Albacore, Thunnus alalunga

Albacore, Thunnus alalunga. Fish caught from coastal waters off Ensenada, Baja California, April 2016. Length: 1.25 m (4 feet 1 inch). Weight: 15 kg (33 lbs). Catch, photograph, and identification courtesy of Chris Wheaton, Fullerton, California.

The Albacore, Thunnus alalunga, is a member of the Mackerel or Scombridae Family, and known in Mexico as albacora. Globally, there are eight species in the genus Thunnus, of which six are found in Mexican waters, two in the Atlantic, one in the Pacific, and three in both the Atlantic and the Pacific Oceans.

The Albacore has an elongated fusiform slightly compressed torpedo-shaped body that is designed aerodynamically for speed. They are dark blue dorsally transitioning to silver-white ventrally. They have a faint iridescent blue band along the sides. Their anal and second dorsal fins are light yellow; their anal finlets are dark; the margin of the caudal fin is white; and their first dorsal fin is deep yellow. The body is deepest just anterior to the second dorsal fin. Their anal fin has 11 to 16 rays followed by 7 or 8 finlets; their caudal fin is deeply forked with 2 small keels separated by 1 large keel at the base; their first dorsal fin has 11 to 14 spines with a long base and is larger and deeper than the second with a strong concave outline; their second dorsal fin has 12 to 16 rays followed by 9 finlets; and, their pectoral fins are exceedingly long (a key to quick identification), approaching half the body length and reaching well past the origin of the second dorsal fin. They have 25 to 31 gill rakers on the first arch. The body is covered with small scales.

The Albacore is a pelagic species found worldwide in tropical and subtropical waters. They are mainly found offshore from the surface to depths of 1,185 m (3,890 feet). They reach a maximum length of 1.52 m (5 feet 0 inches) and 60 kg (133 lbs) in weight. As of January 1, 2024, the International Game Fish Association world record stood at 77 cm (2 feet 6 inches), with the fish caught in New Zealand Waters in February 2022. The corresponding weight record is 40 kg (88 lbs) with the fish caught off the Canary Islands in November 1977. They are a highly migratory species with juveniles of the Pacific making trans-Pacific migrations between Japan and the west coast of North America in the spring and early summer and returning in the late fall and winter. They are normally found in surface waters with temperatures between 15.6°C (60°F) to 19.4°C (67°F); larger Albacore can be found in 13.5°C (56°F) to 25.2°C (77°F) waters. They are always found in schools and can also form mixed schools with Bluefin Tuna (Thunnus maccoyii), Skipjack Tuna (Katsuwonus pelamis), and Yellowfin Tuna (Thunnus albacares), with whom they compete for food. These schools may be associated with floating objects, including sargassum weeds. They are opportunistic daytime feeders with juveniles consuming planktonic crustaceans and larger fish preying on a combination of small crustaceans, fish, and squid. They have the ability to undergo diel (vertical) migrations and follow their prey to depths of 300 m (985 feet) in the Pacific and 600 m (1,970 feet) in the Atlantic but normally stay above the thermal incline due to their need for high levels of oxygen in the water. They remain near the surface at night. In turn they are preyed upon by billfish, dolphins, sharks, and other tunas. Reproduction is oviparous with fairly long reproduction times with sexual maturity not reached for 5 years in both sexes. Each female releases between 800,000 and 2,600,000 eggs annually, which are released in two batches. Larger females produce more eggs than smaller females. Fertilization is external with eggs hatching in one to two days; eggs and larvae are both pelagic. They are fast growing but have a high mortality rate. Immature individuals have sex ratios of 1:1 but males dominate mature fish. They have lifespans of up to twelve years.

The Albacore is a resident of all Mexican waters of both the Atlantic and the Pacific Oceans. In the Atlantic they are found within the Gulf of Mexico and the east coast of the Yucatán Peninsula in the Caribbean. In the Pacific their range is limited to the entire West Coast of Baja and to the southern half of the Sea of Cortez.

 The Albacore is a straightforward identification due to exceedingly long pectoral fins with one possible exception. Juvenile Bigeye Tuna, Thunnus obesus, also have long pectoral fins but those have rounded tips.

From a conservation perspective the Albacore is currently classified as NEAR THREATENED, with possible extinction in the near future. In certain parts of the world where their populations are below maximum sustainable yield, their fishery is believed to range from Moderately Exploited to Over Exploited. The Albacore are one of the four main tunas (Albacore, Bigeye, Skipjack, and Yellowfin) that are fished heavily commercially and that support global populations both economically and as an important food source. Commercially the Albacore are caught via pole and line, longlines, trolling, and purse seines. They are also a by-catch of the swordfish fisheries. They are an exceptional food fish with most sold canned. They are the only tuna sold as “white meat” which increases their price and reduces their demand. They are known to contain mercury with larger fish having higher concentrations. They are also a top recreational fish with heavily concentrated efforts made in waters off Northwest Baja during certain times of the year. They are found well offshore and require long runs; they are generally located by monitoring temperature breaks and rapidly trolled jigs and plugs and then caught on live bait such as anchovies, sardines, and herrings. They are known for their hard strikes and powerful runs. One of the complexities of determining the status of Albacore catches globally is that many other species are called “albacore” via local cultures including Blackfin Tuna, Kawakawa, Little Tunny, Swordfish, Yellowfin Tuna, and Yellowtail Amberjack. Albacore are relatively abundant, fast growing, and are very fecund but have long reproduction cycles with high mortality. Their catch rates are heavily monitored globally. Current annual landing rates are on the order of 300,000 tons and are continually increasing. Their global population has declined by as much as 37% (from 800,000 tons to 500,000 tons) over the last twenty years. Annual catch quotas and a ban on the use of driftnets are currently in place in some areas of the world.