ORONO, Maine — June 27, 2014 — As a group of researchers floated down the Penobscot River, they took note of the evident changes in one of Maine’s most cherished and historied waterways. Above the old Veazie Dam site, the end of a boat ramp hung several feet above the river’s surface. Boom islands, built of cobble and timber, had resurfaced after decades underwater. And the rafting guides craned their necks, searching for recently formed hydraulics.
Since the removal of the Great Works Dam in 2012 and Veazie Dam in 2013, people have watched the lower Penobscot take a new shape, some with more interest than others. “Look at that beautiful esker,” said Sam Roy, a Ph.D. student at the University of Maine School of Earth and Climate Sciences. On a laminated U.S. Geological Survey map, he traced the contours of a glacial deposit with his finger down the west banks of the Stillwater and Penobscot rivers.
Roy was one of several UMaine students invited on a Friday rafting trip down the Penobscot to study the riverbed with sonar technology. Led by two Maine Rafting Expeditions guides, the group began its journey in Old Town, just below the Milford Dam. After piling into two whitewater rafts, professors and students juggled paddles and sonar equipment as they floated downstream.
“Primarily, we’re interested in the structure of the bottom of the Penobscot River and the changes to that bottom as a result of everything that’s gone on, including human interventions, floods, dam removals and all the other things that have been a part of the history of the river in the last 200 years,” said Sean Smith, assistant professor at UMaine’s School of Earth and Climate Sciences."
A fluvial geomorphologist, Smith is devoted to understanding streams and rivers. For several years, he’s been interested in researching the Penobscot River, which is the largest river system in the state, stretching 109 miles from its headwaters in northern Maine to the ocean.
“The bottom line is, you can’t manage any river effectively unless you know how it works and responds to direct and indirect influences of geology, climate and humans,” Smith said.
Soon after launching, the rafts encountered rapids below the Milford Dam.
“You’ll want to stow away things you don’t want to get wet,” warned rafting guide Arthur Dickey as he steered toward the frothing waves ahead.
While for a scientist, a changing river could mean new habitat for wildlife and an opportunity to test new technologies, for a whitewater paddler, a shift in a river could mean a new and exciting run. That’s the case for Dickey, owner of Maine Rafting Expeditions.
“There’s a lot more water here than I was expecting,” Dickey said, pointing out a “fun hydraulic” that he’d have to remember for his next trip down the river.
After the whitewater, the group set down the paddles to set up the equipment that would map the bottom of the river with sonar.
“Our interest in the bottom is for what it means to the fish,” said Gayle Zydlewski, associate professor at the UMaine School of Marine Science.
Zydlewski is studying sturgeon, a large primitive-looking fish that moves along the river bottom, disturbing substrate to feed on plants and animals.
The Penobscot River historically supported spawning populations of both the endangered shortnose sturgeon and the Atlantic sturgeon, according to the Penobscot River Restoration Trust.
Read the full story and watch the video at The Bangor Daily News