Herring are returning to Merrimack River in record numbers this year

  • At Amoskeag Dam in Manchester, New Hampshire Fish and Game biologists use a trapping facility to collect fish, put them into tanks, and then truck those fish to local streams and ponds.  ELODIE REED—Monitor staff

  • Carpenter speaks with Steve Rollins of Eversource at Amoskeag Dam last week. New Hampshire Fish and Game biologists go to the dam – where there’s a hydroelectric station – to collect and haul trapped fish.  ELODIE REED /Monitor staff

  • Herring, shad and American eel are the species that Fish and Game biologists haul from dams like the Amoskeag in Manchester to dump in ponds and streams.  ELODIE REED—Monitor staff

  • In addition to the hydroelectric station used by Eversource, Amoskeag Dam is home to a fish trapping facility.  ELODIE REED—Monitor staff

  • Herring – hundreds of them – are dumped into Northwood Lake last week.  ELODIE REED—Monitor staff

  • These herring were trucked from Amoskeag Dam in Manchester before being placed in Northwood Lake.  ELODIE REED / Monitor staff

  • Carpenter looks out across Northwood Lake, where he just dumped hundreds of herring last week.  ELODIE REED—Monitor staff

  • Herring swim in a tank at Amoskeag Dam last week before being transported to Northwood Lake.  ELODIE REED/ Monitor staff

  • A herring is held out by Eversource employee Steve Robinson at Amoskeag Dam in Manchester, where the power company has a hydroelectric station.  ELODIE REED—Monitor staff

  • New Hampshire Fish and Game biologist Matt Carpenter moves herring into a tank full of water and fish bound for Northwood Lake. A record number of herring have been counted in the Merrimack River this year. ELODIE REED / Monitor staff

  • Herring are dumped, along with water, into a truck that would take the fish upstream to Northwood Lake in Eposm.  ELODIE REED—Monitor staff

  • Water runs in the fish ladder at Amoskeag Dam in Manchester.  ELODIE REED—Monitor staff

  • Matt Carpenter gets his Fish and Game truck ready to haul fish from Amoskeag Dam in Manchester to Northwood Lake in Epsom last week.  ELODIE REED—Monitor staff

Monitor staff
Published: 5/26/2016 2:15:36 AM

Hauling fish out of the Merrimack River and trucking them past dams into streams and ponds has been part of New Hampshire life for decades, but this year biologist Matt Carpenter has faced an unexpected complication: too many herring.

“This is the first year we’re seeing what we really wanted to see, in terms of returns,” said Carpenter, a Fish and Game biologist, as he drove 2,500 herring from Amoskeag Dam in Manchester to Northwood Lake in Epsom. “But it’s a lot of work. This method really isn’t sustainable.”

The numbers this year are huge. As of Monday, more than 336,000 herring (including the species known as alewife) had been counted as coming up the river from the Atlantic Ocean at the Essex Dam in Lawrence, Mass., the first dam on the Merrimack River. That’s five times as many as were counted at Essex Dam all of last year, which saw the most herring since 1994, and the season still has weeks to go.

The result is almost an embarrassment of riches. So many herring were trying to come up the fish ladder at the Amoskeag Dam last week that the equipment for pulling them up for loading into trucks was overwhelmed. In Lawrence, herring have almost overloaded the “fish lift” that pull them up over the dam. Further, the fish have shown up at unusual times, including afternoon and evening, making Carpenter face once of the least pleasant activities in New England: driving a large, slow truck around Eastern Massachusetts at rush hour.

This bounty is slightly ironic because only two years ago efforts to accomplish this with Atlantic salmon in the Merrimack River were abandoned. Atlantic salmon is the best known of the species of fish that breed in streams but live most of their life in the ocean, traveling up and down rivers between those two locations. But fewer than 100 salmon returned in most years.

In 2013, the federal government ended salmon restoration efforts in the Merrimack River, following a similar cutback in the Connecticut River. Officials are now concentrating on rivers in Maine.

Carpenter said the failure with salmon shouldn’t discourage efforts to restore other species of what are known as anadromous fish, notably herring, shad and American eel.

Returning a salmon run to the river would have a direct and obvious benefit, drawing fishermen. But few people are interested in fishing for herring, and although shad is a game fish, it’s not highly prized, “not as flashy and exciting as salmon.”

“It’s a challenge to get people excited,” Carpenter admitted. “Herring is a forage fish. It supports the ecosystem and has lots of predators – bass, pickerel, rainbow trout, osprey – but that’s an indirect benefit.”

Still, the return of a real, sustainable herring run would be a boon for the restoration program, which has struggled in the face of changing ocean conditions, river pollution and dams, and competing species like small-mouth bass, which consume young anadromous fish returning to the sea.

A good herring run might even prod the next big, expensive step in restoration: Building fish ladders at the Hooksett Dam and the Garvin Falls Dam in Concord. These would allow herring and shad, in theory at least, to make it much further upriver without having to be trucked around.

And spending a morning with Carpenter shows that trucking them around is a real pain.

The herring that were hauled out of the Merrimack River at Amoskeag Dam last week were generally 3 to 4 years old and about a foot long. They had been lifted over the Essex Dam in Lawrence, made their way over the fish ladder at the Pawtucket Dam in Lowell, Mass., and then struggled up the fish ladder at Amoskeag.

In Manchester, they were pulled out of the ladder in a big tank, then manually moved by net into a truck carrying 2,000 gallons of water in two huge tanks, which Carpenter drove 40 minutes to Northwood Lake. This truck was paid for largely by donations from various groups; two other trucks provided by the U.S. Fish and Wildlife Service are also part of the project.

This isn’t the sort of work that can be done at leisure; when the fish decide to arrive, they have to be moved.

“We get a few, then there’s a bunch, usually it’s strong for a week, 10 days, then it tapers off,” said William Smagula, vice president for generation at Eversource Energy, whose job involves balancing the needs of fish passing the dam with the needs of turbines that can generate 16 megawatts of electricity.

On Wednesday, after making the drive to Newfound Lake, Carpenter attached a 2-foot-diameter tube to the tanks and released the herring in a three-minute cascade of fish and water.

They’ll spawn in the lake and head down river this summer or fall, back to the ocean – assuming they don’t get chopped up by turbines along the way. Their youngsters will have the lake imprinted in their brains through a mysterious process that’s not understood, and after they get old enough to return to the ocean and mate, they will want to come back there to spawn – although that’s not possible because of dams.

“You could expect the population to take off on the Merrimack River if they can access spawning habitat (currently blocked) because of dams,” Carpenter said. “We could sustain the run with in-basin fish, giving prod to build fish passages farther north.”

There is a cautionary note in the celebration of herring, however. The number of returning fish hit similar levels in the Merrimack River from 1988 to 1991, leading to celebration that the run had been restored, but then crashed and almost disappeared; fewer than 1,000 fish returned in some years.

Nobody is quite sure why the population rose back then, or why it fell for two decades, or why it has risen again. There are just too many places in the complicated life of an anadromous fish where things can go wrong.

We’re fixing some obstacles, by cleaning up the Merrimack River and adding dam passages. But some obstacles, notably the way oceans are warming and getting more acidic due to climate change, are beyond the control of anything that New Hampshire can do.

Still, it’s worth the effort, Carpenter said, even if that effort can never end.

“It will always be a managed run,” he acknowledged. “It will never be back the way it was” before industry arrived in New England.


David Brooks bio photo

David Brooks is a reporter and the writer of the sci/tech column Granite Geek and blog granitegeek.org, as well as moderator of Science Cafe Concord events. After obtaining a bachelor’s degree in mathematics he became a newspaperman, working in Virginia and Tennessee before spending 28 years at the Nashua Telegraph . He joined the Monitor in 2015.



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