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
USS Skipjack (SS-184) upward angle developed almost immediately, forcing the submarine to surface. By the time control of the boat had been regained, the water in the torpedo room was only a few inches from the top of the water tight door, but fortunately there were no casualties, and "Skipjack" resumed the attack. The submarine then torpedoed and sank the converted seaplane tender "Okitsu Maru" (). She returned to Pearl Harbor on 7 March. Following repairs, "Skipjack" participated in performance tests on new torpedoes in cold water off the Pribilof Islands until 17 April and then headed for the Mare Island Navy Yard