Steven Spielberg’s Jaws opened across North America on June 20 1975, and immediately tapped into the primal human fear of being hunted by a huge, savvy predator.

Set on a fictional island off the coast of New England, the film depicts an epic battle between three men on a boat and an enormous great white shark. Jaws was hugely popular, grossing a record US$100 million in its first 59 days.

Young and already mad about sharks, I left the film wanting to know more about their behaviour and ecology. But films affect people in different ways, and the movie has since spawned what social scientists call “the Jaws effect”.

This contended that sharks became widely demonised as a result of the film’s depiction of them as relentless killers obsessed with attacking humans. Director Spielberg’s inspired use of fleeting glimpses of the shark’s fin knifing through the water, accompanied by the film’s sinister and unforgettable music, heightened those feelings. That’s how Jaws affected us. But 50 years on, how have shark populations fared?

Get your news from actual experts, straight to your inbox. Sign up to our daily newsletter to receive all The Conversation UK’s latest coverage of news and research, from politics and business to the arts and sciences.

Both Spielberg and Peter Benchley, Jaws author and screenplay contributor, regretted the film’s influence on public perception of sharks. Indeed, Benchley became an advocate for shark conservation who enjoyed working with scientists (I was invited onto his radio show to discuss my research satellite-tracking basking sharks).

In the years following the film’s release, increasing numbers of sharks – including the movie’s great white – were reportedly killed in shark fishing tournaments that had risen in popularity.

Sharks grow slowly, take a long time to reach sexual maturity and have relatively few offspring. This makes many species vulnerable to overfishing. Fishing at this level removes too many sharks from the population too quickly, such that the remaining sharks cannot replace them fast enough, and the population declines. A recorded decline can be relatively large if the starting population size is already small, like that of top predators such as the great white shark.

Several data sources, including rod-and-reel and longline fishing, indicate a significant decline in the abundance of white sharks in the 1970s and 1980s along the US east coast where the film is set. The Jaws effect in action?

Actually, rapid declines were not limited to US waters. White shark catches in bather protection nets off the southeast coast of Australia recorded a similarly large decrease in the mid-1970s. And this particular source suggests white shark populations had begun declining from the mid-1950s, 20 years before Jaws.

Additional factors, such as commercial overfishing, were obviously at play. The film’s influence probably exacerbated white shark declines that were already happening.

Globally, the white shark has been assessed as vulnerable by conservationists, with a decreasing population trend. Fortunately, there are signs of recovery.

National protection measures for white sharks were implemented in the 1990s where these animals were formerly abundant, like the US, South Africa and Australia, and worldwide protections came a few years later.

Since the 1990s, there have been apparent increases in abundance off the US east coast (when populations are so small and data so sparse, a short-term increase may not be a lasting trend). Welcome signs that measures such as prohibiting catches in 1997 are having a positive effect following decades of over-exploitation. But this species is still vulnerable to incidental capture, so protection measures must be maintained and enforced to sustain any recoveries.

The Jaws effect was not limited to great white sharks. Many other large sharks were captured and killed in shark fishing tournaments that became more common following the film. Unfortunately, the killing continues in remaining US tournaments today.

But over the past few decades the overwhelming cause of large shark declines globally, particularly in the open ocean far from shore, has been the expansion of industrial-scale commercial fisheries targeting sharks for their fins and meat.

It was estimated in 2024 that fishing vessels are killing around 100 million sharks a year – a number that rose during the last decade. Nearly a third of shark species are now threatened with extinction.

It was estimated in 2021 that the global abundance of shark and ray species which prowl the open ocean (such as the oceanic whitetip or shortfin mako) has declined by an average of 71% since 1970 due to rocketing fishing pressure on the high seas (areas beyond national jurisdictions).

My own research analysing shark satellite tracks in collaboration with over 150 shark scientists, showed that 24% of the space used by these sharks each month on average falls under the footprint of surface longline fisheries. These include vessels that can deploy lines 100km-long carrying 1,000 baited hooks for up to 24 hours. We found the overlap was even greater, about 75%, for commercially valuable species such as the blue shark.

More sharks die in these overlap hotspots than in adjacent areas, according to more recent research.

Demystifying Jaws

Are there any signs of recovery for these species under existing management measures? For many oceanic sharks, the answer is still no.

At present, measures in place (if any) on the high seas are insufficient to safeguard populations. There is very little or no protection of shark activity hotspots. And some of the measures, such as shark finning bans, have been shown to be ineffective.

My colleagues and I revealed that catches of internationally protected species are sometimes 90 times greater than official reports.

So there is still a very long way to go to rebuild global shark populations.

Jaws helped promote a negative image of sharks that has no basis in reality. Rather, shark behaviour appears as complex in some cases as that of birds and mammals.

Tracking sharks revealed they can migrate thousands of kilometres to feed in specific remote habitats, before returning to the very same place they left months before. Some prefer to hang out with familiar individuals, and sharks even form persistent social networks. Giant basking sharks take part in speed-dating-like behaviour when they form courtship swimming circles at the end of summer.

The serial killer image has probably made it harder to convince people to sympathise with the plight of sharks. Jaws came at a time when very little was known about sharks, so fiction filled the void.

But there are now more shark scientists thanks to Jaws. Demystifying these creatures has been the first step to their potential recovery.

Don’t have time to read about climate change as much as you’d like?

Get a weekly roundup in your inbox instead. Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. Join the 45,000+ readers who’ve subscribed so far.

David Sims has received funding from the European Research Council, the European Commission’s Horizon Europe programme and the UK Natural Environment Research Council.