Every summer the water off Southern California’s coast becomes a bit more crowded — and not just with people. Sharks return from their winter migration to warmer waters south of the border.
In recent years, shark populations have also been recovering from much lower numbers in past years, prompting more frequent sightings.
Near Dana Point on Wednesday, for instance, a school of sharks was seen swimming near several people in the water. There’s video of it, posted online by the Orange County Sheriff’s Department.
Earlier this week, young sharks were also spotted very close to the Long Beach peninsula. And a young woman was badly bitten at the end of April, off San Onofre.
But there’s no reason to freak out, says Dr. Chris Lowe with the Shark Lab at Cal State Long Beach. Lowe joined KPCC on All Things Considered to answer some burning questions about beach safety, why there are so many sightings this time of year, whether this year is any different, and the nitty-gritty of how scientists study shark behavior.
Why are there so many sharks so close to shore right now?
Well, that’s an interesting question, and we’re not exactly sure. It’s a little early in the season to see these young white sharks so close to the beaches. Normally, that starts around June or July, so this earlier phenomenon could be related to the water temperature. We’re not exactly sure.
White sharks, as in great white sharks, as in all those rows of teeth?
Exactly. These are what we call white sharks, same as the great white, and this is a nursery for white sharks in the northeast Pacific. Southern California beaches have been known to be a nursery for at least a century.
What other types of sharks are common in this area?
We have a lot of other coastal species, like leopard sharks, which are really beautiful sharks. We have other species called gray smooth-hounds; soupfin sharks; occasionally sevengills will pass along our beaches.
You were out in the waters last night off the Long Beach Harbor. Give us a snapshot of what you saw out there.
Yesterday morning we managed to capture a 6-foot baby white shark and put a transmitter on it, and then we could follow it. My students were able to track it all day long, and we were tracking it most of the night. We lost it a couple times. It basically moved all throughout L.A. Harbor, Long Beach Harbor, and then this morning returned back to Belmont Shores, where the tag popped off, and we were able to recover that. So we were able to figure out a little bit about how these sharks move.
Anything about that shark’s behavior surprise you, or its movement in the water?
Well, we won’t know until we download all the data. Hopefully in the next week, we’ll have a better idea of what that shark did. But we do know that it didn’t stay at Belmont Shores all night. We know that it moved away, and traveled throughout much of Long Beach Harbor before returning back to Belmont Shore. And that’s a really interesting question: Why do they hang out there during the day?
How do you catch a shark? I imagine they don’t go quietly.
Actually, white sharks are kind of big babies. Once you get them entangled in a net, then it becomes really easy to handle them. We use an entanglement that we can set right in front of the shark and just target that individual, and we can literally have the shark flipped upside down, and when you flip them upside down, they go to sleep. And then we can attach the transmitters, let them go, and follow them and see where they go.
What do you do if you’re swimming in the ocean and you spot a shark? What should you NOT do?
Well, if you’re in the ocean, you spot a shark, that’s a cool thing for the day! I think a lot of people have this notion that if they see a shark, that the shark’s going to attack them, and that’s simply not true. I think the chance that people will see sharks is going up, and that’s not necessarily a bad thing. It’s that people do have to start to recognize behaviors. So if the shark starts rapidly moving towards the person, and veering away, and then coming back and getting closer and closer, that is a sign of potential aggression, and that’s when people should back away. We always recommend you always keep your eyes on the shark. That shark knows that you’re watching, and by keeping your eyes on the shark, the shark’s less likely to come in and try anything, and you can move away and get out of the water.
Is there any particular movement that a swimmer might make that would make them more attractive to a shark or signal, “Hey, I’m food?”
Well, we don’t really understand why sharks occasionally bite people. We have a lot of hypotheses about that, but no real good data. We always say, when you look at how many millions of people use Southern California beaches for surfing, swimming, all these ocean activities, and there have been these little white sharks out there for at least a decade, nobody’s bothered anybody. That tells us that people out there swimming are not necessarily drawing sharks in. So I think what people have to remember is that the statistics tell us that as long as they’re doing what they’re doing, they’re probably OK, but occasionally accidents can happen.
So this woman that was bitten off San Onofre, she was just a victim of bad luck?
Again, it’s hard to say. We don’t know exactly why sharks bite people sometimes. It could have been that she was in the wrong place at the wrong time. And frankly without examining the evidence, we don’t even know what species or the size of shark that was involved in that. It was more likely a white shark, but we don’t know that for sure. So it’s hard to tell people, you know, what they can expect when we don’t even understand these aspects of their behavior.
There’s been some speculation that an El Niño could make a return soon. What could that do for the local shark population?
That’s a really interesting question and unfortunately it’s one that we don’t have a good answer for yet. Because shark populations have been over-fished for many decades, we don’t know what populations looked like before we entered these kinds of weather patterns, so we don’t know how the sharks’ behavior will change. What we have learned in the last 10 years is that things like El Niño can greatly change even a baby white shark’s behavior. Normally, baby white sharks are highly migratory. In the winter, when our water temperatures cool down, they all quickly swim to Baja, and will over-winter in waters there that are equivalent to our summer temperatures. And then the next spring, some of those sharks will migrate back to Southern California. During a strong El Niño, none of the sharks that we had tagged that summer left. They all stayed, and that was because our winter water temperatures never get below 60 degrees. So from that project, we’ve learned that water temperature can greatly affect the migratory pattern of at least baby white sharks. We don’t know how it will affect the pattern of juveniles, or sub-adults or even adult white sharks. So we still have a lot to learn.
This interview was edited slightly for clarity and length.