ORLEANS — For years, the technology has been as elusive as, well, great white sharks. Now, a system that can detect and report white sharks in real time is being tested at three Cape beaches, including Nauset.
On Tuesday, the Atlantic White Shark Conservancy’s Sharktivity app reported a white shark off Newcomb Hollow Beach in Wellfleet, the site of last year’s fatal shark attack. The shark wasn’t spotted by a beachgoer, a boater or a spotter pilot; it was detected and automatically reported by a buoy.
Cynthia Wigren, the Conservancy’s executive director, said it’s important to understand the system’s limitations.
“This will just detect tagged sharks and it is not a guarantee of safety,” she said. The detector buoys work by receiving signals from acoustic tags, which researchers have affixed to more than 170 sharks in the past decade. “When a tagged shark swims within range of the receiver (100-200 yards) an email will be sent immediately. Nauset Beach safety officials will receive these emails,” Wigren said.
The Newcomb Hollow buoy was deployed in late July, and no date have been set yet for the Nauset Beach installation. A third buoy will be positioned at Head of the Meadow Beach in Truro.
The Nauset buoy will be manufactured by Boston-based Innovasea, which acquired Vemco, the Canadian company that makes the acoustic receivers already in use around the Cape. Those receivers collect information about tagged fish that pass nearby, but the data remains in the receiver until it is manually downloaded. The new buoy uses mobile phone technology to transmit that information in real time. Each buoy costs upwards of $14,000.
“We’ve actually been testing real-time receiver technology over the last six years with limited success,” Wigren said. While the deployment of this system is taking place even as beach managers are investigating various shark detection and mitigation options, that timing is coincidental. “The AWSC does not make recommendations regarding beach management,” she said.
Stakeholders will be not only evaluating the system’s effectiveness, but will be looking at the various factors that might cause real-time reports to be delayed, including gaps in cell phone coverage. The receivers themselves can also be hampered by acoustic interference.
Perhaps as early as next month, consultants from the Woods Hole Group are expected to issue the results of their survey of possible shark mitigation measures. That study is supported by the Cape Cod Commission, the Friends of the Cape Cod National Seashore, and the Atlantic White Shark Conservancy, as well as the state and the six Lower Cape towns.
Seeking to further reduce the risk of a shark attack this summer, members of the regional shark working group installed more strongly-worded shark warning signs, as well as emergency call boxes and special “Stop the Bleed” first aid kits on remote beaches. While Labor Day weekend is just a month away, peak shark season off the Lower Cape is just beginning.
“Based on tagging data, we know that August through October are the peak months of activity,” Wigren said. “We hope that an increased awareness this season will lead to beachgoers following shark safety tips and altering, if necessary, how, where and when they use the water, which will ultimately reduce the chance of negative human/shark encounters,” she said.
In its widely distributed safety brochure, the regional white shark working group advises swimmers to remember that while sharks hunt for seals in shallow water, they should stay close to shore, within reach of rescuers. Paddlers and swimmers should stay in groups and should avoid areas where seals are present or schools of fish are visible. They should avoid murky water, limit splashing, and follow any advisories posted by beach managers and lifeguards.
Many beachgoers and others are making use of the Shartivity app, though that comes with some drawbacks, Wigren noted.
“We are pleased that the app has become extremely popular. More than 300,000 users have downloaded the app at this point,” she said. But the system was originally designed to send out 10,000 push notifications at a time, and with the increased number of users, the app has experienced some delays. “We are working with the app developer to fix the delay,” Wigren said.
This article was corrected on Aug. 13 to reflect that the buoy manufacturer Vemco has been acquired by Innovasea.