Skipjack tuna addition, skipjack's livers were tested globally for tributyltin contamination. TBT is an organotin compound introduced into marine ecosystems through antifouling paint used on ship hulls, and has been determined to be very toxic. About 90% of skipjack tested positive for contamination, especially in Southeast Asia, where regulations of TBT use are less rigorous than in Europe or the US. Skipjack tuna is used extensively in Japanese cuisine, where it is known as . Besides being eaten seared () and raw in sushi and sashimi, it is also smoked and dried to make katsuobushi, the central ingredient in dashi (a common
Skipjack-class submarine Fleet Reactor) during development. The S5W was used on 98 U.S. nuclear submarines of 8 classes and the first British nuclear submarine, , making it the most-used US Navy reactor design to date. "Skipjack" was authorized in the FY 1956 new construction program and commissioned in April 1959. Each hull cost around $40 million. "Skipjack" was certified as the "world's fastest submarine" after initial sea trials in March 1959, although the actual speed attained was classified. The "Skipjack"s remained the fastest US nuclear-powered submarines until the first of the "Los Angeles" class entered service in 1974. This was due to