Four Great Whites Detected At Block Island - The Fisherman

Four Great Whites Detected At Block Island


The Atlantic Shark Institute (ASI) announced that they have detected four great white sharks so far, during the early part of their 2021 white shark research season. All four sharks were detected off Block Island, RI on their acoustic receiver array. “This now brings our total white shark detections to 14 different individuals off Block Island since this study began in 2019”, shared Jon Dodd, the Executive Director of the Atlantic Shark Institute. “Interestingly, not one of the 14 sharks we’ve detected has come through a second season”, he added.

Of the four white sharks recently detected, the two largest were females. One was a 12-foot female tagged in August of 2019 off Cape Cod, MA and the other was an 11-foot female tagged in 2021 in Canada.

“One of the great things about our growing receiver array is the ability to track these sharks more closely as they maneuver around Block Island and adjacent waters”, Dodd continued. Last year the ASI deployed seven different receivers around Block Island and this season they were able to increase that number to nine. Each additional receiver allows the ASI to better view the fine-scale movements of these white sharks which they report is adding significantly to the value of their research, and how these sharks spend their time in RI waters. “Two of these white sharks were detected on a new receiver that we just added through the generosity of Mike Flood and Flood Ford. Without the support of folks like Mike, those sharks would have gone undetected and the value of this critical research would be less than it could have been”, Dodd continued.

The nine acoustic receivers around Block Island allow researchers to detect any tagged shark that comes within approximately 1,000 yards of any of the receivers. Each tagged shark has a unique code that is only associated with that shark, which is the reason the Atlantic Shark Institute can use that code to determine the size, sex and tagging date of any shark that they detect. Fewer than 300 white sharks have been tagged in the Northwest Atlantic using this technology and that makes these detections all the more critical.

“Each season we log more detections, more data, greater specificity on fine-scale movements and each one is adding significant value to this study and a greater understanding of this iconic species in Rhode Island waters”, Dodd shared.

This study is being done in partnership with the RI Department of Environmental Management. To learn more about the non-profit Atlantic Shark Institute, or to support this critical research, you can visit them at or on Facebook or Instagram.