Ten years ago, you could go on a whale shark tour at Gladden Spit and almost be certain of seeing at least one whale shark and you would probably see several. In recent years, there have been very few sightings. What happened to this endangered species?

Whale sharks are the filter feeders on zooplankton, fish spawn, and small fish and crustaceans. They traditionally came to Gladden Spit for the snapper spawning aggregations around the time of the full moon in March, April, May, and June.

One obvious explanation is reduced food due to fewer snapper than there used to be, presumably due to overfishing but there seem to be several factors at play.

They still show up regularly off the Yucatan Peninsula where there is a large upwelling bringing food to the surface and they are known to travel tremendous distances in search of food.

According to Defenders of Wildlife, a US-based NGO, “Shark species around the world face a wide variety of threats, including overfishing and as a target species and as bycatch. Whale sharks are the world’s largest living fish. Their migratory patterns cause them to travel between national Exclusive Economic Zones and into the high seas over the short term, while also migrating farther away from shore over their lifetimes. The global population of the whale shark has decreased by more than 50% in the last 75 years, resulting in its listing on the IUCN Red List as Endangered globally. Whale sharks are protected in many countries and are listed in several international treaties. Many large-scale whale shark fisheries have closed because of protections for the whale shark that have been implemented over the last twenty years.

The fact that these protected species are a target in some places is particularly disheartening and infuriating.

PetPedia says that “One Chinese fish factory processes around 500–600 big sharks each year, including whale sharks. The number of processed sharks gets more serious when we consider that whale shark numbers are already measured in thousands and that there might be more such factories.”

The World Wildlife Fund claims that Whale sharks are highly valued on international markets for their meat, fins, and oil. They are threatened by both unregulated fisheries and are also victims of bycatch. This photo from the Philippines is a graphic illustration.

MARALLIANCE has recently undertaken to provide some answers to what is happening at Gladden Spit.

If you would like to read more about whale sharks, check out these links: