Atlantic Shortfin Mako Shark (Isurus oxyrinchus)

• Population estimates for Atlantic shortfin mako are unknown. Studies indicate shortfin mako shark may be overfished in the North Atlantic. South Atlantic populations are not likely overfished as they are not fished as heavily.
• NOAA's National Marine Fisheries Services manages shortfin mako shark domestically, but the United States also works with Regional Fisheries Management Organizations to increase shark management worldwide.
• 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 popular seafood species.

Sustainability Status

Biomass: Atlantic shortfin mako was assessed in 2004 but results were inconclusive.
Overfishing: Unknown
Overfished: Unknown
Fishing and habitat: Shortfin mako shark are fished with pelagic longlines in the Atlantic and Gulf (primarily targeting swordfish and tunas). Longline gear has few impacts on open water habitats.
Bycatch: Finfish, along with sea turtles, marine mammals, and seabirds were identified as bycatch concerns for the pelagic longline fishery in the 2003 Highly Migratory Species Bycatch Reduction Plan. Pelagic longline gear sometimes catches non-target finfish with little or no commercial value, as well as species that cannot be retained by commercial fishermen due to regulations, such as billfish. Pelagic longlines may also interact with protected species such as marine mammals, sea turtles, and seabirds. Area closures are used to decrease bycatch by closing the areas with the highest rates of bycatch. Vessel Monitoring Systems are required on pelagic longline vessels to enforce closures and monitor the fishery. Circle hooks are also required to increase post-release survival of animals that are inadvertently caught. Additionally, pelagic longline fishermen must attend workshops to learn how to properly handle and release these animals. NMFS is addressing marine mammal interactions through the Pelagic Longline Take Reduction Team.
Aquaculture: There is currently no commercial aquaculture of mako shark in the United States.

Science and Management

In the Atlantic and Gulf of Mexico, mako shark is managed by NOAA's National Marine Fisheries Service (NMFS) Highly Migratory Species (HMS) Management Division through the 2006 Consolidated Atlantic HMS Fishery Management Plan (FMP). This FMP combined the 1999 FMP for Atlantic Tunas, Swordfish, and Sharks (and its 2003 amendment) and the Atlantic Billfish FMP. The 1999 FMP included numerous measures to rebuild or prevent overfishing of Atlantic sharks in commercial and recreational fisheries, such as quotas, recreational minimum sizes and retention limits, and limited access in commercial fisheries.

Because highly migratory species move throughout large areas of the Atlantic Ocean 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. The United States plays an important part in negotiating with Regional Fisheries Management Organizations, including the International Commission for the Conservation of Atlantic Tunas (ICCAT), the Food and Agriculture Organization of the United Nations (FAO), and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), to increase shark management worldwide.

The NMFS Northeast Fisheries Science Center, in conjunction with scientists at Moss Landing Marine Laboratories, California, is continuing a comprehensive aging and validation study for shortfin mako. In addition, a collaborative program with students and scientists at the University of Rhode Island examining the biology and population dynamics of the shortfin mako in the North Atlantic continues to research age, growth, reproductive parameters, migrations, and predator-prey relationships between shortfin mako and its primary prey, bluefish.

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: In tropical seas worldwide.
• Habitat: The shortfin mako shark is a pelagic species, which means its habitat ranges widely in the upper zones of the oceans. Juveniles are also common in neritic waters, from the low-tide line to the edge of the continental shelf in oceans.
• Life span: The maximum age has been estimated to be about 11.5 years, but female mako sharks may live for 25 years.
• Food: Mako sharks feed on fast-moving fishes such as swordfish, tuna, and other sharks.
• Growth rate: Slow
• Maximum size: Adult females are bigger than their male counterparts, often exceeding 13 feet in length and weighing as much as 1,100 pounds.
• Reaches reproductive maturity: Late sexual maturity; females mature at 4 to 6 years.
• Reproduction: Relative to other marine fish, sharks have a very low reproductive potential. Mako sharks have a 2-year reproductive cycle, and a gestation period of approximately 12 months. Litter sizes range from 12 to 20 pups (although only a handful of litters have been examined). These pups are large at birth, effectively reducing the number of potential predators and enhancing their chances of survival. During mating, the male shark inseminates the female with copulatory organs, known as claspers, that develop on the pelvic fins.
• Spawning season: Late Winter to mid-Spring
• Spawning grounds: Unknown
• Migrations: Mako sharks are a highly migratory pelagic species, often traveling over entire ocean basins.
• Predator/prey interactions: Mako shark feeds at the top of the food chain, preying on fast-moving fishes such as swordfish, tuna, and other sharks. Since sharks are at the top of the food chain, they have few predators besides 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.

Role in the Ecosystem

As top predators in the sea, sharks provide a valuable balance to the marine ecosystem. Humans are one of the few species that prey on sharks, killing over 100 million per year (killer whales and other sharks are also predators).

Additional Information

Market name: Mako Shark
Vernacular names: Blue Pointer, Bonito Shark, Atlantic Mako Shark
Longfin mako sharks are also marketed as Mako Shark, but landings of longfin mako are currently prohibited by U.S. fishermen in the Atlantic.

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.

The North Atlantic shortfin mako population has experienced some level of stock depletion, as suggested by historic catch trends and models. The current stock may be below the biomass needed for maximum sustainable yield (B_MSY), suggesting the species may be overfished. Depletion rates in the South Atlantic are less severe.

Note: The results of the Atlantic shortfin mako shark stock assessments should be considered preliminary in nature due to limitations on quality and quantity of the catch data available.

Landings

Landings refer to the amount of catch that is brought to land. In the Atlantic and Gulf of Mexico, commercial landings of shortfin mako sharks ranged from a low of 129,088 pounds in 2000 to a high of 217,171 pounds in 2004.

Note: Only domestic commercial landings are shown in the graph.

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 the 2006 Consolidated Atlantic Highly Migratory Species Fishery Management Plan

Important Dates

Late 1970s-1980s – Growing demand for shark products encourages expansion of the commercial fishery
1980s – As catches accelerate, shark stocks suffer a precipitous decline
1989 – Peak commercial landings of large coastal and pelagic (includes mako) sharks reported for the Atlantic and Gulf
1993 – NMFS implements FMP for Sharks of the Atlantic Ocean; establishes recreational harvest limits for all sharks
2003 – Amendment 1 to the Atlantic Shark FMP eliminates commercial minimum size restrictions, implements commercial fishing seasons, imposes gear restrictions to reduce bycatch, and implements a time/area closure off the coast of North Carolina
2004 – ICCAT adopts a recommendation concerning the conservation of sharks caught in association with fisheries managed by ICCAT; includes reporting of shark catch data, a ban on shark finning, a request to live-release sharks that are caught incidentally, a review of management for shortfin, and a commitment to conduct another stock assessment of selected pelagic shark species no later than 2007

Notes and Links

General Information:
NMFS Shark Web Site

NMFS Office of Sustainable Fisheries Highly Migratory Species Division - Sharks

Fishery Management:
2006 Consolidated Atlantic Highly Migratory Species (HMS) Fishery Management Plan (FMP)

Stock Assessments:
NMFS Highly Migratory Species Stock Assessment and Fishery Evaluation Reports