For the third year, Wiscasset Middle School seventh graders, led by natural science teacher Sue Kistenmacher and Lynne Flaccus of the Sheepscot Valley Conservation Association enjoyed a day of field research at SVCA’s Palermo Preserve in Palermo.

And this year’s trip May 12 included a bonus, in addition to the perfect spring weather: a lucky chance to watch at the Head Tide Dam in Alna, on the way up to Palermo, as field workers from the Maine Department of Marine Resources removed salmon, alewives and other fish from the large traps just below the dam. 

The workers each day count and release all the fish caught in the traps, but before they release the young salmon, called smolt, they measure and weigh them, and also take scale samples, as part of an effort to monitor progress in the long-term effort to restore runs of salmon, along with alewives and other migratory fish, to Maine rivers.

Flaccus, herself an experienced natural science educator, had visited the class in the days before the trip to join Kistenmacher in briefing the students on what they would be looking for, and how to go about collecting their samples.

The students came to the river supplied with illustrated guides and detailed log-sheets for recording what they found under the rocks and along the edges of the stream.  At the preserve, after a 10-minute hike to the water's edge, and a demonstration by Flaccus of non-disruptive collection practices, the students fanned out along the shallow river in five-member teams to do their work.  As they collected and identified, they called out the names — caddisflies, dragonflies and many others, whose immature stages live under water and fall into the category of benthic macroinvertebrates. 

The presence or absence of these creatures is an important indicator of stream health, and thus is an important subject of study in stream monitoring programs.

The teams generally found what they had been prepared for, but the discoveries nevertheless brought cries of delight and recognition. The teams also used sophisticated equipment lent by Gulf of Maine Research to measure the water's dissolved oxygen, pH, salinity and temperature, and took notes on the makeup of the riverbed, the shoreline and the character of the surrounding landscape.  Photographers made visual records of the location and the collected specimens, and record keepers entered detailed specimen data on their log sheets for compilation and analysis later in class.  All the specimens then were returned to the river.

For more information, see the SVCA website, www.sheepscot.org.