Several nations agreed last week not to catch whale sharks while fishing for tuna. Whale shark numbers have declined in recent decades, along with the populations of other shark species, but whale sharks are often targeted intentionally.
Tuna and other economically important fish species often congregate underneath whale sharks as the sharks feed. Fisheries can use sightings of whale sharks to determine where schools of tuna probably are. The fishing boats surround the groups of fish with a purse net, catching both the school of tuna and the whale shark, plus any other fish that happen to be there.
Whale shark meat is popular in some places in Asia. Catch numbers around Taiwan reported have shown a decrease of 80% in whale shark populations between 1980 and 2000.
However, several nations have created a thriving tourist industry around the whale sharks. In all cases, the tourism brings in more money than the whale shark fisheries ever did. Mexico, Australia, the Philippines, Tanzania, Seychelles, Maldives, Belize, and Honduras have developed significant tourism around sighting and swimming with the whale sharks in their waters. The life cycle of whale sharks is not fully understood and more study is needed.
The agreement binds larger tuna-fishing nations, such as the United States, China, and Japan not to fish for whale sharks and to free any that accidentally get tangled in their nets, then report the incident.
Whale shark photo via Shutterstock