In 1998, outside of Fort Wayne, Indiana, a hydraulic excavator at Buesching’s Peat Moss & Mulch stripped back a layer of peat and struck bone in the underlying marl. Bone is the right word: This bone belonged to a mastodon, and mastodons are still fresh bodies in the dirt, not petrified fossils entombed in the rock. Although they might be popularly imagined living way back with the dinosaurs, the Ice Age megafauna went extinct only moments ago, in staggered waves over human history. The last mammoth, for instance, died after the first pyramids were built. Yet we know little of the lives of these animals with which we shared the planet for hundreds of thousands of years.

The mastodon pulled from the Indiana muck now lives in the state museum, looming over visitors, a stand-in for his entire species and epoch. Such relics rarely get to speak of their own lives. That this animal, nicknamed Fred, might have had his own biography is betrayed only by the ominous hole on the underside of his skull. “It got a tusk tip into the cheek,” says the University of Michigan paleontologist Daniel Fisher, grimly signaling to the roof of his mouth. That is, the mastodon was probably killed by another one. But inscribed in Fred’s own bowed tusks scientists have found a “ticker-tape record of his entire life.” Written in bone are 13,200-year-old memories of a mastodon living in the twilight days of his species. He migrated across the Midwest with the seasons, living in a world about to change forever.

This is Fred’s story, as best as Fisher and his colleagues can tell.

By all indications, Fred was a happy young mastodon, his welfare secured by a doting mother and the watchful aegis of his aunts. The planet had been emerging from the depths of the last ice age for thousands of years, and where there were once ice sheets, chalky-blue glacial lakes, and barren plains of gravel carved by braided rivers of meltwater there was now only the memory of the moraines that the ice sheets had left behind. The taiga forest trailed the ice, and then the deciduous trees moved in during this age of climate change. But mastodons don’t live on millennial timescales, and all Fred knew was that he was well cared for by his herd, and that he had plenty to eat in the forest. Walnut, hickory, oak, maple, and black and white spruce trees lined the great marshes of the Midwest. Fred picked from lakeside sedges beside stag moose, camels, and giant beavers as the matriarch kept watch for dire wolves. His tusks grew vigorously in these youthful salad days.

“There’s a time when they’re young and life is wonderful,” Fisher told me. “Particularly if they have the good luck to be the calf of the matriarch, every effort is made to see that they get good food, starting with extra milk.” Because of the cruel math of mastodon reproduction, male calves would have been nursed longer than females. Although females were likely to have mating success in their lives, competition for mates among the males was a winner-take-all blood sport in which male mastodons would likely sire many offspring or none at all. Preparation for the sorts of battles that would ultimately take Fred’s life, then, began in the nursery.

This was Fred’s story until age 12. His tusks grew robustly each year until—well, they suddenly didn’t. In adolescence, Fred likely started acting like a jerk. Fred had to go.

“Sometimes they get way too rowdy, and they’re trying to sort of ‘practice mate’ with their cousins and siblings—not that they would get anywhere—but … they don’t know when it should stop,” Fisher said of the similar adolescent angst seen in modern elephants. “So they will actually get kicked out of the herd. All of a sudden you see a year where the tusk grows half of what it did before. You think the sky must have fallen. What happened to these guys?”

At this point, isotopes in Fred’s tusks began recording a mastodon bildungsroman of sorts, as the animal struggled to come to terms with onrushing adulthood.

To unravel this coming-of-age story, Fisher and his colleagues, led by Joshua Miller at the University of Cincinnati, targeted two of the subtle signals recorded in the animal’s tusks, which grew layer by layer from the base outward, over the course of his life and which were made from the world around him.

We move through life picking up the signatures of the places we visit, unknowingly sampling from a palette of isotopes distilled by mountain ranges, by the vastness of the continent, and by the changing of the seasons. And because we are what we eat and drink, we reflect this porous exchange with the geosphere in our tissues and in our bones. Spend time far from the ocean, drinking water filtered by the long, evaporative journey overland, and your hair will know. Pluck the feather from a peregrine falcon or the barnacle from a humpback, read its isotopes, and you will learn of lengthy migrations over land and sea, recorded in years past. Even the heights of soaring mountain ranges, long since eroded to nothing, are preserved in the isotopes where they once stood, the measurable lightness of the ancient water that once capped their peaks in snow persisting in the rocks left behind.d.

Amazingly, the shifting signature of isotopes in Fred’s tusks provides a rough map of the animal’s movements thousands of years ago. Earth’s continents are mosaics of old granite magma chambers, frozen lakes of basalt, ancient limestone seafloors, the coals of bygone swamps, the sandstones of erstwhile deserts and beaches, and so on—all lathed by erosion, each lending its own isotopic flavor to the local environment. This isotopic landscape has been mapped in detail by geochemists, so when Fred sampled from this surface geology over the course of his lifetime, drinking from lakes or patiently gnawing at spruce twigs, the strontium in his tusks recorded an approximate geochemical GPS of his wanderings.

Fisher's children assist in the excavation of a tusk in 1998; Fisher later used a bandsaw to cut a thin slab from the center of the animal’s tusk. (Courtesy of Daniel Fisher)

What this signal reveals is a home range that hardly budged in Fred’s early adolescence, while the hale and hearty growth rates of childhood dramatically fell off. Kicked out of the herd but unprepared to strike out on his own, Fred was likely extraordinarily stressed. The crisis is familiar to those who study the mastodons’ modern relatives. “The elephant will just stand maybe a mile away from the herd,” Fisher said. ”They know they can’t come close or the matriarch will shoo them away. They can’t have what they want, but they don’t know how to strike out for themselves yet. So they just stand and bawl and bellow at the margin of the matriarchal herd until finally they realize, There’s nothing for me here.”

That is, until they finally accept that childhood is over, and it’s time to go. This was a painful time—a time of privation.

“Once they’ve left the herd, it takes them a few years to learn how to feed themselves, and they don’t get back on their former trajectory until two to three years later,” Fisher said.

Only at this point does the strontium in Fred’s tusks indicate a growing range, as he set out from home, moving hundreds of miles over the landscape, learning to live on his own.

Migrating across the Midwest, his range potentially reaching from Illinois to Ohio, Fred plucked water lilies from the great marshes in the early autumn. He spent winter nights trudging through the fresh snowfall in moonlit clearings. Perhaps he thought back to his herd in the quieter moments. He gently wrapped his trunk around maple leaves and stripped spruce tips and buds from branches in the early spring. But this was a dangerous time as well: Males on their own are more vulnerable to accidental death than females, and if Fred had fallen into the muck, his aunts would not have been there to help pull him out. Nevertheless, after years of successful independent living, his growing confidence marked by a range that came to span more than 100 miles, Fred would pick up a new obsession: visiting northern Indiana at the same time each year. In the early summer, for at least the last eight years of his life, he would return here for explosions of mastodon-on-mastodon violence.

“Again and again and again every year—slam, slam—always at the same time of year, and always at the same season,” Fisher said, “which ultimately became the season of death.”

This cycle of violence was revealed by a second signal in Fred’s tusks, encoded in oxygen isotopes, which tracked the steady sawtooth tick of the seasons passing by and provided a kind of calendar kept in dentin. (Water with lighter oxygen would evaporate and precipitate in the brutally cold Pleistocene winters; heavier oxygen in the tusks, meanwhile, signaled the return of the ancient summer.) Combined with the isotopic record of Fred’s location, one that reveals regular migrations to northern Indiana near the end of his life, and the trauma recorded in annual scars in his tusks, these signals indicate to Miller that Fred’s dangerous early-summer pilgrimages were made in search of mates.

“Towards his death, when he is big enough and strong enough and hormonally enriched enough, he’s going through these annual cycles where he’s finding this region he’s only going to in the summer, and that includes the place where he’s found at death,” Miller told me. “It’s an annual migration to what we think are the mating grounds.”

Given mastodons’ remarkably long gestation times of about 22 months, and the extreme seasonal climate of the late Pleistocene, reproduction had to be exceptionally well timed so that their offspring could be born at the right time of year to maximize survival. This had the effect of concentrating competition over mates into an extraordinarily intense window. And so, each year Fred would return to the mastodon colosseum of greater Fort Wayne for incredibly violent rounds of combat.

“I have to say, it’s an almost shocking part of their biology,” Fisher said. “Elephants do do this to an extent, but I think mastodons did it even more than elephants.  Elephant bones by comparison are gracile, slender—they’re like twigs compared to mastodons. We have evidence of mastodons just beating each other apart.”

The fact that Fred survived as many years as he did suggests that, until he met his grisly end, he fought well and likely found mating success, Fisher said. But evolution doesn’t make allowance for graceful exits. And so, Fred the mastodon was kicked out of his herd at age 12, roamed the Midwest, and was gored and died at 34, about 13,200 years ago.

This was one of the last of the elephant kin in North America. Fred’s species had millions of years in its rearview and mere millennia until extinction. He had lived the kind of boisterous, peripatetic, and ultimately tragic life that was perhaps typical of a venerable lineage that had survived wild climate swings, hundred-millennia-long planetary winters paced by the sinuous changes of northern sunlight, and the tug of celestial bodies. But where the planet had rocketed out of ice ages before and the megafauna had kept up, now an unprecedented actor stepped on the landscape.

“If you look at past deglaciations, some of which were even larger in magnitude, you don’t see extinctions,” the University of Nebraska at Lincoln biologist Kate Lyons told me. “Mammals were able to track their climate with no problem. There’s nothing different about this time, other than the arrival of humans.”

Though he was killed by another mastodon, Fred’s body bears witness to this growing presence of humans. He didn’t merely fall into the bog that ultimately preserved him for posterity; he was packaged for the future, his carcass carefully stashed in the mire, the meat carved off his bones, his tusks lovingly laid side by side. As the ice retreated, as it had many times before, the mastodons would fall away, and the humans who buried them would inherit the Holocene. Our own populations were swelling, and megafauna extinctions that had already hit Eurasia, Australia, and even Africa in the tens of millennia before were now sweeping the Americas.

“If you look at the selectivity of the extinctions at the end of the Pleistocene, what you see is that every time Homo sapiens arrive in a new landmass, the average body size of mammals there drops, usually by an order of magnitude or more,”  Lyons said. “Going into an area and killing large-bodied mammals and driving them to extinction actually seems to be a signature of our species.”

In North America, where the extinctions that took the mastodons struck during a broader, millennia-long period of deglaciation, this background climate stress—which had proved survivable many times without humans on the landscape—suddenly became lethal. In our own time, as the climate is changing with a rapidity almost unknown in the geologic record, it’s an open question whether life could keep up without us in the way—much less with the patchwork of human infrastructure and farmland that now carpets the continents.

“We’re changing climate as much in 100 years as it changed over a couple thousand years over the past deglaciations. But to me the bigger problem is actually the barriers to dispersal that we put up,” Lyons said. “At least some elephant populations we know … will migrate thousands of kilometers. But for many of them, they’re essentially fenced into these game preserves. And there’s a lot of human conflicts when they get out.”

For this reason, Joshua Miller, Fisher’s colleague, calls animal migration of the sort revealed in Fred’s isotopes perhaps “the most endangered behavioral type” on our modern planet. He plans to put his forensic tools to work not only in deciphering the ranges of extinct animals but on elephant tusks going back centuries to reconstruct what remains an unknown baseline for the animals, even in historical times.

“We really have very little understanding of their requirements for landscape use,” he said. “What does an elephant really need to be happy?”

After the humans arrived, Fred stayed in his lightless bog for millennia as the land was worked above, the forests shaped by fire and the fields sowed with corn, beans, and squash. Then, in the moments before he was dug up, disease swept the continent, and guns followed. Where mastodons once battled, humans now slaughtered one another. The crops were burned, the great marshes of Indiana were drained, and many of the people were sent on a Trail of Death. In the centuries since, the forests and marshes have mostly been replaced by a checkerboard of soybeans and corn. Coal made from strange jungles that grew hundreds of millions of years earlier was pulled up from deep under the Midwest and ignited. Now the seaside dunes of northern Indiana, at the edge of the great glacial lakes, breathe fire from iron bellows, and the future of all elephants on Earth is threatened by the same processes that transformed this world in a matter of centuries. But when it’s over, this story will still be written in bone.

This article was originally published in Hakai Magazine.

On a sweltering day in July 2019, Summer Locknick plodded along Cavendish Beach on the coast of Canada’s Prince Edward Island, among hundreds of people lounging on the red-tinted sand. The air smelled of sunscreen as the visitors worked on their tans, blew up inflatable rafts, and cooled off in the sea. Locknick, however, was not there to relax. With a GPS unit and a tablet in hand, she circulated in the crowd, asking people if they knew about an often-overlooked threat slinking through the surf.

Rip currents are one of the deadliest hazards along the coast, yet beachgoers rarely pause to consider them before heading into the water. “Most people who go to a beach aren’t aware of what a rip current is,” Locknick says. These belts of seawater, which can be wider than a four-lane highway, cut through the surf and flow away from the shore, pulling unsuspecting bathers beyond their depth. Rips, as they’re known colloquially, can occur on any beach with variations in breaking waves—even on the shores of North America’s Great Lakes—and have been measured to flow as fast as a raging river. Struggling against a rip current leads to exhaustion for even the strongest swimmers.

Worldwide, rips cause hundreds of drownings and necessitate tens of thousands of rescues every year. In Australia, where about 85 percent of the population lives within an hour’s drive of a coast, rips cause more fatalities than floods, cyclones, and shark attacks combined. In 1938, one of the country’s most popular beaches, Sydney’s Bondi Beach, was the site of an infamous rip-current tragedy: Within minutes, roughly 200 swimmers were swept away by a rip, leaving 35 people unconscious and five dead. More often, however, rips take one life at a time, only garnering so much media attention. For many casual beach visitors, the toll of rip currents goes unnoticed.

Locknick had only vaguely heard about rips as an undergraduate student at the University of Windsor in Ontario. During a stint as a research assistant in a coastal geomorphology lab, she grew increasingly intrigued by the currents and the reasons people get caught in them. During her graduate studies in 2019, she surveyed 500 people at Cavendish Beach and nearby Brackley Beach to learn how beachgoers perceive the hazard in Prince Edward Island, a province where rips have caused several drownings in recent years. Although almost three-quarters of beach users said they knew what a rip current is, only 54 percent could correctly define it. In addition, under half of the people she surveyed remembered seeing either the warning signs and an even smaller percentage remembered the colored flags denoting surf conditions that were posted on or near the main access point to each beach. Additionally, very few  could recall what color the flags had been—green for calm, yellow for moderate, or red for dangerous conditions. “I was genuinely shocked,” Locknick says.

Chris Houser, a professor in the department of earth and environmental sciences at the University of Windsor, who oversaw the work, has seen the same trend throughout his research. Houser started his academic career studying the physical processes that shape the coast but has since branched out to explore the human side of beach safety. While living in the United States in the late 2000s, he began examining public perceptions of rip currents and warning signs, later expanding his work to Australia and Costa Rica, where he has collaborators, and, most recently, to Canada. He notes that many people disregard, misunderstand, or fail to notice warning signs. And sometimes signs are misleading. A major pitfall in many communities’ attempts to save lives from rips is assuming that the warnings work. “You can have the signs; you can have the flags,” Houser says, “but they’re not going to fix the problem.”

Deciding what to put on a sign is not straightforward either: Rips are varied, complex features, and a single piece of advice doesn’t guarantee survival. Saving people from rips, researchers have realized, calls for an approach that goes beyond posting signs. It requires understanding what leads to rip-risky decisions in the first place.

Part of the challenge of preventing rip-related drownings stems from the lack of a simple method to escape them.

Rip currents form when waves pile water near the shoreline. The water then gushes back out to sea, taking the path of least resistance. It might flow along channels carved in between sandbars or next to solid structures, such as jetties or rocky headlands. These types of rips can reappear in the same location year after year. Others are more erratic, creating fleeting bursts of seaward-flowing water on smooth, open beaches. People often mislabel rip currents as undertows or rip tides. Rip currents are not caused by tides, however, and undertows are a different, weaker current, formed when water pushed onto the beach moves back offshore along the seabed. Some telltale signs of a rip include a streak of churned-up, sandy water or a dark gap between breaking waves.

It’s not surprising that rip currents are often misunderstood by the public because, for decades, beach-safety experts also had an oversimplified perception of their mechanics. In some of the earliest research on rips in the mid–20th century, American scientists watched sticks and pieces of kelp float out to sea and described lanes of flowing water extending a few hundred meters offshore. This work formed the basis for the popular view of rip currents as jets flowing perpendicular to the beach, shooting out past the surf. To escape the river of current, experts recommended that bathers swim parallel to the beach—a message once broadcast through education campaigns and warning signs in the United States and Australia. As it turns out, that approach may not always work.

In 2010, researchers using floating GPS units to track the trajectory of rips found that the currents often flow in circles. By swimming parallel to shore, people may inadvertently end up struggling against an oncoming current, says Jamie MacMahan, professor of oceanography at the Naval Postgraduate School in California, who led the research. Only about 10 percent of the GPS units he and his colleagues threw into rips were swept beyond the breaking waves. If a swimmer were to float and ride a rip’s circular path back toward shore, they may be returned to safety.

MacMahan’s findings caused controversy among beach-safety experts, says Robert Brander, a professor in biological, earth, and environmental sciences at the University of New South Wales in Sydney, Australia. To learn what strategy works best, Brander and MacMahan had swimmers test both tactics in various rips around Sydney.

Their research shows that neither strategy is foolproof. “There’s not one single piece of advice in terms of floating or swimming parallel that is guaranteed to work in every rip current,” Brander says. Swimmers should stay calm and may need to consistently reassess their chosen strategy and switch to another if they find it isn’t working. But making such rational decisions goes against instinct. Through interviews with rip-current survivors, Brander learned that most people panic and try to swim straight back to shore, against the current. Any advice they may have heard about escaping becomes useless when fear takes hold.

Rip-current survival is clearly more complicated than safety experts long thought. As a result, they shifted focus: educating people on how to avoid the hazard altogether.

In the summer of 2008, a couple lugged a cooler, folding chairs, and a beach umbrella along a white-sand beach in Pensacola, Florida, looking for a place for their two preschool-aged children to swim. They plopped their gear in front of what looked like the perfect spot: a calm ribbon of turquoise water surrounded by shin-high waves. As the children began splashing in the sea, Houser rushed over. The scientist had been studying the movement of sediments along the beach when he noticed the family heading toward what seemed to him like a clearly dangerous spot. Couldn’t they see the rip current? he asked the couple. Hadn’t they seen the signs?

Although the family had noticed the signs posted along the beach, they still hadn’t spotted the rip. To understand what had gone wrong, Houser realized that he had to look beyond coastlines and currents. He had to study people.

The signs posted at Pensacola Beach were created as part of the nationwide Break the Grip of the Rip campaign of the U.S. National Oceanic and Atmospheric Administration (NOAA). The signs showed an illustration of a rip, in which the rip was pale blue and the beach curved out. In reality, a rip current often appears darker than the surrounding surf in a U-shape, including at Pensacola. The signs also portrayed a rip from above, not from the viewpoint of a person standing on the beach. “What a real rip looked like was totally different,” Houser says.

The NOAA sign was only intended to tell people to get out of a rip by swimming parallel to shore, but Houser and his colleagues learned that beachgoers were using the poorly designed sign as a guide on how to spot one. Nearly half of the people the researchers surveyed at three beaches in Texas thought the same NOAA sign was “helpful” or “very helpful” for identifying a rip. The majority of those people couldn’t spot a rip when they were later presented with photographs of the beach, however. Because beachgoers were misinterpreting the sign, they were looking for the wrong visual cues, Houser says.

Even when beachgoers know what to look for, rip currents are difficult for the average person to see. And people tend to ignore warnings when they don’t align with their own perceptions, Houser says. When waves are small, for example, people assume the water is safe, even though rips may still pose a hazard.

The presence of others and past experiences at the beach can also sway judgment. When beachgoers see others enjoying the water, they are inclined to believe conditions are safer than they are. And if people who decide to enter the water despite warnings are lucky enough to avoid getting caught in a current, they may think warnings are overblown.

Plus, by the time people’s feet hit the sand, the vast majority aren’t even thinking about safety, says Brander. “They’re just thinking about having a good time.”

To get ahead of some of these issues, several countries have adopted campaigns that aim to educate people about rips before they get to the beach, when they are in a more receptive frame of mind. In Australia, safety experts have disseminated information through ads at bus stations and airports and on social media. Brander has also released harmless purple dye into rips, with footage of the dramatic streaks appearing on TV and online videos. The effectiveness of these interventions is only beginning to come to light, with some research suggesting they can improve public understanding of the hazard. In Canada, where beach safety has been slower to develop, efforts to educate people about rip currents are only starting.

On the rugged west coast of British Columbia’s Vancouver Island, a 16-kilometer stretch of sand is one of Canada’s most popular beach destinations. Located in Pacific Rim National Park Reserve, Long Beach runs between the communities of Tofino and Ucluelet, and on the beach’s north end, a green-capped mound roughly the size of a Manhattan city block protrudes from the surf. The islet, known as Lovekin Rock, is accessible by foot on the lowest of tides, enticing visitors to reach its flanks. When the tide sweeps in, however, the rock forms a rip current that can catch walkers off guard.

“It’s a notorious location,” says Karla Robison, an avid surfer and environmental and emergency safety specialist based in Ucluelet. In 2019, Robison was using the rip that hugs Lovekin Rock to paddle out for a surf when she noticed someone in the water, clinging to the side of the islet. Robison pulled out of the current into a still section in front of the rock. As she reached the man, she saw that he was blank-faced and pale. He also wasn’t wearing a wetsuit, which can be dangerous in the region’s frigid water. Whether from cold or fear, he was frozen, she says.

Robison helped the man onto her board and, along with another surfer, towed him back to shore. Later, she learned that he had been walking out to the rock with his son when the tide came in. While the son fought his way back to the beach, the growing current swept the father into deeper water, until he was stopped by the rock. The situation could have been worse, Robison says. In recent years, several people have drowned in the same area.

The rip around Lovekin Rock is a prime example of how swiftly rip currents can change. Scientists have found that rips are not only influenced by tides, but also by various environmental factors, such as the location of shifting sandbars, which make forecasting rips difficult. The strength of a rip is only one aspect of its danger, however—a more important predictor of how deadly a rip may be is the number of people in and around it.

In Pacific Rim National Park Reserve, safety experts are grappling with the issue of growing crowds combined with limited public awareness of coastal hazards, including rips, unexpected waves, and cold water. Randy Mercer, a park-visitor safety technician, was struck by the problem on a tempestuous day about 10 years ago. He was trying to warn beachgoers that waves pummeling the shore could roll beached logs or knock people off their feet, but he couldn’t keep up with the hordes of storm watchers pulling into the parking lot. Since then, visitation to the region has only increased. In 2019, more than one million people visited the park—nearly 50 percent more than in 2011. “Every year is a record year,” Mercer says. Local authorities don’t have a standardized approach for tracking rip-related occurrences, but Parks Canada responded to 82 marine and coastal incidents near Lovekin Rock between 2004 and 2015.

To enhance public safety, Mercer led a collaboration between Parks Canada and the Districts of Tofino and Ucluelet, with input from tourism groups and the Tla-o-qui-aht and Yuu-thlu-ilth-aht First Nation, among others. In 2017, the team launched a campaign, called CoastSmart, to educate visitors about coastal hazards. Mercer, Robison, and their colleagues standardized warnings at beach-access points. But knowing that signs alone aren’t enough, they also emulated education campaigns abroad, such as those in Australia.

Visitors may now encounter safety information on brochures, LED highway signs, and an interactive website. Local businesses, such as hotels and surf shops, also share information in person and online. The goal, Mercer says, is to reach people at multiple stages throughout their trip, starting from the point they start planning a visit. This increases the chances of getting information across, and compared with signs, face-to-face interactions are more likely to get people to change their behavior, he says. In that vein, local ambassadors, such as artists, educators, and professional athletes, use their social influence to help spread public-safety messages. Recently, the CoastSmart team also developed a map of persistent rip currents in the area to help visitors avoid them.

The program has increased the consistency of safety messages, says Keith Orchiston, the District of Tofino’s emergency program coordinator, who helped develop CoastSmart. Without consistent reporting, however, it’s unclear whether the program has actually reduced the number of incidents. Robison believes rip-related occurrences are still a problem, and because the region has no surfguards to carry out rescues at the beach, the responsibility often falls to locals.

Surfguards are one of the few proven means of preventing drownings, Houser says, but they can’t be stationed at every beach. Parks Canada ran a surfguard program in Pacific Rim National Park Reserve for about 40 years, but canceled it in 2012. Tofino local Doug Palfrey estimates that during the 36 years he served as a guard, he and his colleagues rescued between six and 20 people each year, largely from the Lovekin Rock rip.

In the absence of surfguards, researchers may be able to harness what they have learned about beachgoers’ decision-making to steer them toward safer choices when they arrive at the coast. People tend to pick a spot to swim based on convenience, and beach-access points can unintentionally funnel people toward persistent rips.

At Sydney’s Bondi Beach, a busy bus stop and several hostels happen to be positioned close to a rip current fittingly called Backpacker’s Express on the beach’s southern end. Tourists get off the bus, drop their bags, and head straight into the water, Houser says. By engineering beach-access points, safety experts could guide people to swim in safer locations. Existing rip-current forecasts also tend to cover large areas and often don’t factor in a beach’s underlying morphology, which limits their value for any specific beach, Houser says. Accurate, localized forecasts could help beachgoers make better decisions.

Houser will soon put these ideas to the test. Earlier this year, he secured funding to create a real-time, localized warning system at Station Beach: a sandy shoreline along Lake Huron in Kincardine, Ontario, that abuts a jetty, where a rip often forms. Over the next three years, Houser and his colleagues plan to develop a hazard rating that is true to conditions at various spots on the beach. A set of traffic lights at each access point will warn of low-, moderate-, or high-risk conditions, and an app will provide suggestions on where to swim. Houser and his colleagues also intend to track pedestrian traffic to inform a beach-access redesign, ensuring that people are guided away from the rip current.

If the project is successful, similar tactics could be implemented at other beaches, including along coasts, Houser says. But he is cautious about getting ahead of himself. Researchers now understand many of the human factors that undermine rip-current safety, but overcoming them is a whole other challenge.