Photographer John Clarke Russ captures amazing' images of this remarkable research off the coast of Scituate, Massachusetts.
Jeff Kneebone, a marine biologist with the Massachusetts Division of Marine Fisheries, releases a freshly-tagged Atlantic cod into Massachusetts Bay.
A commercial trawler motors across Massachusetts Bay. Cod and other groundfish species have been declining in numbers for decades throughout the Gulf of Maine.
Technicians implant an acoustic tag into a cod aboard a commercial fishing trawler in Massachusetts Bay. The data will help scientists and policy-makers restore cod numbers.
Fisheries researchers keep track of each cod tagged so that they can provide valuable data about fish movement and use of habitat.
Jeff Kneebone (left), from the Mass. Division of Marine Fisheries contractor, and The Nature Conservancy's Chris McGuire, right, discuss cod findings during a research trip to tag and study cod aboard the "Yankee Rose."
The acoustic tags are not much bigger than lipstick and don't harm the cod.
A tagged cod swims in a holding tank aboard the commercial fishing boat "Endeavor" shortly before the fish's release into the waters off Scituate, Massachusetts.
Ten miles off the coast, the Boston skyline looms in the sunset. Once a strong part of the Massachusetts coastal economy, restoring cod and other groundfish in the Gulf of Maine may yield many benefits.