The shortfin mako shark is one of the fastest fish in the ocean. But the shark’s staggering swimming speed, of up to 60 mph, has not stopped it from falling victim to overfishing, according to a new study from Guy Harvey’s Research Institute.
A satellite tagging project found the rate at which mako sharks were being killed by fishermen was 10 times higher than previously believed.
Of 40 sharks tagged by Mr. Harvey’s research team, based out of Florida’s Nova Southeastern University, 30 percent were captured in fisheries.
Previous data on shark kills has depended on self-reporting from fishermen and is of questionable reliability, according to Mahmood Shivji, senior author of the study and director of the institute.
He said real-time tracking of mako sharks using satellite tags to see how many were captured showed mortality rates far in excess of what was being reported by the fishing industry.
“From a conservation and protection point of view, this is huge,” said Bradley Wetherbee, a research scientist from the University of Rhode Island’s Department of Biological Sciences and a member of Mr. Harvey’s institute.
“It’s vital that we have the most accurate data possible to aid decision-makers in managing marine life populations sustainably. If they have inaccurate information, it is much more difficult to make the correct decisions for properly managing populations. Everyone wants the populations managed in a sustainable way.”
Michael Byrne, the paper’s lead author and postdoctoral fellow at the Guy Harvey Research Institute, said mako sharks roam large swathes of ocean, entering the territorial waters of numerous countries.
“The tracking data also showed these mako sharks entered the management zones of 19 countries, underscoring how critical it is for countries to work together closely to manage and conserve these long-distance oceanic travelers,” he said. Mr. Shivji said he hopes the data will help fuel smarter conservation and management programs. “We have to have sustainable approaches to fishing,” he added.
“Sharks might get a bit of a bad rap in the media, but these apex predators are vital to the overall health of our oceans. You remove them from the equation and, quite honestly, we don’t know how far those ripples will be felt. One thing we do know is it won’t be inconsequential.”