Knowing the exact location of white sharks off Cape Cod beaches is obviously important, both from a scientific and safety perspective. And that means the network of shark spotters – professional and amateur alike – plays a critical role.
A new partnership between the North Chatham-based Atlantic White Shark Conservancy and the New England Aquarium aims to boost that network by encouraging more people to report shark sightings through the Conservancy’s Sharktivity smartphone app. Under an agreement announced last week, the Conservancy will contract with the Aquarium to have its shark expert, John Chisholm, verify sightings sent through Sharktivity before posting them publicly. Chisholm, an adjunct scientist with the Aquarium, has been studying sharks his whole life and has been tracking public shark sightings for many years.
Both organizations have been active in shark education and research, “but it’s a bigger collaboration now,” Chisholm said. The goal “is to try and generate these public white shark sightings and gather information that can be used for different scientific studies” as well as public safety alerts, he said.
“The Conservancy has really spearheaded the effort to keep the community informed and safe as possible regarding white sharks, and the New England Aquarium is excited to join and amplify this effort,” said Aquarium Senior Scientist Nick Whitney.
“Citizen scientists play a crucial role in the Conservancy’s mission to educate the community and improve public safety, and we rely upon and value their sighting data reported through the Sharktivity app,” Conservancy CEO Cynthia Wigren said.
While many of the white shark sightings come from experienced shark spotters like researchers, beach managers and harbormasters, many also come from boaters or beachgoers who spot a telltale fin breaking the water. Once those reports are verified by an expert, they’re posted on the app so other users can take appropriate action – including getting out of the water if necessary. It was concern over public safety and the need for real-time shark tracking that helped inspire the creation of Sharktivity, Chisholm said.
“But in addition, it’s for gathering sightings and information that can go back to the science of trying to study white sharks in the area,” he said. If someone sends a photo of a sighting through the app, he’s usually able to identify the species, and sometimes can compare marks and notches on the shark to photos in the Conservancy’s database of individual animals. “Then there’s a data point,” he said.
So how many of the crowd-sourced shark sightings are valid?
“The last one I got was a picture of someone’s cat in a little shark crate,” Chisholm said with a laugh. And then there are the pranks, where the prankster inserts a friend’s phone number. When Chisholm calls to get the details, “the friend has no idea what I’m talking about,” he said. But the vast majority of reports are well-intentioned, Chisholm said.
Among those, false sightings have typically been basking sharks, which have a more rounded dorsal fin, larger size, more uniform coloration and larger gill slits than white sharks. Sometimes people report seeing the fins of sunfish, which are a similar shape but often bob up and down, unlike shark fins. More recently, though, people have been reported seeing fins when they’re actually spotting the heads of gray seals, Chisholm said.
Verifying shark sightings involves contacting the reporting party and checking any photos or video they have. “Thankfully, almost everyone’s walking around with a camera, thanks to cell phone technology,” he said. When there is no photo, verifying a report becomes more difficult detective work and involves Chisholm asking a series of questions designed to tease out what the species was, without leading the witness one way or another.
“It’s a good opportunity for me to communicate with people,” educating them about sharks and other marine life, he said. If the sighting is something other than a white shark, he tries to break the news gently.
“Most of them accept it, but you can just hear the disappointment in their voices when they realize it, because everybody wants to see a white shark,” Chisholm said.