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) a "down the throat" spread of three torpedoes that sank the "Kanan Maru" (). Two days later, the submarine intercepted a three-ship convoy escorted by a destroyer and she fired two torpedoes that severely damaged the merchant ship, "Taiyu Maru" (). Then she let go with four more that quickly sank the cargo ship, "Bujun Maru" (). On 17 May, "Skipjack" sank the passenger-cargo ship "Tazan Maru" () off Indochina before heading back to Fremantle. Following participation in performance tests for the Mark 14 torpedo, "Skipjack" sailed for her fourth war patrol on 18 July 1942, conducted along the northwest