We are fortunate enough to encounter many different sharks on our dive sites. But don’t worry – they are all harmless! It is very common misconception about the risk sharks are to humans – and particularly to divers.
One of the most common sharks we encounter in bothe the Komodo National Park and at the Similans is the the Whitetip Reef Shark. In Thailand – we find these at several of our sites, but they seem to be most frequent visitors at the deep drop offs of Christmas Point and North Point. From our Komodo Dive center, we find them in several places, almost always on the deeper sites.
We are fortunate enough to encounter many different sharks on our dive sites. But don’t worry – they are all harmless! It is very common misconception about the risk sharks are to humans – and particularly to divers.
One of the most common sharks we encounter in both the Komodo National Park and at the Similans is the the Whitetip Reef Shark. In Thailand – we find these at several of our sites, but they seem to be most frequent visitors at the deep drop offs of Christmas Point and North Point. From our Komodo Dive center, we find them in several places, almost always on the deeper sites.
Whitetip Reef Sharks are among the most interesting animals on the reef. They are common at the Similans and in the Komodo National Park. Its scientific name is Triaenodon obesus, but it’s anything but obese! While they have the same general fearsome shape as their Great White cousins, Whitetip Reef Sharks are rarely over five feet long and usually much shorter – nothing to fear at all! They are rarely aggressive toward humans.
Whitetip Reef Sharks coexist with two other very similar sharks, the Blacktip Reef shark and the Grey Reef Shark. While all three species range from the shores of Madagascar to the reefs of Hawaii (and on to South America for the Whitetip reef shark), they generally do not migrate. All three species occupy different niches in the reef across their range. Black tips and greys are “crepuscular” – meaning they are most active at dawn and dusk, while Whitetips are most active at night.
Each species also has slightly different habitat preferences. Whitetips prefer depths of roughly 10-30 meters and the clear waters of the reef front. Blacktips occur near shore, often in lagoons, at depths of less than 15 meters. Grey Reef Sharks inhabit depths below 20 meters in both forereef and backreef environments.
Daytime hours find Whitetips resting in deeper water. Their resting habits differ in different parts of their range. In Hawaii, they commonly rest in lava tubes, while in Costa Rica, they often lie on unprotected sandy bottoms, totally exposed. They tend to rest in groups, often snuggled together, and sometimes in self-made stacks. Scientists have speculated that their communal resting may help other small fish (including wrasses and goby) keep them clean. If so, the selection of resting location in different regions may have to do with what types of species perform cleaning.
Interestingly, Whitetip Reef Sharks are the only sharks in their group that can lie still on the bottom, because they are able to pump water past their gills. Other sharks without this ability suffocate when they stop swimming.
Nighttime is hunting time for the Whitetip Reef Shark. They prowl the reef, entering holes to take prey that larger sharks can’t reach, snatching fish that retreat into fortresses to rest at night. They’re anything but graceful when attacking prey. They attack violently, often scraping and tearing their skin on the sharp rocks of the reef.
Although they’re skilled at snatching prey from tight spaces, they’re poor at getting prey in open waters. They may, however, congregate at reef drop-offs, awaiting unsuspecting creatures floating up from below. They also occasionally try to hustle catches from seals. Unlike most sharks, Whitetip Reef Sharks rarely get stirred into a feeding frenzy. They hunt in groups, but it’s every shark for him or herself!
Like most animals, Whitetip Reef Sharks fear several predators. Most are their own shark brethren, especially Tiger Sharks, although a few other species are known to attack them. The relative abundance of predator species may also determine their resting habits.
Whitetip Reef Sharks are among the most interesting animals on the reef. And because they don’t attack humans, they’re one of the easiest sharks for humans to observe.
