SURRY — The alewife has always played an integral part in Maine ecology.
The slender, silver fish spends much of its life at sea. Every spring, though, a certain number of them swim up freshwater streams to spawn in ponds and lakes.
Problem is, alewife runs have been plummeting for over a century — and humans are pretty much entirely to blame.
According to a pamphlet produced by the Maine Department of Marine Resources (DMR), dams, pollution and overfishing have all factored into their demise.
Those losses have created problems not just for the foot-long silver surfers, but for individuals at every level of the food chain. For one thing, people who caught, smoked and ate alewives have been losing a staple.
When one Maine village dammed off an alewife run in the 1800s, for example, residents in the neighboring hamlet were none too pleased.
“It was difficult to persuade the aggrieved people to forbear using violence to open a passage for ye fish,” a contemporary chronicler wrote of the reaction. “The cry of the poor every year for want of the fish… is enough to move the bowels of compassion in any man that hath not an heart of stone.”
Not just people devour alewives, though. Striped bass, tuna, osprey, skunks and turtles are among the countless number of species that consume them.
Enter Susan Hand Shetterly, a Surry author whose latest children’s book, “Swimming Home” (Tilbury House Publishers, 2014) follows a school of alewives from the ocean back to their spawning grounds in fictional Lily Lake.
“Often they looked like one big fish flashing silvery scales, but they were many fish with gray-green backs, silver bellies, and sharp tails,” Shetterly writes, focusing her narrative on a particular alewife named Pesca.
“Pesca and her school felt something pulling them. It was Lily Lake, where they had hatched from eggs in water that was not salty like this ocean water, but sweet and muddy.”
Shetterly’s largely unsentimental and un-anthropomorphized prose — combined with the cool, rich hues of Blue Hill illustrator Rebekah Raye — depicts the perils at every step of the journey.
A harbor seal torpedoes after the school at one point. Two pages later, Pesca just escapes a bald eagle’s three, razor-sharp talons.
Not every member of the animal kingdom is out for the fish. Chubby-cheeked beavers munch on saplings, while tiny, shrimp-shaped plankton give the alewives their own chance to play predator.
It’s when the alewives make it to a brand new road over Lily Stream, though, that we meet their gravest menace.
“Under the road a pipe lay on a pile of stones,” Shetterly wrote. “The lovely water of Lily Lake poured through it and splashed down into the stream. The people who had set the pipe under the road had forgotten about the alewives.”
The alewives shimmy, jump, slide, skid, somersault and backflip, yet none can surmount the pipe and continue upstream.
Anyone who travels from Ellsworth to Blue Hill should know the culvert that inspired “Swimming Home,” a Tilbury House Nature Book.
In Surry village, Route 172 crosses Patten Stream. Under that road is a pipe that, while letting water through, largely obstructs an alewife run once thought to support 250,000 returning fish.
Several years ago, a committee of residents formed to help revive the run.
Every spring, the group hoists alewives over the culvert using sturdy nets. But according to Shetterly they’ve also tried to rig several ladders for the alewives.
One was blown away by the force of the downstream water. The other one simply wasn’t used by the alewives, according to Norman Mrozicki, one of the group’s founding members.
This past year, with help from a variety of groups — DMR, the Gulf of Maine Council, the Maine Coastal Program — the group landed a grant that paid for environmental engineering firm Wright Pierce to design a sturdier, more aesthetically pleasing “ladder” for Patten Stream.
The group is now raising funds to build the structure, which would consist of a series of pools at different heights that will be easier for the fish to climb.
Shetterly has spearheaded the effort, according to Mrozicki, a Surry resident who hadn’t been aware of the culvert problem until the author drew it to his attention. “She’s the prime mover in this whole phenomenon,” he said.
While Shetterly’s new book isn’t directly connected to her conservation campaign, it’s related.
She’s written the book over the last year, she said, for the same reasons she wrote the children’s book “Shelterwood” in 1999. In that work, an old woodsman describes to his granddaughter the importance of old growth forests.
“I really believe that we’ve got to teach kids as much as we can, because they’re going to have so much to do to get this right,” Shetterly said. “I have a grandson who’s going to be in this world when it’s not as wonderful as it was at my age.”
The failure of their two alewife ladders, Shetterly added, was “discouraging, so I thought I have to write something for kids about the value of migrating fish.”
That value isn’t only measured in food, Shetterly explained. To research her book, she interviewed experts like Claire Enterline, an alewife researcher at Maine DMR.
Not only do culverts prevent other fish like smelts, eels, trout and salmon from moving upstream, Shetterly said. The blockage also prevents the exchange of nutrients when fish cross between salt- and freshwater.
Phosphorus, for example, can cause algae to grow in freshwater ponds, but alewives returning to sea remove some of the chemical, Maine DMR research has shown.
Anecdotally, Shetterly also described two eagles she recently spotted perched and eyeing her bird feeder, as if they might be fast enough to eat a squirrel or dove making use of it. “They’re confused,” she said. “We need more alewives for them.”
In “Swimming Home,” Shetterly’s lesson is driven home by a man and his son. Like the Surry residents who assist the alewives over the Route 172 culvert, the man and boy transport Pesca and her fellow fish upstream in buckets.
The story closes with the duo watching over the lake.
They may have saved one school of alewives, the father muses, but “The trouble is, more will be coming.”