In the canal, water flows downward from the locks toward the ocean. Construction of another, sea-level canal through Panama has been proposed. In this case, sea snake entry into the Caribbean is high on the list of possible ecological consequences that have to be considered. Sea snakes have been observed moving up into river mouths and continuing into freshwater lakes. Apparently, water salinity is not physiologically detrimental to them, as long as they can find suitable food.
Most sea snakes feed on fish, fish eggs and eels.
Aside from man, the universal predator, there are few animals that attack or regularly feed upon sea snakes. Teleost fish, including the Moray eel, catfish, large grouper, and blue cod may occasionally feed upon sea snakes. Many fish will not eat sea snakes for reasons which are not fully understood, but it is known that these snakes, eaten whole, are capable of inflicting fatal bites on the stomach walls of predator fish. Incredibly, they have actually been reported to then escape through the dead fish's mouth. Some sea birds are also known to prey upon sea snakes.