Pacific Spiny Dogfish (Squalus acanthias)
- There are no estimates of population size for Pacific spiny dogfish.
- The West Coast spiny dogfish fishery is managed based on historical catch. Trip limits are also used to limit catch. There are no directed fisheries for spiny dogfish in Alaska; they are only caught incidentally in groundfish fisheries.
- Shark is a low-fat source of protein that is high in selenium and vitamins B6 and B12. 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.
- Spiny dogfish is commonly used as the fish in "fish and chips" and is one of the world's most abundant species of shark.
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| Nutrition Facts |
| Servings 1 |
| Serving Weight
100g |
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| Amount Per Serving |
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| Calories 130 |
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| Total Fat |
4.51 g |
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| Total Saturated Fatty Acids |
0.925 g |
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| Carbohydrate |
0 g |
| Sugars |
0 g |
| Total Dietary
Fiber |
0 g |
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| Cholesterol |
51 mg |
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| Selenium |
36.5 mcg |
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| Sodium |
79 mg |
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| Protein |
20.98 g |
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 Dogfish are often regarded as a menace to fisheries because they cause damage to nets and lines and rob hooks.
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Did you know?
Spiny dogfish may once have been the most abundant living shark in the world. However, it is commercially fished worldwide and has been heavily depleted in many locations. Directed fisheries for spiny dogfish often take larger individuals, which are usually mature females, significantly impacting on recruitment.
Sharks are long-lived species with slow growth to maturity and large maximum size. The productivity of shark populations therefore, is very low relative to most commercially exploited fish, making them more susceptible to overfishing.
Spiny dogfish are the most abundant and economically important shark off North American coasts. In recent years, large numbers of dogfish have been taken in commercial trawl, set net, and longline fisheries, especially in Puget Sound, to supply foreign markets. They are a major commercial species on the other side of the Atlantic and are commonly used in fish and chips.
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Part of both their common and scientific names comes from the sharp spines sheathed by toxic tissue on their dorsal fins, which are the only threat this shark poses to humans.
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Dogfish often travel in large schools, which feed avidly on their journeys. The schools number in the hundreds and tend to divide up according to size and gender, although the young, both male and female, tend to stay together.
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Sustainability Status
Biomass: There are no biomass estimates available for Pacific spiny dogfish.
Overfishing: Unknown
Overfished: Unknown
Fishing and habitat: Off the West Coast, spiny dogfish are targeted by both bottom trawl and non-trawl gears. Both types of gear come in contact with the ocean floor to varying degrees. Trawling involves the towing of a funnel shaped net or nets behind a fishing vessel. A bottom trawl is a trawl in which the doors, the footrope of the net, or both are in contact with the seabed. Non-trawl gear, specifically bottom longline gear, also comes in contact with the ocean floor. The bottom longline fishery involves the setting out of a horizontal line to which other lines (gangions) with baited hooks are attached. This horizontal line is secured between anchored lines and identified by floating surface buoys, bamboo poles, and flags. There is no directed fishery for spiny dogfish in Alaska, and so there are no impacts on habitat.
Bycatch: Yelloweye and canary rockfish, both overfished groundfish species, are caught as bycatch in the West Coast dogfish fishery. Since spiny dogfish are not targeted by fisheries in Alaska, there is no bycatch.
Aquaculture: There is currently no commercial aquaculture of spiny dogfish in the United States.
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Science and Management
Spiny dogfish is included in the Pacific Fishery Management Council's Groundfish Fishery Management Plan (FMP) as part of the "Other Fish" complex (all of the unassessed Groundfish FMP species that are neither rockfish nor flatfish). The acceptable biological catch (ABC) for the "Other Fish" complex is based on historical catch. The targeted harvest level, called the optimum yield (OY), is set as half of the ABC as a precautionary adjustment for these unassessed stocks. Separate trip limits were established in 2006 for spiny dogfish to limit the harvest of this species. All sectors of the groundfish fishery are limited by the need to rebuild the groundfish species that have been declared overfished. Commercial fisheries are restricted by coastwide, depth-based closed areas designed to protect overfished groundfish species. Spiny dogfish are generally not targeted by sport fisheries on the West Coast. However, due to the voracious feeding nature of spiny dogfish, they tend to be caught incidentally in all recreational fisheries and are generally considered a nuisance by anglers.
There are no directed fisheries for sharks in the Bering Sea or Aleutian Islands (BSAI) or in the Gulf of Alaska (GOA), but some sharks are caught incidentally in other directed commercial fisheries. They are currently included as part of the "Other Species" complex in the BSAI and GOA Groundfish Fishery Management Plans. A total allowable catch is set annually for the Other Species management category.
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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 the North Pacific Ocean, spiny dogfish are found from the Bering Sea to Baja California. They are more common off the U.S. West Coast and British Columbia than in the Gulf of Alaska or the Bering Sea and Aleutian Islands region.
- Habitat: Spiny dogfish inhabit the shelf and upper slope waters in depths up to 4,050 feet, but most are found in waters less than 1,150 feet deep. Spiny dogfish are common in inland seas, such as San Francisco Bay and Puget Sound, and in shallow bays from Alaska to central California. Males are generally found in shallower water than females, except for pregnant females that enter shallow bays to pup. Immature juveniles tend to inhabit the water column near the surface and are not available to the targeted fishery until they mature and descend to the bottom. Subadults are found on muddy bottoms when not found in the water column. Adults live on the bottom.
- Life span: Sharks are a long-lived species. The life of a spiny dogfish shark typically spans decades. Females can live up to about 70 years. They live longer than males, which only live to a maximum of 36 years.
- Food: Spiny dogfish feed on small, schooling pelagic fish such as herring, and small invertebrates, such as shrimp, crab, and squid.
- Growth rate: Slow - about 0.6 to 1.4 inches per year.
- Maximum size: Adults usually range in size from 2.5 to 3.4 feet, although they can reach a maximum size of 4.3 feet and 22 pounds.
- Reaches reproductive maturity: Females reach sexual maturity between 16 and 35 years, with an average age of 24; males reach maturity at 11 to 19 years, with an average age of 14.
- Reproduction: Males and females mate annually. Female spiny dogfish have between 2 and 12 eggs each per season. Eggs are fertilized internally. Depending on area, their gestation period lasts 18 to 24 months, the longest of any vertebrate. Females release their young during the spring in the midwater zone in shallow waters. Small litters (4-7 pups) are common, but litter size may range from 2 to 20 pups. The number of pups per female increases with the size of the female. Newborn pups range in length from 8.7 inches to 1 foot.
- Spawning season: Females release their young in the spring, after a gestation period of 18 to 24 months.
- Spawning grounds: Pregnant females enter shallow bays to pup.
- Migrations: Spiny dogfish can travel long distances; in fact, a tagged dogfish from Queen Charlotte Sound (off British Columbia) in 1980 was recovered off the northeast coast of Japan in 1982. Dogfish often migrate in large schools numbering in the hundreds. They feed avidly on their journeys. The schools exhibit north-south coastal movements and onshore-offshore movements that are not completely understood. Schools tend to divide up according to size and gender although the young, both male and female, tend to stay together. They migrate seasonally to stay within their preferred temperature range. They also make daily migrations from the near bottom during the day to the near surface at night.
- Predators: Spiny dogfish are preyed upon by a variety of shark species, including sixgill, sevengill, leopard, and great white; by a variety of larger fishes, such as lancetfishes, and some rockfish; and by some marine mammals.
- Commercial or recreational interest: Both
- Distinguishing characteristics: Dogfish are a slim shark with a narrow, pointed snout and distinctive white spots. They have two dorsal fins with ungrooved large spines. Their bodies are grey above and white below.
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Role in the Ecosystem
Spiny dogfish are top level predators. They are an opportunistic feeder, taking whatever prey is available. Their diet consists primarily of fish, especially sandlance, herring, smelts, cods, capelin, hake, and ratfish; and of invertebrates, particularly shrimp, crabs, worms, krill, squid, octopus, jellyfish, and sea cucumbers. Fish become a more important part of their diet as the dogfish grow larger. Most of the diet of juveniles consists of pelagic prey, generally small invertebrates, where as the adults prey largely on benthic organisms. Spiny dogfish may compete with sablefish, Pacific cod, soupfin shark, and sea lions for food. They are preyed upon by a variety of shark species, including sixgill, sevengill, leopard, and great white; by a variety of larger fishes, such as lancetfishes, and some rockfish; and by some marine mammals.
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Additional Information
Market name: Shark, Dogfish
Vernacular names: Spring Dogfish, Spiked Dogfish, Grayfish, Spur Dog, Picked Dogfish
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Biomass
Biomass refers to the amount of Pacific spiny dogfish 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.
There are no biomass estimates for spiny dogfish at this time. Spiny dogfish are captured periodically in NMFS bottom trawl surveys of the Bering Sea and Aleutian Islands, but biomass estimates are very low as dogfish are not as common in this area.
Landings
 Landings refer to the amount of catch that is brought to land. There are currently no directed commercial fisheries for shark species in federally or state managed waters of Alaska, and most incidentally caught sharks are not retained. Recent catches in the Bering Sea and Aleutian Islands have averaged only 8 metric tons whereas catches in the Gulf of Alaska have been considerably higher averaging about 500 metric tons. A plant in Kodiak, Alaska has recently been retaining some spiny dogfish. Spiny dogfish are also retained as incidental catch in some State managed fisheries.
Off the West Coast, landings of spiny dogfish have varied between 1990 and 2006 from a low of 250 metric tons in 1996 to a high of 1,392 metric tons in 1994.
Note: U.S. 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 NMFS Annual Commercial Landings Statistics using "SHARK, SPINY DOGFISH" as Species and "PACIFIC" as State
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Important Dates
1978 – Gulf of Alaska FMP is approved and implemented; sharks included in "Other Species" management category which includes squid, sculpins, sharks, and octopi
1979 – Bering Sea and Aleutian FMP is approved and implemented; sharks included in "Other Species" management category which includes squid, sculpins, sharks, and octopi
1982 – Pacific Coast Groundfish FMP is approved and implemented
2004 – First stock assessment of sharks completed for BSAI and GOA
2006 – Limits on commercial harvest implemented for West Coast
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Notes and Links
General Information:
NMFS Sustainability Species Identification - Spiny dogfish
Fishery Management:
Pacific Coast Groundfish Fishery Management Plan
Full Bering Sea and Aleutian Islands Groundfish Fishery Management Plan, Appendix only
Full Gulf of Alaska Groundfish Fishery Management Plan and Appendices
Stock Assessments:
2006 BSAI Shark SAFE
2006 GOA Shark SAFE
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