CHATHAM (CBS) — After a summer full of shark sightings and beach closures, the Atlantic White Shark Conservancy is close to wrapping up shark tagging season. A record 46 sharks have been tagged so far, the most ever in one season.
“Just because fall is here doesn’t mean that the sharks are gone,” said Greg Skomal, fisheries biologist for the Massachusetts Division of Marine Fisheries.
On a late October day, the air was crisp as high cirrus clouds streamed across the sky, but no wet weather was expected. Water conditions on the outer Cape near Chatham were nearly calm with visibility perfect at times.
Early in the morning, Skomal and his team packed a research vessel docked in Chatham for what would be a busy day ahead.
“Fantastic day. We had plenty of sharks around,” Skomal said. “This is the time of year when the really big ones move in. They may be coming down from Canadian waters as they migrate south, and they come by Cape Cod to grab a snack on their way.”
Skomal and his team tagged the biggest shark of the season – a 15-foot great white shark. It was not far from shore, where its afternoon snack, a seal, was laying on the beach.
“A lot of times they are pretty mellow and saving their energy to when they need to accelerate to kill a seal. They conserve their energy wisely.” Skomal explained.
Skomal, along with the Atlantic White Shark Conservancy, has been tracking and tagging white sharks off the coast of Cape Cod this season collecting data for new research.
“People think that a shark is a shark is a shark, but they’ve got a lot of unique characteristics– pigment patterns, spot patterns,” explained Megan Winton, a research scientist for Atlantic White Shark Conservancy. “We saw the one that had the big scar down the side of the body today. So all of those are characteristics are things we use to identify it.”
Scientists follow a specific process before tagging a shark. First, they make sure it’s not one they have tagged before. They use a omni-directional hydrophone that allows them to listen for the presence of a tag on an animal.
The team also takes video of the shark to catalog and compare after. If the shark has no tag, it’s a quick trade from a camera to a tagging spear, and it’s game on.
“The tags that we are putting on these sharks are acoustic transmitters. They will ping for up to 10 years. We have an array of receivers all over Massachusetts,” Skomal said.
The tags will ultimately help scientists determine the near-shore behavior of these fish.
“We’re trying to figure out or get a better handle on when, where and how white sharks attack and kill prey. And this is mostly because of the public safety issues we had last year and that persist this year,” Skomal said.
On this trip, with the help of a spotter plane, the team saw over a dozen sharks.
Skomal is hopeful the tagging process will bring new light to these mysterious creatures. “If we can pinpoint where these sharks are attacking and killing seals, then I think we can better advise the public on where and when they should swim.”
The research team has tagged over 200 sharks in the last several years.
“We’ll get a history of individual sharks for years to come,” Skomal said. “There are a lot of sharks that we saw today that already had tags, that we knew. Some we tagged last year, some we tagged 3 or 4 or 5 years ago. So we can look at their patterns of behavior as they come back each year and see if they change from year to year to year.”
While the team will study the past sharks, they are also looking to tag new ones. Shark activity peaks in our coastal waters between August and October.
“Yeah we will tag up until early November if the weather cooperates. We’ve had a bad weather stretch the last three weeks, and it’s great to get back out again and tag five, which is the most we’ve tagged in a single day since we started,” Skomal said. “It’s a testament to the fact we’ve been able to shift our focus to getting out as many tags as we can, and also there is a lot of sharks around.”
To learn more about white shark research off our coast visit the conservancy’s website.