Bigeye tuna live in deeper, cooler waters than other tropical tunas. They are bigger than Albacore and skipjack but smaller than the famed bluefin. They are a highly migratory fish that roams all the world’s oceans in tropical and subtropical zones. Two separate and distinct stocks of bigeye live in the Pacific: an eastern stock and western/central stock.
Bigeye have a metallic, dark blue back and white belly. Their first fin on their back is deep yellow and the rest are a pale yellow. Their finlets are bright yellow with black edges, which distinguishes them from the yellowfin. They have streamlined, torpedo-shaped bodies adapted to fast and continuous swimming. With a high fat content, the reddish-pink meat of the bigeye is prized by sashimi lovers.
Bigeye tuna have a life span of seven to eight years and reach reproductive maturity at around three years. The species is very productive, spawning throughout the year in tropical waters and seasonally in cooler waters. Females can spawn almost daily, releasing millions of eggs. Their most productive spawning periods are in the spring and fall. Females release their eggs near the sea surface where they are fertilized. Juvenile bigeye stay close to the surface, but move into deeper water as they mature. They grow quickly reaching about 6.5 feet in length. They are also known to gather around drifting flotsam (natural floating debris), anchored buoys, whales and other large marine mammals. They are at the top of the food chain and feed on other fish, squid and crustaceans.
Handlining is a small-scale fishing method in which fish harvesters jig for tuna with weighted hooks, troll at low speeds with lures, attach hooks and lines to makeshift floats, and even use kites to dangle lures along the sea surface to attract tuna.
This fishery uses a longline to catch a variety of pelagic fish on the high seas such as tuna and swordfish. A deep-set longline is used to primarily target tuna and a shallow-set longline is used to target swordfish or mixed species including bigeye, Albacore and yellowfin tuna. Baited hooks are attached to a line that floats in the ocean using buoys and flagpoles.
This fishery uses a variety of artisanal hook-and-line methods to catch coastal pelagic fish such as tuna, marlin, swordfish, mahi mahi, wahoo (ono) and others. A pole and line with live bait scattered into the water is used to catch feeding skipjack tuna. Trolling with lures and lines, and handlines with lures, lines and bait bags are used to target larger fish such as bigeye tuna, swordfish, mahi mahi and wahoo.