The Downeast Lakes Land Trust (DLLT) led a group of 15 advanced placement biology students from Lee Academy on a water quality monitoring expedition to Mattakeunk Stream in Lee, ME.
“Mattakeunk Stream is known by a few colorful colloquial names,” said Lee Academy teacher Susan Linscott, as she encouraged students to consider the human activities which currently and historically affected the stream. “Septic systems from houses and dorms along the steam used to drain right into the stream, but that has all changed now.”
Previously, students had tested water in Mattakeunk Stream for dissolved oxygen as well as acidity. They were curious to see if a macroinvertebrate survey would support their chemical analysis. Armed with kick and dip nets, students waded out into Mattakeunk Stream to collect a sample of benthic (bottom-dwelling) invertebrates. The nets were emptied into five gallon buckets waiting on the stream’s edge, and a myriad of animals emerged.
Back at the school’s lab, students sorted out mayflies, damsel flies and caddis flies as well as a large number of hellgrammites. “Some of these animals are more sensitive to pollution than others,” explained DLLT Education and Communication Manager Tanya Rucosky. “Mayflies and alder flies have exposed gills, which are easily irritated by acidic water, pesticides and fertilizers.”
The four inch long water scorpion which students found, on the other hand, sported a long “snorkel” which allowed it to breath from the air. Water scorpions and beetles not only breathe air, but have wings, which can carry them away from highly polluted water. “These animals are useful as a barometer of long term water quality, not just a snap shot. Using physical and chemical testing tells us only about this exact moment, but no river is the same twice. Macroinvertebrates tell us what has been going on in the waterway for the last few months. What we hope to see in a healthy stream is both a high level of species diversity, both sensitive and tolerant animals, as well as a high population density.” said Rucosky.
After identifying and sorting the animals of Mattakeunk Stream (including examining a few small vertebrates in the form of 2 trout and a juvenile salamander) students determined that the water quality was quite good. “We knew our chemical test might be unreliable, so this has been a great way to ground truth our earlier work.” said Linscott. Students now are feeling a new sense of appreciation and respect for this once maligned waterway.