Seneca Lake Research Plan

Research question: How does the water quality of Seneca Lake affect the plant and animal life in the lake?

Variables

Controlled: amount of water being sampled at each location
Independent: depth of locations
Relevant: pH and DO of locations

The pH and DO of the water in an aquatic ecosystem is very important to the plant and animal life living there. According to the USGS Water Science School, a pH below five can affect the reproduction of fish. If it is below 4, adult fish will begin to die. According to Lenntech, a water with too high alkalinity can also affect fish. In water with a pH of about 9.6, gills and eyes may be damaged and the fish may die. The Science on Seneca manual says that a pH of less than 5 or higher than 8.5 will place a strain on plant life. Dissolved oxygen is also important in an aquatic ecosystem because plants and animals need the oxygen in the water to use for respiration. When it falls below 3 ppm, (Science on Seneca manual) fish cannot survive. Water with a high DO level is considered healthy. Low DO can affect an ecosystem in many ways, such as harming the biodiversity (oocities.org) and allowing dangerous chemicals to dissolve into the water. An example is cadmium, which stays solid in the presence of oxygen and sinks to the bottom of lakes. If the water lacks much oxygen the cadmium will dissolve, which is a problem because it's poisonous to fish.

Citations:

"Dissolved Oxygen." Dissolved Oxygen. Utah State University, n.d. Web. 28 Oct. 2015.

"Effects of Changes in PH on Freshwater Ecosystems." DissolvedOxygen. Lenntech BV, n.d. Web. 28 Oct. 2015.
Halfman, B., J. Halfman, C. De Denus, T. Curtin, and S. Myers. Science on Seneca. Geneva, New York: HOBART AND WILLIAM SMITH COLLEGES, 2008, 2011. PDF.

"PH -- Water Properties." PH: Water Properties, from the USGS Water-Science School. USGS, n.d. Web. 28 Oct. 2015.

"Water Treatment Solutions." Effects of Acids and Alkalis on Aquatic Life. Lenntech BV, n.d. Web. 28 Oct. 2015.

Hypothesis: The pH and DO will both be at safe levels for the support of plant and animal life in the lake, and both will be healthy.

Controlling variables:

• Using the same amount of water at each location for each test
• It will be done on the same day

Procedure:

• Collect water sample to perform pH test
• Turn pH meter on, remove cap to expose glass bead
• Pour at least an inch of water into a glass beaker rinsed with lake water and place pH meter in the beaker
• Let number on readout stabalize for 5-10 seconds and record
• Rinse off pH meter with distilled water, replace protective cover, and turn off
• Find LaMotte sample bottle. Add 8 drops of the manganese(II) sulfate solution (bottle 4167) followed by 8 drops of the alkaline potassium iodide azide solution (bottle 7166).
• Carefully cap the bottle and mix by inverting gently. Allow precipitate that has formed to settle on shoulder of the bottle. Wait 3-4 minutes for this.
• Add one gram of sulfamic acid (bottle 6286) to the solution. Cap the bottle and mix until the white crystals and precipitate have completely dissolved.
• Pour solution into the titration tube, up to the 20 mL line. Add 8 drops of starch solution.
• Fill the Direct Reading Titrator (0337) up to the 0 mark with the sodium thiosulfate solution (bottle 4169).
• Insert titrator though the small hole in the cap of the titration tube and titrate solution slowly. Swirl the solution until the blue color disappears permanently with one drop of titrant. You may have to fill the titrator more than once. Record how much titrant you used before refilling. 
• Dump remaining contents of the LaMotte bottle and titratration tube into labeled waste container. Rinse with distilled water and place back into kit.