HOUMA, La. — Each June and July near the full moon, the northern Gulf of Mexico hosts a mysterious gathering of whale sharks.
Dozens of the hulking black sharks with white spots glide about with mouths agape as they skim the water's surface during a 12-hour tuna egg buffet of sorts.
A decade ago, records of these unusual gatherings existed only in fishermen's tales.
Scientists have spent the last decade piecing together an understanding of the fish's existence in the northern Gulf and tracking these gatherings that have also been reported in other parts of the world.
"In the past we were amazed just to see 16 animals. ... Then look back to 2010, there were 16 to 20 of the animals everywhere you turned," said Eric Hoffmayer, National Oceanic and Atmospheric Administration research fisheries biologist. "Staying in the water with those guys, it was just a surreal experience."
Hoffmayer began researching the whale sharks' habits and habitat in the northern Gulf in 2002. Today the project is a collaborative effort between scientists at the University of Southern Mississippi, NOAA and the Louisiana Department of Wildlife and Fisheries.
The whale shark is the ocean's largest fish, growing more than 30 feet long and in some cases weighing 20 tons.
LWDF fisheries biologist Jennifer McKinney said these assemblies coincide with tuna spawning events and consistently occur near the Ewing Bank, about 100 miles from Cocodrie.
Researchers are investigating many aspects of the gatherings including whether they are the result of an "evolutionary memory" or the sharks opportunistically following spawning fish.