Restoring a fishery, one click at a time

Alewives underwater. Photo by Edwin Barkdoll

I work at Maine Maritime Academy, where my students and I are known (somewhat affectionately, some what derisively) as “fish counters”. To the deckies and engineers that make up the majority of the student body, studying the workings of the ocean and all the fish (and other living creatures) in it amounts to just counting fish (they are wrong of course, and they know it, but the joking epithet persists). As a naturalist, I’ve never pursued fish. They live under the water, where I can’t breathe. This quality alone puts them low on my list of naturalist endeavors. So I’ve never been a fish counter, or fish watcher, or fish appreciator of any sort, until now.

I’ve been volunteering to count alewives, small anadramous fish native to the east coast of North America. These fish are a particular form of herring that migrate from salt water, where they spend most of their lives, to fresh water ponds to breed. Historically virtually all of the streams and rivers that empty into the Gulf of Maine had some kind of alewife run in them, though numbers declined post European colonization due to dams and over harvesting. Recent years have seen a renewed interest in the fish and restoration of these historic fish runs. And it isn’t just for supplying the widows with alewives (an actual statute on the books in Woolwich), there is evidence (unsurprisingly) that freshwater and marine ecosystems are connected, and the health of the sea run herring impacts the health (and rebound) of ground fish stocks.

This is all wonderful, I support all of it. I want the widows to get their alewives, and the ground fish to get theirs. I want to see streams crammed full of fish surging upstream. I want to see communities turn their attention to this neglected spring phenomenon, and sink to their knees in awe. But mostly, I got involved for my own personal curiosity. I wanted to see these fish in action.

The clicker.

Counting alewives takes remarkably little training. When I met Mike Thalhauser of Maine Center for Coastal Fisheries at the end of Walker Pond in Brooksville it took all of 30 seconds for him to show me where to stand and where to look, clicking on a click counter each time you see a fish. Do it for 30 minutes, and record your data on the data sheet. Easy peasy. Walker Pond is the head of the Bagaduce River and like so many coastal rivers and streams, at one time featured a dam at the spot where the pond flows into the stream that becomes the river. The dam no longer has utility, but its remnants continue to create an impassable barrier to any fish trying to travel from the brackish marsh at the head of the Bagaduce to the fresh water of Walker Pond. To allow the sea run fish to get to the pond, a fishway around the dam was created, and unlike modern fish ladders, this one simply looks like a forest stream. (Unfortunately I don’t know what was the purpose of the dam—grist mill? Log mill?, or the age of the fish way—Brooksville Historical Society members—can you fill in the gaps?). To count the fish, you stand at the top of the fish way, where there is a small concrete passage where the fishway stream enters the pond (really an impoundment just above the dam, which then leads to the large body of the pond proper). We count the fish and Mike crunches the numbers, trying to get an estimate on how many fish are returning to spawn in Walker Pond. The number of fish helps him, the town of Brooksville and the DMR determine if it would be possible to institute a sustainable community harvest of alewives in the future, if that were even desired. It also just helps the community and the state get a baseline on the alewife population, so any changes up or down in the future have something to be measured against. That’s the technical part, I expected all of that, and I was happy to get involved to help contribute to this community/citizen science data collection effort. And I benefited too, learning more about these fish, hidden in plain sight, and meeting the people in my community who are passionate about restoring them.

I brought my niece with me one day to count and she loved it!

What I didn’t expect was the personal impact this had on me. It sounds a little silly but counting these fish turns out to be a form of mediation. You focus you attention on a small area of the pond, you stand quietly to minimize any disturbance you might create. You watch and wait. You watch as the fish come from the rushing water of the fish way and swim out into the still waters of the pond. You have to keep your attention there. You can’t let your eyes or your mind wander far. Your brain floats quietly nearby, thinking soft thoughts and noticing the reflection on the water of the gulls and osprey flying over head, listening to the calls of the assorted birds in the nearby forest, smelling the sometimes overpowering apple blossoms, all the while watching that one and a half foot gap and the shallow gravel bottom in front of it for the dark fuselage of a fish.

The fish are all different in their reactions to making it to the pond. Some are cautious, sneaking through the last bit of turbulence, hugging the bank. Others act overwhelmed, after fighting their way up the high energy water of the stream, they enter the pool and pause, swimming right at the opening to the fishway, as if they can’t believe they aren’t having to thrash around in turbulent water anymore. Others shoot through the opening as if catapulted, not pausing, but on a mission. More often that not they pass through in groups, enough so that I imagine there is a conservation of energy in following in someone’s slip stream. I imagine that they know each other. Sometimes a few fish will enter the pond and then swim around restlessly just above the fishway, not moving on until another fish swims through to joins them.

This alewife has been swimming around in the pond for a few minutes, you can see how it has changed color, lightening up to match the bottom.

I learned that they change color. When they first emerge from the fishway, they are dark grey on top (all the better to camouflage themselves against the dark bottom when viewed from above by a hungry airborne predator). Within a few minutes of swimming in the shallow and open pond, they lighten up, turning a sandy color, easily blending in with the light gravel bottom. I learned that they can hear things, and feel things. When I stamp my foot on the ground, the fish in the pond all react. When a heavy truck goes by on the road, they scatter.

I got a sense of the ecosystem in action. I saw a mink swimming under the water, hugging the bank. I watched a muskrat, again swimming under the water, foraging for the fresh water mussels I could see from where I stood (who knew that muskrats eat mussels? I didn’t!). One day a cormorant was fishing in a pool of fast water below the dam, another day a common merganser was busy fishing in the impoundment above the dam. One day I saw billions of small water fleas (a type of planktonic crustacean) streaming in the current, being carried down stream, so thick they darkened the water in a visible plume. On virtually every day there were ospreys, occasionally more than I could count, and bald eagles, and great blue herons, in densities that belied my traditional understanding of carrying capacity. One day when the osprey count was especially high, I sat in my car after counting and watched osprey after osprey dive down and splash into the water right where I had been standing. The osprey clearly know what I had to be taught, the fish are easiest to see when they first come into the pond.

The fishway, the sneaky route around the dam. Still challenging for sure.

I wouldn’t have had this experience if I didn’t commit to being a fish counter. That commitment locked me into a structure. Four days a week, rain or shine, for half an hour mid day, I would be there, standing on the grass at the edge of the pond, watching the water. I am not disciplined enough to make that happen without some kind of external accountability, and I am grateful to Maine Center for Coastal Fisheries and the tri-town alewife working group for letting me help. The run on Walker Pond is pretty much over now. Adults that have been in the pond and spawned are now starting to head back down stream. Later in the summer and fall, the juveniles spawned this spring will follow them.

Most of us spend time in nature in an effort to be awed, one way or another. These sea run fish link the ocean to the land in a fundamental way, a way that inspires awe. Our run may be over but others are still going on. Find one and stare at the water until you see a fish.

 

 

 

Sarah O'Malley

About Sarah O'Malley

Sarah is a science educator, naturalist, writer, tide pool fanatic and burgeoning obsessive trail runner. From personal experience she believes strongly in the restorative power of contact with nature, especially experiences that make your heart beat a little faster or get your hands and feet dirty. She lives on the Blue Hill peninsula with her husband and two dogs.