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FAU study shows adult blacktip sharks use shallow water to avoid hammerheads

Video recorded in waist deep water off Palm Beach Co.
Posted at 12:35 PM, May 14, 2020

BOCA RATON, Fla. — A new study by Florida Atlantic University is gaining new insight into the habits of blacktip sharks.

FAU said the video, recorded by a drone off the southeast coast of Florida, shows adult blacktip sharks fleeing to shallow waters when confronted by a great hammerhead shark.

The researchers said this is the first evidence of blacktips using shallow waters as a refuge from a hammerhead.

FAU said several juvenile shark species use shallow water as nursery sites so their young can grow, reducing their risk of attacks from predators.

However, prior to this study, there was no documentation that showed large adult sharks also swim in shallow waters to avoid predators.

FAU study shows adult blacktip sharks use shallow water to avoid hammerheads

Results of the study were published in the Journal Fish Biology.

FAU said on three separate occasions a drone recorded video of a hammerhead shark approaching blacktip sharks in waters about waist deep less than 150 feet off Palm Beach County.

The average length of the blacktips was under 6 feet while the hammerheads were at least twice that size.

FAU said three separate videos were recorded during the day on Feb. 28, 2018, Feb. 28, 2019 and March 3, 2019.

“In two of the three videos, the hammerhead shark actively chased one or more blacktips toward the shore but was unsuccessful at capturing its prey,” said FAU Dr. Stephen Kajiura in a written statement. “The chases ended with the hammerhead making a sharp turn away from its intended prey and the shore, back into deeper waters. The chasing events showed the hammerhead struggling as it experienced difficulty following the blacktips into the shallow waters.”

Researchers said the seasonal occurrence of large numbers of blacktip sharks off Palm Beach County, Florida, provide an excellent opportunity to conduct studies on sharks.

(Video credit: Stephen Kajiura and Joshua Jorgensen)