Buzzards Bay Coalition to restore part of Weweantic River to help fish
South Coast Today
By ARIEL WITTENBERG
awittenberg@s-t.com
October 13, 2014 12:00 AM
WAREHAM — Take a look at the bridge at Horse Shoe Mills on the Weweantic River and it’s not difficult to see why fish migration there is virtually non-existent.
The bridge is made of thick concrete; beneath it is a decrepit wooden wall that once entirely blocked the flow of water. Today, the dam is still there with only a small, 1-square-foot hole allowing water to flow.
“In the spring, when the ice is melting and it’s high tide, it’s basically like a fire hose, the pressure builds up so much,” says Brendan Annett, vice president of watershed protection at the Buzzards Bay Coalition.
The Weweantic River is the largest in Buzzards Bay, and the location of Horse Shoe Mills, at the end of Station Road just north of where Interstate 195 passes over the river, makes it a perfect location for pelagic, or migrating, fish to come and spawn.
The remnants of the mill, however, make that nearly impossible.
While herring migration has been increasing rapidly in other SouthCoast rivers, it is virtually non-existent in the Weweantic because of the blockage under the bridge.
“It was meant to block the water, that was the point,” Annett said of the bridge, a remnant of an old horseshoe factory, where water was redirected to turn turbines to power the plant. “Today, it just constricts the river and is an obstacle to the fish.”
Now, the coalition is hoping to change all that with a $365,000 grant from the trustees of the Bouchard Oil Spill to remove the dam and restore the river. The project will mimic another coalition effort to increase herring migration on the Acushnet River by deconstructing a saw mill there, which has had great success. This summer, more than 10,000 herring swam up the Acushnet River to spawn, a 68 percent increase over the previous year.
The Horse Shoe Mills blockage on the Weweantic is located at a very environmentally valuable area because the river is still intertidal there. At high tide, salt water comes up the river; at low tide the fresh water flows out. That makes it the perfect spawning ground for a number of migrating fish, including rainbow smelt, herring, white perch, hogchoker, tom cod, lamprey, sea-run brook trout and American eel.
All of these species are important, but the blockages make migrating nearly impossible.
The rainbow smelt, for example, will swim up the river and try to spawn just before the bridge blockage, Annett said, but during low tide their eggs are left high and dry.
“The part of the river where this mill was built is basically still part of the bay and, it really effects the whole ecosystem and a lot of natural processes,” Annett said. “Luckily, there are things we can do to take care of the problem and get the fish moving again.”
In Acushnet, that process involved removing a dam from the river and replacing it with a graduated “fish ladder” to make it easier for the herring to climb upstream. There, the coalition also “deconstructed” the river bank, removing concrete that made the river look more like a canal and replacing it with a more natural looking bank.
Having only received its grant for the Weweantic work last week, the coalition isn’t exactly sure what actions it will take, but removing the blockage under the bridge will definitely be part of the project.
“The fish population here is barely hanging on in spite of the blockages here,” Annett said. “The expectation is that, with our help, it can bloom.”
Follow Ariel Wittenberg on Twitter @awittenberg_SCT.
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