I’ve been hearing about the Herring River Restoration Project since I moved to Wellfleet in 2004. Restoring tidal flow to the 1100-acre saltwater estuary, which was diked in 1908, is an effort that’s been decades in the making — and hands-on work finally began in early 2023. But in the meantime, saltwater started overwashing into the river’s floodplain through an eroded dune at Duck Harbor in 2021 and accelerated this past winter. So the other day I sat down with retired Cape Cod National Seashore ecologist John Portnoy who’s been observing the estuary since 1979, to talk about what some of these changes mean for the ecosystem’s food species.
"Nature decided that it had waited long enough," he explained. "And so it’s happening faster, much faster than planned. And the plan was to do it, you know increase tidal range gradually, and manage the vegetation in a gradual fashion, but now it’s a matter of trying to catch up with the saltwater killing the freshwater vegetation."
One of the saltwater flood sites is about a mile from my house, and until this winter it was a wet, swampy area with lots of freshwater plant species. Now almost all the vegetation for about a quarter-mile stretch is dead.
I'm looking at places where I've picked blueberries, I've picked service berries. There's all these food species, elderberries. And all of a sudden it looks completely different.
"It's going to be different for sure. It already is different. And yeah, the blueberries really took a beating. But at the same time what Duck Harbor is showing us a lot sooner than we expected to see is that all these estuarine species are coming right back. It started with millions of seedling saltmarsh plants. And then people saw mummichogs, and there's thousands of mummichogs in those ditches now."
Mummichogs are small fish also known as mud minnows and like some of the other species that have started showing up, they’re important food for bigger fish like striped bass, flounder, and bluefish.
"And then we’ve seen silversides. And what else, I heard that there are sticklebacks up there, which are estuarine fish---and eels. Oh, there are eels up there. Lots of eels showing up in minnow traps. The Seashore has started a fish monitoring project up there. And, not just little eels, but big eels."
The eels are a big deal. Until the 1970s, when the old, failing dike was replaced with a new structure, the Herring River was home to an important commercial eel fishery. And it’s been hard to know whether or not restoring tidal flow to the river will bring the eels back — because exactly how and where they reproduce is still somewhat of a mystery.
"Starting out with adults, they live in freshwater, grow in freshwater for years, many years. And then at a certain point, they become sexually mature when they’re really big and they turn silver and their eyes get big and they turn into these strange looking creatures and swim out to sea. And we really don't know what happens after that, except people have found eel larvae in the Sargasso Sea, so it's assumed that they swim all the way from Herring River in Wellfleet, and a lot of other rivers on both sides of the Atlantic and spawn in the Sargasso Sea. And then they die."
The return of the eels is a hopeful sign for the Herring River Floodplain — an indicator that while change is currently happening faster than planned and in some places looks more like death than rebirth, the return of the saltwater is jumpstarting a rapid restoration.
"Even the scientists involved in the project are encouraged and surprised at how fast they've come in. And you know, this, these include a lot of either directly or indirectly commercially important species."
When he says indirectly, John is talking about the mummichogs and silverbacks and other baitfish that are returning.
"And then the fish that directly gain will be the big fish that eat the little fish. And those are the flounders and bluefish and even cod and tautog and all sorts of species. You know, that's why people are restoring marshes. It's not just for aesthetic reasons. It's for important food species."
It’s still early on — too soon to tell whether or not the return of the little fish in these small areas will bring the big ones when the full river comes through. But it’s exciting to imagine its vitality returning — and perhaps one day the land where I once stood picking blueberries and service berries will be a good place to cast a line and reel in a keeper.
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