Living in the open-water areas of the Hawaiian Islands is a predator that has set the record for speed and agility among the sharks of the oceans. The shortfin mako shark (Isurus oxyrinchus) is one of the largest of the mackerel sharks, averaging lengths of 10 feet and reaching weights of up to 1,221 pounds.
It is one of two known types of mako, the other being the rarely seen longfin mako (Isurus paucus), of which very little is known. Both shortfin and longfin mako sharks are also a related to the Great White shark. Both types of mako sharks are distinguishable for their metallic blue coloration on the dorsal side, with a white underside that serves as camouflage in their open-water environment.
In Hawaiian waters, makos may be found at depths of up to 114 feet, although they have been captured at record depths of 918 feet. Shortfin mako sharks are found globally and prefer temperate to tropical environments, preferring water temperatures between 62.5 to 71 degrees Fahrenheit. Members of this species are also somewhat endothermic, capable of maintaining their own internal body temperatures, which is a rare trait in sharks because most are exothermic, with internal body temperatures dictated by the surrounding environment.
Mako sharks are known to have an enormous migratory range, having been tagged and traced up to 2,452 nautical miles. It's believed that as seasons change toward the winter months in northern climates, they'll migrate to warmer waters. While little is known about their lifestyles, they are believed to be a solitary species of shark.
Shortfin makos are well known for their speed and agility and have been clocked in at record speeds of up to 50 mph. This enables the shark to quickly chase down prey as well as outrun potential threats.
They are known to feed on pelagic fish, such as swordfish and tuna as well as smaller sharks and squid. Rarely, sea turtles and marine mammals are also eaten. Their high speeds also give them the ability jump to great heights and have been known to leap out of the water up to 30 feet. It has been theorized that the ability of this shark to jump to such heights enables it to rid itself of parasitic animals, such as copepods that latch onto the shark's gills, fins and mouth to feed on blood.
As is true with all shark species, there is great concern that mako shark populations are on the decline. Shortfin mako sharks reproduce at a very slow rate of only four to 25 pups per litter after an estimated 15- to 18-month gestation period.
The U.S. National Marine Fisheries Service strictly regulates the legal catch but some still end up as by-catch, unintentional catch as a result of fishing activities. Additionally, the speed, agility and strength of this shark have made it a target of sport fishermen. They put up a strong fight and will often jump as a defense.
In Hawaii, mako sharks were a relatively common catch and were even found at fish markets in Honolulu. They were sold for meat and fins, which were prized for shark fin soup, until possession and sale of shark fins were made illegal in the state of Hawaii in 2011.
This top predator, like all sharks, is essential for maintaining the health and balance in the world's oceans and its future will rely on conservation efforts and respect of people everywhere.
* Mike Ogata is an ocean naturalist at the Maui Ocean Center. He has worked at the aquarium for 15 years, beginning as a volunteer in the Education Department. "Ka Mo'olelo Moana," or "The Ocean Story," is a monthly column submitted by the Maui Ocean Center. It is open from 9 a.m. to 5 p.m. daily in Maalaea. For more information, call 270-7000.