The shark is nature’s most perfect predator (excluding man). Sharks have existed for over 350 million years, even before the time of the dinosaurs. The sharks featured on this boat tour include the Gray reef, Galapagos, Sandbar and Hammerhead. In Hawaiian legend, each island has its own shark god. The king shark god of Oahu is Kamohoali’i. His lair is an underwater cave off of Pearl Harbor. (We will not be visiting Kamohoali’i). He is the top shark god and elder brother of the fire goddess Pele. Kamohoali’i is also known as Moho, the provider of the canoe which brought Pele to Hawai’i from Tahiti. The ancient Hawaiians hunted sharks for their meat, teeth and skin. Heiaus or temples were built in honor of the shark gods. Just as each island has its own shark god, many Hawaiian families had personal shark aumakuas, or guardian spirits. Watching a shark rise from the depths is an unforgettable experience, a primal adventure.
Galapagos Sharks
The Galapagos shark is an aggressive requiem shark that is dark gray on top and has an off-white belly. Its tail has a black edge. There is a ridge running between the dorsal fins (the fins on the shark’s back). The Galapagos shark was named in 1905 from specimens found near the Galapagos Islands (in the Pacific Ocean off the coast of Ecuador).
The Teeth in upper jaw are serrated and triangular. Teeth in the lower jaw are narrower. They average about 10 feet (3 m) long but can reach 12 feet (3.7 m) long. Galapagos sharks are benthic feeders, eating prey taken from the ocean floor. Their diet includes bottom-dwelling squid, fish, and octopus.
The Galapagos shark have high concentrations off the North Shore of Oahu and live in warm waters. They prefer depths ranging from 200-800 feet (60-244 m). The Galapagos shark is found in tropical seas near islands.
At birth the 6 to 16 pups are about 22-32 inches (57-80 cm) long. when they are very young, these pups stay in shallow waters away from adult Galapagos sharks, thus avoiding cannibalism (being eaten by other members of their species).
Sandbar Sharks
Sandbar Sharks in Hawaii are among the most popular deep water coastal sharks in Hawaii. Chances of seeing a sandbar shark are very rare unless one actually takes a boat out to the deeper parts of the ocean.
Most visitors of Hawaii will encounter these species of sharks when going out on a shark feeding tour or shark cage tour. These types of sharks in Hawaii are not aggressive towards people in the water, even if bait or chum is present. They are curious and will approach divers or snorkelers however this is strictly for the purpose of investigation.
Hammerhead Sharks
The hammerhead shark has a wide, thick head with the eyes at the margins. The head is indented at the center of the “hammer,” which is almost rectangular in shape. This shark is gray-brown above with an off-white belly. The first dorsal fin (the large fin on the top of the shark that most people associate with sharks) is very large and pointed. Teeth are triangular with extremely serrated edges. The average hammerhead shark is up to 11.5 feet (3.5 m) long. The largest reported was 20 feet (6 m) long. These large sharks average about over 500 pounds (230 kg) but can weigh as much as 1,000 pounds (450 kg). There are 9 species of hammerhead sharks, ranging in size from about 3 feet (0.9 m) long to over 20 feet (6 m).
The hammerhead is a fierce predator with a good sense of smell that helps it find its prey, eating fish, including rays, and other sharks, squid, octopuses, and crustaceans. Also known to be cannibalistic. Stingrays seem to be a particular favorite of the great hammerhead. It kills the ray by using its “hammer” to pin the stingray down while it takes bites from the ray’s wings.
The hammerhead swims in warm and relatively warm water along the coastlines. They live over the continental shelves and the adjacent drop-off (the upper part of the mesopelagic zone) to depths of about 260 feet (80 m). The hammerhead is found in tropical and sub-tropical waters worldwide and migrates seasonally to cooler waters during the summer. The hammerheads are viviparous, giving birth to live young. The 20-40 pups are about 27 inches (70 cm) long at birth.
Grey Reef Sharks
Though you most likely won’t see the Grey Reef Shark on your cage diving tour, here is some information on them.
Of the forty species of sharks found in Hawaiian waters, gray reef sharks are among the most common. More plentiful in the Northwestern Hawaiian Islands than locally, they sometimes can be seen cruising near rugged, steep drop offs, where the reef ends abruptly. They favor the leeward sides of islands, strong currents and depths of 320 to 900 feet.
Grays are easily identifiable by the black border on the very edge of their tails and lower fins. They have no black on their dorsal fins, a characteristic that distinguishes them from the black tip reef shark. In some parts of the world, a slight white streak can be found on the back edge of the gray’s dorsal fin.
In Hawaii gray reef sharks reach a maximum size of about 6.2 feet though larger ones have been recorded elsewhere. Estimated life span is at least 12 years during which they enjoy a varied diet consisting of squid, octopus, crustaceans and fish.
Like other sharks, gray reef sharks have marvelous senses that help them to find food and to navigate. These include the ability to detect electrical energy fields through a series of sensory pores called the ampullae of Lorenzini. “Electroreception” allows a shark to find prey on a dark night, in murky waters or buried in sand. This amazing sense also enables sharks to detect the earth’s magnetic field and use it to travel to and from favored hunting or mating grounds.