Albacore, the tuna that eats squid and never stops swimming
Most tuna hunt fish, but albacore mainly eat squid and their relatives, including a tiny deep-water species from the Atlantic and Mediterranean. They cannot rest, since they need a constant flow of oxygen, and young ones may cross the entire Pacific between Japan and North America before turning two.
The albacore, or longfin tuna, is named for pectoral fins that can reach 30 percent of its body length. Dark blue above and silvery below, it roams tropical and temperate seas from 59 degrees north to 46 degrees south, from the surface down to 600 metres, usually in water of 10 to 25 degrees Celsius. Pierre Joseph Bonnaterre first described it in 1788 and placed it among the mackerels; it moved to the tuna genus Thunnus in 1983.
It is a restless traveller. Atlantic and Pacific populations do not seem to mix, but North Pacific fish head each year to waters off northern Baja California or off Washington and Oregon, while North Atlantic fish visit the Bay of Biscay every summer. Behaviour varies by place: off Baja they dive below 200 metres by day and return to the surface at night, whereas off the Pacific Northwest they stay near the top. Tagging work by NOAA scientists and fishermen since the 1970s revealed the juvenile ocean crossings. They school with skipjack, yellowfin and bluefin, sometimes around drifting sargassum.
Spawning usually runs from November to February. A 20-kilogram female can release 2 to 3 million eggs, which hatch outside her body in a day or two, and the young stay near their birthplace for a year. Oddly, most albacore have a larger right testis or ovary.
Commercially the fish launched an industry: in 1903 an experimental pack of 700 cases in southern California led to American tuna canning. Albacore remains one of four tunas supporting Pacific island economies, where tuna fleets and processing can supply 3 to 20 percent of GDP in some places. Once rated Near Threatened, it moved to Least Concern in 2021 as quotas helped declining stocks recover. Labels are another matter: an Oceana study from 2010 to 2013 found 84 percent of white tuna samples were really escolar.
Source: Albacore
