Remember that scene in Raiders of the Lost Ark when Indiana Jones peers into the Well of Souls and sees the floor writhing with snakes? Well, there’s a stretch of coastline in Southern California that’s kind of like that, but the creatures moving there aren’t snakes. They’re stingrays.

Why’d it have to be stingrays? Well, there’s a reason.

Seal Beach is one of those places with a perfect mix of environmental ingredients that make it a favorite spot along the coast for these prolific, mysterious and sometimes dangerous animals.

Locals and lifeguards have a name for it: Ray Bay.

What’s crazy is not that stingrays are here (they have been for a long, long time), but how many there are. According to research led by Dr. Chris Lowe at California State University, Long Beach Shark Lab, Southern California’s nearshore waters may host one of the densest concentrations of stingrays anywhere in the world. In some surveys, patches of seafloor the size of a football field are effectively carpeted with them. “We’ve done snorkel surveys where you cannot see sand,” Lowe says.

The Shark Lab has long been the state’s premier institution for understanding the behavior of sharks and rays. Lowe, who has led the lab for nearly three decades, is tall, fit, and deeply fluent in all things elasmobranch, the group of cartilaginous fishes that includes sharks, rays, skates, and chimaeras. He has become one of California’s most recognizable voices on these animals, a steady, authoritative presence for television, news, and documentary crews trying to make sense of what’s happening just offshore.

The lab, which sits landlocked on the California State University, Long Beach campus several miles from the beach, blends indoor workspaces with outdoor holding areas, where large circular seawater tanks temporarily house sharks and rays for study. It has a rough, garage-like feel, crowded with shark paraphernalia. Dried jaws line the counters, climb the walls, and hang from the ceiling. The place feels like a mix of working lab and Quint’s weathered shack in Jaws, a space where serious science and ocean obsession sit side by side. My colleague Tod Mesirow and I recently spent a day with Dr. Lowe in the lab and learned a great deal about stingrays and why they, rather than sharks, are actually one of the most dangerous animals off the coast of California.

Four species of stingrays live along this part of the coast, but one dominates: The round stingray. About the size of a dinner plate, the round stingray is one of the most abundant fish in Southern California’s coastal waters. Hundreds of thousands flap and burrow at wave breaks along the shore at any given moment.

And Seal Beach is, in some ways, engineered for them.

The San Gabriel River empties into the ocean at Seal Beach at a wide channel beloved by surfers. River currents deliver a steady supply of fine sediment that creates soft, sandy bottoms, ideal for burying, a common behavior of stingrays to avoid predation. There’s also a breakwater here that slows currents, allowing sediment to accumulate. Even more importantly, nearby power plants, including the Haynes Generating Station and the Alamitos Energy Center, discharge warm water into the coastal zone, raising water temperatures and helping create conditions that stingrays favor year-round. “They use all these conditions for mating and for pupping,” Lowe explains.

Stingrays don’t lay eggs. They give birth to live young, and the round stingray does it quickly. Gestation lasts only about three months, one of the fastest reproductive cycles among sharks and rays. Females mature in just a few years and can produce multiple litters over a lifetime of roughly 15 years. Add warming ocean temperatures, which are making Southern California even more hospitable, and you have the conditions for a major population surge. “As climate change is warming the water, it’s actually making Southern California even more appealing, and they’re going to start marching even further north,” Lowe says. Get ready, Northern California.

At the same time, another factor has led to a rise in stingray populations. For much of the 20th century, many of the stingray’s natural predators were depleted. Sea lions and seals were heavily hunted. Many have fallen to diseases like leptospirosis, a bacterial kidney affliction that causes high mortality, with over 370 confirmed cases in late 2025. Large fish like giant sea bass went into decline due to overfishing. Sharks were reduced. Without those pressures, stingray populations exploded.

That said, now, the balance may be tilting back. Slightly. Juvenile great white sharks feed heavily on stingrays. “Baby white sharks, their favorite things to eat are what we call stingray pancakes,” Lowe says. In an ecological twist, the return of white sharks may actually make beaches safer. “When there are a lot of white sharks off your beach, they’re keeping you safer because they’re eating the stingrays that are far more likely to injure people than the sharks are themselves.”

Tough choice, right? Do you want more sharks or more stingrays? For now, the rays dominate the shallows.

Stingrays are, in many ways, perfectly designed for this life. Stingrays are part of an ancient lineage of cartilaginous fishes, closely related to sharks. Lowe sometimes calls them “flat sharks”. Their bodies are compressed, their eyes sit on top, and their mouths and gills face downward, ideal for feeding on clams, worms, and crustaceans buried in the sand.

As they feed, they reshape the environment. Stingrays suck up sediment to uncover prey, then expel it, oxygenating the seafloor and cycling nutrients. “They’re really important tillers of the soil,” Lowe says. Without them, coastal sediments could become stagnant and foul-smelling. “They help keep our beaches healthy.”

But this same behavior brings them into conflict with humans.

Stingrays bury themselves as a defense strategy, hiding from predators. It works well against sharks. It works less well against people.

“Our feet don’t have eyes,” Lowe says, and when someone steps directly on a ray’s most sensitive area, where its organs sit, it reacts instantly, and its tail snaps upward. The spine strikes into a swimmer’s ankle or foot. Ouch.

The result is one of the most common marine injuries in California.

To test how stingrays inflict pain, the Shark Lab developed a fake human foot to step on different parts of the rays. What they discovered will come as a surprise to many people: “If you step on the margin of the fin or the nose, they won’t flip,” says Lowe. “They’ll wiggle away. But if you step on the organs, the most sensitive part is when they flick.”

At Seal Beach alone, lifeguards treat up to 350 stingray injuries each year. Across Southern California, estimates suggest at least 10,000 people are treated annually, and likely more. “That is an underestimate,” Lowe notes, since many stings go unreported.

Still, there is quite a bit of data.

“Lifeguards there have been treating stingray injuries for 40 years and keeping records,” says Lowe. “We’ve been using those records to understand more about stingrays, what they do there. And that research has now made the round stingray the best studied stingray in the world.”

The sting injury itself is a mix of mechanics and chemistry. The spine is a modified scale with serrated edges. It punctures cleanly going in but tears on the way out. Venom coats the spine in a mucus, plunging into tissue and triggering intense pain that often builds over 10 to 15 minutes as it creeps up the leg.

Treatment is simple but surprisingly effective. “Hot water works like magic,” Lowe says. Immersing the wound in hot liquid breaks down the venom, easing pain. Lifeguards up and down the coast are equipped with buckets, heaters, and increasingly, portable treatment kits. Forget the whole pee on the wound thing. Urine is neither hot enough nor in any way chemically effective against stingray stings.

Infections, however, are a real concern. Roughly 25 percent of injuries can become infected, due to bacteria or debris left in the wound.

The good news is that most stings are preventable.

The simplest solution is something lifeguards repeat constantly: the stingray shuffle. Instead of stepping normally, you slide your feet along the sand, digging your toes in a bit. That motion nudges buried stingrays, giving them time to flee. “If you shuffle your feet and you nudge them, they’ll skitter away,” Lowe says.

I’ve done the stingray shuffle plenty of times wading into Southern California waters and have never been stung, which is more than Chris Lowe himself can say.

“I’ve been stung so many times. And it is painful,” Lowe says. He warns again of taking the injury seriously: “If you start to see redness and intensity, it could be some of the barb broke off, or grains of sand have gotten into the wound and are causing infection.”

Still, Lowe says he has respect for the animals and hopes people don’t see them as creatures that are somehow out to sting us. Stingrays are not aggressive. They are defensive. “They only do that to defend themselves,” Lowe says of the sting. They’re not invading the beach. They are using a habitat that, in many ways, has been shaped to suit them. Perhaps it’s us who need to adapt. That’s the central message Lowe draws from years of studying these animals, the so-called “flat sharks.”

“By understanding more about the animal, which is our main purpose in doing science, and getting that to the public in a way that they can understand and appreciate, is changing the way they look at it. And they don’t look at them as being these animals that are out to get them or hurt them.”

Next time you step into the water at a Southern California beach, enjoy it. Just don’t forget the shuffle.