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 species, none were found. In addition to the extirpation of the skipjack shad from Minnesota and Wisconsin, the ebony shell ("Fusconaia ebena") and elephant ear ("Elliptio crassidens"), both state endangered mussels for which the skipjack is the sole host during their larval stages, are threatened to be extirpated as well. In order to keep their distribution from shrinking further, humans need to decrease the number of dams that are constructed, or construct dams that skipjack shads are able to migrate through. In addition to hindering their migration, dams reduce flow. Skipjacks prefer areas with fast flowing water. In addition, it