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 (SSN-585) reduced her speed noticeably. During her shakedown cruise in August 1959, she became the first nuclear ship to pass through the Straits of Gibraltar and operate in the Mediterranean. Following post-shakedown availability at Groton, Connecticut, the nuclear submarine conducted type training and participated in an advanced Atlantic submarine exercise from May through July 1960, which earned the submarine a Navy Unit Commendation, and also a Battle Efficiency "E" award, an award it would receive three more times. In late 1960, "Skipjack" entered the mouth of a long ship channel leading from the Arctic Ocean to Murmansk in the Soviet Union.