Module 4 • Ecology: Case Study Part II: Collecting and Testing
Next you will collect various water samples and compare them to your standard to estimate their DOC concentration.
Collect samples from as many of the following as possible: 1. A large river
2. A fast-flowing stream 3. A pond or bog 4. Spring water 5. A mud puddle
In addition to these collections, prepare the following samples, using the same method you used with the tea bag of steeping the substances in boiling water for two minutes and then pouring them through a strainer.
1. Fresh leaves or grass (you may use lettuce if none are available) 2. Dead, partially decayed leaves or grass 3. A small handful of dirt 4. Pea gravel 5. Sand
Compare each solution to your standard and record its DOC.
Which had the highest DOC concentration? Why? Which had the lowest? Why? What are some of the factors that influence DOC concentration?