Have you seen any sharks?

by B. N. Sullivan

We decided that the first post about marine life in this blog should be about a shark. Our reason is simple. When new acquaintances learn that we are divers, one of the first questions we are asked is, "Have you seen any sharks?"

The answer to that question is an unqualified YES. We have seen many, many sharks over the years: Little sharks, big sharks, juveniles and adults. We've never seen a great white shark while diving, but we have encountered whale sharks, gray reef sharks, blacktip reef sharks, silvertip sharks, nurse sharks, Caribbean reef sharks, leopard sharks, several kinds of hammerheads, one tiger shark, one Galapagos shark, one thresher, and possibly a few other species that we have forgotten for the moment.

The shark species we have encountered most often is the one in the photo on this page: the whitetip reef shark (Triaenodon obesus; Hawaiian name: mano lalakea). This species is widely distributed in the waters where we have done most of our diving.

The individual in the image above was photographed at Sipadan, an oceanic island off the coast of the Malaysian end of Borneo in the Celebes Sea. The photo was taken near the southern tip of the island on a gentle slope about 20 meters (60+ ft) deep, covered with sand and coral rubble -- and several dozen whitetip reef sharks at rest. It was quite a sight!

This individual was a bit apart from the rest, making it easier to approach for a portrait. Even after I shot off several frames, blasting the poor shark with flashes of light from the strobes each time, it did not leave. (In case you are wondering, that's a remora -- AKA 'sharksucker' -- on the back of the shark.)

Whitetip reef sharks are not considered to be particularly dangerous to divers -- unless the diver has been spearfishing, in which case whitetips have been known to sneak up and snatch away the diver's catch. We don't spearfish, so we haven't had that experience.

During daylight dives, whitetip reef sharks often are encountered at rest in cavelets or sheltered areas of reefs, sometimes in small groups, but usually as individuals. When not at rest, these sharks can be seen swimming over sandy bottoms or a foot or two above a reef. With their slender bodies, they look very sleek as they swim. We've been approached by them on many occasions. Usually they just cruise past while clearly looking us over. Sometimes they pass, and then lazily circle back for another look.

As docile as whitetip reef sharks may seem in the day, they are anything but docile when pursuing prey. On more than one night dive we have seen a whitetip reef shark streak past and nail a snoozing critter so quickly it could take your breath away. And they have no compunction about bashing the coral to grab their prey!

Whitetip reef sharks are creatures of habit, at least when it comes to their napping. A diver making a single visit to a reef may be lucky enough to chance upon a whitetip reef shark, but divers who frequent the same reef over and over (as we have done in our home waters) often learn where these sharks hang out. Once a whitetip reef shark's favorite spot is discovered, divers can return again and again on successive dives and quite reliably find the same individuals in the same cavelet or on the same shelf on any given day.

We have always enjoyed seeing these animals, day or night, whether they are swimming, hunting, or peacefully at rest.