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) January and arrived at Port Darwin, Australia, for refit on 14 January. "Skipjack"’s second war patrol, conducted in the Celebes Sea, was uneventful with the exception of an unsuccessful attack on a Japanese aircraft carrier. She returned to Fremantle, Western Australia, on 10 March 1942. On 14 April, "Skipjack" got underway under the command of James W. Coe for her third war patrol, conducted in the Celebes Sea, Sulu Sea, and South China Sea. On 6 May, contact was made with a Japanese cargo ship, and the submarine moved in for the kill. Finding herself almost dead ahead, "Skipjack" fired