Red King Crab (Paralithodes camtschaticus)

• The red king crab population in the Bristol Bay area of Alaska is abundant and healthy.
• Managers have recently implemented the Crab Rationalization Program to decrease fishing capacity (the number of crab fishing vessels and processing capacity in Alaska) to improve conservation and minimize community impacts of regulations.
• Crab provides many dietary benefits including a good source of protein. For more on nutrition, see Nutrition Facts. (USDA)
• In 2005, only about 8% of the total crabs caught in U.S. waters were red king crab, and close to 70% of all king crab consumed in the U.S. were imported.

Sustainability Status

Biomass: Bristol Bay total mature biomass is well above the biomass needed for maximum sustainable yield (B_MSY), at 105% above B_MSY. Pribilof District total mature biomass is 239% above B_MSY. Norton Sound and Aleutian Islands-Adak were assessed in 2005 but no biomass estimates were made.
Overfishing: No*
Overfished: No*
Fishing and habitat: Crab pots can affect habitat when they settle to the bottom and when they are hauled back to the surface, but the extent of the impacts depends on the type of bottom habitat and the portion of that habitat utilized by the fishery. Red king crab are mostly fished in areas of sand and silt bottoms at depths of 120 to 600 feet. Sand and soft sediments are less likely to be affected than other habitat types. Also, pots are considered to be less damaging than mobile gear because they are stationary and come into direct contact with a much smaller area of the seafloor.
Bycatch: Bycatch in directed crab fisheries includes female crab, males under the legal size, and non-targeted crab. Several modifications to pot gear have been introduced to reduce bycatch mortality including escape panels and rings to prevent ghost fishing (when lost pots continue to capture and kill species). Crab fisheries also catch a small amount of other species as bycatch including octopus, Pacific cod, Pacific halibut, and other flatfish, sponges, coral, and sea stars. All bycatch is discarded at sea.
Aquaculture: With help from the NOAA Aquaculture Program, the NOAA Alaska Fisheries Science Center Kodiak Lab and Alaska Sea Grant are currently conducting research aimed at hatching and rearing red and blue king crabs in a large-scale hatchery setting to restore and rehabilitate these once-major, multimillion-dollar wild king crab fisheries around Kodiak Island and the Pribilof Islands in the Bering Sea. This partnership involves fishermen, scientists, and state and federal managers.

*For Bristol Bay and Pribilof Islands; Aleutian Islands/Adak and Norton Sound status is unknown and undefined

Science and Management

Several stocks of red king crab exist in the Bering Sea and Aleutian Islands; these stocks, differentiated by geographic location, include Bristol Bay, Norton Sound, Pribilof Islands, and Aleutian Islands-Adak. Red king crab are cooperatively managed with the State of Alaska through the North Pacific Fishery Management Council's (NPFMC) Fishery Management Plan (FMP) for Bering Sea/Aleutian Islands (BSAI) King and Tanner Crabs. This FMP defers management of crab fisheries to the State of Alaska, with federal oversight. State regulations must comply with the FMP, the national standards of the Magnuson-Stevens Act, and any other applicable federal laws. The State of Alaska has instituted minimum size and sex restrictions, vessels registration, seasons, observer requirements, and gear restrictions. The Pribilof Islands red king crab fishery is closed due to concerns over bycatch of blue king crab.

Surveys of Norton Sound and Aleutian Islands stocks are not regularly conducted. These stocks are generally managed based on catch history and in-season catch performance monitoring.

NOAA's National Marine Fisheries Service (NMFS) implemented a Crab Buyback Program in 2004 to reduce excess capacity and increase economic efficiency in the crab fisheries under the BSAI Crab FMP. Under this program, NMFS paid participants for withdrawing vessels from fishing, relinquishing fishing licenses, and surrendering fishing histories. Buyback programs seek to prevent or end overfishing, rebuild stocks of fish, or improve the conservation and management of a fishery.

The North Pacific Fishery Management Council developed the Crab Rationalization Program to accommodate the dynamics and needs of the BSAI crab fisheries. The program is a limited access system that allocates crab resources among several groups that depend on these fisheries, including harvesters, processors, and coastal communities. This program was developed to address the conservation and management issues associated with the previous derby fishery, reduce bycatch and associated discard mortality, and increase the safety of crab fishermen by ending the race for fish. In addition, the crab Community Development Quota (CDQ) Program protects community interests by allocating 10 percent of the total allowable catch to CDQ groups. The FMP defers management of the crab CDQ program to the State of Alaska with NMFS oversight.

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. For example, scientists have determined the approximate size of male red king crab at sexual maturity to be a length of about 4.7 inches carapace length (CL). Setting size limits (i.e., fishermen cannot keep crab smaller than 7 inches CL allows crab to reach reproductive maturity and reproduce before they are removed from the population.

• Geographic range: Red king crab are widely distributed throughout the Bering Sea and Aleutian Islands, Gulf of Alaska, Sea of Okhotsk, and along the Kamchatka shelf.
• Habitat: Young of the year crab occur at depths of 164 feet or less. They are solitary and need high relief habitat or coarse substrate such as boulders, cobble, shell hash, and living substrates such as bryozoans (tiny animals similar to coral) and stalked ascidians (sea squirts). Between the ages of 2 and 4, red king crab rely less on habitat and tend to form pods consisting of thousands of crabs. Podding generally continues until 4 years of age (at a size of about 2.5 inches), when the crab move to deeper water and join adults in the spring migration to shallow water to spawn. They then migrate to deeper water and settle in waters less than 90 feet for the remainder of the year.
• Life span: Long-lived (10 to 20+ years)
• Food: Varies with size and depth inhabited. Larval crab consume phytoplankton and zooplankton. Juveniles feed on diatoms, protozoa, hydroids, crab, and other organisms that live on the ocean floor. Adults eat an assortment of worms, clams, mussels, snails, brittle stars, sea stars, sea urchins, sand dollars, barnacles, fish parts, and algae.
• Growth rate: Females grow more slowly and do not get as large as males
• Maximum size: Red king crabs can grow to be quite large, larger than blue and golden king crabs.
• Reaches reproductive maturity: In Bristol Bay, males mature at 4.7 inches carapace length (CL), and females mature at 3.5 inches CL (at about 7 years of age). In the Norton Sound area, crab mature at smaller sizes.
• Reproduction: Adult females must first molt in order to reproduce. Males grasp females just prior to female molting, after which the eggs (43,000 to 500,000) are fertilized and extruded on the female's abdomen. The female holds thousands of embryos underneath her tail flap for 11 months before they hatch, generally in April. When the embryos hatch into larvae, they are able to swim about the water column. Red king crab spend 2 to 3 months in larval stages before settling to the benthic life stage. They will molt 5 times before changing into what we would recognize as a crab.
• Spawning season: Generally beginning in January and continuing through June
• Spawning grounds: In shallower waters less than 164 feet
• Migrations: Adult red king crabs annually migrate to shallow water in late winter to mate and then return to deeper waters for the remainder of the year. Some crabs have been known to migrate over 100 miles during this annual migration. Females hatch their young in shallow water each spring and adults molt in shallow water before beginning the migration to deeper water.
• Predators: Predators of red king crab include fishes (Pacific cod, sculpins, halibut, yellowfin sole), octopuses, other king crabs (they are cannibalistic), sea otters, and several new species of nemertean worms, which have been found to eat king crab embryos.
• Commercial or recreational interest: Commercial
• Distinguishing characteristics: Red king crab are the largest of the king crabs.

Role in the Ecosystem

Red king crabs prey on a variety of species depending on their size and depth of water they inhabit. King crabs are known to eat a wide assortment of marine life including worms, clams, mussels, snails, brittle stars, sea stars, sea urchins, sand dollars, barnacles, fish parts, and algae. King crabs are preyed upon by a wide variety of organisms including but not limited to fishes (Pacific cod, sculpins, halibut, yellowfin sole), octopuses, king crabs (they can be cannibalistic), sea otters, and several new species of nemertean worms, which have been found to eat king crab embryos.

Additional Information

Market name: King crab
Vernacular name: none
Blue king crab and Hanasaki crab are also marketed as King crab.

Crab are a prohibited species in all other fisheries - every crab caught incidentally is considered bycatch. Bycatch limits for snow crab were established for groundfish fisheries in 1998.

Biomass

Biomass refers to the amount of red king crab in the ocean. Scientists cannot collect and weigh every single crab 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.

Landings

Landings refer to the amount of catch that is brought to land.

Note: The landings presented are domestic commercial landings.

Biomass and Landings

Are landings and biomass related? Landings are heavily dependent on biomass, management measures in the fishery, and fishing effort. Alaska king crab have had a history of extensive commercial exploitation for 30 or more years, characterized by fluctuations in crab abundance and catch and the development of fisheries for previously unexploited stocks. The red king crab fishery crashed in the early 1980s and has remained depressed ever since, except in southeast Alaska.

Data sources:

Landings from Stock Assessment and Fishery Evaluation (SAFE) Report for the King and Tanner Crab Fisheries of the Bering Sea and Aleutian Islands Regions (2006)

Important Dates

1930s – Japan begins to exploit red king crab in the eastern Bering Sea
Late 1940s-1950s – Short-lived, small-scale American fishery operates in Bering Sea
1958 – The former Soviet Union enters the fishery
1959 – State management of king crab fisheries inside and outside of Alaska waters begins. Since statehood in 1959, U.S. fishers have harvested nearly 2 billion pounds (907,185 metric tons) of red king crab worth $1.6 million from Alaska waters, making red king crab the second most valuable species, second only to sockeye (red) salmon.
1960 –Adak fishery begins
1961 – Harvest of red king crab in Dutch Harbor begins
1964 – U.S. arranges bilateral fishing agreements with Japan and U.S.S.R.
1964 – Adak fishery peaks at 21 million pounds (9,525 metric tons)
1966 – Dutch Harbor harvest peaks at 33 million pounds (14,969 metric tons)
Late 1960s – U.S. replaces foreign fisheries
1974 – Foreign fisheries cease
1977 – Secretary of Commerce adopts and implements a Preliminary Fishery Management Plan for the foreign king and Tanner crab fisheries in the eastern Bering Sea, banning foreign fishing for king crab
1977 – Commercial fishery begins in Norton Sound (prior to this, red king crab taken for subsistence use only)
1977-1980 – Bristol Bay experiences all-time record landings, peaking at 129.9 million pounds (58,922 metric tons)
1979 – Commercial landings peak in Norton Sound at 3 million pounds (1,361 metric tons)
Early 1980s – Fishery crashes, possibly due to overfishing, predation, and changing environmental conditions. The top four historical producing areas are completely closed to red king crab fishing for the first time. Red king crab populations have remained depressed statewide, except in Southeast Alaska, since 1983.
1984 – Bristol Bay stock recovers slightly; limited fishery reestablished
1993 – Bristol Bay stock declines again
1989 – Fishery Management Plan for Bering Sea/Aleutian Islands King and Tanner Crabs approved
1994-1995 – No fishery in Bristol Bay
1996 – Harvest rate for Bristol Bay crabs was reduced to 10% of the mature males to allow stock rebuilding
1996-1997 – Adak fishery closed
1999 – Pribilof Islands red king crab fishery closed
2005 – Crab Rationalization Program implemented

Notes and Links

General Information
North Pacific Fishery Management Council

North Pacific Fishery Management Council King and Tanner Crabs of the Bering Sea and Aleutian Islands Area: Species Profile (1998)

Fishery Management
North Pacific Fishery Management Council FMP for BSAI King and Tanner Crabs (1998)

North Pacific Fishery Management Council Summary of the FMP for BSAI King and Tanner Crabs (1998)

Stock Assessments
Stock Assessment and Fishery Evaluation (SAFE) Report for the King and Tanner Crab Fisheries of the Bering Sea and Aleutian Islands Regions (2006)