In the Pacific, swordfish range from Asia to the Americas and from northern waters off Alaska to the southern reaches of South America. Juvenile fish, especially, like warm water and are found only in tropical regions. Adults have a greater temperature tolerance and range widely over the Pacific, spawning in the tropics and feeding in temperate regions. Swordfish concentrate in areas where food is abundant, along frontal zones where ocean currents meet to create turbulence and sharp temperature breaks. The Pacific Ocean has five major frontal zones where swordfish congregate, and these are where most fishing occurs.
Swordfish abundance is related to oceanic cycles, and cycles are influenced by climatic conditions.
Water temperature, availability of food, and fish migration patterns all play a role, influencing fishing success. Japan, Chile, Mexico, and Peru, as well as California, employ gillnets to capture swordfish. Scientists consider Pacific Ocean swordfish stocks to be in good condition and able to withstand increased catches. California's swordfish fishery has a small impact on Pacific swordfish stocks, yet California fishermen are the most strictly regulated of all Pacific Rim fleets. In fact, swordfish is one of California's most important fisheries.