Aussie scientists discover shocking gap in great white shark research

Scientists missed invisible forces inside every great white for decades – and what they found changes everything we thought we knew.

For decades, we’ve studied the ocean’s most fearsome predator through a dangerously incomplete lens, and Australian researchers say what we’ve been missing could change everything we think we know about great white sharks.

A world-first study claims tro have exposed a startling gap in marine science: despite being one of the most researched apex predators on Earth, scientists have almost no understanding of the microscopic organisms living inside great white sharks.

And those tiny hitchhikers could be influencing everything from shark behaviour to unexpected encounters with humans.

Scientists say what’s living inside great white sharks could be influencing their behaviour in ways we’ve never measured. Picture: AP

Researchers at Charles Sturt University have identified at least 116 parasites inhabiting great white sharks, mostly tapeworms and copepods, yet virtually nothing is known about how these organisms affect shark health, decision-making or behaviour.

The revelation has sent shockwaves through the marine science community, exposing enormous blind spots that span entire oceans.

“We have next to no understanding of how these organisms influence shark health, energy use, decision-making, behaviour, susceptibility to stress, or even patterns we assume to be ‘attacks’. In other words, we are looking at sharks and seeing only the surface,” Professor Shokoofeh Shamsi, Professor in Veterinary Parasitology at Charles Sturt University, said.

The groundbreaking study, published in the International Journal for Parasitology: Parasites and Wildlife, represents the most extensive review to date, probing scientific literature from around the world and specimens from major museum collections, including the Smithsonian and Australian Helminthological Collection.

Australian researchers have identified 116 parasites in great whites – but have almost no idea what they actually do to the sharks. Picture: Wikimedia Commons

What makes the findings particularly concerning is the sheer scale of what’s unknown. Professor Shamsi and co-researcher Associate Professor Diane Barton discovered that nearly all existing research on shark parasites is purely descriptive – scientists have identified what’s there, but have no idea what it actually does.

“This global mapping shows enormous blind spots, vast regions with no parasite data at all, despite the great white sharks’ worldwide range,” Professor Shamsi said, pointing to records from the US, South Africa, New Zealand and Australia.

Despite being one of Earth’s most studied predators, the microscopic world inside great white sharks remains almost entirely unknown. Picture: Wikimedia Commons

The implications are profound. In other species, parasites and microbes are known to influence energy levels, stress responses, feeding behaviour and decision-making. Yet in great white sharks, these invisible biological forces remain almost entirely unstudied.

“The biggest discoveries about great white sharks may lie in what we have never studied – their parasites and microbiome,” Professor Shamsi said.

“By studying their parasites and microbiome, we uncover silent forces that may influence their behaviour, resilience and ecological role.”

Researchers say invisible biological forces inside every great white may be shaping decisions, energy levels and stress responses. Picture: Brett Mensforth

While the researchers emphasise there is no evidence linking parasites to shark-human interactions, they argue it’s crucial to consider how they might shape shark behaviour in ways science has never measured.

“Great white sharks are extraordinary animals and global icons, but even they are not immune to the microscopic world and the hidden communities living inside them – parasites, microbes, and other symbionts – remain almost unknown,” Professor Shamsi said.

The study also raises questions about how human activities might be affecting sharks in ways we’ve never considered.

Pesticides, pollutants and land-based pathogens wash into coastal waters, moving through food webs and reaching apex predators.

Parasites act as sentinels of these changes, revealing when ecosystems are stressed or breaking down.

The groundbreaking study exposes enormous blind spots spanning entire oceans in our understanding of great white sharks.

“Human activities on land directly influence the health of marine predators, and this is why Charles Sturt University regional researchers play a national role in marine conservation, despite being inland,” Professor Shamsi said.

That inland perspective, she argues, is actually an advantage.

“What happens on land does not stay on land; it travels through waterways, food webs and ultimately shapes the health of marine giants like great white sharks.

“Our research helps reveal those hidden connections.”

Professor Barton highlighted the critical role museum collections play in making these discoveries possible, preserving irreplaceable biological material that can be revisited with new technologies.

Scientists say we have ‘next to no understanding’ of how parasites and microbes might influence shark encounters with humans. Picture: 7News

“Museum collections preserve irreplaceable biological material,” she said.

“They allow us to revisit specimens with new technologies and uncover insights that were impossible to detect when the samples were first collected.”

Perhaps most telling is what the researchers discovered about the broader scientific community’s awareness of this gap.

A recent major publication, White Sharks Global: Proceedings and Recent Advances in White Shark Ecology and Conservation, contained no chapters on parasites or microbiomes whatsoever.

“Their complete absence underscores the depth of this blind spot, and is why our review is a timely corrective, the first step toward understanding the invisible layers of biology that may shape great white shark health, behaviour, and long-term survival,” Professor Shamsi argued.

The researchers stress that parasites shouldn’t be viewed as villains, but as storytellers – revealing pollution levels, prey stress and the pressures facing marine ecosystems.

Ignoring them, they argue, leaves conservation efforts fundamentally incomplete.

Researchers are questioning whether factors we’ve never measured could be influencing unexpected shark encounters with humans. Picture: NCA NewsWire / Jeremy Piper

“Parasites provide early warnings about ecosystem stress, pollution and shifting food webs,” Professor Shamsi said.

“Healthy oceans depend on recognising the small things, like the hidden architecture of parasites and microbes.”

The study poses a provocative question that challenges decades of shark research: “What if part of a shark’s behaviour, including unexpected encounters with humans, is influenced by factors we’ve never measured?”

“We do not yet know, and that is precisely why this research is crucial,” Professor Shamsi said.

As human activities continue in the world’s oceans at a rate of knots, understanding these invisible biological forces have become increasingly urgent.

The answers, researchers suggest, may lie not in studying sharks more but in finally studying what’s inside them.

Originally published as Aussie scientists discover shocking gap in great white shark research