AP BIO - In the trenches

The AP Biology class took a trip to the Pymatuning Laboratory of Ecology (PLE) in Linesville PA on the 8th and 12th. PLE is the largest ecological research facility of its kind in PA. It is a part of the University of Pittsburgh and provides hands on courses to college students, research facilities for University staff, and conducts outreach programs for middle and high school classes. The goal of the field trip was to give our students the opportunity to conduct field research on location and gain experience using science tools not readily available in the classroom. The of the two days was on limnology, the study of inland waters.

On Thursday, the students took the University flat-bottom boat on Conneaut Lake. The goal was to collect samples and data from the deepest part of the lake to determine the trophic classification of the lake. In order to do this samples of the water and benthos (bottom soil) were collected. Students used the Secchi disc to determine clarity, a YSI multiprobe to determine a vertical profile of dissolved oxygen and temperature, a Van Dorn bottle to collect water for chemical analysis (pH, alkalinity, turbidity, total phosphorous, and chlorophyll a), plankton nets to collect phtyo- and zooplankton, and the Ekman dredge to collect the benthic sample. Some of the data was taken and recorded on the boat while others were taken back to the lab for analysis and examination.

On the second day of study the students went to two locations along Linesville Creek; an urban and a rural setting. While in the streams the goal was to compare the stream chemistry and the macroinvertebrate populations at the two locations to determine if there was a difference presumably because of the difference in the amount of pollution that makes it to the stream at different points due to vegetation and drainage differences. The students used D-nets to sample the invertebrates by kicking up the sediment to release the organisms. 

Once back at the lab with the samples the students used identification guides to determine the different species at each location under magnification. The data was then used to determine the species diversity at different points in the stream using the Simpson's Diversity Index. In addition the students completed total phosphorous, alkalinity and dissolved oxygen comparisons.