In May 2025, Sasha Milsky found herself on the banks of the Penobscot River, watching thousands of rainbow smelt swim up inch-deep tributaries on their way to spawning grounds. With flashlights and headlamps, she and a team from the Penobscot Nation, University of New Hampshire (UNH) and University of Maine (UMaine) scooped fish after fish from the water, implanting each with an acoustic tag. 
It started in 2009 when Dr. Matthew Breece, now assistant professor of marine science at St. Mary’s College of Maryland, was conducting his master’s research with Dr. Dewayne Fox at Delaware State University. They wanted to understand how Atlantic sturgeon were using habitat in the Delaware River.
A seal on the beach with a satellite tag attached to its back and an acoustic tag on its back flipper.
To monitor growing seal populations in Rhode Island waters, researchers have turned to acoustic telemetry as a new source of information. Combined with satellite tag data and DNA barcoding, researchers are building a picture of seal behavior in Rhode Island and evaluating the success of rehabilitation efforts. 
Today, new technologies help us collect more information about marine environments and the species that inhabit them than ever before.
Three people on a boat touch a sea turtle that is sitting on the edge of the boat. The turtle has a tag attached to its shell.
The Mid-Atlantic sea turtle biology and behavior project utilizes acoustic telemetry, satellite telemetry, biological sampling, remotely operated vehicles, and oceanographic sensors to collect data on sea turtles in the Mid-Atlantic region and learn about their environment.
The head of a white shark that is underwater just below the surface. The shark has been caught and has a hook and line in its mouth.
The Rhode Island acoustic array consists of approximately 45 acoustic receivers deployed in the coastal waters of Rhode Island. It provides vital information about species, especially sharks, living in and passing through Rhode Island waters.

For more information about the ACT Network or to find out how to become a member, please contact east.coast.telemetry@gmail.com