Whale shark

Why in News?

Recently, a rare live sighting of a whale shark by scuba divers off the Visakhapatnam (Chinna Rushikonda) coast renewed focus on marine conservation.

• Whale shark is the world’s largest living fish and a gentle, slow-moving shark.
• Scientific Name – Rhincodon typus.
• Habitat – Epipelagic (sunlight zone) and coastal–oceanic waters.
• Occurs from surface waters to depths exceeding 1,000 m.
• Nearshore coastal waters; food-rich zones close to shore during winter due to plankton blooms and shoaling fish.
• Distribution – Circumtropical and warm temperate seas worldwide.
• Found in the Atlantic, Indian and Pacific Oceans.
  • In India – Migrates along the coastline with sightings in the eastern coast, including Visakhapatnam, Kakinada and Machilipatnam.
• Characteristics – Individuals can grow to about 10 metres in length and weigh between four and five tonnes.
• Diet – Filter feeder.
• Feeds primarily on plankton, small nekton, and fish eggs
• Behaviour – Highly migratory species.
• Forms seasonal aggregations linked to food availability (plankton blooms).
• It trails shoaling fish and is unbothered by the presence of scuba divers.
• Uniqueness – Despite its massive size, it is a gentle, plankton-feeding shark and not aggressive.
• Threats – Targeted and incidental fishing.
• By-catch, especially during beach seine fishing in winter.
• Strandings and ship strikes.
• Irresponsible tourism.
• Marine pollution and plastic ingestion.
• Climate change is affecting productivity and migration patterns.
• Conservation Status – Need for improved monitoring, fisheries management, and international cooperation.
  • IUCN – Endangered
  • Wildlife (Protection) Act, 1972 – Schedule I
• Ecological Significance –
• Plays a role in regulating plankton populations.
• Indicator species for ocean health due to its sensitivity to environmental change.
• Highlights that Vizag’s coastal waters support diverse marine ecosystems requiring urgent conservation.

References

1. TH | Whale shark
2. ToI | Whale shark
3. Whale Shark | IUCN