No other fish can swim as fast or far as tuna; its fins help reduce turbulence and drag as it swims through the water.

Taxonomic description

• Has a sleek torpedo-shaped body for fast movement. 
• Dark blue on the back, which changes from yellow to silver down to the belly.
• Dorsal and anal fins are bright yellow giving the fish its name.
• Difficult to distinguish from other tuna species except for the elongated, sickle-shaped dorsal and anal fins found on large adults. ^[1]
• Can grow to be 1.8 m (6 feet) long and over 180 kg (400 lbs). ^[1]

Distribution

• As a highly migratory fish, yellowfin tuna is found in warm seas all over the world except the Mediterranean. ^[1]
• Can travel across the entire ocean basin. ^[1]

Life history

• Fast growing, with a somewhat short life span of 6 to 7 years. ^[1]
• Most yellowfin tunas are mature enough to reproduce around age 2 or 3. ^[1]
• Spawns at sea throughout the year in tropical waters, and from the spring–summer in cooler waters. ^[1]
• 24° C (75° F) is thought to be the lowest temperature limit for spawning. ^[1]
• Can produce two to seven million eggs per spawn. ^[1]

Habitat

• Travels in schools of similarly sized fish.
• Mostly found in the surface layer (≤100 m or 330 ft) of the open ocean above the thermocline, but is capable of diving over 1000 m (3300 ft). ^[1]
• Typically found in water temperatures between 15° – 31° C (59° - 88° F). ^[2]
• Known to make migratory trips to higher latitudes as the temperature of the water increases. ^[1] 
• Gathers in areas with high productivity where smaller prey is available.
• Feeds opportunistically in open ocean on small fish, squid and invertebrates such as pelagic crabs. ^[1,2]
• Predators include sharks, billfish and large marine mammals. 

Yellowfin tuna, like other tuna species, is highly migratory. It can travel across entire ocean basins and therefore requires cooperative international management to ensure its abundance and sustainability.

Seasonal availability

• The fishery is open year-round, and is mostly recreational off San Diego in August & September.

Regulatory and managing authority

• Internationally overseen by the Inter-American Tropical Tuna Commission (IATTC) and the Western and Central Pacific Fisheries Commission (WCPFC). ^[1]
• 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. ^[10]
• 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. ^[11,12]

Gear type

• Mostly caught by purse seines, but troll, hook-and-line, & pelagic longlines are also used. Hook and line is used recreationally.

Status of the fishery

• NOAA defines the population as “abundant” and fishing rate as “sustainable”. ^[1]
• Monterey Bay Aquarium’s “Fish Watch” lists hook-and-line tuna as “Best Choice”. ^[3]
• Most regulations focus on reducing the catch and mortality of non-target species.
• U.S. fishermen responsibly harvest tuna by following strict international and domestic regulations aimed at reducing fishery impacts on other species (e.g., longliners use special hooks and bait that reduce bycatch; fishers train in the safe release of non-target species; vessels are regularly monitored by scientists & managers who reassess management actions as needed). ^[1]

Potential ecosystem impacts

• This species is fairly resistant to fishing pressure given early maturing, high fecundity, moderate life span, & wide distribution. ^[4]
• Troll & hook-and-line methods have relatively low bycatch ^[5] whereas purse seines and long lines potentially result in moderate to high bycatch of species associated with yellowfin schools if actions are not taken to reduce bycatch and mortality rates. ^[1]
• Purse seiners using fish aggregating devices (FADs, manmade floating objects) to attract yellowfin must take precautions to avoid bycatch of juvenile yellowfin & non-target pelagic species. 

Yellowfin is sold as “light tuna” when canned, is called “ahi” when sold fresh or frozen, and called “maguro” when in sushi.

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Edible portions

• Usually sold as rounds, loins, or steaks.  

Description of meat

• Has a mild, meaty flavor; firm texture.
• Flesh has a deep red color when raw.

Culinary uses

• Can be eaten raw or cooked, and is popular grilled or seared. ^[8]
• For tips on grilling tuna, visit The Spruce Eats. ^[8]
• For seared ahi tuna recipes, visit yummly. ^[9]

Nutritional information  

• Raw (3 oz, 85 g). ^[5]

Toxicity report

• No consumption advisories are listed for troll or pole-caught yellowfin as these methods catch younger tuna with lower mercury levels. ^[3]
• Potential for mercury accumulation in larger tuna only (caught by seine or longline). Recommended servings that can safely be eaten per month are 4 or more for adults, 3 for kids 6-12 yr old, 3 for kids 0-5 yr old. ^[7]

Seasonal availability

• Yellowfin tuna is available fresh in San Diego from August–September. ^[6]

Over 40 species of symbiotic parasites live on the gills and within the guts of yellowtail. ^[2]

Taxonomic description

• Has a blue body, yellow tail, and silver sides with a bronzy stripe along the lateral line. ^[2]
• Grows to 2.5 m in length and weighs up to 36.3 kg, with the largest weighing in at 41.3 kg (91.1 lbs). ^[2]

Distribution

• Found along the eastern Pacific from southern Washington to Mazatlán, Mexico (for California Yellowtail). ^[1]

Life history

• Has an average lifespan of 5-6 years with a max of 12 years. ^[2]
• Females can spawn at 2-3 years old and release up to 150 eggs during spawning, but about 100 eggs are fertilized at a time. Yellowtail eggs are externally fertilized, with the females releasing eggs into the water column, and the males spraying sperm over the eggs. ^[2]
• Spawning occurs during the summer, from June to October. ^[10] Younger females spawn once during the spawning season, while older ones can spawn multiple times. ^[2]

Habitat

• Lives near rocky reefs, kelp beds, and offshore islands. ^[2]
• The eggs and larvae are eaten by mollusks, echinoderms, crabs, and fish. ^[2]
• Common predators of adults are great white sharks, California sea lions, and humans; the fish’s blue and silvery color is an adaptation to help camouflage from predators. ^[2]
• Preys on round herring, sardines, squids, anchovies, and California flying fish. ^[2]

No California Yellowtail can be taken commercially if it is less than 28 inches (71 cm) long. ^[9]

Seasonal availability

• Fishing is open year-round, but between May and August limits to pounds of yellowtail per boat apply. ^[4]

Regulatory and managing authority

• As established by the Marine Life Management Act, the California Fish and Game Commission regulates the fishery, and the California Department of Fish and Wildlife manages this fishery. ^[12]
• As yellowtail is caught as bycatch by fisheries targeting other species, this species is not included in any specific fishery management plan, but still falls under the jurisdiction of NOAA fisheries under the Marine Mammal Protection Act and CDFW and CFGC as per the Marine Life Management Act. ^[6,12]

Gear type

• Sometimes caught as incidental catch in the drift gillnet fishery, and is also targeted with hook and line. If targeting yellowtail with drift gillnets, the mesh size must be ≥3.5 inches. ^[6]

Status of the fishery

• Is a largely sought after sportfish, but no decline in population sizes has been detected. ^[7]
• Commercial catch declined when purse seining (1973), and later, gillnets (1994) were banned in California waters (CDFG 2001). ^[1]
• There is currently no stock assessment or fishery management plan in place for California yellowtail. ^[1]
• Currently no conservation acts apply. ^[1]

Potential ecosystem impacts

• Yellowtail is a secondary and tertiary consumer in its ecosystems, so its presence helps create the population structure for its prey. Removal of yellowtail may impact populations of its prey and predators. ^[2]

Known as Hamachi in sushi, this fish has a buttery texture due to its naturally high oil content. ^[3]

Edible portions

• The meat (muscle), head and roe are edible, remaining parts may be used in broth or soups. ^[3]

Description of meat

• Light red to pink in color, and buttery due to its high oil content. ^[3]

Culinary uses

• Yellowtail is commonly used raw in sushi as sashimi or smoked. ^[3]
• It is sold fresh and frozen, and whole, in fillets or steaks. ^[3]
• Recommended cooking styles include broil, grill, and saute.
• For yellowtail recipes, visit Yummly. ^[13]

Nutritional information 

• 66% of the calories are from protein, while the rest 34% are from fat. ^[10]

Toxicity report

• Yellowtail have high levels of histidine, which is converted to histamine by bacteria when the fish spoils and can cause histamine toxicity. To avoid this, make sure to refrigerate the fish properly and do not eat if spoiled. ^[5]

Seasonal availability

• It is available year round. ^[1]