April 27, 2013 — River herring's tenacity is something state and national environmental groups are banking on as they try to save a species whose population has dropped 90 percent in the past 90 years.
You might call river herring nature's underdog.
Attracted to rushing water, the fish swim upstream, darting over rocks and ledges to the ponds of their birth where they will reproduce.
"You just think about these tiny little poor fish trying to swim against the current and dodge the fish and the birds that are pecking at them," Buzzards Bay Coalition Vice President of Advocacy Rachel Jakuba said. "It's just so impressive to see these little fish come back. It's an amazing feat."
River herring spend most of their time in the Atlantic Ocean but come to fresh water to breed. The 6-inch-long fish are caught commercially and also are a food source for other commercial fish such as cod.
The largest threat to herring is dams and other blockages to their migration.
"If they can't swim upstream, they can't reproduce, and that knocks your population down pretty fast," Jakuba said.
That's a problem environmentalists say they have already taken steps to fix in the form of a three-stage restoration effort in the Acushnet River.
There, herring migration was blocked for years by three dams that kept herring migration to below an average of 400 fish per year.
From 2002-07, the National Oceanic and Atmospheric Administration and the Division of Marine Fisheries teamed up using funds from the New Bedford Harbor Trustee Council to remove the dams and replace them with "nature-like fishways" to ease the fish migration.
For example, at the Acushnet Saw Mill site, an 89-inch-tall dam once stopped herring in their tracks. That dam was deconstructed into a fish ladder of nine 9-inch-tall steps that curve around the river bend.
According to NOAA's Jim Turick, the steps were specially designed to attract the fish and help them up the river, with the stone steps arranged specifically to make the water flow at certain speeds.
The ladder rungs are spread out so as to allow the fish room to rest before darting over the steps in order to make it to their spawning ground.
Read the full story at the New Bedford Standard-Times