Lab #4 Oakland Ravine and Lake: Water Quality

1. The pH levels are fairly constant for inlet and outlet. The dissolved oxygen(dO), on the other hand, varies very much between the inlet and the outlet. The measurements of the pH and the dO of the water do not differ greatly. By comparing the two graphs given I can see that both the pH and the dissolved oxygen are lover in the winter. I think this is related to the amount of sunlight that the water receives and also the temperature of the water. In the given maps the dO drops off very sharply at various points. I would assume this is a sign of eutrophication. That would also explain why in the winter the dO is much more steady up to a certain depth. The explanation being that the cold weather has killed off many plants, therefore the plants can’t choke the oxygen supply.

INLET 7.3 7.3 7.05 1.7 5.5 5.5 Over-range
LAKE 7.8 7.8 7.64 1.5 9 9 .42
OUTLET 7.5 7.5 7.35 .9 6 6 .48

2. These organisms were found in the sample of water we looked at on the slide. I would say that the organisms are about the size of a fine pencil point. The look like specs in the water to the naked eye, but under the magnifying glass they look extremely detailed and large. I think I found a synedra and a copepoda. Because these organisms are so small they must eat very small particles maybe from dead plants and animals in the water. They are probably just about the lowest on the food chain. Their existence most likely supports many other life forms.
3. Discussion- This lab was pretty interesting. I liked actually doing lab tests and then finding out the results. I don’t understand why every pond across America isn’t eutrophied. If the abundance of nutrients comes from cars and pollution, then wouldn’t it be seeping into just about every body of water, therefore causing eutrophication.? This lab explains why many times I will see dead fish floating around in ponds near my
house in upstate New York. I’ve gone fishing in one particular pond and every time you reel it back in the hook would have been filled with algae and plant matter. Now I know that it’s not a healthy pond.