Very little is known about whale sharks, primarily because of the difficulty in conducting field research on the elusive giants who are thought to spend the majoring of their lives diving to depths below 980 m. The whale shark (Rhincodo typus) is the biggest fish in the sea, believed to grow to lengths of up to 20 meters in length and weighing in at over 34 tons. Whale sharks are filter feeders, feeding on microscopic plankton and small free swimming nektonic creatures such as squid and fishes. They are highly migratory, distributed in tropical and warm temperature seas around the globe in areas of high plankton productivity. Whale sharks have been sighted year round around the island of Koh Tao, on popular dive sites such as Chumphon Pinnacle, Southwest, Shark Island, No Name, and Twins.

Although these docile creatures have no known natural predators in the wild, the global whale shark population is at risk due to human interactions, mainly of the fishing industry, targeting whale sharks for their meat, oil, and fins. Fishing for whale sharks was banned in Thailand under Section 32 (7) of the Fishing Act B. E. 2490 in 2000. It is not known how great the effects of the fishing industry have had on the world’s whale shark populations, however, as little is still known about whale shark migratory patterns and population sizes.

Whale sharks are generally considered harmless and non aggressive towards humans, however, we at Save Koh Tao wish to encourage positive encounters between divers and whale sharks in the water and ask that the following general guidelines, promoted by The Shark Trust, the Australian Department of Conservation and Land Management, and PADI and the Project AWARE Foundation be followed for both your own safety and for the safety of the sharks.

 Code of Conduct for Swimmers and Divers (*link)

    * Do not attempt to touch, ride, or chase a whale shark
    * Do not restrict normal movement or behavior of the shark
    * Maintain a minimum distance of 3 meters from the head and 4 meters from the tail (caudal fin) of the whale shark
    * No flash photography
    * Do not use underwater motorized diver propulsions near a whale shark

For more information please see:

ECOCEAN Whale Shark Photo-identification Library (Australia)

Shark Trust

The Whale Shark Project (Shark Trust and Project AWARE)

 Below is the most current data that we have about the whale sharks around Koh Tao that have been reported to our website:

Shark Database Background Information

Identifying Shark Species

• Blacktip Reef Shark (Carcharhinus melanopterus)

- Black coloration at the tip of the first dorsal fins, and the ventral caudal lobe

- Average size is 1-1.2 metres, maximum size recorded is 1.8 metres

- Usually found in shallow reef area

• Bull Shark (Carcharhinus leucas)

• Grey Reef Shark (Carcharhinus amblyrhynchos)

- Black coloration at the caudal fins, streamline looking

- Average size is 1.2 metres, maximum size recorded is 1.8 metres

- Inhabit coastal water

• Leopard Shark (Stegostoma fasciatum)

- Elongate long caudal fin, blunt short snout, with brown spotted (adult)

- Average size 1.5-2.3 metres, maximum size recorded is 3.5 metres

- Usually found resting on the bottom

• Tiger Shark (Galeocerdo cuvier)

- Short blunt snout, distinctive dark bar patterns on the body

- Average size is 3.4 metres, maximum size recorded is 7.4 metres

- Inhabit wide range of habitats

• Whale Shark (Rhincodon typus)

- Broad flat heat, distinctive pale pigmentation all over the body, white underside

- Average size 7 metres, maximum size recorded 13 metres

- Usually found feeding for plankton near the surface

• Others (Sphyrnidae,? Carcharhinidae??)

Gender Identification

Male : Claspers present

Female : No Clasper / Sign of Pregnancy

Shark Anatomy for Identification Purpose

Identification Marks

• Bites

• Fishing Hook

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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