Fish Out of Water

By last Tuesday, a full week of sunshine dramatically melted snow statewide. Yet in the chilly shade of the green hemlock forest ravine, snow remained a foot deep. Swollen by melting snow, normally placid Needleshop Brook thundered in a mighty torrent from its forested headwaters in aptly named Hill toward its confluence with the Merrimack River.

Earth Day: a small plastic bucket brigade moved along the banks of Needleshop

Brook and the nearby Smith River, skirting snow banks and rapids, wading in forty-seven degree water while sloshing inch-long baby Atlantic Salmon “fry” gently out into the current above gravel and rocky cobbles along quiet stretches of river.

It seemed more like “fry day” as ten volunteers and three Fish and Game Department fisheries staff met a USFWS fish hatchery truck loaded with 70,000 salmon fry to be stocked in tributaries of the Upper Merrimack River. The effort on day four of what will be ten long, full days of salmon stocking continues a decade-long project to reintroduce Atlantic Salmon to their historical habitat each spring.

The salmon fry were hatched in North Attleboro MA back in February and raised for the past 8 weeks at a Fish Hatchery in Warren. They are stocked in new homes while still absorbing their yellow yolk sacs – before they ever feed for the first time.

Salmon Science

By this summer, six-months-old surviving salmon fry will grow to fingerling size. In two years, they become “smolts” and begin their downstream migration, running a gauntlet of dams and hydro plant turbines which have been improved in the past decade to improve downstream fish passage.

Salmon smolts prepare for a rigorous life in the Atlantic Ocean along the coast of Greenland. After three years at sea, sea-run salmon return as adults to natal New England streams to spawn. Unlike western salmon which spawn and die, Atlantic salmon lay eggs and then return to sea, able to return again to spawn in subsequent years.

“Anadromous” fish include salmon, shad, river herring, alewives, smelt and lampreys that can live in both fresh and salt water. All share variations on a very complex life cycle that requires metabolic gymnastics and heroic migrations. The complicated life cycle subjects these fish to high stream flows, migration obstacles including dams and hydropower plants, water pollution and a constant gauntlet of predators. In recent decades, dam removals, fish passage improvements, cleaner water and land conservation efforts have set the stage for salmon restoration. According to Matt Carpenter, an anadromous fisheries biologist at the NH Fish and Game Department “PSNH has done a good job with Ayes Island, Garvins Falls, Hooksett and Amoskeag dams. Downstream fish passage isn’t a big issue – we’ve found densities of two-year old salmon smolts at 50 fish per 100 square meters in our sampling plots with fish survival rates of 80% for downstream passage.”

Stocking Baby Salmon

Inch-long salmon fry are measured in increments of 180 fish per ounce into plastic buckets of 46-degree water. The 2,160 fish in a 12 ounce dose or more typically 1400 fish in an 8 ounce dose are pre-prescribed based on the specific fish habitat features along 0.2 mile increments of various river segments. Fisheries technician, Ben Nugent nets, measures, pours and dilutes to fill four buckets with salmon fry on the tailgate of a green NH Fish and Game fish tank pickup truck. Nugent gives instructions to typically desk-bound land conservation professionals - two of my colleagues from the Forest Society: Chris Wells and Brian Hotz joined by Jack Terrill, a fisheries grant administrator for the National Oceanic and Atmospheric Administration (NOAA) National Marine Fisheries Service (NMFS).

Hotz and Wells worked with Terrill’s office last year to purchase a specific tract of Smith River frontage in Hill where salmon are stocked annually by NH Fish and Game biologists. This year, NOAA fish funds are helping to purchase a conservation easement on 960 rugged, remote acres of forestland located around March Pond in Hill, opposite the Ragged Mountain Ski Area in Danbury. While it’s unfair to say the office guys were like fish out of water, their wide smiles belied the joy of leaving desks behind to spend a perfectly warm and sunny Earth Day enjoying the fruits of their labors while restoring salmon to the Smith River. Terrill says: “This project is a tangible expression of the NMFS mission to ensure adequate stocks of Atlantic Salmon.” With regard to recent land conservation, Terrill adds “anytime we can reduce the development pressure along these headwater brooks, it’s good for the salmon.”

Turns out if you want to restore native fish to the Merrimack River watershed, you need to protect the forests of the headwater streams where the fish life cycle begins.

Dwindling Returns

Smiles while stocking salmon fry represents hope in the face of steep, yet not insurmountable, odds. The results of more than a dozen years of salmon stocking efforts have thus far not yielded many happy returns. In Maine, returns of sea run adult salmon have dwindled in the past decade from tens of thousands to thousands down to hundreds in the Kennebec and Penobscot rivers. According to Terrill “A big unknown is what is really happening in the open ocean… with a buyout of the Canadian salmon fishing fleet and the virtual closure of the salmon fishery in Greenland, we would have expected to see higher rates of sea run salmon returns.”

Matt Carpenter agrees. “Its been tough – we really don’t know what happens in that first winter after our salmon smolts leave estuaries to migrate to the west coast of Greenland… If nothing else, I’d like us to better understand what the problems are.” Recent studies have begun to sample and track the adult phase salmon living in the open Atlantic ocean prior to the age of 5 years when they attempt to migrate to freshwater to spawn; running the river gauntlet once again- this time, swimming against the current.

Carpenter remains cautiously optimistic about the success of the salmon restoration efforts. “By protecting forests and cleaning up our rivers, we’ve put a lot of attention into restoring anadromous fish habitat.” New studies have recently begun to allow biologists to sample the distinct DNA of successful sea returning adult salmon. Fisheries biologists use genetic analysis linked to careful records of brood stock DNA kept at fish hatchery facilities to determine which genetic strains, which years of stocking and even which individual streams have consistently produced the more successful adults – the fish that have successfully run the gauntlet twice.

When asked if the efforts are worth the return, Carpenter snaps a quickly: “We have a moral obligation to try to restore keystone species. With improved fish habitat, we can successfully restore a charismatic species with a very complex life cycle.” According to Carpenter, trees help make the salmon restoration possible. “Without a largely-forested landscape, this wouldn’t work. Forests reduce pollutants from impervious surfaces in a watershed, provide shade to keep water cool and well-oxygenated, stabilize steam banks and flows and filter-out sediments to reduce siltation of cobble and gravel streambed substrates where fish eggs are deposited during spawning and where salmon fry hide after we stock them today.” 

Fisheries technician, Ben Nugent is even more succinct: “This project is really for future generations” he concludes.