We will head to out to a site on campus, you will be placing bottles at depth as you can. Procedure Measure the depth at the site. This can be done by using the weighted line, letting it sink to the bottom, and marking on your string the top of the water level. Use the measuring tape to calculate the depth. Record in the table. Use the Pasco temperature sensors to take the temperature just below the surface of the water. Record this value in the table. Lower the Pasco temperature probe lower into the water, until you notice a big temperature change. Using your stick measure the depth this change occurred at. Using the water sampler, collect water samples for each of your 6 containers. Your instructor will provide you information on site about how to use the water sampler, as well as the depth in which you should collect your sample. Fill your bottles using the water sample and allow the water to overflow the bottle until the volume of the bottle has been displaced three times. Two of your bottles will be used to record your initial DO, two will be used as the light treatment, and two will be used as the dark treatment. Measure the DO of two of your bottles, record this value in the table under Initial DO. Using aluminum foil, completely wrap your two dark bottles. Tie the bottles to the string at the depth designated by your instructor. Using your weighted line, deposit your four bottles below the surface, and tie the string to the stakes provided by your instructor.
- Use the Values in the table to calculate and record the community respiration using the formula: Community respiration = DOinit- DOdark
- Calculate and record net and grows photosynthesis using the formula: Net photosynthesis = DO light — DOinit
Gross photosynthesis = community respiration + net photosynthesis
Questions: - Was your hypothesis supported? Why do you think you got the results you did?
- Does productivity rate reflect the depth of the water sampled?
- If the biomass and number of planktonic animals far exceed the amount of algae how would that affect each of the three community variables calculated in steps 11 and 12.
- In what environments would oxygen cycling be unimportant?
- A surprising number of coral species and other reef invertebrates have algae growing symbiotically in their tissues. What are some adaptive advantages to that relationship?
- Oxygen dissolves more readily in cold water than in warm water. Yet deep lake water is often nvunpn nnnr 1A/hIr is thic
the case?
Sample Solution