Whale sharks, the largest living fish species, are classified as endangered on the IUCN Red List of Threatened Species. Over the past 75 years, populations have declined by more than 50% worldwide, and by up to 63% in the Indo-Pacific region. Because whale sharks take up to 30 years to become sexually mature, populations can only recover slowly from threats like hunting for fins, meat, and oil, habitat loss, and entanglement in fishing nets.