Skipjack tuna commercial tunas, and its population is considered sustainable against its current consumption. Its fishing is still controversial due to the methodology, with rod and reel or fishery options being promoted as ecologically preferable. Purse seine methods are considered unsustainable by some authorities due to excess bycatch, although bycatch is said to be much reduced if fish aggregation devices are not used. These considerations have led to the availability of canned skipjack marked with the fishing method used to catch it. Skipjack is considered to have "moderate" mercury contamination. As a result, pregnant women are advised against eating large quantities. In
Skipjack-class submarine the increased size of the "Thresher" and "Sturgeon" classes, which retained "Skipjack"s S5W power plant, plus the introduction of the "skewback" screw, which was quiet but mechanically inefficient. The "Skipjack"s saw service during the Vietnam War and most of the Cold War. The "Skipjack"-class submarines were withdrawn from service in the late 1980s and early 1990s except for , which sank on 5 June 1968 southwest of the Azores while returning from a Mediterranean deployment, with all 99 crewmembers lost. The gap in the hull-number sequence was taken by the two one-of-a-kind submarines and . Skipjack-class submarine The "Skipjack" class