Updated: December 6, 2023
Researchers from the UH Mānoa Hawaiʻi Institute of Marine Biology Shark Research Lab were returning from conducting field work when they spotted seabirds flying over what they suspected was a bait ball (where small fish swarm in a tightly packed spherical formation near the surface while being pursued and herded by predators below).
Researcher, Mark Royer went into the water to see what else was in the water and was surprised to see a 30-foot whale shark.
The whale shark was feeding on nehu (Hawaiian anchovy) and Royer says the video captures a large aggregation of predators both small and large including ʻopelu (mackerel scad), kawakawa (mackerel tuna), aku (skipjack tuna), sandbar sharks and seabirds, who were also feeding on the nehu.
“While all the small nehu were being drawn to the surface from all the predators, the whale shark was coming in and using its massive mouth to come up to the surface, open it, and then the suction would cause all the fish to funnel into its huge mouth,” said Royer.
The incident was reported on Nov. 2, a mile off Kāneʻohe Bay near Kualoa Ranch.
The whale shark is the worldʻs largest fish and though it is known to be in Hawaiian waters, it is a rare a captivating sight, according to researchers. “It is surprising. They are here more often than we think, however they are probably hard to come across because like I said, I didn’t see this animal until I hopped in the water,” said Royer.
Lelewaʻa is ʻōlelo Hawaiʻi for whale shark, likely named for their propensity to approach and lean on canoe outriggers according to the late historian Samuel Kamakau.
Whale sharks are known to approach boats standing idle in the water. “It is important to be mindful and respectful, let them approach, don’t aggressively approach and disturb them,” researchers said.
“It would swim and approach our boat that was nearby, put its head up to it and go back down and repeat that over and over again. That’s a behavior that whale sharks sometimes exhibit is that if your boat is standing still in the water they will approach you,” said Royer.
The UH Mānoa HIMB Shark Research Lab investigates the behavior, physiology and ecology of sharks and other fish.