the black-blotched porcupinefish (Diodon liturosus), the silver sweeper (Pempheris schwenkii), and the nocturnal speckled squirrelfish (Sargocentron punctatissimum) all appeared in the temperate water samples, revealing a hidden layer of biodiversity.¹ As Dr. Hayes notes, “These are exactly the kinds of fish that divers are most likely to miss”.¹

A Complementary Power

This discovery does not render the traditional diver obsolete. In a fascinating reversal, the study found that for the common, established temperate species, the pattern flipped. Divers were often better at detecting these local residents than the eDNA analysis was.¹ This crucial finding highlights that eDNA is not a simple replacement for visual surveys but a powerful complement.

The differing strengths of the two methods reflect the ecological reality of a species migration. An invasion is a process, not a single event. It begins with a few pioneering individuals arriving in a new area, where their numbers are low and their presence is ephemeral. At this early stage, their eDNA signal is like a faint whisper in a vast ocean, but it is a whisper that can be picked up by sensitive genetic analysis, while a diver would need immense luck to physically encounter one of the rare newcomers. As a species becomes established and its population grows, its physical presence becomes more obvious and its eDNA signal becomes stronger, making it detectable by both methods. The study’s results demonstrate how these tools can be deployed strategically: eDNA acts as an unparalleled early warning system, detecting the first signs of an invasion, while visual surveys remain essential for monitoring the abundance and impact of established populations, both native and new. By combining the two, as Dr. Hayes concludes, “we can better track species on the move, giving us the clearest view yet of how climate change is reshaping our reefs”.¹

Section 2: An Oceanic Conveyor Belt in Overdrive

The discovery of tropical fish in the temperate kelp forests of New South Wales raises a fundamental question: how did they get there? The answer lies not just in the water, but in the powerful, continent-spanning forces that move it. The east coast of Australia is the site of a massive oceanic conveyor belt, a “river” of warm water known as the East Australian Current (EAC), and this conveyor belt is now stuck in overdrive.¹⁸

A Global Warming Hotspot

The EAC is the western boundary current of the enormous South Pacific subtropical gyre, a vast, swirling mass of water that circulates between Australia and South America.¹⁹ The current acts as a heat conduit, picking up warm water in the tropical Coral Sea and transporting it poleward along Australia’s coast. For marine life, it is also a larval superhighway, carrying the tiny, free-floating offspring of tropical species southward.

In recent decades, this region has become one of the planet’s most intense hotspots for ocean warming. While global average sea surface temperatures have risen, the waters of the western Tasman Sea are warming at a rate almost four times the global average.²⁰ Since 1950, sea surface temperatures in southeast Australia have climbed by a staggering 1.2°C, and projections indicate a further increase of 0.3°C to 1.2°C by 2040.²² This accelerated warming is not a passive process; it is being actively driven by a fundamental shift in the behavior of the EAC itself.¹⁸

The Drivers of Intensification

The EAC is strengthening and pushing further south than ever before. The physical evidence is unequivocal: over the past 60 to 70 years, the current has extended its poleward reach by approximately 350 kilometres.²⁰ This dramatic change is the result of a cascade of effects that begins high in the atmosphere and extends to the depths of the ocean.

The primary driver is a change in large-scale wind patterns over the South Pacific. Intensifying westerly winds in the high latitudes are acting like a giant paddle, causing the entire South Pacific gyre to “spin-up” and accelerate.²¹ This atmospheric shift is, in turn, directly linked to the hallmarks of the Anthropocene: increasing concentrations of greenhouse gases and the depletion of the stratospheric ozone layer.²³ These factors alter a major climate driver known as the Southern Annular Mode (SAM), which governs the position and strength of the westerly wind belt.

The consequences for the EAC are profound. The energized gyre pushes more warm water into the current, increasing its volume and velocity. Climate models project that the volume transport of the EAC extension will increase significantly at the expense of other flows in the Tasman Sea.²¹ Furthermore, the current’s southern extension is becoming more turbulent and unstable, shedding more heat-bearing eddies that propagate southward into the Tasman Sea.¹⁸ These eddies act as spinning reservoirs of warm, tropical water, dramatically increasing the frequency and intensity of marine heatwaves in what were once reliably temperate regions.²¹

Beyond Temperature

The changes wrought by the supercharged EAC extend beyond just temperature. The chemistry of the ocean is also being transformed. As the ocean absorbs more atmospheric carbon dioxide, its pH decreases. The waters of southeast Australia have already experienced a 26-30% increase in acidity, with another 30% increase projected by 2040.²² At the same time, because warmer water holds less dissolved gas, oxygen levels have declined by 2% and are expected to fall a further 5% by 2040.²²

This causal chain—from global atmospheric changes to altered wind patterns, an accelerated ocean gyre, an intensified EAC, and finally to rapid regional warming and chemical shifts—reveals a crucial truth about our changing climate. Its impacts are not uniform or monolithic. Specific geographic and oceanographic features, like the great western boundary currents of the world’s oceans, act as powerful amplifiers. They take the background signal of global warming and concentrate it, creating regional hotspots where the pace of change is far more rapid and the ecological consequences are far more immediate. The EAC is not just a passive victim of a warming world; it is an active agent of transformation, a physical mechanism that is redrawing the biological map of an entire continent’s coastline.

Section 3: When New Neighbours Devour the Lawn

The arrival of tropical species in temperate waters is more than just a scientific curiosity; it represents a fundamental reorganization of the ecosystem. This process, known as “tropicalization,” can trigger cascading consequences that unravel the very fabric of established biological communities.²⁸ In the temperate reefs of southeastern Australia, the front line of this transformation is the kelp forest, and the new arrivals are not behaving like polite guests.

The Importance of Kelp Forests

Kelp forests are one of the most productive ecosystems on Earth. Often called the “trees of the ocean,” these large brown algae are foundation species, meaning they create the three-dimensional habitat that supports the entire community.³² Their dense canopies provide critical shelter and nursery grounds for hundreds of species of fish and invertebrates, while their fronds are a primary food source. They are the cornerstones of valuable commercial and recreational fisheries for species like rock lobster and abalone, underpinning an Australian marine economy worth over $10 billion annually.³⁴ The health of the entire temperate coastal ecosystem is inextricably linked to the health of its kelp forests.

The Threat of Herbivory

The primary threat posed by the influx of tropical fish is a dramatic increase in grazing pressure, or herbivory. Many of the species detected for the first time by Dr. Hayes’s eDNA study, such as surgeonfish and parrotfish, are voracious herbivores.⁴ In their native coral reef habitats, this function is vital. Their constant grazing keeps fast-growing algae from smothering the slow-growing corals, thereby maintaining the health of the coral reef.²⁷

However, when these highly efficient herbivores are transported into a temperate ecosystem, their ecological role flips from beneficial to destructive. Temperate kelp forests evolved with a different, less intense level of grazing pressure. The arrival of these new consumers, whose metabolic rates and appetites are further boosted by the warming waters, introduces a level of herbivory that the kelp forests are not adapted to withstand.³⁵ It is a profound “functional mismatch” that can destabilize the entire system.

The evidence of this mismatch is stark. A long-term study off the coast of northern New South Wales, near the Solitary Islands Marine Park, documented the complete disappearance of kelp forests from all survey sites over a ten-year period.³⁵ This deforestation coincided with a 0.6°C rise in water temperature and a more than threefold increase in the abundance of tropical and subtropical herbivorous fish. Grazing marks on the remaining kelp increased sevenfold. In field experiments, researchers transplanted kelp to the seafloor only to watch it be devoured by tropical rabbitfish and drummer fish within hours, at an average rate of 300 bites per hour.³⁵

A Global Pattern of Deforestation

This phenomenon is not unique to Australia; it is a global pattern repeating in other warming hotspots where tropical herbivores are expanding their range.

• In southern Japan, rising winter temperatures have allowed tropical rabbitfish and parrotfish to survive year-round, increasing their grazing rates. The result has been the disappearance of over 40% of the region’s kelp and algal beds since the 1990s and the subsequent collapse of the valuable abalone fishery.²⁸
• In the eastern Mediterranean, herbivorous rabbitfish that entered from the Red Sea via the Suez Canal have proliferated as the sea has warmed. Their intense grazing has created hundreds of kilometres of deforested “barrens” on the seafloor and has been linked to a 40% decrease in the variety of local marine species.²⁸

Ecological Cascades and Novel Interactions

The loss of kelp is just the beginning of a cascade of ecological changes. The ultimate outcome of unchecked tropicalization is often a “phase shift,” where the entire ecosystem flips from one state to another. A complex, vibrant, three-dimensional kelp forest can be transformed into a simplified, two-dimensional seascape dominated by low-lying algal turfs or barren rock grazed clean by sea urchins.²⁷ This represents a catastrophic loss of habitat complexity, productivity, and biodiversity.

These new interactions cut both ways. While the invaders thrive, native species often suffer. Studies have shown that temperate fish like the Australian Mado become more stressed, feed less, and are more likely to flee in the presence of their new tropical competitors, potentially leading to their local extinction at the warmest edges of their range.³⁸ In a surprising twist, however, some tropical fish appear to benefit from their new neighbors. By shoaling with local temperate species, they can learn to identify new predators and locate unfamiliar food sources, which boosts their survival and allows them to grow larger in their new home.³⁸ This complex web of interactions—competition, adaptation, and predation—will determine the ultimate configuration of the novel ecosystems being forged by our warming oceans.

Section 4: A Planet in Motion

The silent invasion of Australia’s temperate reefs is not an isolated event. It is a local manifestation of a global phenomenon that is reshaping the entire biosphere. As human-caused climate change alters temperatures, weather patterns, and habitats, life on Earth is undertaking a great migration. The biological map of our planet is being redrawn in real time.

A Global Exodus

The scale of this planetary redistribution is staggering. According to a study cited by Dr. Hayes, climate change has already prompted more than 12,000 species to shift their home ranges across terrestrial, freshwater, and marine environments.¹ Research from the University of Southern California suggests that roughly half of all species on Earth are currently on the move, a mass migration driven by the search for cooler, more hospitable climates.³⁹ The general pattern is a predictable march towards the poles and a climb to higher altitudes on land, or a descent into deeper, cooler waters in the sea.³⁹

The ocean, with its relative lack of physical barriers, is the arena for some of the most rapid and dramatic shifts. Marine species are, on average, moving poleward six times faster than their terrestrial counterparts.²⁴ This exodus is being documented across the globe:

• In the North Atlantic, warming waters are driving commercially vital fish stocks northward. American lobster, red hake, and black sea bass have shifted their population centers north by an average of 145 miles since the 1970s.⁴² This has profound implications for fisheries, with projections suggesting a 20-30% decrease in harvests for the US East Coast by 2060 as traditional fishing grounds become less productive.⁴³
• In the Northeast Pacific, extreme marine heatwaves have triggered massive, albeit temporary, habitat dislocations. During the infamous 2014-2015 heatwave known as “The Blob,” the habitat for many species shifted more than 700 kilometres north.⁴⁵ This had devastating consequences for California sea lions; their primary prey moved far beyond the foraging range of nursing mothers, leading to the starvation of thousands of pups.⁴⁵ During the same event, the range of smooth hammerhead sharks shifted north by as much as 2,800 kilometres.⁴⁵
• In the frigid waters of the Bering Sea, key species like walleye pollock, snow crab, and Pacific halibut have also shifted north by an average of 41 miles since the 1980s, moving away from the coast into cooler waters.⁴²

Winners, Losers, and Novel Ecosystems

This great planetary reshuffling is creating a world of ecological winners and losers. The fate of a species often depends on its ability to move. Highly mobile species and those with generalist diets are better equipped to track the shifting climate isotherms.⁴⁶ In contrast, species with slow dispersal rates or highly specific habitat requirements—such as mountain-dwelling pikas that cannot cross warm valleys—are at the highest risk.⁴⁰ Climate change is thus having a “winnowing effect,” filtering out the slow and specialized, and favoring a less diverse, more “weedy” assemblage of organisms.⁴⁷

The result of this process is not necessarily a net loss of species in any one location, but rather a massive turnover in community composition. In the ocean, range extensions are happening about five times faster than range contractions, meaning that for many locations, species gains from warmer latitudes are outpacing local losses.²⁴ This is leading to the formation of “novel ecosystems”—communities composed of species combinations that have never existed before.²⁴

This reality poses a fundamental challenge to the traditional paradigms of conservation. For a century, the goal of conservation has largely been preservation: protecting species and habitats in situ, often within the fixed boundaries of a national park or marine reserve. But what happens when the climate inside a reserve becomes unsuitable for the very species it was designed to protect? What is the management goal for a temperate marine park that is being colonized by tropical corals? The sheer scale and speed of climate-driven species redistribution forces a paradigm shift. Conservation in the Anthropocene can no longer be solely about preserving a static snapshot of the past. It must evolve to become about managing a dynamic and uncertain future. This will require a new focus on protecting ecological processes, ensuring connectivity between habitats to facilitate migration, and developing adaptive strategies for the novel ecosystems that will come to define our planet.

Section 5: The Future of Seeing

The silent invasion of the world’s oceans is a crisis of immense scale, but it is also a powerful driver of scientific innovation. The very speed and complexity of the changes are forcing ecologists to develop new ways of seeing—tools that are faster, broader, and more sensitive than ever before. The forensic-inspired work of Dr. Hayes and her colleagues is at the vanguard of this technological revolution, and it offers a glimpse into the future of environmental monitoring in a world of constant flux.

eDNA as a Revolutionary Tool

Environmental DNA is emerging as a transformative tool for biodiversity science. Its advantages make it uniquely suited to the challenges of the 21st century. It is a non-invasive method that is both cost-effective and relatively simple to perform, allowing for widespread sampling even in remote or inaccessible environments like the deep ocean.⁹ This opens the door to monitoring programs on a scale that would be impossible with traditional, labor-intensive methods.

Perhaps most importantly, eDNA offers unparalleled sensitivity. As the Australian study demonstrated, it can detect the faintest signals of new arrivals—the rare, the cryptic, and the nocturnal—providing an early warning system for ecological change that was previously unattainable.¹ The potential for automation is also a game-changer. Researchers are already developing robotic eDNA samplers that can be deployed on moorings or autonomous vehicles, collecting samples daily or even hourly for weeks or months at a time.¹³ This will provide a high-resolution, near-real-time view of marine life, allowing scientists to track the pulse of the ocean as it responds to everything from seasonal cycles to marine heatwaves.

Challenges and the Path Forward

Despite its immense promise, eDNA is not a panacea. For the technology to reach its full potential as a global monitoring tool, several key challenges must be addressed.

• Standardization: The field is still young, and methods for collecting, processing, and analyzing eDNA samples can vary widely between labs. Establishing universal guidelines and best practices is crucial to ensure that data from different studies are comparable and can be integrated into global databases.¹⁴
• Reference Libraries: A genetic sequence identified from an eDNA sample is only useful if it can be matched to a known species in a reference database. While these libraries are growing rapidly, they are far from complete, particularly for the vast and under-studied biodiversity of the world’s oceans. A concerted global effort to sequence the genomes of more species is a critical prerequisite for unlocking the full power of eDNA.¹⁶
• Interpretation: The eDNA signal is a proxy for a species’ presence, not a direct count. Scientists are still working to understand the complex factors that influence this signal, such as how quickly DNA is shed by different species, how long it persists in the environment before degrading, and how far it can be transported by ocean currents. Refining our understanding of this “eDNA ecology” is essential for moving from simple presence/absence data to more quantitative estimates of biomass and abundance.¹²

Conclusion: Monitoring a World in Flux

The ultimate lesson from the kelp forests of New South Wales is one of synthesis. The future of understanding and managing our rapidly changing planet lies not in the replacement of old methods with new ones, but in their intelligent integration. The deep historical context and on-the-ground reality provided by visual surveys are essential for interpreting the vast and sensitive datasets generated by eDNA. Together, they provide the “clearest view yet” of a biosphere in motion.

The work of scientists like Dr. Hayes provides the tools not to halt the immense changes underway, but to see them with unprecedented clarity, to understand their mechanisms, and, hopefully, to anticipate their consequences. The small bottles of seawater collected today are more than just samples; they are, as one researcher put it, “time capsules”.¹⁶ They are archives of a world in profound transition, a genetic record of the species that are arriving, the species that are departing, and the novel communities being forged in the crucible of a warming climate. They are the fingerprints of a planet on the move, and they will be an invaluable legacy for the future generations who will inhabit the world we are now creating.

Endnotes

1. Hayes, C., Mitchell, A., Booth, D. J., & Nagelkerken, I. (2025). Study on eDNA and visual surveys to track fish migration. Diversity and Distributions. As cited in University of Adelaide. (2025, September 25). Fishy forensics improves tracking of fish migrations.
2. Booth, D. J. (2025). As cited in Xinhua. (2025, September 25). Researchers in Australia combine eDNA, visual surveys to track fish migrations.
3. Hayes, C., Mitchell, A., Booth, D. J., & Nagelkerken, I. (2025, September 22). Fish ‘fingerprints’ in the ocean reveal which species are moving homes due to climate change. The Conversation.
4. Ibid.
5. Hayes, C. (2025). As cited in University of Adelaide. (2025, September 25). Fishy forensics improves tracking of fish migrations.
6. Hayes, C., et al. (2025). Diversity and Distributions. Species detection data.
7. Ibid.
8. Ibid.
9. Kelly, R. P., Port, J. A., Yamahara, K. M., & Crowder, L. B. (2021). Comparing eDNA metabarcoding and underwater visual census for marine biodiversity monitoring. PLOS ONE.
10. Ibid.
11. Ibid.
12. Ibid. See also: Harrison, J. B., Sunday, J. M., & Rogers, S. M. (2020). Marine environmental DNA: approaches, applications, and opportunities. Advances in Marine Biology.
13. Kelly, R. P., et al. (2021). PLOS ONE. See also: U.S. Geological Survey. (2024). Environmental DNA and Robotics for Offshore Renewable Energy Development.
14. Kelly, R. P., et al. (2021). PLOS ONE. See also: Meyer, K. M., et al. (2023). A systematic review of data accessibility and usability in marine eDNA metabarcoding.
15. Kelly, R. P., et al. (2021). PLOS ONE. See also: Jeunen, G.-J., et al. (2023). Environmental DNA provides a new approach for biodiversity assessment in the Southern Ocean. ICES Journal of Marine Science.
16. Kelly, R. P., et al. (2021). PLOS ONE. See also: Gold, Z., et al. (2022). A manager’s guide to using eDNA metabarcoding in marine ecosystems. PeerJ.
17. Kelly, R. P., et al. (2021). PLOS ONE.
18. Ridgway, K. R., & Hill, K. L. (2012). The East Australian Current. A Marine Climate Change Impacts and Adaptation Report Card for Australia.
19. Ibid.
20. Ibid. See also: CSIRO. (2012, January 30). Warming in the Tasman Sea a global warming hot spot. Redmap Australia. (n.d.). Climate change on the Apple Isle’s doorstep: EAC warms Tasmanian waters.
21. Oliver, E. C. J., & Holbrook, N. J. (2014). Extending our understanding of South Pacific gyre ‘spin-up’: Modeling the East Australian Current in a future climate. Journal of Geophysical Research. See also: Ridgway, K. R., & Hill, K. L. (2012).
22. Australian Fisheries Management Authority. (2023). Climate impacts on south-east Australia’s fisheries. See also: Ridgway, K. R., & Hill, K. L. (2012).
23. Ridgway, K. R., & Hill, K. L. (2012). See also: Zhai, Z., et al. (2022). Intensification of the East Australian Current After <1400 CE.
24. Ridgway, K. R., & Hill, K. L. (2012). See also: Fogarty, H. E., et al. (2021). Species on the move around the Australian coastline: A continental-scale review of climate-driven species redistribution in marine systems. PMC.
25. Ridgway, K. R., & Hill, K. L. (2012). See also: Zhai, Z., et al. (2022).
26. Ridgway, K. R., & Hill, K. L. (2012). See also: Vergés, A., et al. (2014). The tropicalization of temperate marine ecosystems: Climate-mediated changes in herbivory and community phase shifts. Proceedings of the Royal Society B.
27. Vergés, A., et al. (2014). See also: Chin, A., et al. (2010). Vulnerability of fishes of the Great Barrier Reef to climate change. Great Barrier Reef Marine Park Authority.
28. Vergés, A., et al. (2014). See also: University of New South Wales. (2014, July 9). Beautiful but a threat – tropical fish invasion destroys kelp forests.
29. Ibid.
30. Hayes, C., et al. (2025, September 22). The Conversation. See also: Vergés, A., et al. (2021). Tropicalisation of temperate reefs: trajectories and ecosystem functions.
31. Ibid.
32. Glasby, T. M., & Gibson, P. T. (2022). The role of urchin-grazed barrens in the ecology of rocky reefs in New South Wales. Marine and Freshwater Research.
33. Ibid.
34. NSW Department of Primary Industries. (n.d.). Kelp monitoring program.
35. Vergés, A., et al. (2017). As cited in University of New South Wales. (2017, January 16). Invading fish threat to kelp forests.
36. Vergés, A., et al. (2014).
37. Hayes, C., et al. (2025, September 22). The Conversation. See also: Glasby, T. M., & Gibson, P. T. (2022).
38. Mitchell, A., Hayes, C., Coni, E. O. C., Booth, D. J., & Nagelkerken, I. (2025). Tropical fishes can benefit more from novel than familiar species interactions at their cold-range edges. Journal of Animal Ecology. As cited in University of Adelaide. (2025, July 28). Tropical fishes on the move survive better with temperate neighbours.
39. University of Southern California Viterbi School of Engineering. (2022, September). In a Warmer World, Half of all Species Are on the Move. Where Are They Going?
40. Ibid. See also: World Wildlife Fund. (n.d.). Climate Change and Species.
41. U.S. Environmental Protection Agency. (2024, June). Climate Change Indicators: Marine Species Distribution.
42. Ibid.
43. U.S. Environmental Protection Agency. (n.d.). Climate Change Impacts on Ocean and Marine Resources.
44. Ibid. See also: Fulton, E. A., et al. (2024). Climate change is a major contributor to the decline of some of Australia’s most important fishery species. ICES Journal of Marine Science.
45. National Oceanic and Atmospheric Administration Fisheries. (n.d.). Ocean Heatwaves Dramatically Shift Habitats.
46. Smith, S. D. A., et al. (2022). Asynchronous invasion of functional niches during tropicalisation of temperate communities. PMC.
47. World Wildlife Fund. (n.d.). Climate Change and Species.
48. Vergés, A., et al. (2021). See also: Fogarty, H. E., et al. (2021).
49. Kelly, R. P., et al. (2021). PLOS ONE. See also: Meyer, K. M., et al. (2023).