Some scientists are raising concerns about the practice. Little is known about the region's sea snakes, including what species and how many live there, so it's not clear whether the harvest is sustainable.

An overharvest, these researchers worry, could jeopardize potential medicinal discoveries. Compounds in venom, once processed and administered in controlled amounts, can be beneficial in treating human ailments like heart disease.

The sea snake catch—a side job for the region's Vietnamese squid fishers—takes in over 80 tons (73 metric tons) of the marine reptile annually. That's roughly 225,500 individual sea snakes per year, valued at over $3 million.