The 1995 "Turbot war" between Spain and Canada could have been resolved with US participation in UNCLOS

The effects of overfishing may be the most devastating in Canada.ⁿ²²¹ As a result, Canada has made drastic decisions in an attempt to save the fish stocks. In the 1990s, the northern cod fishery off the Grand Banks near Canada collapsed.ⁿ²²² Canada made the unpopular decision to close the fishery in an attempt to maintain sustainable fish stocks within its EEZ. 

The decision focused attention on nations fishing the same stocks outside Canada's EEZ.  The result was the socalled "turbot [cod] war," an open conflict with fishermen from outside Canada who were perceived to be contributing to the problems on the Grand Banks.  In 1995, a Canadian vessel fired warning shots and impounded the "Estai," a Spanish fishing vessel operating on the Grand Banks off the coast of Newfoundland.  In a discussion about the United States' ratification of UNCLOS III, U.S. Senator Claiborne Pell argued before the U.S. Senate that similar incidents could be avoided in the future if UNLCOS III gains widespread support:

Had Canada and Spain both been party to the Law of the Sea Convention, this dispute could have been settled without the firing of shots. Regrettably, such incidents are the result of the growing uncertainty that prevails with regard to high seas fisheries and will only be avoided if the Convention on the Law of the Sea becomes a widely recognized instrument on which ... to establish a lasting regime for those fisheries.