Seneca Lake Lab

Research Question: How does the depth of Seneca lake effect the amount of life?

Controlled Variables: The type of tests we take, the time we take the tests will be pretty much the same ( same season, same day, same weather conditions, etc. )

Independent Variable: The depth of the water

Relevant Variables: We must make sure that the tests are conducted as similarly as possible. The level of pollution, temperature, season, are all relevant variables

Background Info: Seneca Lake is the deepest of all the Finger Lakes in New York State, reaching up to depths of 618 feet.  Seneca Lake is the geographic center of all the Finger Lakes as well, with the town of Geneva on Northern tip and Watkins Glen on the Southern end of the lake.  Seneca Lake's water is maintains a fairly moderate temperature throughout the year, the water has high levels of dissolved oxygen, allowing for all types of life throughout various depths.  The water supports numerous types of fish, some of which are Lake Trout, Smallmouth Bass, and Yellow Perch.  Plant life also thrives, with pondweeds, waterweeds, plantain, stoneworts and muskgrass being prevalent in the water and on the shores of the lake.  In-text Citation.

Hypothesis: Evidence of life will be consistent throughout all depths of the lake, while life low on the food pyramid will be at the higher depths while the tertiary consumers will most likely be at lower depths.  

Methods to Control Variables: I want to measure turbidity, dissolved oxygen, temperature, and pH levels at all depths.  Taking all the same tests at all locations, even multiple trials of the tests at all three locations would all go to further eliminate human error and control variables.

Procedures:

Dissolved Oxygen:

1. Gather the dissolved oxygen kit.
2. To the 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).Some water may drip off the sides.
3. Carefully cap the bottle, mix by gently inverting - then allow the orange-brown precipitate that has formed to settle below the shoulder of the bottle (about 3-4 minutes).
4. Using the 1 gram spoon provided in the kit (0697), add one level spoonful of sulfamic acid (bottle 6286) to the solution in your LaMotte sample bottle. Cap the bottle and mix until both the reagent (white crystals) and precipitate (brown crystals) have completely dissolved and you obtain a clear brown-yellow solution.
5. Pour this clear brown-yellow solution from the LaMotte bottle into the titration tube and fill it up to the 20 ml line.
6. Use the plastic eye-dropper provided in the kit, add 8 drops of the starch solution to the titration tube. At this point, the solution should change color to a bluish-green.
7. Fill the Direct Reading Titrator (0337) up to the 0 mark [looks like a syringe, marked 0-10 ppm] with the sodium thiosulfate solution (bottle 4169).
8. Insert the titrator you just filled through the small hole in the cap of the titration tube and titrate the solution slowly. Swirl the titration tube until the blue color of the solution disappears permanently with one drop of titrant (i.e., you are looking for a color progression from green-blue to blue to light blue to colorless). You may have to fill the titrator more than once. Be sure to record how much titrant you used before refilling. The direct reading titrator is calibrated in units of parts per million (ppm) dissolved oxygen, therefore, be sure to record all of these units.

Temperature:

1. Use the Ship's onboard "CTD" to gather temperature measurements.

Turbidity:

1. Take Cup that has Secchi Disk on it and slowly lower it into the lake until it disappears. Record the height at which it disappeared.
2. Pull the Secchi Disk back up until it can be seen again record that.
3. Repeat steps 1 and 2, 3 more times, and collect average of the three trials

pH Testing:

1. Fill up a vial with lake water
2. ASAP after getting water sample turn the pH meter on
3. Remove the cap to expose the glass bead
4. Pour at least an inch of water into a beaker rinsed with lake water
5. Place the pH meter in the beaker
6. Let the number on the readout stabilize for 5-10 seconds
7. Read the pH number and record it.

Final Questions: How good is this food going to be?

Also - what are the possible implications of whatever results we may find while on our excursion to Seneca Lake?