CHARLEMONT — Ted Castro-Santos carefully performed abdominal surgery on the shore of the Deerfield River. His “patients” were approximately 30 brown trout, each caught, anesthetized and fitted with an abdominal radio tag before being released into the river.
These surgeries marked the beginning of a two-year study that will investigate the movement of brown trout in the Deerfield River. The radio tags will show where the trout are located in the river and their movement patterns, Castro-Santos said.
This is particularly interesting to scientists and recreational fishermen because it will show how the trout react to the river’s daily “hydro-peaking” flows, or increases and decreases in water levels, which come from the Fife Brook hydroelectric dam releasing or withholding water.
Although radio-tagging fish isn’t new, this type of study is at the forefront.
“It’s the first time we know in Massachusetts, maybe the country, I’m not sure, but certainly in Massachusetts that we’ll be tracking the movement of trout and the impacts of a hydroelectric river,” said Michael Vito, president of Deerfield River Watershed Trout Unlimited 34, the local organization that funded the study.
Presently, much of the knowledge of how trout move in the Deerfield River is anecdotal, which is why the current study is important to provide hard data, Vito said.
The study will collect data on how changes in water flow in the winter influence trout spawning and the data will be reviewed by biologists from the Silvio O. Conte Anadromous Fish Research Center, a U.S. Geological Survey laboratory in Turners Falls.
A report with the data will be given to the Massachusetts Department of Environmental Protection, which, Vito said, has a say in the process of the renewal of Brookfield Power’s license on the Fife Brook hydroelectric dam.
“We don’t know what we’re going to find,” Vito said, adding that the current study piggy-backs on two year-long studies that Deerfield River Watershed Trout Unlimited performed from 2017 to 2019 on how changes of water level from the dam influence trout eggs in the winter.
Vito emphasized that winter water levels are the key to the issue because they affect trout eggs and, by extension, the number of trout in the river the next year.
In their previous studies, Deerfield River Watershed Trout Unlimited found that winter water levels were often below the trout nests, killing the trout eggs, Vito said.
The next step for scientists and Deerfield River Watershed Trout Unlimited is studying the movement of trout.
“We know how hydro-peaking is impacting spawning beds. Now we’ll be able to examine how hydro-peaking is impacting the fish,” Vito said.
“If we find that hydro-peaking flows have any negative impacts on these fish, we can work to get these (flow) rates adjusted properly,” he continued.
Even if negative impacts are found, there are many steps before the issue can be mitigated.
“There’s a lot of decision making that needs to be done,” Vito said. “We’re trying to sway the decision making in the trout’s favor.”
At a riverside surgery unit, set up on the back of a raft, Castro-Santos sewed up a small incision on a trout’s belly as Matt O’Donnell monitored the electro-anesthesia. Both O’Donnell and Castro-Santos work for the U.S. Geological Survey at the Silvio O. Conte Anadromous Fish Laboratory.
Nearby, Jadziah Hannon-Moonstone, who works for the U.S. Fish and Wildlife Service in Vermont, collected data on trout length.
Although none of the science agencies funded the study, the scientists participated in radio tagging because they could contribute skills, like fish surgery, said Castro-Santos. He added that each tracker costs $200 and estimated that the total amount for tagged fish is $6,000.
Going forward, monitoring the trout will be a large volunteer effort of “citizen-scientists,” Vito said. The radio tags will report the location of the fish to a team of volunteers, who drive adjacent to the river and pick up the trout’s radio signals with portable receivers and antennae. Data will be collected four times a week, twice in the morning and twice at night, to better understand how the hydro-peaking flows influence the trout’s movement, Vito said.
Currently, there are over 40 Deerfield River Watershed Trout Unlimited volunteers, Vito said, adding that he expects that number to grow and incorporate anyone interested in this project. Vito urges anyone interested in volunteering to email the group at email@example.com.
For Deerfield River Watershed Trout Unlimited members helping out on the river on Tuesday, there was a link between how the group’s studies could improve river health, and by extension, could improve local business.
A healthy ecosystem “improves the river, which improves the fish. And by improving the fish, it helps drive the local economy,” said Chris Jackson, a fly fishing guide who lives in Charlemont. Jackson was a founding board member of Deerfield River Watershed Trout Unlimited and has held multiple positions within the organization.
Fishing on the Deerfield River “is starting to get popular. The word’s getting out,” said Mike Didonna, a Deerfield River Watershed Trout Unlimited member and owner of Deerfield Fly Shop. Didonna reported seeing license plates from New York, New Jersey and New Hampshire around the Deerfield River.
Reach Maureen O’Reilly at firstname.lastname@example.org or 413-772-0261, ext. 280.