The shortfin mako shark ( Isurus oxyrinchus ), a large mackerel shark, is also known as the blue pointer or bonito shark. Commonly referred to as simply the mako shark, this name is shared with the longfin mako shark (Isurus paucus). The word "mako" originates from the Māori language, where it refers to either the shark itself or a shark tooth. In English, following Māori usage, "mako" serves as both the singular and plural form.
Description and Biology
The shortfin mako is known as the fastest shark species, capable of reaching speeds up to 74 km/h (46 mph) in bursts. They can grow up to 4 m (13 ft) in length and weigh as much as 570 kg (1,260 lb). Adult specimens typically measure between 2.5 to 3.2 m (8.2 to 10.5 ft) in length and weigh 60-140 kg (130-310 lb). Females are usually larger than males, with some mature females exceeding 3.8 m (12 ft) in length and 550 kg (1,210 lb) in weight. One exceptional specimen caught off the coast of Italy in 1881 was reported to weigh 1,000 kg (2,200 lb) at a length of 4 m (13 ft).
These sharks have a cylindrical body shape with a vertically elongated tail. Their coloration exhibits countershading, with a brilliant metallic blue dorsally and white ventrally, creating a distinct line of demarcation. The underside of the snout and the area around the mouth are white. Juveniles have a clear, blackish stain on the tip of their snout, and larger specimens tend to have darker coloration extending onto areas that are white in smaller individuals.
Shortfin makos are endothermic, meaning they can maintain a body temperature higher than the surrounding water. They achieve this through a heat-exchange circulatory system, allowing them to stay 4-5.5 °C (7-10 °F) warmer than the water around them. This adaptation contributes to their speed and agility.
Habitat and Distribution
Shortfin mako sharks inhabit offshore temperate and tropical seas worldwide. They are pelagic species, found from the surface to depths of 150 m (490 ft), generally far from land, but occasionally closer to shore near islands or inlets. They are seldom found in waters colder than 16 °C (61 °F). Their range includes the western Atlantic, from Argentina and the Gulf of Mexico to Browns Bank off Nova Scotia. While they are neither abundant nor rare in Canadian waters, they are commonly found in New Zealand waters.
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These sharks travel long distances in search of prey or mates. A female tagged off California in December 1998 was captured in the central Pacific by a Japanese research vessel, demonstrating a journey of over 2,776 km (1,725 mi).
Diet and Feeding Habits
The shortfin mako shark feeds primarily on cephalopods and bony fish, including mackerel, tuna, bonito, and swordfish. However, their diet also includes other sharks, porpoises, sea turtles, and seabirds. They have even been known to consume dead organic matter.
Makos hunt by lunging vertically upwards and tearing off chunks of their prey’s flanks and fins. They often swim below their prey, giving them a higher probability of a successful attack. In Ganzirri and Isola Lipari, Sicily, some shortfin makos have been found with swordfish bills impaled in their heads and gills, suggesting that swordfish can seriously injure or even kill them.
Shortfin mako sharks consume about 3% of their body weight each day, taking approximately 1.5-2.0 days to digest an average-sized meal. In comparison, the less active sandbar shark consumes only 0.6% of its weight daily and requires 3 to 4 days for digestion. An analysis of the stomach contents of 399 mako sharks ranging from 67-328 cm (26-129 in) indicated that bluefish are a preferred food source from Cape Hatteras to the Grand Banks, constituting 77.5% of their diet by volume.
Larger shortfin mako sharks, over 3 m (9.8 ft), possess interior teeth that are considerably wider and flatter than those of smaller makos. This adaptation allows them to effectively prey on dolphins, swordfish, and other sharks. They also scavenge long-lined and netted fish. The bite of a shortfin mako shark is exceptionally strong, with the strongest bite force ever recorded for a shark being measured at Mayor Island in New Zealand in 2020, registering approximately 3,000 lbs.
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Life History and Reproduction
Shortfin mako sharks are slow to reproduce. Females only reach sexual maturity at 18 to 21 years and have a gestation period of 15 to 18 months, with a three-year reproductive cycle, which means they will only produce 3 to 4 litters in their lifetime. The shortfin mako shark is a yolk-sac ovoviviparous shark giving birth to live young. Developing embryos feed on unfertilized eggs (oophagy) within the uterus during the 15- to 18-month gestation period. They do not engage in sibling cannibalism unlike the sand tiger shark (Carcharias taurus). The four to 18 surviving young are born live in the late winter and early spring at a length of about 70 cm (28 in). Females may rest for 18 months after birth before mating again.
A common mating strategy of shortfin mako sharks has been documented as using multiple paternity as a mating strategy, known as polyandry. Polyandry is where the females mate with more than one male. Shortfin mako sharks bear young on average every three years.
Shortfin mako sharks are aged by sectioning vertebrae - one of the few bony structures in sharks - and counting growth bands. The age of shortfin mako, and therefore important parameters, such as age at sexual maturity and longevity, were severely underestimated until 2006 (e.g. claims of sexual maturity at 4-6 years, claims of longevity as low as 11 years), because of a poorly supported belief that shortfin mako sharks deposited two growth bands per year in their vertebrae. This belief was overturned by a landmark study which proved that shortfin mako sharks only deposit one band in their vertebrae per year, as well as providing validated ages for numerous specimens. Natanson et al. (2006) aged 258 shortfin mako specimens and recorded:
- Maximum age of 29 years in males (260 cm or 8.5 ft fork length (FL))
- Maximum age of 32 years in females (335 cm or 10.99 ft FL)
- 50% sexual maturity at 8 years in males (185 cm or 6.07 ft FL)
- 50% sexual maturity at 18 years in females (275 cm or 9.02 ft FL)
Similar, validated age findings were made (median age at maturity in males 7-9 years, median age at maturity in females 19-21 years, longevity estimates 29 years and 28 years respectively) in New Zealand waters.
Due to this error, fishery management models and ecological risk assessment models in use around the world were underestimating both the longevity and the age at sexual maturity in shortfin mako sharks, particularly in females, by two-thirds or more.
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Intelligence and Behavior
Of all studied sharks, the shortfin mako has one of the largest brain-to-body ratios. This large brain size prompted investigations into their intelligence. Studies have shown that shortfin makos are fast learners, able to differentiate between threatening and non-threatening researchers. They rely on smell, hearing, and vision when hunting, rather than electroreception.
Conservation Status and Threats
The shortfin mako is currently classified as Endangered by the IUCN, having been uplisted from Vulnerable in 2019 and Near-Threatened in 2007. The species is included on Appendix II of CITES, which regulates international trade.
The main threats to shortfin mako sharks are overfishing and bycatch. They are targeted by both sport and commercial fisheries for their fins and meat, and are also caught unintentionally in driftnet fisheries targeting other species. In 2017, the International Commission for the Conservation of Atlantic Tunas (ICCAT) declared the north Atlantic population as ‘overfished’.
The species’ long lifespan and slow reproductive rates make population recovery a challenge. Increased conservation and management efforts are required to allow for population replacement and for young animals to reach adulthood. In November 2021, ICAAT members agreed to a retention ban on shortfin makos in the North Atlantic for the years 2022 to 2023 to allow for population recovery.
Interactions with Humans
Mako fishing is a prominent activity around the world. As one of the fastest species in the ocean, they offer acrobatic flips, fast runs, and strong fights, which all greatly entertain anglers. Traditionally, the sharks are hooked through the use of chum and baitcasters; however, fly fishing for them has become more popular, particularly in San Diego, California, where one of the three known worldwide mako rookeries is located.
ISAF statistics records 9 shortfin attacks on humans between 1980 and 2022, three of which were fatal, along with 20 boat attacks. Many attacks involving shortfin mako sharks are considered to have been provoked due to harassment or the shark being caught on a fishing line.
Of all recorded attempts to keep pelagic shark species in captivity, the shortfin mako shark has fared the poorest, even more so than the blue shark and the great white shark.
Management and Conservation Efforts
Atlantic sharks are managed under the Consolidated Atlantic Highly Migratory Species Fishery Management Plan. This plan includes:
- Permits are required, and only a limited number of permits are available.
- Commercial quotas and limits on how many sharks can be landed per fishing trip.
- Gear restrictions and requirements.
- Fishing season is generally year-round, but individual commercial shark fisheries close when the quota is reached.
- Shark dealers are required to attend Atlantic shark identification workshops to help them better identify shark species.
- Prohibited species-there are more than 20 species of sharks that cannot be landed (e.g., white, dusky, basking, longfin mako, night). Some of these species look similar to the species that can be landed. The recreational shark identification can help with identification.
- The Shark Conservation Act requires that all sharks, with one exception, be brought to shore with their fins naturally attached.
- Compliance guides are available for all commercial and recreational regulations across Atlantic highly migratory species fisheries.
NOAA Fisheries conducts various research activities on the biology, behavior, and population health of Atlantic shortfin mako. The results of this research are used to inform management decisions for this species.