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
Skipjack shad skipjack shad populations seem to be minimal in the southern parts of their distribution. Dams have limited the natural distribution of the species. Skipjacks are no longer found in high numbers in the northern reaches of their distribution because of their inability to migrate over large impoundments. The Minnesota Department of Natural Resources (DNR) webpage tells us that "Further research into the species' life history and ecological requirements is needed. It is known that lock and dam structures hinder migration of skipjack shads during the early spring. If the skipjack shad is to be reestablished in Minnesota and Wisconsin, where