With an invitation to visit Sara Radamaker’s Elver Lab at the Darling Marine Center, students learned of the innovative business model Sara is developing to create new aquaculture opportunities for people in Maine.  The elver season is in swing and is the most lucrative fisheries, pound for pound of any of the commercial species “fished” in Maine.  Maine is one of only two states that sustainably harvest very young American eels, otherwise known as elvers.

Our marsh is home to a healthy elver run that is harvested and students can know that the marsh is vital habitat for elvers as well as for many, many species of wildlife, and serves an ecological function to connect the land and sea.

Students toured Sara’s lab, and also Charlie Walsh’s oyster aquaculture lab, and met two grad students who described their research to reliably age lobsters and to collect lobster larvae settlement data with which to monitor population trends several years down the road.

One of our important tasks during the spring is to measure the volume of water coming out of the marsh.  This volume impacts the ease of fish passage into the marsh.  When there’s plenty of water spilling out of the marsh, the alewives may have an adequate column of water to swim up through and into the marsh.  More likely, as the volume of water decreases throughout the spring, in May when we might expect alewives, the water flow may be an issue.  We have learned that the biology of alewives don’t allow them to jump as salmon do.

We’ve learned that the culvert that was replaced in the late summer of 2015 was engineered with weirs (internal sections that trap water and create pools) based on the water flows of three similar “gauged” streams that had measured water flows and were located in New Hampshire and Massachusetts!  We want to collect data to “ground-truth” these water flows and to know, over time, what the expected flow out of our marsh is when alewives are migrating.  This information would be essential to providing adequate fish passage, as is the goal of the Conservation Commission, and why a “nature-like fishway passage” is the next step to allowing alewives to return to the marsh.

Looking with an eye for details…making measurements…Students worked in small, self-selected groups, using a rubric to guide their content as they completed a final draft of a site description. The last stages of the work involved a peer feedback process giving “warm” and “cool” feedback according to a protocol, with which groups could consider revisions. 
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Revisions were made and the quality of their final illustrations and text descriptions changed significantly.  Here is a final site illustration and description created by Anna Kingsbury, Allison Gill and Audrey Leavett.

Site Description

“Our 8th grade class has been going down to the marsh to try to bring the alewives back. We have found that the outlet stream is 111 feet long. There is a granite pillar that is about 4 ½ feet tall, and ⅓ of the way upstream from the culvert. Three and a half feet downstream from the pillar, there’s a tree stump. The line of rocks is located between the pillar and the tree stump. The line of rocks goings from the east to the west bank and measures 20 feet long. The rocks help to break the surface of the stream. The water upstream from the line of rocks, which is more of a pool than a stream, is about 14-15 inches deep. The water downstream of the line of rocks has a faster current.

Upstream from the rock pillar (on the east side) is squishy mud that makes your boots get stuck. The floor downstream from the pillar is mostly rock and is easier to walk on.

There’s a pile of boulders about ½ of the way upstream from the culvert on the west bank. The widest part of the stream is 26 ½ feet. This is from the boulders on the west side straight across to the east side of the stream.

Ten feet downstream there is a little pool that the water from the outlet flows into, made by rocks. The outlet is 5 feet wide. There is a tree on the east bank that hangs next to the outlet.

This is our site description of the St.George outlet stream.”