High-tech acoustic buoys work to keep coastal areas safer from sharks

Great White Shark off Cape Cod
This summer, new technology is helping biologists track shark activity off the coast of New England.

Cape Cod is full of big sharks this summer, including many great whites. With the help of a number of other groups interested in sharks, state officials are working to monitor large predators while also making beaches safer for tourists.

On a recent weekend, 12 shark sightings were reported in the Cape Cod Beach area, with some toothy predators seen just 50 yards from the beach. A new “Sharktivity app” is in the works, allowing summer beachgoers to report shark sightings, alerting others to the presence of predators.

But more technology is being used to monitor sharks.

The Massachusetts Department of Fisheries and Wildlife (MassWildlife), in partnership with the Atlantic White Shark Conservation Society, has placed two sonic receiver buoys near Wellfleet Beach near the tip of Cape Code, southeast of Boston. One floating sea buoy is located near Newcon Hollow Beach and the other is located in the Lecount Hollow-Maguire Landing Beach area.

Last summer, the Atlantic White Shark Conservation Society deployed buoys on the Cape Town coastline. But the Wellfleet buoy is new this summer. Acoustic buoys detect sharks, which are equipped with transmitters that show their location to acoustic receivers.

The number of great white sharks detected by sonic receivers near Cape Cod has risen for eight straight years. According to the Atlantic White Shark Conservation Society, 132 sharks were spotted last year, up from 11 in 2013.

“We tag more (sharks) every year, so this will automatically lead to more detections,” shark biologist Greg Skomal told the New England News Collaborative (NENC). “We also expand our receiver array a little bit every year, or other researchers put in receivers and we can get their data.”

Skomal said the number of white sharks around Cape Cod has increased in recent years because predators are feeding on the growing number of seals in the area.

Skomal is part of a team of scientists sharing shark data from 200 acoustic buoys deployed along the coast. Only a few buoys provide real-time data because the technology is expensive, at nearly $20,000 per buoy.

Shark watchers also use drone cameras to monitor large predators along the coast. Drones cruised over the beach and compared the collected images with acoustic data. However, drone cameras have limitations.

“Sometimes the water is so clear it looks like the Caribbean Sea,” scientist Megan Winton told NENC. “Other times it looks like chocolate milk and you really can’t see anything. It’s a very dynamic field.”

Cape Cod’s obsession with modern-day sharks began in September 2018, when a man was killed by a shark near Wellfleet. A month earlier, another man was seriously injured after being hit by a shark near Truro, a Cape Cod town.

Human sharks are sure to be encountered in the Cape Cod area during peak beach tourism in August, September and October, Skomal said.

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