Jordan Brook Ladder Allows Herring To Follow Their Noses

To certain river herring, there's no place that has quite the olfactory allure of the freshwater portions of Jordan Brook. But the magnetic attraction of that particular piece of water for those particular fish, stirred every spring by memories of smells imprinted at birth, had been confounded for 300 years. That's when the brook was dammed for a grist mill just at the place where the brackish tidal waters of Jordan Cove meet the fresh waters of the brook.

• The adult herring would swim in from Long Island Sound to the cove, seeking the freshwater place where they were born and could start the next generation, only to meet the impenetrable obstacle of the dam. Some would still spawn just below the dam, but if the eggs drifted too close to the nearby brackish water, they would die. Spring herring runs that once numbered in the thousands had dwindled to just dozens of fish.
• “Hundreds of years ago, people put up dams all across this watershed,” said Curt Johnson, project director of Save the Sound, during an event celebrating the opening of a fish ladder on the brook. “The problem is, the fish would come up here and say, 'Damn! I can't get through.' They were blocked from the places they had traditionally come.”
• Opened just a few weeks ago, herring have already been seen using the 65-foot ladder to scale the 11-foot height over the dam and reach the fresh waters of Jordan Mill Pond at the top, said Steve Gephard, supervising fisheries biologist for the state Department of Environmental Protection. The ladder channels water from the pond into the lower brook, and the herring — also called alewife — instinctively find the upstream path.
• “The little ones memorize the odor of the brook,” explained Gephard, standing on a footbridge over the dam to explain how the ladder works. “It's the chemical identity of the stream. Jordan Brook is different from Bride Brook, and that's different from the Shetucket River.”
• The design used for the fish ladder is called the Alaskan Steeppass. It consists of two prefabricated aluminum chutes fitted to multiple upright angled plates that slow the velocity of the water to speeds herring are comfortable swimming against, about 3 to 4 feet per second, Gephard explained. Between the two sections is a concrete resting pool.
• The ladder is suitable not only for herring, he added, but also for sea-run brown trout that travel from salt water to fresh water to spawn. Construction began last fall, and involved cutting a notch in one side of the dam's spillway, removal of some bedrock from one side of the brook and construction of a stone weir at the entrance to the ladder to help direct the fish there.
• The section of brook where the dam and ladder are located is between a town park, Jordan Mill Park, on one side, and the offices of Integrated Technologies Inc. on the other.
• In anticipation of the opening of the fish passage, Gephard said, DEP staff for the past several years has been hand-carrying bucket loads of the herring that swim into Bride Brook in Niantic over to Jordan Brook, so that they spawn there instead. (Judy Benson)