I have friends who think that because I swam with hundreds of sharks in the Tuamotus last spring, I’m exceptionally brave. But I wasn’t comfortable swimming with those sharks because I’m daring: It’s because I’ve learned to tell one species from another. And when it comes to swimming with sharks, species is everything.
The sharks I snorkeled with in the South Pacific were nearly all coral reef residents: white-tip reef shark, black-tip reef shark and gray reef shark. All three, also found in Hawaii, sometimes eat octopus and squid but mostly eat reef fish, and unless people are crowding them or spearing fish around them, reef sharks aren’t interested in humans.
Of the 400 or so shark species, the three most dangerous to people are bull sharks (not found in Hawaii), great whites (offshore and rare here) and tiger sharks, the species responsible for most bites in Hawaii.
I use the term "bite" rather than "attack," because tiger sharks aren’t attacking when they sink their teeth into human flesh. This is simply how the fish checks whether an item it has come across is food. Unfortunately the shark’s teeth are so sharp that this checking often causes injury.
In the mid-20th century, when Hawaii had a spike in the number of shark encounters with oceangoers, a state-sanctioned culling of sharks took place. Between 1959 and 1976, anglers caught and killed 4,668 sharks. Among those were 554 tiger sharks, meaning that 4,114 sharks not implicated in wounds to humans died simply for their sharky shape. As it turned out, the tiger sharks died for no good reason, too. Even with 554 individuals removed, there was little decrease in the number of Hawaii shark incidents.
After several shark-bite fatalities occurred from 1991 through 1993, the state again considered culling. This time, though, UH researchers lobbied the Legislature to fund a tracking study on tiger sharks. Marine biologists wanted to test the assumption that tiger sharks have small, coastal home ranges.
They do not. The studies showed that the species is a roamer, crossing channels between islands and sometimes diving to 1,000 feet. This proved that as far as public safety goes, fishing for tiger sharks in the area of an incident is useless.
With Hawaii, particularly Maui, having a higher number of shark clashes in 2012 (11) and 2013 (12, with one fatality) than in previous years, UH researchers are now at it again, catching, tagging and following male, female and juvenile tiger sharks. You can follow the tagged sharks at oos.soest. hawaii.edu/pacioos/projects/sharks.
To create effective management strategies, biologists must know how, when and where tiger sharks swim, feed and breed. Research is the reasonable response.
I’ve never seen a bull, great white or tiger shark while I was in the water, and if I did, I would get out fast. But if my next shark encounter is with any other species, I’ll consider it another thrilling moment of sharing the ocean with one of its most awesome native inhabitants.
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Reach Susan Scott at www.susanscott.net.
