The Hippo


May 28, 2020








86 miles

At the Amoskeag Fishways Learning Center in Manchester, which features a fish ladder operation allowing migratory fish access farther upstream, Executive Director Helen Dalbeck hasn’t seen any American shad, though they have been spotted downstream in recent years. New Hampshire is at the top of the shad’s natural range, so not spotting them at the dam in Manchester isn’t necessarily cause for concern. Fishways staff members see lots of sea lamprey, which appear to be thriving. To Dalbeck, Fishways staffers are telling the story of the river, including the fish that navigate its waters. 
If fish reach Manchester, that means they’ve navigated 86 miles of river and two dams — no small task. Herring also swim up the state’s coastal rivers, such as the Lamprey River and the Exeter River. So far this year, officials have reported strong herring runs in Massachusetts rivers. Dalbeck was hopeful she’d be seeing plenty of herring this year. 
The different species all do things a little differently when it comes to spawning and returning to the ocean. American shad swim upstream in the spring and spawn right away, then they turn around and head for the ocean right away. River herring and Atlantic salmon swim upstream in the spring, but they remain in the streams until fall when they spawn and then return to the ocean. 
The weather plays a definitive role. Species of fish have specific requirements to be able to travel upstream and to spawn. Temperature and water level play key roles in the spawning runs. 
Public Service of New Hampshire, which owns and operates the dam in Manchester, installed a new eel-way this year. The Fishways has one passageway specific for eels to allow them to make their way up and down the river. American eels are catadromous, which means they are born at sea, mature in freshwater streams and then return to the ocean to spawn. 
Sea lamprey return to rivers to spawn, but they die after they spawn. Salmon, herring and shad can spawn multiple times, although some fish die of exhaustion.
Federal law requires the fish ladders to be operating until July 1. The dam on Black Brook in Manchester was removed in recent years, and that could make for great spawning habitat for herring. Herring seek out relatively slow-moving water where streams become almost pond-like for spawning. Salmon, on the other hand, prefer smaller tributaries where water moves faster and is colder, Dalbeck said. 
The plight of the river herring 

River herring — the term essentially refers to blueback herring and alewife — are feeling pressure, as is the American eel. In 2006, the Amoskeag Fishways Learning Center watched more than 3,000 herring swim up the fish ladders. But each year since, Executive Director Helen Dalbeck said, there has been one, two or no herring at all at the Fishways. She said one staff member started in 2007 and so she hasn’t seen herring yet. The fish are facing two major impacts: striped bass are eating river herring in great numbers at the mouth of the river in Newburyport, Mass., and river herring are being unintentionally caught commercially by fishermen targeting Atlantic herring. 
“These guys are in trouble,” Dalbeck said. 
A lot of folks don’t want to see herring listed on the endangered species list. Dalbeck would like to see some protections put in place now so that listing them can be prevented. 
Jake Kritzer, a scientist with the Environmental Defense Fund, said there are probably three categories of impact on river herring during their time at sea. One is predation by marine mammals, seabirds and other fish, such as striped bass. Another impact is bycatch, which refers to the unintentional catching of fish by commercial fishermen. In this case, fishermen are targeting Atlantic herring, mackerel, squid and butterfish, but may end up catching river herring. Another potential impact is climate change, and scientists don’t necessarily have a handle on how that might be affecting herring, Kritzer said. 
“Bycatch is the ocean impact we can most immediately address. Unfortunately, data on the volume of bycatch are sparse and noisy, but estimates in recent years have approximated or exceeded the coast-wide catch in the directed in-river fisheries,” Kritzer wrote in an e-mail. “There are likely impacts of climate change that we don’t fully understand, such as changes in temperatures, currents and plankton distribution and abundance that affect growth, survival and migrations.”
The Atlantic States Marine Fisheries Commission recently passed an amendment to its shad and river herring fishery management plan. The amendment calls for a default closure of directed fisheries along the coast, but with the opportunity for states to continue fishing in rivers where sustainability is demonstrated. That action represents a rare reversal of the burden of proof, whereby fishing can only continue if standards are met, Kritzer said.
However, many commercial and recreational fishermen see a significant inequity in the fact that most in-river fisheries have closed while oceanic bycatch continues unabated. To address those concerns, the New England Fishery Management Council and the Mid-Atlantic Fishery Management Council are developing amendments to fishery management plans for the Atlantic herring and squid, mackerel and butterfish to address river herring bycatch. 
“Of course, in addition to improved fisheries management, considerable work is still needed along the coast on fish passage, water quality, invasive species control, habitat restoration, and other aspects of watershed management,” Kritzer said. 
Fish ladders can help alleviate that problem, but ladders are never entirely effective and they do not correct other problems caused by dams, such as thermal pollution and disruption of natural flow patterns and sediment transport, as well as the creation of conditions suitable for many invasive weeds that would not survive in colder, faster-flowing, low-nutrient river systems, Kritzer said. 
River herring, which are eight to 10 inches long at the time of their spawn, are considered “forage fish” — that is to say they are essentially prey species, which is why people should care about them. If herring numbers are down, that has significant impacts throughout the marine food chain. Striped bass, a prized game fish, depends on herring, as do humpback whales, seals, a variety of bird species, and other fish species, such as bluefish. Those animals aren’t alone; the list of herring-eaters is long. It also includes cod, bluefish, tuna, ospreys, bald eagles, herons, otters, raccoons, freshwater bass and white perch.
“They school up like flocks of birds under water,” Dalbeck said. 
Anglers often use herring and American eels for bait, when fishing for striped bass or bluefish. The dramatic rain events of the last few years could also be playing a role in the lack of river herring in Manchester. It’s difficult for biologists to know exactly what is impacting herring from year to year. 
“Indeed, they are one of the most important forage fish species on the Atlantic coast, especially in terms of the sheer diversity of species that feed upon them and the diversity of ecosystems in which they play a role,” Kritzer said. 
As a migratory species, they have a seasonal importance that depends on where river herring are at different times of the year. For example, river herring return to spawn in rivers right around the time ospreys return from overwintering in Central America, South America and the Caribbean. At that time, osprey urgently need to replace energy stores depleted by their long journey, while re-building their nest and preparing to breed. For most of the time ospreys are up north, river herring are out to sea. But the fish are present in large numbers during these crucial first few weeks, and therefore are critical to osprey populations, Kritzer said. 
“In freshwater and estuarine ecosystems, river herring are also affected by multiple anthropogenic impacts, including dams and other barriers to migration, alter flow patterns, impaired water quality, invasive species, habitat alterations, and mismanagement of directed fisheries,” Kritzer said. 
Efforts have been made, through dam removal and fish ladder operations, to provide herring with accessibility to spawning grounds. Dalbeck said the freshwater ecosystems are ready and willing partners for herring. But the ocean is a different story. Attention hasn’t been paid to the ocean and its impacts in the same way, she said. 
“Just because they spawn in the river doesn’t mean that’s the end of the story,” Dalbeck said. “You need both ecosystems to be healthy.”
Falcons, too

The Amoskeag Fishways Learning Center is more than just fish. On Saturday, May 19, the Fishways will host a Peregrine Falcon Festival with the fifth-graders at the Webster School in Manchester from 11 a.m. to 3 p.m. The event will feature two live peregrine falcon presentations. There will be telescopes to be used for viewing the falcon pair that have made their home on Brady Sullivan Tower in Manchester. Bring binoculars. The festival costs $3 per person or $6 per family. Call 626-3474. Visit
Free Fish Finale

The Amoskeag Fishways Learning Center will celebrate its Fish Finale on Saturday, June 9, from 11 a.m. to 3 p.m. The Fishways will be highlighting the American eel. Typically, the Fishways hosts a Lamprey Appreciation Day, but last year interest waned. Helen Dalbeck, Fishways executive director, laughed that the community had suffered from lamprey fatigue. The celebration will involve presentations regarding all four migratory fish species. Each staff member at the Fishways took one migratory species to cover. The program is free. Visit


Salmon, a love story
Why this mating season may be make or break for this favorite native fish


Leaping from the water in shimmering, torpedo-like streaks when hooked and at times growing to more than 20 pounds, the Atlantic salmon is considered by many the king of kings when it comes to fly fishing. 

There is a certain poetry in trying to entice a silver salmon to rise to a fly — just the rise is enough of a thrill for some. It’s also not something very many people get to experience. 
The problem for anglers and for the ecosystem is that there aren’t many Atlantic salmon in New Hampshire. The Merrimack River has been dammed since the mid-1800s and earlier in some cases. That’s how long it’s been since anadromous fish — that is, fish that are born in freshwater, spend their lives in the ocean, and return to freshwater to spawn — have had the run of the river. 
The state does have a brood stock program, in which it stocks rivers with Atlantic salmon from a hatchery. They are wild fish that were taken in at the Essex Dam in Lawrence to maximize their breeding potential in a controlled setting. Once the fish can no longer breed, they are released into the river for anglers. That gives some salmon enthusiasts the opportunity to target a species that has long been in trouble. 
Something happened last year, though. In recent years, the number of salmon that arrive at the Essex Dam averaged 121 fish. All of a sudden 402 salmon arrived at the dam. 
“That’s the big news,” said Helen Dalbeck, of Amoskeag Fishways Learning Center in Manchester. 
After years of removing the fish in Lawrence and using them at the hatchery, officials haven’t seen a return on the investment — until last year. Four hundred salmon isn’t a lot, given that thousands of fish used to swim upstream before people installed dams on rivers. But 402 is a hopeful number. While the news was good in Lawrence, similar increases were recorded on salmon rivers throughout Maine and Canada. 
Biologists are going to try something new this year. They’re going to try to let salmon do it on their own. They’ll still take some fish out and take them to the hatchery. But they’ll let a number of fish navigate the fish elevators in Lawrence and Lowell, and hope the fish turn left off the Merrimack River and swim west on the Souhegan River. With the Merrimack Village Dam in Merrimack removed in 2008, a 14-mile stretch of river was opened that salmon would hopefully find appealing for spawning. 
“The Souhegan River is now accessible,” said Joe McKeon, a biologist with the federal Fish and Wildlife Service. He’s one of the people coordinating the restoration effort. “We’re really focusing on that. …We’ve got a stretch of river that we can now work with.”
Officials began stocking the Souhegan River a few years ago, and salmon are due to return this year.
“We’re waiting to see what happens this spring,” McKeon said, adding biologists are hoping to see similar returns this year. As of last week, 12 salmon had arrived in Lawrence, two of which were Souhegan River salmon. It’s very early in the spawn now, although the conditions this spring could push the spawn up a little this year.
Environmentalists, river lovers, biologists, and anglers now have some hope to hang their hats on. 
“It’s kind of exciting to wait and see,” McKeon said. “We’ll see most of the salmon coming back by July 4. … We’ll have a good sense by then of what’s going on.”
But salmon aren’t alone in their long-thwarted quest to spawn in the tributaries of the Merrimack River.  The salmon is joined by river herring, American shad, sea lamprey and American eel in their migratory journey to reproduce. Dams, overfishing, predators and other environmental factors have caused major problems for migrating fish. 
“Many of the stocks are depressed East Coast-wide, not just the Atlantic salmon, although the salmon more so than others,” McKeon said.
There is currently a petition to list river herring as endangered. The National Oceanic and Atmospheric Administration has the task of assessing river herring stocks to see how they’re doing and what’s impacting them. 
There is also a petition to list the American eel, which spends 15 to 20 years living in freshwater lakes and rivers before it migrates back to the ocean to spawn. 
The issues are similar for all: impediments, such as dams, predation and commercial fishing. People also use herring and eels as bait to catch striped bass.
“All of these things are converging at this point and that’s what we’re confronted with,” McKeon said. 
American shad, the largest members of the herring family reaching four or five pounds, historically arrived in the Merrimack River as much as 80,000 strong. The numbers have dropped to 10,000 or 20,000 fish. Both the hatchery in Nashua and the hatchery in North Attleboro, Mass., have been retooled to accommodate shad as well.
The silver salmon

The first salmon fry was released into the Merrimack River under the salmon restoration program 35 years ago. The program is funded by the federal Sport Fish Restoration Program. Salmon had been missing entirely from the Merrimack River watershed prior to 1976, the original population extirpated by dams in the early 1800s.
To get the restoration program rolling in the Merrimack River, biologists took “donor stock” from rivers in Maine that still had existing, albeit challenged, Atlantic salmon population. The effort in Maine north of the Kennebec River is termed a recovery, because the salmon populations were not completely wiped out. It’s a restoration effort in New Hampshire, Massachusetts, Rhode Island, Connecticut and southern Maine, since salmon stocks were wiped out. Officials are engaged on the Connecticut River, as well as the Pawcatuck River in Rhode Island, although officials are phasing out efforts there in order to focus on the Merrimack River, McKeon said. 
Wildlife officials will stock about the same number of fry in the Merrimack River basin as they have in past years, but they’re focusing their efforts this year. That’s because, considering the better returns last year, officials don’t want to stock on top of fry that may have hatched in the wild. Officials released adult salmon into the Souhegan, Baker and upper Pemigewasset rivers. Through radio-tagging and counting salmon nests, officials were able to confirm spawning. Most of the fry will be stocked in the southern portion of the state, in Massachusetts and in Connecticut. Officials will stock a small number of fry in the Keene area. 
School classrooms have also historically participated in the stocking efforts, using the program as part of their curriculum. Dalbeck said some classrooms will stock the Piscataquog River in Manchester this year instead of the Souhegan. Spawning salmon could potentially reach the Fishways this year, Dalbeck said.
The plan was for officials to keep the first 300 returning salmon in Lawrence at the fish hatchery in Nashua, where eggs are used to produce millions of juvenile salmon, which are in turn stocked throughout the watershed. Until last year, officials only exceeded the 300 salmon target once, with 331 fish in 1991. 
After they are born, salmon spend typically two years in freshwater before they migrate to the ocean, where they will typically spend another two years, before returning to freshwater to spawn. They spend their first year at sea feeding off the southern edge of Greenland and they spend their second winter off the coast of Labrador. The spawning journey is a perilous one. Along with little accessible, spawning habitat, fish fall victim to predators, as well as simple exhaustion. 
Officials at the hatchery in Nashua and in North Attleboro, Mass., will hold onto baby salmon until they reach the fry stage, whereupon about one million fry are seeded throughout the river system. Hatcheries keep some of the salmon longer, until they reach the smolt stage. In the wild, it typically takes two years for salmon to become smolts. In a controlled hatchery setting, biologists can grow salmon into smolts in one year. Those smolts are then stocked throughout the system. 
Typically, biologists will release smolts below the Essex Dam in Lawrence in April. They found that if smolts were released farther up the watershed, they’d get hung up on the various dams in the system, and by the time they reached the estuary, they were leaving at the same time striped bass were migrating in. Striped bass would be formidable predators for the young salmon. Releasing the smolts in Lawrence gives them a better chance of making it to the ocean before the striped bass arrive in numbers, McKeon said. 
“The striped bass rebounded and they’re raising havoc,” McKeon said.
The depletion of the river herring stock is also causing problems for smolts. River herring historically arrived to spawn in rivers in the hundreds of thousands. That thick mat of fish provided ample cover to juvenile salmon on the way out. Striped bass and other predators were fixated on the herring. But today, herring are arriving by the tens of thousands — still a lot of fish certainly, but in those numbers they don’t provide nearly the cover they once did. 
“It’s just critical that the salmon get out,” McKeon added. 
On the way back from the ocean, the salmon that were deposited in Lawrence return to the same spot to spawn. It’s a shift in strategy. Historically, about 65 to 70 percent of the salmon stocks in the Merrimack River traveled to the White Mountains area to spawn. But with so many impediments and so few fish, officials are instead focusing on the lower tier of the river. 
But ocean conditions play a huge role for salmon. Salmon face predators. They face habitat degradation. Thankfully, they don’t face a commercial fishing industry anymore.
“We know that the marine phase has not been good for salmon,” McKeon said, adding biologists suspect there has been a shift in the salmon’s forage base in the ocean. “We think we might now be seeing something positive occurring in the ocean, coupled with the Souhegan River.” 
But biologists don’t want to get too optimistic. They have been trying for decades, after all, to restore salmon in the region. 
“If ocean survival is cyclical, then it is reasonable to believe that salmon restoration can succeed,” said Matt Carpenter, a fisheries biologist who coordinates New Hampshire’s salmon restoration program, in a state press release. “However, if there has been a fundamental shift in the North Atlantic ecosystem because of a changing climate or other factors, then salmon restoration may not be possible.”
Biologists clipped fins on all the salmon that were released into the Souhegan River. That way, they can identify them when they return. Last year, of the 402 salmon in Lawrence, about 65 were Souhegan River salmon. Officials had released 80,000 smolts in the Souhegan River. Some of those 65 Souhegan River salmon now have radio tags on them to better help biologists track their movements. 
“This spring we are indeed going to let them swim the river,” McKeon said. Still, biologists are hedging their bets a little. They’ll let about 50 percent of the fish that arrive in Lawrence swim the river, and they’ll take the other half to the hatchery as they’ve typically done. 
“Maybe the better approach is to focus on the lower river where there are fewer environmental problems,” McKeon said.
That’s what biologists are hoping, anyway. 
Factors at play

Biologists are also tracking where the salmon hold in the river. They don’t travel upstream and immediately turn around and return to the ocean. Salmon run the river in the spring, but they remain in the river all summer long before they spawn in the fall. The fish typically seek cooler, faster moving water. They seek out a gravel bottom for spawning, McKeon said. The thinking is that salmon would hold in cool pools throughout the summer months. 
There is some level of concern that anglers may accidentally catch spawning salmon. For one, the state has a brood stocking program in which it stocks the Merrimack River and the Pemigewasset River with salmon from the hatchery that are done breeding. When brood stock salmon are released, they are large fish, some weighing 15 pounds or more. Anglers have taken notice, and it is certainly possible anglers targeting brood stock salmon could unintentionally catch returning Atlantic salmon, McKeon said. 
If the salmon has a tag, it’s a brood stock salmon. If it doesn’t, anglers must return it to the river immediately. Additionally, it is possible to confuse Atlantic salmon with brown trout. McKeon said biologists will be working hard to educate the public about the differences. 
Beyond anglers, low water levels could also pose a problem for the spawn. Still, McKeon said in the wild, salmon would certainly experience years with low water. 
“To me, it’s exciting because for the first time we can actually put fish into a system and let them tell us where they want to be,” McKeon said. “…Until there’s fish in it, we don’t really know what they’re going to do.”
The life cycle for salmon in the Connecticut River is proving perhaps too troublesome right now. It’s a much longer migration to reach the Gulf of Maine and it’s possible that warming trends are reducing salmon habitat in the Connecticut River. It is possible salmon stocks won’t be successful that far south. 
It’s a three- to four-year evaluation period. The return was great last year. Biologists are anxious to see what 2012 brings. The results will help dictate restoration efforts going forward. If they’re strong, officials will probably continue with the shifted strategy that’s focused on the Merrimack River watershed and the Souhegan River. If it isn’t a strong return, they may have to shift again.  
Officials are considering whether to pull back on hatchery production and instead focus on determining whether natural reproduction is possible. Two years from now, biologists will be able to sample for juvenile salmon, called parr. 
“This will allow us to measure the reproductive success of salmon that spawned naturally in the watershed,” Carpenter said. “Within five years, we should have a better understanding of what to expect from salmon that are allowed to run the river. This information, along with trends in ocean survival, will ultimately determine if successful salmon restoration can be achieved for the Merrimack.”


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