By Katia Silva, Marine Biologist and Guide at Cabo Trek
Whale sharks, the largest fish in the world, are actually a harmless filter-feeding species of shark. Only 3 species of sharks are filter feeders including whale sharks, basking sharks, and megamouth sharks. Despite their enormous size, the average whale shark is typically 32 feet long and weighs 20,000 lbs. Whale sharks eat by straining small organisms like plankton, schooling fish, and squid from the water. A whale shark can have up to 3,000 teeth at once and between 300 and 350 rows of teeth. They have a streamlined body with a flattened, broad head.
The whale shark occurs in approximately 124 countries worldwide. Whale sharks may be one of the longest living animals in the world, with an estimated lifespan of over 100 years. They are oceanic and coastal, tropical to warm- temperate pelagic sharks. The whale shark is generally encountered close to, or at the surface. It is often seen far offshore, but also comes close inshore and sometimes enters lagoons of coral atolls.
Baja California Sur is one of the few places in the world you can swim with whale sharks in shallow waters and close to the port. Every October whale sharks travel in large numbers to the Sea of Cortez, at La Paz Bay. Sometimes divers have been surprised while diving in the Protected Area Flora and Fauna of Cabo San Lucas and have amazing encounters with these animals.
They are gentle giants and have been listed as vulnerable by the IUCN. Despite protection by the government, the species faces various threats such as becoming bycatch when caught by local fishermen and getting stranded. The lack of knowledge about whale sharks' ecology also hinders conservation efforts.
They face a negative impact from humans through irresponsible tourism practices, fishing, as well as injuries from boating and ocean recreation. In traditional Chinese medicine, whale shark parts including their fins are often used, which is one of their biggest threats. Climate change has impacted many species in the world, and whale sharks are no exception. The changing climates lead to a loss in their prey species, and the development of coastal regions creates marine pollution which takes away large portions of their habitat.
The whale shark season in La Paz is from October to April. You can support the conservation of this species. On your next trip to Baja California Sur, try swimming side by side with this wonderful animal and you will experience one of the most overwhelming experiences of your lifetime!