Whale sharks (Rhincodon typus) are the largest fish on the planet today and can reach lengths of more than 60 feet (18.2 meters). Five of these endangered creatures have recently been spotted off the coast of Anna Maria Island, on Florida’s Gulf Coast, FOX 13 News reported on June 8.
But it seems the majestic whale sharks have a preference for certain “hotspots” all over the world and can be regularly seen flocking to specific locations in the planet’s oceans.
According to Science Daily, whale sharks like to gather in about 20 locations around the globe, particularly off the coasts of Australia, Belize, the Maldives, and Mexico.
Although no one has been able to pinpoint the exact reason for this strange occurrence, a new study by the University of York in the U.K. and the Maldives Whale Shark Research Programme (MWSRP) ventures an explanation for the coastal aggregations of whale sharks.
The research, published in the journal PeerJ, argues that these prime spots the giant fish prefer to amass at share a number of traits that might justify the whale sharks’ choice of venue for their habitual congregations.
“Whale sharks can travel huge distances around the globe and the existence of such a small number of known aggregation sites suggested there had to be something about the depth and shape of the underwater terrain in these areas that makes them appealing,” points out study co-author James Hancock from MWSRP.
For one thing, these areas offer access to sharp sea-floor drops that can lead the whale sharks off into deep water, where they can search for food. Just like the whales from which these creatures get their name, whale sharks feed by swallowing large amounts of water with their enormous, gaping mouths and filtering out zooplankton, small fish, and invertebrates.
At the same time, these select whale shark “hotspots” include access to warm, shallow waters, where these massive fish can climb up to the surface and bask in the sunlight to warm up their huge bodies.
Study supervising author Dr. Bryce Stewart, from the Environment Department at the University of York, explains what could motivate the whale sharks to exhibit this collective behavior.
“Sharks are ectotherms, which means they depend on external sources of body heat. Because they may dive down to feed at depths of more than 1,900 meters, where the water temperature can be as cold as 4 degrees, they need somewhere close by to rest and get their body temperature back up.”
Another thing that the researchers have noticed is that these prime locations may be more abundant in food, treating the whale sharks to a royal buffet.
“Steep slopes in the sea bed also cause an upwelling of sea currents that stimulate plankton and small crustaceans such as krill that the whale sharks feed on,” says Stewart.
The researchers hope that their study will aid in the conservation efforts made to protect the endangered whale sharks. By revealing these creatures’ behavior and highlighting the “hotspots” where they are most likely to take up residence in, the scientists are encouraging people to stay out of the whale sharks’ way and to preserve these locations as undisturbed as possible.
Science Daily notes that whale shark populations have declined at an alarming rate over the last 75 years. Man is also responsible for some of the threats looming over these gentle giants, which have been injured in boat strikes on many occasions, as vessels of all sizes circle around their favorite areas in hopes of catching a glimpse of the planet’s largest fish.