Context: According to a report by the Central Marine Fisheries Research Institute, India is now the second-largest shark fishing nation in the world, following Indonesia. In order to conserve its population, whale sharks were included in Schedule I of the Wildlife (Protection) Act of India, 1972, rendering the capture and killing of the fish a cognizable offense.
- They were the first-ever species to be protected under this Act, after which the Ganges shark (Glyphis gangeticus) and Speartooth shark (Glyphis glyphis) were added to it.
- Despite the protection, whale shark landings (i.e. dead caracass) were common on India’s West coast, especially in Gujarat.
- Whale sharks are found in all the tropical oceans of the world. Their white spotted coloration makes these gentle giants easy to distinguish, and popular with snorkelers and divers at sites where they aggregate off the coast.
- Whale sharks have a broad distribution in tropical and warm temperate seas, usually between latitudes 30°N and 35°S.
- They are known to inhabit both deep and shallow coastal waters and the lagoons of coral atolls and reefs.
- Australia is one of the most reliable locations to find whale sharks.
- Regular sightings have also been recorded from many other regions including India, the Maldives, South Africa, Belize, Mexico, the Galapagos Islands, Southeast Asia and Indonesia.
- This species is thought to prefer surface sea-water temperatures between 21 – 25°C. C.
- The sharks (regularly) appear at locations where seasonal food ‘pulses’ are known to occur.
- Whale sharks are fish, and therefore obtain oxygen via their gills.
- They have no physiological requirement to swim at the surface – unlike air-breathing whales and dolphins.
- They can remain away from the surface for long periods.
- Whale sharks are regarded as highly migratory- long-distance migrators travel to and from areas of increased food abundance.
- Natural events (e.g. weather patterns) and the particular physical geography of a region can influence productivity and availability of food.
- Warm tropical surface-waters are often nutrient-poor, in contrast to areas of cold-water (nutrient-rich) upwellings. Some e.g. another filter-feeder – the humpback whale.
Do you know?
- Whale sharks (Rhincodon typus) are the largest shark, and indeed largest of any fishes alive today.
- They feed on plankton and travel large distances to find enough food to sustain their huge size, and to reproduce.
- IUCN status: Endangered
- Like human fingerprints, whale sharks have a unique pattern of white spots which allow individual sharks to be identified.
- Large numbers of whale sharks often gather in areas with abundant plankton food—making them prime tourist attractions.
- The distribution of whale sharks indicates the presence of plankton and the overall health of our oceans.
- Demand for their meat, fins, and oil remains a threat to the species, particularly by unregulated fisheries.
- They are victims of bycatch, the accidental capture of non-target species in fishing gear.
- The skin is used for leather which is made into boots and bags, and liver for oil.
- The fins were earlier harvested for shark fin soup, a sought-after delicacy in Southeast Asia and China.
- However, exporting shark fins was banned in India in 2015.