Habitat:
Similar to bluefin tuna, yellowfin tuna's circulatory system acts to retain metabolic heat. This warms their bodies above ambient temperature and allows them to process food and transport oxygen more efficiently. Their ability to stay warm does not match the near warm-blooded bluefin tuna, and as a result, their migration range is more limited by water temperature. The bulk of the population is found at oceanic habitats within 20º latitude of the equator and typically in waters at least 64 ºF. Water temperatures of 68 ºF or higher are often associated with higher catch rates. Their sensitivity to cooler temperatures also limits vertical movements to the relatively thin layer between the thermocline and surface.

Diet:
Trolling offshore at least 20 miles to find the right temperature edges, are the primary methods used by anglers. Trolling involves creating a flashy presentation of multiple lures trolled in the boat wake while moving along at 7-8 nautical miles per hour. Single hook lures with plastic skirts are a common offering and chains or spreader bars of lures are an option to increase the visual attraction. Green is a popular color for yellowfin tuna. The idea is to have a pattern of lures that splash, wiggle and sparkle enough to trick the fish into thinking it is attacking a group of agitated baitfish. Chumming involves introducing a baited hook to yellowfin tuna while the boat is drifting or anchored. Cut pieces of butterfish or silver hake are common baits, and small pieces of the bait are deliberately tossed in the water around the baited hook to attract tuna. These fish offer great possiblities for the light tackle angler.