{"id":22363,"date":"2026-10-15T11:03:52","date_gmt":"2026-10-15T15:03:52","guid":{"rendered":"https:\/\/web.uri.edu\/cels\/?p=22363"},"modified":"2026-10-15T11:53:15","modified_gmt":"2026-10-15T15:53:15","slug":"the-secret-life-of-sharks","status":"publish","type":"post","link":"https:\/\/web.uri.edu\/cels\/news\/the-secret-life-of-sharks\/","title":{"rendered":"The Secret Life of Sharks"},"content":{"rendered":"\n

University of Rhode Island master\u2019s student Owen Fleischer is using accelerometers<\/em> to answer a question with no known answer: what do sharks actually do all day?<\/em>

KINGSTON, R.I. \u2013 Oct. 15, 2026 \u2013 If you want to catch a shark, patience is key. But patience on a boat for 27 hours over a two-day search doesn’t look like sitting still.

Owen Fleischer’s research depends on an unusually demanding sequence of events: catch a shark in the open ocean, bring it on to a boat, attach a specialized tag, release the animal safely, and then find the tag a day later.<\/p>\n\n\n\n

For hours, the University of Rhode Island master’s student and his team cut bait and set hooks. They read the wind and current, adjusting their position based on years of records showing where sharks have been caught before. They drop baited lines with thirty-pound weights overboard, then haul everything back up from 120 feet below hours later.<\/p>\n\n\n\n

The conditions are good. The drift is ideal. Still, nothing. No dramatic chase, no cinematic breach of the surface, no sudden dorsal fin cutting through the water. <\/p>\n\n\n\n

Disappointment builds, but also motivation: If it were easy, someone else would have done this study already. The hours accumulate slowly.

Then, finally, a shark takes the bait.

When the waiting ends<\/strong>

When Fleischer and his team tagged a ten-foot-long common thresher shark just outside Narragansett Bay last month, it was the first time the species had been fitted with a fine-scale behavioral tag (accelerometer) equipped with a video camera. The tag would record 100 data points per second for 24 hours, creating an extraordinarily detailed record of a day in the life of an animal that spends almost all of its time out of human sight. <\/p>\n\n\n\n

After days spent working for this moment, the atmosphere on board changed instantly. Elated cheers at the first sight of the shark emerging from the depths quickly shifted to a quiet hum of concentration recognizing the urgency. <\/p>\n\n\n

\n
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Fleischer holds two of the fine-scale behavioral tags provided through the Guy Harvey Foundation. The one on the left had previously been deployed and recovered. <\/figcaption><\/figure>\n<\/div>\n\n\n

Alongside Dr. Kathleen Carroll, assistant professor of applied quantitative ecology; undergraduate students Luke Johnson and Makenzie Denzler; and Ph.D. students Christopher Hickling and Kayla Austin, Fleischer and his research team moved with practiced coordination: keeping water flowing through the shark’s gills, holding it steady, documenting everything from its length to the coordinates of the location, and watching for signs of how the animal was responding and whether it was safe to proceed.<\/p>\n\n\n\n

The work is physically demanding and precise. There is little room for error when you have only a few minutes with a wild animal and a tiny piece of equipment to attach.<\/p>\n\n\n\n

It was the moment Fleischer had been waiting for, but he didn’t try to prolong it. “As soon as the shark’s on board, all I’m thinking about is how fast we can get it back in the water,” he says.

When it was released, he briefly jumped in beside it, wearing a mask and flippers. Not for the thrill, he notes, but to be ready to help if it needed support. He remembers the brilliant white of the shark\u2019s underside against the dark water as it steadily swam off. <\/p>\n\n\n\n

“I was so relieved,” he says.

A day in the life of a shark <\/strong>

Fleischer came to URI as an undergraduate to study sharks. Now, as a master’s student working in Dr. Carroll\u2019s Quest Lab<\/a>, he is investigating something humans know surprisingly little about: what sharks do as they move through the ocean. <\/p>\n\n\n\n

Scientists understand sharks’ broad-scale movements; satellite tags, for example, reveal migration routes. But knowing where a shark goes doesn’t tell us what it’s doing there.<\/p>\n\n\n\n

“We don’t know anything about what sharks actually do in a day,” Fleischer says. His fine-scale data, covering when and where a shark dives, how it moves, and how its behavior shifts, is meant to close that gap.<\/p>\n\n\n\n

The tag, provided through the Guy Harvey Foundation, contains an accelerometer, pressure and temperature sensors, a camera, and buoyant syntactic foam. The accelerometer’s movement data lets Fleischer calculate metrics such as tail-beat frequency and overall dynamic body acceleration, a proxy for how energetically an animal is moving. <\/p>\n\n\n\n

A timed-release mechanism detached the tag after 24 hours. It floated to the surface, where a satellite transmitter helped researchers locate it. The shark had been tagged just outside Narragansett Bay; the tag came off near Martha’s Vineyard.

What one shark can (and can\u2019t) tell us<\/strong>

Fleischer\u2019s initial analyses of what is likely the world’s first fine-scale depth profile for the species indicate differences in the shark’s use of the water column between day and night. He also observed a dive profile unlike those documented in blue and mako sharks living in the same general habitat.

The significance isn’t that this one shark can tell scientists what all common threshers do. “This is one fish,” Fleischer explains, \u201cand its behavior could look very different from the species as a whole.\u201d <\/p>\n\n\n

\n
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Left to right: Professor Graham Forrester; Brian Caccioppoli, who captained the R\/V Warfish; Kayla Austin; Makenzie Denzler,; Christopher Hickling; Anna Gray; Professor Kathleen Carroll; Luke Johnson; and Steven Sisson. Owen Fleischer is in front.<\/figcaption><\/figure>\n<\/div>\n\n\n

His work establishes a baseline and opens questions scientists haven’t had the tools to answer until now: How does a shark move through the water column? How much does its swimming change between day and night? How can two species in the same ocean environment use it in fundamentally different ways?<\/p>\n\n\n\n

Beginning to answer those questions takes specialized technology, physical labor, meticulous planning, and respect for the fact that the wild introduces variables that cannot be controlled. No matter how well a team prepares, the ocean can simply say no. <\/p>\n\n\n\n

Patience is key, but also persistence. Because if you want to know what a shark does when no one is watching, first you have to catch one.<\/p>\n","protected":false},"excerpt":{"rendered":"

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