A Date with the Domino Fish, Whale Shark Watching

It’s whale shark season and these gentle giants are gathering in a stretch of ocean between Holbox, Contoy and Isla Mujeres to filter feed on the plankton that is plentiful during the summer months.

The largest living fish, whale sharks can reach lengths of up to 60 feet and is known locally as the pez domino due to its dappled grey or dark blue skin. Mexican biologists have used the distinctive markings to compile a catalog of local sightings. When divers encounter a whale shark they take a photo of a patch of skin behind the gills and above the left pectoral fin. The pattern of dots and stripes recorded does not change or fade with age and can be used to identify individual fish, almost like a fingerprint. The location of the fish is recorded with a GPS reading and the findings are used to monitor whale shark movements. Some whale sharks are even being marked with a satellite sensor to study migration patterns.

Using a combination of photos, GPS and Cessna flights, biologists studying the Mexican Caribbean whale sharks have been able to identify many of the whale sharks. They believe that there may be as many as 200, the largest concentration in the world.  Given the area’s importance, a marine reserve was created in 2009 and biologists, conservationists and local fishermen are working together to ensure that the fish are not overexploited and driven from their feeding grounds.

Similar studies are being carried out in Belize where biologists from York University in the United Kingdom have discovered similar gatherings or aggregations. Whale sharks gather in the Gladden Spit Marine Preserve at full moon in April and May when Cubera snappers spawn. Scientists in Australia believe that coral spawning may also attract the whale sharks.

A whale shark sighting is an unforgettable experience for summer visitors to the Mexican Caribbean, click here to see a whale shark video. Available from late May to September, these small group eco excursions depart from Cancún, isla Mujeres or Holbox and are accompanied by a knowledgeable guide. Apart from whale sharks, dolphins, sea turtles, manta rays and a variety of birds may be spotted during the day. For more information and reservations, contact Thomas More Travel at tourdesk@royalresorts.com or call in at the Royal Resorts travel desk on your next vacation.

Isla Mujeres is hosting a Whale Shark Festival on July 16-18.

Our thanks go out to Thomas More Travel and Eco Colors for this video.