As this issue of The Dragon appears, many people in midcoast Maine are eagerly awaiting the spring run of alewives, the herring-like anadromous fish (meaning they move from fresh water to salt water) that are what St. George Conservation Commission member Les Hyde refers to as a “keystone species.” “Keystone” because alewives eat plankton, produce a lot of eggs and are an oily fish that are high in nutrients for other fish. As Hyde puts it, “If you don’t have alewives, there are a lot of other fish you don’t have, too.” Fish like Atlantic salmon, cod and hake.
While the alewife runs in Damariscotta Mills and Warren are the most notable ones in the midcoast, until the late 1980s, there was also a significant native run of alewives into the marsh in Tenants Harbor. The fish followed a route from the harbor into Ripley Creek, under a stone bridge on Route 131 and on up the outlet stream from the marsh and over the dam into the marsh itself. Then the state Department of Transportation (DOT) replaced the stone bridge with a new metal culvert. The problem was that the culvert was positioned too high above the creek for the town’s native alewives to navigate their way back to the marsh to spawn. Unlike salmon, alewives don’t leap. “They can swim flatwise,” Hyde notes, “so they don’t need much water to swim, but they do not leap.”
An effort to restore the alewife population was first spearheaded nearly 10 years ago by St. George resident John Shea, resulting in the state’s restocking of the marsh with alewives over the course of 2009 to 2013. The hope was that these fish would spawn here, leave their fry in the marsh over the course of the summer and then these young fish would leave (moving through the metal culvert with the flow of water out of the marsh) to spend the next four years at sea. The hope was that by the time they were ready to return to spawn, a new alewife-friendly culvert would be in place to welcome them.
The DOT installed the new culvert in.the fall of 2015. Hyde says that is when Alison England and her science students at the newly independent St. George School gave the effort to bring the alewives back a badly needed shot in the arm.
“When we withdrew from the regional school unit, many of the staff met regularly over the summer to articulate a collective mission and vision for our school,” England recalls. “It was a very empowering process to talk with one another about our ideas of what education could look like, and about the kind of school we wanted to be here in St George. Those ideas included having our students feel connected to their community in the sense of both people and place. We also wanted them to develop a sense of stewardship of the natural resources that make St George such a special place. To me, bringing that vision to life meant engaging students in place-based science projects that are meaningful to the community and that help solve problems. So I went to the Conservation Commission to ask how our students could help the Commission.”
The answer, Hyde says, was to help the Commission determine, now that there was a new fish-friendly culvert in place, whether conditions were right for the return of the alewives. England embraced the project as an opportunity for her students to engage in “citizen science,” a model of volunteerism where community members play a role in science research and see themselves as contributors to solving authentic community issues. “My hope,” says England, “was that doing a community-based project like this would help our students see science in a more practical and tangible way.”
One of the most important questions that needed answering was whether the flow of water out of the marsh was sufficient to allow fish passage into the marsh. Another was whether there had been changes to the marsh since the last runs. Finally, as May approached in 2016, there was the question of where were the offspring of the stocked alewives?
“We combined science and math classes and worked on site practicing our methods, then collecting our ‘official’ data that we would communicate to the Conservation Commission,” England explains. “As we gained momentum in understanding the nature of our questions about whether the water flow would be adequate and whether the site conditions were optimal, students started forming their own questions and would suddenly appear while I was teaching other classes and ask if they could grab a pair of waders and go check on something they were wondering about—like the height of the water in the culvert during a particular part of the tide cycle or if they could use a GoPro camera to see if fish were coming into the culvert. Students even borrowed the waders over the weekend to check the water conditions and the culvert.”
As the students wrote in the “Abstract” section of their report to the commission, “Early in the season water flows were adequate to provide passage up into the marsh, especially with flood tides (spring tides) early in May. Alewives in neighboring midcoast communities began heavy migrations upstream the third week of May (May 15-21) after a cool, yet dry start to the month.”
It wasn’t until May 25th that the students saw alewives in the Tenants Harbor culvert. The problem, the students’ report noted, was that “by then, water flow from the marsh outlet was inadequate to bring them farther upstream. As of May 25th, average heights of high tides do not provide adequate water flow beyond the upstream end of the culvert, given the lack of flow from the marsh.”
Based on interviews with community members who were familiar with the conditions in the marsh before the metal culvert was installed, the students found that “the water levels of the marsh are nearly two feet lower than during historical runs of alewives.” In addition, “the habitat of the outlet stream is different today than in the past. The water is not as deep as before and does not have deeper pools of water that alewives could ‘rest’ in before going into the marsh. The habitat on Ripley Creek is different than when alewives ran. Today there is no water that is pooled either by a man-made structure or rocked pools for alewives to ‘rest’ as the tide goes out.”
Based on their findings the students made several recommendations to the Conservation Commission for how to improve conditions for the alewives. This past March the Commission brought a number of biologists to the project site to determine which of the recommendations should be pursued. “One of the recommendations was to raise the water level in the marsh,” Hyde noted, “but that would require restoring the old dam and the biologists said ‘We are into stream restoration now, not dam restoration.’ The students also recommended creating small resting pools in Ripley Creek and the outlet stream to help the alewives get up into the marsh, which we all agreed would be a good approach.”
So developing an engineering plan for the stream restoration—Hyde is hopeful the Nature Conservancy will prepare this—and finding funds to implement it is now firmly on the Commission’s agenda as the necessary next steps to bringing the alewives back to Tenants Harbor. “We’re calling our effort stream restoration, restoring the ecosystem to what it was,” Hyde says. “That’s our goal. Bring back the fish! That stretch of stream from the culvert to the marsh is also pretty ideal habitat for smelt, so when that engineering is done it will be done with alewives in mind but also with smelt in mind.”
As for the effect of the alewife project on her students, England points to what may seem like the most intangible aspect of their impressive “citizen science” research activities, but which to her is the most important one—the excitement the students felt when alewives were first sighted in the culvert. “While two students were out one day, they found an alewife wedged in a glass jar, halfway through the culvert. That really got us all excited that maybe, despite such dry conditions, that alewives could be returning. When alewives were actually seen swimming in the culvert it was like we had wished them back. It was on the day of our last observation of stream flow, as we literally measured zero flow! It seemed unbelievable that they were really there. In the morning, as we took turns tip-toeing over to view the culvert, several students at a time, community members began pulling into the parking area or pulling over on the road. A day or so later, the Conservation Commission, with their special permit, allowed students to net and carry alewives into the marsh to spawn. When students can literally say they helped alewives back into the marsh, that makes a lasting impact!”—JW
(“Report to the Conservation Commission from the St. George School Eighth Grade Class, June 1, 2016” is posted on the town’s website (stgeorgemaine.com). Click on the “Documents” section and scroll down to the Conservation Commission heading.)
PHOTOS: Alison England