North Coast (Oregon Border to Point Arena)
North Central Coast (South of Point Arena to Half Moon Bay)
Central Coast (South of Half Moon Bay to Point Conception)
Santa Barbara (Point Conception to Point Dume)
South Coast (Point Dume to Mexico border)
Commercial bluefin tuna fishing usually utilizes the purse seine method, which uses floating objects to attract schools of tuna. [10,11]
- Body is streamlined and black or blue with grey-green iridescence; underside has spots of silver or grey, which appear as bands; second dorsal to tail fins are yellow with black edges. 
- Tip of the pectoral fin does not reach the front of the second dorsal fin and has a lunate tail. 
- Averages 1.5 m (4 ft 11 in), in length and weights around 60 kg (130 lbs), with record length of 3 m (9 ft 8 in), and weight of 450 kg (900 lbs)! 
- Primarily found in sub-tropical and temperate Pacific Ocean between 20-50 degrees North; also in tropical waters off New Zealand in the Tasman Sea. 
- Spawns from mid-April to June, in the Sea of Japan and the southwestern North Pacific Ocean, during this time the females produce up to 10 million eggs a year. 
- When young, it migrates over 8,000 km (5,000 mi) from the Sea of Japan to the coast of California to feed and grow for several years. 
- Travels up and down the California coast between Washington and Mexico until about the age of 7 when it returns to the coast of Japan to spawn. 
- Matures at around 5 years and has a life expectancy of 26 years; average lifespan is 15 years. 
- Pelagic; as one of the fastest fish in the ocean, it travels in large schools in open-water, coastal sea or near seamounts. [3,1]
- Starts off its larval stage by selectively eating tiny copepods, and eventually moves up the food chain to be a generalist predator who eats a variety of prey, including squid, anchovies, and even crustaceans! 
- Predators of this fish include, sharks, orcas, and pilot whales; it also faces human fishing pressure which is of particular concern when targeted in spawning areas. 
- Migration and spawning patterns are affected by increasing ocean temperatures, acidification, and nitrate levels; and decreased dissolved oxygen concentrations and trophic production associated with climate change. 
- Mostly caught from May to October, but also available year-round 
Regulatory and managing authority
- Internationally overseen by the Inter-American Tropical Tuna Commission (IATTC) and the Western and Central Pacific Fisheries Commission (WCPFC). 
- Along the Pacific West Coast, the fishery is overseen by NOAA fisheries and, as established by the Magnuson-Stevens Act, the Pacific Fishery Management Council through the West Coast Highly Migratory Species Fisheries Management Plan. 
- As established by the Marine Life Management Act, the California Department of Fish and Wildlife (CDFW) collects data on this fishery through the Pelagic Fisheries and Ecosystems Program. [19,20]
- Primarily caught by purse seines. 
- Fishing gear is selective and allows for the live release of any unintentionally caught species. 
Status of the fishery
- Declared overfished and subject to overfishing by NOAA; overall decrease in population size since the 1950s; recently assessed at less than 6% of historic levels. [7,8]
- There is some controversy over whether or not this species is under threat of extinction, as the IUCN listed this species as 'Vulnerable' in 2014, while a 2017 NOAA study declared the species to be of low risk for extinction. [4,7,8]
- Due to concerns about overfishing, regulations now require a permit to harvest, annual quotas or subquotas, gear restrictions, time and/or area closures, and minimum size limits. [3,1]
- Bluefin tuna aquaculture has started in other regions, but not in California. 
Potential ecosystem impacts
- Fishery is subject to risks of bycatch associated with purse seine and longline gear types. [6,12]
- Currently, the impact of overfishing and aquaculture for this species on the pelagic food web is not well understood. 
- Similar to beef, different cuts of bluefin tuna meat have different names and prices. Because bluefin tuna consumption originated in Japan, these names are in Japanese. 
- The more common and lower-valued cuts are called akami, while the more expensive, fattier cuts are called toro. The most well-known cuts are otoro and chutoro, which come from the lower belly to the head and the belly at the center and rear, respectively. 
Description of meat
- Bluefin tuna is a deep red color when raw, has a high fat content, and has the firmness and appearance of beef steaks. [10,14]
- Typically served raw in sushi and sashimi, and cooking is generally not advised. 
- Considered an oily fish when raw, and is a good source of protein, thiamin, selenium, vitamin B6, and omega-3 fatty acids. 
- Nutritional information for 100g raw bluefin tuna on table. 
- This fish is available year-round, but most are caught in between May and October. 
 NOAA Fisheries. Pacific Bluefin Tuna. Web. https://www.fisheries.noaa.gov/species/pacific-bluefin-tuna. Accessed: 4 March 2019.
 Marlin (2016). The Biggest Bluefin Tuna Fishing Record: After 40 years, this catch remains the biggest tuna ever recorded by the IGFA. Web. https://www.marlinmag.com/bluefin-tuna-record-revisiting-history Accessed: 9 March 2019.
 Craig, M., Bograd, S., Dewar, H., Kinney, M., Lee, H., Muhling, B., Taylor, B. (2017). Status Review Report of Pacific Bluefin Tuna (Thunnus orientalis). U.S. Department of Commerce, National Oceanic and Atmospheric Administration, La Jolla, CA, USA. https://repository.library.noaa.gov/view/noaa/16990
 Pacific Bluefin Tuna Status Review Team (2017). Status Review Report of Pacific Bluefin Tuna (Thunnus orientalis). Report to National Marine Fisheries Service, West Coast Islands Regional Office. 1-99 https://www.westcoast.fisheries.noaa.gov/publications/fisheries/migrator...
 Ottolenghi, F. (2008). Capture-based aquaculture of bluefin tuna. FAO Fisheries Technical Paper. No. 508. Rome, FOA. 00. 169-182. https://pdfs.semanticscholar.org/897b/0cc729d01af30fa1be9a1dfbf71f1f6512...
 Seafood Watch Consulting Researcher. Monterey Bay Aquarium.2018. Bigeye Tuna, Pacific Bluefin Tuna, Skipjack Tuna, Yellowfin Tuna: Unassociated purse seine (non-FAD), Floating object purse seine (FAD). https://www.seafoodwatch.org/-/m/sfw/pdf/reports/t/mba_seafoodwatch_tuna...
 Seafood Watch Consulting Researcher. Monterey Bay Aquarium. 2016. Pacific Bluefin Tuna (Thunnus orientalis). 1-84. https://www.seafoodwatch.org/-/m/sfw/pdf/reports/t/mba_seafoodwatch_blue...
 NOAA Fisheries. 2018. Bluefin Tuna Stock Assessment. Web. https://swfsc.noaa.gov/textblock.aspx?Division=FRD&ParentMenuID=189&id=2.... Accessed 18 March 2019.
 Smithsonian Institution. 2017. The Great Pacific Migration of Bluefin Tuna. Web. https://ocean.si.edu/ocean-life/fish/great-pacific-migration-bluefin-tuna. Accessed 25 Mar 2020.
 NOAA Fishwatch. 2019. Pacific Bluefin Tuna. Web. https://www.fishwatch.gov/profiles/pacific-bluefin-tuna?_ga=2.21138867.9.... Accessed 25 Mar 2020.
 International Seafood Sustainability Foundation. 2020. Fishing Methods: An Overview. Web. https://iss-foundation.org/about-tuna/fishing-methods/#:~:text=Pole%20an.... Accessed 1 July 2020.
 Seafood Watch Consulting Researcher. Monterey Bay Aquarium. 2018. Albacore Tuna, Bigeye Tuna, Pacific Bluefin Tuna, Southern Bluefin Tuna, Swordfish, Yellowfin Tuna: Drifting Longline. Web.https://www.seafoodwatch.org/-/m/sfw/pdf/reports/t/mba_seafoodwatch_alba.... Accesed 1 July 2020.
 AsiaPacific-Fishwatch. n.d. Pacific bluefin tuna. Web. http://www.asiapacfish.org/index.php/species/item/27-pacific-bluefin-tun.... Accessed 1 July 2020.
 Otoro. 2020. Delicious Otoro Sushi. Web. http://otoro.com/. Accessed 1 July 2020.
 aes256. 2020. Photo of bluefin tuna in Japan. Web. http://photozou.jp/photo/show/296250/118149451. Accessed 1 July 2020.
 Puchner, T. flickr. 2008. Roter Thun, Bluefin Tuna (Thunnus thynnus) in Thunfischmast. Digital image. Web. https://flickr.com/photos/tom_puchner/3362791138. Accessed 18 February 2021.
 Kate. Unsplash. 2019. Photo of bluefin tuna. Digital image. Web. https://unsplash.com/photos/BRnnJ6vVNdY. Accessed 1 July 2020.
 City Foodsters. flickr. 2015. Bluefin tuna (Spain). Digital image. Web. https://flickr.com/photos/cityfoodsters/16949461958. Accessed 18 February 2021.
 Marine Life Management Act. n.d. California Department of Fish and Wildlife. Web. https://wildlife.ca.gov/Conservation/Marine/MLMA. Accessed 24 August 2020.
 Overview of the Pelagic Fisheries and Ecosystems Program. n.d. California Department of Fish and Wildlife. Web. https://wildlife.ca.gov/Conservation/Marine/Pelagic#52132542-overview. Accessed 9 December 2020.