Plankton
Plankton are microscopic plants and animals in the water. Plankton are not only an indicator of water quality but also the primary food source of the James River Spinymussel.There is a variety of plankton common to the James River Watershed, as shown in a Chart A. Phytoplankton composition and biomass can represent the effects of long term environmental conditions on the living environment. The changes of seasons and time of day can cause a fluctuation in plankton content as the nutrients, temperature, and light changes. A diverse plankton group is more likely to be a stable community and face a smaller chance of collapse than the plankton species that experience single blooms like in eutrophication. Eutrophication is an increase in phytoplankton levels due to addition of artificial or natural nutrients which depletes oxygen levels.
Testing Protocol
Plankton collection is done by using a plankton fishing net. A net similar in design to the one we used can be viewed on the left. For our tests, the net was suspended in the water column and water and plankton were collected at the base of the net in a small plastic container. This test was repeated several times and the water was stored in a larger container and taken back to the lab. This container was then placed in a refrigerator to preserve plankton viability before samples of water were viewed under a microscope.
The plankton collection data is inconclusive. Plankton was not collected at every river and was neither consistently observed nor identified. We did observe zooplankton when we were able to look at the creek samples under the microscope, however we were did not keep track of the plankton and identify them under the microscope to determine diversity.