A whale shark dives near the surface in waters off the coast of Mexico
September 4, was
National Wildlife Day but it's never too late to celebrate the wildlife with whom we share our planet. One of the most majestic and mysterious is the whale shark. It's the biggest shark there is, 30 feet or more in length and weighing in at around 10 tons.
Not only do we share our planet with these creatures but looks like I also share my neighborhood as whale sharks are found in the warm waters of the Gulf of Mexico. I'm sure I've never seen one because who could forget a gigantic polka-dot whale shark who likes to swim with people?
The polka-dot whale sharks have remained mysterious because until recently there was no knowledge of where this largest fish that has ever existed migrated or gave birth. A new study has just been completed at the Mote Marine Laboratory in Sarasota, Fl which is providing some answers.
The study was conceived by Robert Hueter, a marine biologist at Mote Marine Laboratory in Sarasota, Fla. Hueter swims with sharks, and has done so for 40 years, but he has a special fondness for whale sharks. "This is the largest fish as far as we know that's ever existed — there's nothing bigger in the fossil record," he explains. "But it's a very unusual kind of shark in that it's not a top predator; it feeds on plankton."
Plankton are the flotsam of tiny plants and shrimplike animals that float in the ocean. The whale shark just opens its mouth — about twice the size of a manhole cover — and sucks them in. It filters out the plankton much the way a baleen whale filter-feeds.
Robert Hueter tags a whale shark off the coast of Mexico. The tags measure location, depth and water temperature, then relay the data back to a lab.
Hueter describes the research in the journal PLOS One. He says the whale sharks' far-flung travels demonstrate that protecting this rare species will require international collaboration, not unlike the protection given migrating bluefin tuna. Already the research has led Mexico's government to protect the sharks' big feeding grounds there.