2013 Annual Stream Census

On the morning of Saturday, March 23rd, Conservancy staff and a team volunteers ventured out into Mill Creek for our 17th annual Surber Day. The sky was blue, the air was crisp, and the water was chilly! The Annual Surber Census takes place each March and is the day on which the Conservancy collects macroinvertebrate samples from Mill Creek.

A total of eight samples are taken from four sites along Mill Creek and then returned to the Norah Goldfine StreamWatch Lab where our dedicated StreamWatch volunteers spend each week meticulously sorting, counting, and identifying the thousands of macroinvertebrates in the samples.

These tiny little bugs that live along the streambed are extremely important for a variety of reasons. Not only are they an extremely important part of the aquatic food chain, they are also very helpful for determining the water quality of Mill Creek because of their sensitivity to water pollution.

By assessing the macroinvertebrate population that exists in Mill Creek over the last 17 years, we have been able to monitor the long-term health of Mill Creek.  As stormwater runoff and harmful pollutants have increased over the years, we have been able to track the impact of these threats on Mill Creek by studying the declining macroinvertebrate population.

If you are interested in learning more about the health of Mill Creek and the other streams in Lower Merion, please check out the latest 2013 Mill Creek Report. If you are interested in becoming a StreamWatch volunteer, please click here. Thank you to all of the volunteers who came out to this year’s Surber Day and to the dedicated StreamWatch volunteers who volunteer their time each week in the lab!

To read Executive Director, Patty Thompson’s, Main Line Times column about the Census, click here.