CE/NR 797 Lab : Water Chemistry 

[Prepared by R. Fortner for “Digital and Field Techniques for Coastal Environment Studies,” 7/02]

 Rationale: Lake Erie’s reputation as a “dead” lake was based primarily on its being too much alive! Nutrients in the form of phosphates  and nitrates encouraged an overgrowth of algae and instituted a cycle of events that led to disappearance of desirable species of fish while other species experienced massive die-offs. How is the lake doing today in terms of its nutrient load and dissolved oxygen?

 Objectives: With successful completion of this lab, students will be able to  

• Demonstrate methods of measuring temperature, dissolved oxygen and conductivity at different depths

• Report the origins and quantity of nitrates and phosphates in Lake Erie water

• Develop and analyze a GIS model of water chemistry changes in the Bay and Lake

 Materials: for sampling -- DO meter, conductivity meter, secchi disk, fine-mesh plankton net, baby-food jars for sample storage, tape and marker for labeling jars, nitrate and phosphate test kits, data sheet, clipboard.  For analysis:

 Procedure:

• With your team of 2-3 students, learn how to use instruments to measure water depth, dissolved oxygen, water temperature at known depths, chlorophyll, phosphate and nitrate concentration. Data may be collected, shared and discussed as a team, but individual lab reports are required.

•   Concurrent with data collection for the Water Circulation Lab, collect Lake data on a transect from Gibraltar to the Red Can buoy, and Bay data at docking buoys almost to the Boardwalk. Certain other data will be collected less frequently as in the following schedule:

                                                          Location (identify by GPS)                                                

Measurement	Frequency	Transect Bay     Lake	Can buoy	Bay center	City docks	Team
Dissolved oxygen profile	Daily	√           √
Temperature profile	Daily	√           √
Conductivity (surface m)	Daily	√           √
Secchi transparency	Daily		√	√
Plankton	MWF		√	√
Chlorophyll	MWF		√	√
Phosphate	MWF		√
Nitrate	FSS am				√

 Data Collection Sheet ( download by clicking the link) 

  Results:  

• Post data at regular intervals for use by entire class.  Be alert to anomalous data and examine collection methods/equipment for uniformity and accuracy.  

• Develop an Excel spreadsheet to array the data from all measurements and locations. There will be additional measurements on field trips (other islands, and samples from Toledo to Huron), and these should be added to the dataset too for geographic range and comparison of land uses contributing to changes in the water.

• As the term progresses, lab report guidelines will be distributed.  
  

Water Chemistry Lab Report Guideline

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