Students learn to use water quality testing equipment, and apply the results to making inferences about where water samples came from.. This ties into the course by teaching a skill (using water quality tools) and teaching students how water isn’t the same everywhere. Previously, students watched a video of water quality being sampled in the area, and the importance of each parameter was described. Next, students will perform these same tests in situ.
Estimated Time of Activity:
Two 90 minute periods
Goals: Process Skills, Content Knowledge, Attitudes:
- Students will learn to use a water quality testing equipment.
- Students will learn some factors that influence water chemistry.
- Map of area from which water samples were taken.
- Handout: Water quality lab sheet
- 1 hydrometer and 1 water quality test kit per group
- 2 c. water sample per qroup
Students complete homework from EstuaryLive 2006 video, which is reviewed in class.
- Review assignment from EstuaryLive. Focus on factors that influence salinity, nitrogen and pH. Discuss how these factors affect living things.
- Show water testing equipment. Allow class to guess how each piece of equipment is used.
Demo: ask for a volunteer student to come up and demonstrate using each item. Students will record the steps the person takes, highlighting any problems.
- Teacher: Label water samples numerically (1, 2, 3). On map, label collection sites alphabetically (A, B, C). Record for your personal recollection where each sample came from, but do not disclose to class.
- Show class water samples (they will likely look different). Show map. First discuss based on map the water quality parameters students are likely to observe from each location. Discuss aloud, then allow students to record their hypotheses as to the source location of each water sample.
- On board, copy data table from student lab handout.
- Each group of students collects 1 water sample and 1 testing kit. Ascertain that each student knows which water sample (1, 2, 3) they are working on.
- Students follow testing procedures described on their handout and demonstrated in part 1.
- One student from each group records group data onto chart on board. All students record class data.
- Using data from board, students update their hypotheses as to source of each water sample. On sheet they will record why they made any changes to original hypothesis.
- Give students correct locations, lead discussion on factors that influenced water quality at each location.
- Students answer questions from sheet.
Students will record results onto lab sheet.
Students will answer questions described on lab sheet.
- The instructor should order water testing equipment and try it out in advance. There may be ways to simplify enclosed instructions.
- The instructor should select diverse water collection sites (salt, brackish, fresh). Samples can be collected and refrigerated anytime in advance.