Atlantic Shortfin Mako Shark (Isurus oxyrinchus)

• Population estimates for Atlantic shortfin mako are uncertain. The latest stock assessment by ICCAT in 2008 indicates that shortfin mako shark may be overfished in the North Atlantic. Assessment information about the South Atlantic population is inconclusive.
• The Highly Migratory Species Management Division of NOAA's National Marine Fisheries Services manages shortfin mako shark domestically, but the United States also works with Regional Fisheries Management Organizations worldwide to manage sharks.
• 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: According to the 2008 stock assessment, Atlantic shortfin mako biomass estimates range from 95% to 165% of target levels.
Overfishing: Unknown – current U.S. status is under evaluation
Overfished: Unknown – current U.S. status is under evaluation
Fishing and habitat: In the U.S. Atlantic and Gulf of Mexico, shortfin mako shark are generally caught commercially as bycatch by pelagic longliners that are targeting swordfish and tuna, and recreationally by rod and reel. Pelagic longline gear has no impact on ocean floor habitats, because it does not come in contact with the bottom.
Bycatch: 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 minimize bycatch by closing ocean areas that historically have the highest rates of bycatch, and Vessel Monitoring Systems are required on U.S. Atlantic 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, U.S. Atlantic pelagic longline fishermen must attend workshops to learn how to properly handle and release these animals. The Atlantic, Caribbean, and Gulf of Mexico pelagic longline fishery is designated as a Category I fishery according to the List of Fisheries published annually by NMFS as required under the Marine Mammal Protection Act. This means that annual mortality and serious injury of certain marine mammal stocks in this fishery are greater than or equal to 50% of the Potential Biological Removal level (the maximum number of animals, not including natural mortalities, that may be removed from a marine mammal stock while allowing it to be at sustainable levels). NMFS is addressing this challenge through the Pelagic Longline Take Reduction Team, which works to reduce serious injuries and mortalities of short-finned pilot whales, long-finned pilot whales, and Risso's dolphins in the Mid-Atlantic portion of the Atlantic pelagic longline fishery. Rod and reel is considered a Category III fishery, and has minimal impacts on protected species.
Aquaculture: There is currently no commercial aquaculture of mako shark in the United States.

Science and Management

In the Atlantic and Gulf of Mexico, shortfin 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. Amendment 2 to the Consolidated HMS FMP became effective in July 2008, and is the most recent update to the regulations contained in the Consolidated HMS FMP. Regulations include numerous measures to rebuild or prevent overfishing of Atlantic sharks in commercial and recreational fisheries. Some measures utilized to protect shortfin mako shark in U.S. Atlantic fisheries are commercial quotas and trip limits, 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 Organizationsto enhance shark management worldwide, 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).

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 bluefish, its primary prey in the North Atlantic.

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: Found in tropical and temperate 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 shortfin mako sharks may live for 25 years.
• Food: Shortfin mako sharks feed mainly on fishes such as bluefish, 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 - females mature at 4 to 6 years.
• Reproduction: Relative to other marine fish, shortfin mako sharks have very low reproductive potential. Shortfin 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, which 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.
• Predators: Since sharks are at the top of the food chain, they have few predators besides humans, although young shortfin makos may fall prey to larger sharks.
• Commercial or recreational interest: Both
• Distinguishing characteristics: Shortfin 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, shortfin mako sharks provide a valuable balance to the marine ecosystem and have few predators. Younger, smaller shortfin mako sharks may fall pretty to larger sharks from a variety of species. Humans are one of the few species that prey on sharks.

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, Gulf of Mexico, and Caribbean.

Biomass

Biomass refers to the amount of shortfin mako shark in the ocean (by weight). Scientists cannot collect and weigh every single shark to determine biomass, so they use mathematical 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 (BMSY), suggesting the species may be overfished. According to the 2008 stock assessment, the biomass of the South Atlantic shortfin mako population is currently unknown.

Note: Because of the lack of quantity and quality of data used in the 2008 stock assessment, the stock status of the Atlantic shortfin mako shark population is considered uncertain.

Landings

Landings refer to the amount of catch that is brought to land. In the U.S. Atlantic and Gulf of Mexico, commercial landings of shortfin mako sharks ranged from a low of 107,267 pounds in 2006 to a high of 217,171 pounds in 2004.

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

Biomass and Landings

Landings and biomass data can sometimes be used to detect trends in a fishery. Because the biomass data for shortfin mako shark is preliminary, it is difficult to determine if fluctuations in landings since 1999 are a result of fluctuations in biomass, changes fishing effort, or a combination of both. Other factors, such as changes in management measures, market preferences, or environmental conditions may have contributed to changes in landings as well. The shortfin mako is a highly migratory species that moves outside of U.S. waters, therefore fishing practices of foreign countries could affect U.S. Atlantic shortfin mako landings and the biomass of the population. Also, recreational fishing efforts may impact shortfin mako shark populations.

Data sources:
Landings from the 2006 Consolidated Atlantic Highly Migratory Species Fishery Management Plan and 2007 Stock Assessment and Fishery Evaluation Report for Atlantic Highly Migratory Species

Important Dates

1966 – International Convention for the Conservation of Atlantic Tunas is signed creating the International Commission for the Conservation of Atlantic Tunas (ICCAT)
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 shortfin mako) sharks reported for the Atlantic and Gulf
1990 – Magnuson Act amended, giving authority to Secretary of Commerce to manage Atlantic tunas; secretarial authority is delegated to NMFS
1992 – NMFS creates the HMS Management Division to manage Atlantic tunas, sharks, swordfish, and billfish
1993 – NMFS implements FMP for Sharks of the Atlantic Ocean; establishes recreational harvest limits for all sharks
1997 – NMFS reduces recreational retention limit for large coastal and pelagic sharks, including shortfin mako sharks, from 4 to 2 sharks per vessel per trip
1999 – NMFS implements the FMP for Atlantic Tunas, Swordfish, and 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
2006 – Consolidated Atlantic Highly Migratory Species Fishery Management Plan is approved, which requires sharks to be landed with their second dorsal fin attached and creates new time/area closures
2008 – NMFS implements Amendment 2 to the Consolidated Highly Migratory Species Fishery Management Plan to address overfishing of some shark species by instituting new commercial fishing trip limits (33 large coastal sharks per trip) and prohibiting the harvest of sandbar shark (Carcharhinus plumbeus) unless fishing within the newly established Shark Research Fishery

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)

Amendment 2 to the Atlantic HMS Fishery Management Plan

Stock Assessments:
2007 Stock Assessment and Fishery Evaluation Report for Atlantic Highly Migratory Species