Wednesday, December 21, 2016

Phosphorous Inquiry

This month, students have been working in teams to understand the effects of phosphorous on water quality. We quickly discovered that chemistry was going to be very helpful to us. When we tested for dissolved oxygen, we found that the amount of D.O. in Cedar Lake is indicative of a less-than-healthy ecosystem that cannot support the rich biodiversity of healthier bodies of water.

Our next inquiry involved adding different concentrations of fertilizer to water where the small, aquatic plant called duckweed was growing. Six different groups added either .5%, 1%, or 2% fertilizer to their test tubes and collected data over a period of roughly three weeks. We also ran a control group that had no fertilizer added.

The links below will bring you to each group's final lab write-up, where they are communicating their results, analyzing data, and connecting the results to a recent article by Gaen Murphree in The Addison Independent about the sources of phosphorous in Lake Champlain. Almost half of the phosphorous in the lake comes from agricultural runoff and the Otter Creek watershed has been charged with lowering its phosphorous impact on the lake by 5%. That might seem like a tall order, but the Mississquoi Bay watershed needs to decrease its output by 50%!

.5% Concentration Groups
1% Concentration Groups