Pacific Shortfin Mako Shark (Isurus oxyrinchus)

• Population status is unknown, but analyses suggest that shortfin mako shark is not overfished in the Pacific.
• In the Pacific Ocean, shortfin mako shark is managed by both the Pacific and Western Pacific Fishery Management Councils.
• Shark is high in protein and low in fat. It is a good source of niacin, vitamins B6 and B12, and phosphorus and a very good source of selenium. Shark may contain amounts of methylmercury in excess of the FDA's recommended limit for moms, moms-to-be, and young children. For more information, see EPA and FDA advice on what you need to know about mercury in fish and shellfish.
• Shortfin mako shark is a very popular seafood species.

Sustainability Status

Biomass: Unknown; preliminary analyses based on catch and effort data for the U.S. West Coast pelagic drift gill net fishery indicate that the local population biomass in 2000 likely exceeded the biomass at maximum sustainable yield (MSY).
Overfishing: Unknown; while additional information is required, especially for adult mako sharks and on catch beyond U.S. waters, overfishing does not appear to be occurring off the U.S. West Coast.
Overfished: Unknown; see "Biomass" above
Fishing and habitat: Shortfin mako are caught in the drift gillnet fishery off the U.S. West Coast and on longlines in throughout the Pacific. In general, highly migratory species (HMS) fishing gear is not known to directly alter water column habitat because the approved gears that are used in the HMS fisheries do not contact the bottom substrate, but habitat can be affected by inadvertent loss of gear that is left to "ghost fish," and create marine debris that can cause harm to other species in the pelagic environment.
Bycatch: In both drift gillnet and longline fisheries, bycatch of non-target species is a concern. Bycatch in the pelagic drift gill net fishery off the U.S. West Coast is mainly comprised of ocean sunfish and blue shark, although marine mammals and turtles are also occasionally taken. Fisheries regulations limiting both the season and geographic range of the pelagic drift-gill net fishery were implemented to reduce bycatch. NMFS is addressing interactions with marine mammals through the Pelagic Offshore Cetacean Take Reduction Plan. In the western Pacific, both area closures and gear restrictions have helped minimize the bycatch of sharks and marlins, and have reduced protected species interactions. Longline vessels are required to employ special measures to avoid catching sea turtles and seabirds and increase the likelihood of their survival after release. Bycatch reduction is also achieved through non-regulatory means, including outreach to fishermen and engagement of fishermen in research activities and the management process. U.S. efforts to reduce bycatch on all fronts are ongoing, however fisheries outside of the U.S. may land mako sharks in fisheries which do not employ comparable bycatch reduction strategies.
Aquaculture: There is currently no commercial aquaculture of mako shark in the United States.

Science and Management

In federal waters off the Pacific Coast, the shortfin mako shark is managed by the Pacific Fishery Management Council through the Highly Migratory Species Fishery Management Plan (FMP). Prior to that, HMS fisheries off the U.S. West Coast were managed by the states. The first substantial regulations impacting the fishery were implemented in 1990 when both the season and range of the fishery were restricted, and observers were placed onboard to monitor 20% of the trips. In April 2005, new monitoring requirements came into effect with implementation of the FMP. Current regulations require that commercial fishers obtain a permit from NMFS to fish for HMS and maintain logbooks documenting their catch. Recreational charter vessels must also keep logbooks. These measures are intended to improve data collection regarding HMS catches. For recreational fisheries the daily bag limit is two mako sharks. A federal law prohibits "shark finning," where fins are removed and the carcass is discarded.

In the western and central Pacific, mako sharks are also managed by the Western Pacific Fishery Management Council through the Pelagics FMP, implemented in 1987. The FMP governs fishing activities of U.S. and foreign vessels in the U.S. Exclusive Economic Zone (EEZ). Regulations include area closures, gear restrictions, fishing permit requirements, reporting and observer requirements, submission of effort plans, and catch and effort limits. U.S. vessels in the western Pacific are prohibited from using drift gillnets unless they have an experimental fishing permit.

Because highly migratory species move throughout large areas of the Pacific and are fished by many nations and gear types, management by the United States alone is not enough to ensure that harvests are sustainable in the long term. Although mako sharks are not managed internationally in the Pacific, the United States is participating in bilateral meetings regarding shark management with Japan, Spain, Taiwan, the European Union, Canada, China, and Mexico. Recent resolutions on shark conservation and management of the two international fisheries management organizations operating in the Pacific, the IATTC and WCPFC, may result in future monitoring and management of shortfin mako and other pelagic sharks.

Researchers at NMFS Southwest Fisheries Science Center and Pacific Islands Fisheries Science Center are studying Pacific sharks to learn more about their biology, distribution, movements, stock structure and status, and potential vulnerability to fishing pressure. This information is provided to international, national, and regional fisheries conservation and management bodies charged with the sustainable management of pelagic sharks and other HMS.

Life History and Habitat

Life history, including information on the habitat, growth, feeding, and reproduction of a species, is important because it affects how a fishery is managed.

• Geographic range: Mako sharks are found in all world oceans from tropical to warm temperate seas.
• Habitat: The shortfin mako shark is a pelagic species, which means it occurs predominantly in the upper zones of the ocean. Juveniles are most common in coastal waters, with the southern California Bight being an important nursery ground.
• Life span: Because of uncertainty over ageing of mako sharks, the maximum age remains to be conclusively determined; current estimates range from about 15 to 30 years.
• Food: Mako sharks feed at the top of the food chain, preying on a range of pelagic fish and squid including fast-moving fishes such as swordfish, tuna, and other sharks. The diet is varied and opportunistic depending on locally available prey. Recent examinations of stomach contents of makos landed off California have demonstrated an increasing importance of jumbo squid (Doscidicus gigas) in their diet.
• Growth rate: Slow
• Maximum size: Adult females reach a larger size than male mako sharks and can exceed 13 feet in length and as much as 1,100 pounds in weight.
• Reaches reproductive maturity: Male makos reach sexual maturity at a smaller size than females, at about 6.5 feet. Females are thought to reach sexual maturity at a size of about 10 feet. Estimates of age at sexual maturity vary as some uncertainty remains regarding ageing mako sharks, but range from roughly 4-8 years for males and 6-15 years for females.
• Reproduction: Relative to other marine fish, sharks have a very low reproductive potential. Mako sharks have a two or three-year reproductive cycle, and a gestation period of 12-18 months. Litter sizes range from 4 to 30 pups, although only a handful have been examined. These pups are large at birth, effectively reducing the number of potential predators and enhancing their chances of survival. All sharks have internal fertilization. During mating, the male shark inseminates the female with copulatory organs, known as claspers, that develop on the pelvic fins.
• Breeding season: Given the lack of information on the distribution of mature adults and reproductive biology the mating season is not known, however pupping likely occurs in spring and summer.
• Spawning grounds: In general, pupping areas are located off southern California and northern Mexico. Based on the catch of juvenile sharks, the southern California Bight appears to be an important pupping ground for mako sharks.
• Migrations: Mako sharks are a highly migratory pelagic species, often traveling over entire ocean basins. The migrations of primarily juvenile mako sharks in the Pacific have been determined both using conventional and electronic tags. While mako sharks are capable of traveling from California to the central Pacific and even as far as Japan, most documented migrations are much shorter with individuals remaining in the eastern Pacific along the coast of the U.S. and Mexico. The migration patterns for larger individuals likely differ, and it is thought that as mako shark mature they move south and offshore. Ongoing genetic analysis reveals some differences between distant locations across the Pacific suggesting the presence of multiple stocks and limited basin-scale movements.
• Predators: Mako sharks are near the top of the food chain and, especially at larger sizes, have few predators other than humans.
• Commercial or recreational interest: Both
• Distinguishing characteristics: Mako sharks have conical, pointed snouts, long gill slits, dark blue/gray coloring above, light metallic blue sides, and white below. The teeth of the shortfin mako are conical and pointy and protrude forward from the jaw making them visible even when the mouth is closed.

Role in the Ecosystem

As important predators in the world's oceans, sharks provide a valuable balance to the marine ecosystem. In ecosystems where sharks have been overfished, large-scale ecological shifts have been documented. The greatest threat to sharks is over fishing, with estimates of over a hundred million sharks taken in fisheries per year. Other upper level predators, like killer whales and larger sharks may occasionally prey on small makos. Concern about the status of many pelagic sharks is increasing.

Additional Information

Market name: Mako Shark
Vernacular names: Blue Pointer, Bonito Shark, Pacific Mako Shark
Longfin mako sharks are also marketed as Mako Shark.

Biomass

Biomass refers to the amount of mako shark in the ocean. Scientists cannot collect and weigh every single shark to determine biomass, so they use models to estimate it instead. These biomass estimates can help determine if a stock is being fished too heavily or if it may be able to tolerate more fishing pressure. Managers can then make appropriate changes in the regulations of the fishery. Scientists do not believe shortfin mako has been depleted off the U.S. West Coast based on catch and effort data from the pelagic drift gillnet fishery and due to the species' wide range and the low availability of adults to fishing gear.

Landings

Landings refer to the amount of catch that is brought to land. Although commercial catches in the Pacific from 1994 to 1999 were only about 60 to 130 metric tons (132,000 to 286,600 pounds) per year, mako is still the third most valuable species taken in the drift gillnet fishery. Pacific coast catches peaked at greater than 400 metric tons in 1987 then declined especially during the 1990s in part due to changes in fisheries regulations. Recent U.S. Pacific landings have been less than 100 metric tons per year.

Biomass and Landings

Are landings and biomass related? Landings are dependent on biomass, management measures in the fishery, and fishing effort.

Data sources:
Landings from NMFS Annual Commercial Landings Statistics using "SHARK, SHORTFIN MAKO" as Species and "PACIFIC" as State

Important Dates

Late 1970s-1980s – A commercial drift gill net fishery develops off California and rapidly expands as market demands increase
1980s – As catches accelerate, thresher shark stocks suffered a precipitous decline, but mako sharks were not as negatively impacted as they were not specifically targeted
1987 – Western Pacific Fishery Management Council's Pelagics FMP implemented with shortfin mako sharks one of the management unit species
1988-1992 – A longline fishery for mako and blue sharks operated in Pacific coast state and federal waters. Total allowable catch was 80 mt of makos for the final 2 seasons before it was closed due to concerns over catches of immature sharks.
2004 – Pacific Fishery Management Council's Highly Migratory Species FMP is implemented with a harvest guideline imposed for shortfin mako sharks.
2005 – New monitoring requirements established in Pacific under the PFMC FMP.
2006 – IATTC and WCPFC pass resolutions on shark conservation and management calling for better research and periodic stock assessment efforts for the species of greatest concern

Notes and Links

General Information:
Southwest Fisheries Science Center Shark research page

NMFS Shark Web Site

Pacific Fishery Management Council's Background on Highly Migratory Species

Fishery Management:
West Coast Highly Migratory Species Fishing Management Plan

Western Pacific Pelagics FMP

Stock Assessments:
Status of the U.S. West Coast Fisheries for Highly Migratory Species through 2005