Carl Meyer is one of Hawaii’s foremost marine biologists who has been studying sharks — and shark attacks — since moving here in 1993.
The state’s latest shark attack was just last month off Hawaii island, where a surfer was bitten on the hand by what is believed to have been a tiger shark.
In 2012 there were nine unprovoked shark attacks in Hawaii, an increase from three the year before. It’s hardly good news, but only one attack in the islands during the past decade has been fatal — on a Maui surfer in 2004.
Unfortunately, Meyer has little advice on how to avoid an unprovoked shark attack, except perhaps to avoid murky water in areas where rivers or streams feed into the ocean just after flooding, of just stay out of the ocean altogether.
Not satisfying advice, perhaps, but it’s the ultimate conclusion after years of research involving increasingly sophisticated telemetry devices that track and help analyze the behavior of not just sharks but other marine animals as well, including tuna, ulua and even parrot fish.
Meyer is familiar with the ways of island living; he grew up on Jersey, one of Great Britain’s Channel Islands in the English Channel, which, by the way, Meyer said, "is way smaller than Lanai." He learned to surf there, and used it as his base to make surfing trips to France, Portugal, England and Scotland as well.
He first came to Hawaii on a surfing safari in the 1980s and knew then, he said, that "it was one of the places that I really wanted to come back to."
And that’s what he did, after obtaining bachelor’s and master’s degrees in biological sciences from England’s University of Plymouth, and also making contact in Hawaii with Kim Holland, who is, Meyer said, "also a British ex-pat" and "sort of the intellectual father of the shark research program at the Hawaii Institute of Marine Biology."
In 2003, Meyer earned his Ph.D. from the University of Hawaii’s Department of Zoology. He, too, now works at the institute, based on Coconut Island in Kaneohe Bay.
Meyer, 45, is married and lives with his wife Karen and their two daughters, ages 2 and 6, in Pupukea.
QUESTION: So what is up with all the shark attacks around Hawaii lately? They’re up by 200 percent, right? Even though the numbers are small …
ANSWER: Yes, and that’s the very first point that we need to make as scientists, which is that although we’ve seen nine unprovoked shark bites in 2012, relative to a typical annual average of three to four, the numbers are so low that this could simply be down to chance. It does not necessarily indicate any fundamental changes in our marine ecosystem or fundamental changes in the abundance or behavior of the sharks.
Q: Is that an historical average — three to four?
A: We’re looking at a 20-year average of three to four per year. Against that average there are some longer-term trends — a gradual increase in the number of people getting bitten, which is occurring in all places where human populations are increasing. The strongest correlate with the number of shark attacks is size of human population and, as a direct result of that, the number of people going into the ocean for recreational purposes.
Q: What other theories are there?
A: First of all, when you look at the number of shark bites in the state of Hawaii, or really anywhere else, what you’re going to see is that they’re extremely low. And at that very low level, there also are variables, so it’s a noisy signal. Scientifically we’re always trying to be as conservative as possible in our interpretation of facts. So really, when we look at those numbers, the first thing that we say is that this could simply be natural year-to-year variation, due to chance, and it does not imply that anything else is going on.
Q: In that latest attack on Hawaii island, in which a surfer was bitten on his hand by a tiger shark, it didn’t help that he was out in murky water, right?
A: It’s not just the murkiness of the water per se. It’s if you are in an area where there is an outflow of a stream or river, and if you get a flood event. You can imagine that there will be things in that watercourse — dead things and live things — that will wash down and out into the ocean. And, of course, those sorts of things are attractive to sharks. So it’s a good idea to stay out of muddy flood water. Of course, most people realize that those sorts of areas are also loaded with bacteria, which would probably be more of a day-to-day risk for most people … so there’s a lot of reasons not to do that.
Q: What about surf spots that are just generally murky?
A: The murkiness is disconcerting, if you’re surfing, and definitely if you’re talking about river run-off, those are areas to be avoided. But just because it’s a little bit murky doesn’t mean that your risk is up. In Hawaii, for example, people are get bitten in crystal clear water, and without seeing the shark coming.
Q: Most shark attacks come without warning, right? I mean, in the old movies, a swimmer or someone in life raft would see a fin circling around …
A: Indeed.
Q: But that wasn’t realistic?
A: Most people who get bitten by sharks, the first thing that they know is that there’s a big thing latched onto them. They don’t see it coming and they’ve just been bitten. In fact, if you see the shark ahead of time, chances are you’re going to be OK.
Q: Right. But tiger sharks don’t really give themselves away, do they?
A: In the most general terms, a predator wants to avoid being detected by its prey. So depending on the predator, it will use appropriate strategies to avoid detection. Tiger sharks and other coastal sharks are very well camouflaged to make stealthy approaches when they need to. They have that sort of greeny brown color and they blend fantastically well with the underlying reef, so they’re able to sort of sneak along.
We also know that they are very surface-oriented sharks. They’re constantly yo-yoing up and down in the water column, coming to the surface multiple times in a day, multiple times in an hour even. When you look at their diet, it’s clear that taking prey at the surface is something that tiger sharks do routinely. So part of what they’re doing when they come up to the surface is probably looking for things at the surface that might be potential prey. With human ocean recreation, we are generally at the surface or close to it. Think about swimming, snorkeling, surfing, those things.
Q: Divers don’t tend to get hurt?
A: Well, the rate of attack on scuba divers is way low versus other activities. It’s probably both the position of the divers in the water column and also that the scuba divers are exhaling a lot of bubbles, which probably increases the wariness of the shark. I’ve been diving and been approached by tiger sharks; one came very close, and the thing that ultimately sent it swimming away was that my dive buddies exhaled bubbles that hit it right in the snout, and it really didn’t like that.
Q: How big was that one?
A: Probably a 10-footer. I mean, it was enough to get my attention.
Q: What other kinds of sharks are implicated around here?
A: It’s a tough call, really. If you look at the records, what you will see is that in most cases there is no species identification. When you think about it, the only way we can definitively identify the species involved is either we have a very reliable witness observation … or in the absence of that, we’re looking at things like physical evidence — you know, where there’s a tooth that got stuck in the surfboard that got bitten, that sort of thing. More recently DNA evidence has also been used to identify the species involved, but that’s really just an emergent technique.
Q: Are there certain areas where certain sharks hang out?
A: We have never identified a truly territorial shark. It’s clear that some of the smaller species have very well-defined home ranges, where they spend most of their time. That area may be relatively small; you know, a few miles across, or something like that. When you get up to the larger species of sharks, you typically see much higher levels of mobility. So, for example, tiger sharks you could regard as sort of attached to the Hawaiian archipelago for the most part, but individual tiger sharks are routinely moving hundreds or even thousands of miles up and down the Hawaiian chain, and even hundreds or thousands of miles out into open ocean.
Q: What about white sharks? We’re seeing more of those aren’t we? Why are they coming out here? Are they following the whales?
A: Again, that’s something we don’t know. The recent advances in telemetry tools … have allowed scientists to identify behavior that has no doubt been occurring for millennia, but we’ve only been able to just perceive it. So what it’s shown is that white sharks from both California and Mexico are coming out to the Hawaiian Islands. … They’re never common here, but I would describe them as routinely present. And we are getting detections of white sharks at all times of the year, so it’s not a strictly seasonal phenomenon.
Q: Like during whale season?
A: Right.
Q: What about the increased number of turtles and seals?
A: Well, we don’t know, is the straight answer to that. It’s always intriguing to speculate about these things, but …
Q: Should I be nervous if I’m out surfing and I see a bunch of green sea turtles?
A: Well, is there anywhere you can go now where there aren’t tons of green sea turtles? Everywhere I surf, I see tons of them. Think about it this way: Tiger sharks have the broadest kinds of diet, pretty much of any shark species. They eat all kinds of different things, so their presence in the shallow areas is not driven exclusively by the numbers of turtles.
Q: Regarding the shark-watching tours off the North Shore, you researched it and concluded it’s not a safety issue, right?
A: Some people believe that it’s a public safety risk. We’ve never found any evidence of that. And in the course of doing that study, we went out there and we dove at that location probably 50 times, including dives as deep as 240 feet, so we were just swimming around out there with all of those sharks and they never bothered us. They don’t really seem to have much interest in people.
Q: But isn’t there a habit the sharks have adopted of coming when they start chumming the water — and then what, they leave? They go away?
A: First of all, the primary species out there are galapagos and sandbar kinds of sharks. There is somewhere less than 2 percent of other species sighted out there sporadically, so the dominant species for those activities are species that do not have a track record of biting humans. …
Q: To what extent are any of these kinds of sharks actually endangered?
A: Well, certain species have been given a threatened or endangered status by the IUCN (International Union for Conservation of Nature) shark working group, but it’s really a patchwork. … Hawaii is great place to be a shark — it really is — because there’s no targeted fisheries for coastal sharks. … Other places in the Pacific, it’s a really bad place to be a shark because those are the places that are very, very heavily targeted by the commercial shark-fin fishery, and all the evidence suggests that it’s resulted in near extirpation — which is sort of local extinction — of sharks in some areas. So for some species in some areas, it’s really problematic, and some fairly dramatic intervention is required if those areas want to have sustainable populations of coastal sharks.
Q: What is the role of the Hawaii Marine Biology Institute in dealing with this issue of shark attacks?
A: Well we don’t have a direct role, per se. What we do is provide empirical information on shark biology and shark behavior to state agencies and, indeed, to the general public, to help provide a foundation of empirical facts for the purpose of decision-making.
I’ll give you an example right off the bat, and that is that when we first started doing this stuff back in the early ’90s, it was widely believed that tiger sharks were staying in one area, and that really was the cornerstone for the controlled fishing. … But what we found out using our tracking techniques was that, in fact, tiger sharks are highly mobile. It was the opposite of what people had believed for a long time. And that’s a good example of how the information we obtained through research can be given to the state agencies to inform their decision-making.