Sunrise light on a grove of tufa towers emerging from the water of Mono Lake with soft green and dusty-red wild grasses in the foreground, Canada geese in the shallow water with reflections of the rocky towers, and desert hills in the distance.

Lee Vining High School students monitor Mill Creek’s health

Usually the Mono Lake Committee’s Outdoor Education Center hosts groups of kids and young adults from Los Angeles in the Mono Basin for five days and takes them to explore the wonders of the Eastern Sierra while learning about water conservation. This past week the OEC team had the privilege to work with a group of teenagers from just next door: Lee Vining High School biology students.

Lee Vining high school biology students inspect Mill Creek's macroinvertebrates during their field day along Mill Creek. Photo by Santiago Escruceria.
Lee Vining high school biology students inspect macroinvertebrates during their field day along Mill Creek. Photo by Santiago Escruceria.

For several years the OEC program and biology students from the high school have been monitoring Mill Creek, Mono Lake’s northernmost tributary stream that enters Mono Lake just west of Black Point, to gauge stream temperature and pH level, dissolved oxygen content, and the health and quantity of macroinvertebrates living in the stream.

This year’s scientists were freshmen and senior biology students—six students in total, all hailing from the great metropolis of Lee Vining. Mrs. Holt, the high school’s biology teacher, took her students on a mid-morning field trip just six miles north of Lee Vining to Mill Creek. When they arrived, the students were greeted by the OEC team of myself and Edie, as well as one of the Mono Basin’s most seasoned and skilled teachers, volunteer Jean Dillingham. Jean worked with the OEC team to teach the students about the importance of stream health and how scientific experiments can be used to monitor it.

The students themselves performed the first two experiments—measuring temperature and pH, and dissolved oxygen content—and concluded that the stream was in good health, though it was a little warmer than it should be in mid-October, a balmy 47 degrees Fahrenheit. Finally, to reconfirm these tests the students gently pulled up rocks from underwater and used tooth brushes to gently remove little critters from the rocks and place them in ice cube containers, so that the types and numbers of macroinvertebrates could be easily counted. This last step was the unanimous favorite. Nothing catches the attention of high school students like alien-looking mayflies, stoneflies, alderflies, and caddisflies wriggling around! The creatures were released back to the creek after being tallied.