Reaching new heights:
Herring return to the Merrimack in record numbers
Last spring, there was a lot of heavy lifting at the Essex Dam, but no one seemed to mind. In fact, they were thrilled.
For more than 30 years, migratory fish have passed over the dam on the Merrimack River in Lawrence, Massachusetts, by riding in large buckets on a chain-driven fish lift. Last spring, they showed up in record numbers, with nearly 450,000 river herring — that’s blueback herring and alewife — hoisted up and over to continue their journey upstream. The annual average for the last 20 years was less than 25,000.
“This is likely the strongest run since a series of dams created barriers to fish migration in the early 19th century,” said Dr. Michael Bailey, assistant project leader at the U.S. Fish and Wildlife Service’s Central New England Fish and Wildlife Conservation Office. “Thousands have also passed hydroelectric plants on upstream tributaries, where few herring have been seen in the last two decades.”
Victims of progress and popularity
Although hundreds of thousands of herring sounds like a lot, it’s likely a fraction of the number that once swam up the Merrimack to spawn each spring. Centuries ago, the metallic-colored fish were so plentiful in coastal rivers from Florida to Labrador, Canada, that waters ran silver during their annual migration.
In the 1800s, however, many New England rivers, including the Merrimack, were harnessed to power the Industrial Revolution. Dams blocked the way to historical spawning grounds, and herring numbers dwindled. By the late 20th century, loss of suitable habitat and unsustainable fishing practices had caused a significant drop in population.
In need of a lift
Essex Dam, the first barrier upstream from the ocean on the Merrimack, was built in 1845 and was the largest in the world at the time. With a built-in fish ladder, it allowed fish to get by, although not in historical numbers. The lift — as in elevator — added in the 1980s improved passage at the dam, but numerous upstream dams stand between the fish and their goal.
While many herring still get a boost up and over the dam, tens of thousands more now catch a ride in a truck — a fish Lyft, if you will.
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For the last five years, the Service and its partners — the New Hampshire Fish and Game Department and the Massachusetts Division of Marine Fisheries and Department of Fish and Game — have collected herring at the Essex fishway and driven them upstream. The “trap and truck” program whisks the fish past multiple barriers and releases them into good spawning habitat.
Clearing the way
Fish passage engineers with the Service and the National Oceanic and Atmospheric Administration have been working with dam owners to ease the way for fish along the river and its tributaries. Several failing fish ladders have been updated.
Staff at the Service’s New England Field Office work with the Federal Energy Regulatory Commission and dam owners to improve conditions for migratory fish as part of the hydropower relicensing process. Owners have agreed to build new fishways as more herring make it farther upstream.
A boon to many
However they bypass the barriers, more adult herring making it up the Merrimack means more juveniles to return in coming years after maturing at sea. That population growth will benefit everything from commercially important fish, to recreational anglers, to seals and whales — all of whom fancy these fish.
A self-sustaining population without the need for trucking is the long-term goal, and it may be in sight. Bailey finds the prospect exciting, both professionally and personally.
“It’s not often we get to enjoy the fruit of our labors so quickly,” he said. “And as a dad, it’s great to be able to show your kids what you’ve accomplished.”
The herring will return to the Essex Dam in April, and we’re hoping for buckets-full and truckloads by May. As long as they need a lift, the Service and its partners will pick them up.
Catherine Gatenby contributed to this story.
In the last decade, the Service has worked with states and other partners from Maine to West Virginia to remove or replace more than 600 barriers to fish passage, connecting nearly 5,000 miles of river and stream habitat and 28,000 acres of lakes, ponds, and wetlands. These efforts have added more than $1.5 billion to the U.S. economy through increased tourism and recreation, improved water quality, and protection of people and property.
