Pelagic fish Atlantic Ocean, the Gulf of Mexico and the Mediterranean Sea. The term highly migratory species (HMS) is a legal term which has its origins in Article 64 of the United Nations Convention on the Law of the Sea (UNCLOS). The highly migratory species include: tuna and tuna-like species (albacore, Atlantic bluefin, bigeye tuna, skipjack, yellowfin, blackfin, little tunny, Pacific bluefin, southern bluefin and bullet), pomfret, marlin, sailfish, swordfish, saury and oceangoing sharks, dolphins and other cetaceans. Essentially, highly migratory species coincide with the larger of the "large pelagic fish", discussed in the previous section, if cetaceans are added and some
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