Is The Water Safe for Aquatic Life?

Sue Habeck, Tacoma Community College

Summary

In this field activity students visit local water bodies and measure water quality factors and observe the surrounding habitats. Follow-up questions ask students to apply their data to basic chemistry principles, the scientific method, and graphing. They also ponder sustainability issues such as point and non-point sources of pollution (including personal contributions), impacts of pollution, and potential mitigations. A preliminary worksheet about some major water quality factors is included.

Learning Goals

As students complete the water quality worksheet, conduct their field studies, and ponder the follow-up questions they will be working with many "big ideas" in biology: process of science, nutrient cycles, ecosystems, interdependence, homeostasis, and society and technology (as derived by Bill Moore's project http://www.sbctc.ctc.edu/college/_e-assessbigideas.aspx.)

Many sustainability "big ideas" are also integrated into this assignment: water quality, pollution, habitat destruction, bioregional thought, system thinking, responsibility and stewardship, and public health. The hope is that this assignment will inspire students to think more about their personal impacts to ecosystems, to act more responsibly and seek continued education and civic involvement.

Context for Use

This teaching unit on water quality has been used in introductory biology and environmental science courses. Water quality affects everyone and is easy for students to relate to even if they are not science majors. Most students enjoy fieldtrips and are inspired to apply principles they have learned about in class. The hands-on and cooperative nature of water testing helps students appreciate and understand scientific principles and procedures. The breadth of issues connected to water quality (e.g. land use, pollution, laws, personal habits, climate change) allows the teaching unit to integrate many important scientific and sustainability topics.

This unit is effective for introducing the scientific method and introductory chemistry or when studying ecology.

I usually do this activity the first week of the quarter.

Description and Teaching Materials

Two documents are provided here and both are in the format given to students. Both handouts would be easy for an instructor to modify for their own purposes, emphasizing different principles and/or skills.

The preliminary worksheet, "Water Quality Factors", which includes graphs of real water quality data, can be utilized in many ways as homework, collaborative work during class, or not used at all. If the student has already heard some lectures and/or done some reading about introductory chemistry (molecule, ions, pH), the worksheet may take about one hour.

The water testing activity, "Is the Water Safe for Aquatic Life", can be conducted in many ways. Each instructor can decide which factors to measure and which tools to use. The whole class can visit the same site, or can split up to test different sites, or each student can visit different sites on their own time, taking measurements if they have their own kits (like if they are taking an online class) or bringing samples into the classroom to be measured later. If necessary, an instructor can bring in water samples along with information and visuals about the surrounding habitat, but this would not be as effective as the student doing the actual field work. The follow-up questions probably take one hour for most students.

"Water Quality Factors" is a worksheet introducing students to some of the major water quality factors: temperature, dissolved oxygen, acidity, carbon dioxide, nitrate, phosphate and fecal coliform. Graphs of real data are included.

"Is The Water Safe For Aquatic Life?" is a generic handout for students who will be doing water testing. The handout introduces the topic of water quality, offers some general instructions related to measuring water quality, and lists some follow-up questions related to habitat, scientific method, pollution, pollution impacts, and requires some graphing.

Water Quality Factors (Microsoft Word 127kB Oct27 11)
Is the Water Safe for Aquatic Life? (Microsoft Word 213kB Oct27 11)

Teaching Notes and Tips

Titlow Park is a wonderful field site within one mile of Tacoma Community College. We can test Puget Sound, a lagoon, a smaller pond/lagoon, two streams and a storm drain all within a quarter mile walk complete with covered shelters.

It is interesting when students study a water body of their choice (either borrowing some of the test kits or bringing in water samples). It is important to plan some time in class to compare and discuss the data relative to regional maps and knowledge of human activities near the water bodies. This may be possible in an online format if necessary.

It is sometimes possible to extend the water quality lesson by having other classes or people analyze the water for other materials in a chemistry lab.

It is nice to coordinate with local agencies collect water quality data (e.g. Pierce County Stream Team) to share data if possible. If the data is "real" the activity becomes even more meaningful to the students.

Some agencies or nonprofits working in the arena of water quality are happy to come speak to classes (e.g. Citizens for a Healthy Bay in Tacoma, http://www.healthybay.org).

It is especially fun to do this activity in conjunction with a class kayak trip. In Tacoma it has been possible within a class period of nearly three hours to drive downtown, have rental boats delivered to the mouth of Thea Foss waterway (Ruston Recreational Equipment), paddle and go ashore briefly and then return back to class on time. Even though we cannot measure heavy metals or organic compounds, just being on the water amongst the industry and current mitigation projects such as habitat restoration is very invigorating for students.

Assessment

This activity consists of two sets of questions for the students to answer. One or both can be turned in and graded. The information and skills (e.g. using water test kits; graphing) can be integrated into future activities and assessment tools (e.g. quizzes).

Though not quantifiable, you can judge that the activity was effective when the concepts and ideas are brought up again and again by the students. For example:
  • I have noticed that when we subsequently visit other water bodies (e.g. Snake Lake in Tacoma), even when focusing on other topics (e.g. plant diversity), students are automatically keyed into thinking about water quality and want to make comparisons.
  • After pondering the effects of sewage on water quality, students are even more interested in visiting the waste water treatment plant which we usually do at the main facility in the Tacoma Tide Flats or in Chambers Creek near Steilacoom.
  • I have all my students choose a local environmental issue to research, including consulting an expert. The outcome is a formal, persuasive, referenced business letter to appropriate recipients. This water-testing field activity has inspired many students to choose related topics including creosote in railroad ties, replacing culverts to fish-friendly versions, incentives for homeowners to check and replace broken septic systems, increased public education about yard and vehicle care, increased funding for ecological restoration projects, etc.

References and Resources

The instructor will need to decide where students are going to collect water quality data and provide specific instructions (maps and driving directions).

The instructor will need to figure out transportation to the site(s).

To measure water quality the students need access to testing equipment and kits such as thermometers, salinity meters, pH probes or color-change chemicals, etc. The test kits sold in pet stores for fish aquaria are usually just fine! Be sure to use the kits designed for salt or fresh water (some are fine for both).

The instructor should become familiar with how to use the kits and may need to write simple, water-proof instructions directly on droppers or on kits. Extra test tubes allow single test kits to be used by many students so that everyone has something "to do" while at the site.

Be sure to bring waste containers for the chemicals to be poured into and rinse bottles if tubes need to be reused. If necessary, bring gloves and safety glasses.

The instructor must decide how to orchestrate the water testing when at the site(s). Students should always have something to do! It seems helpful for students to try different kits and equipment.

The preliminary worksheet about water quality and the follow up questions to the field activity assume students have access to a source of information such as a textbook, the internet, or lecture notes in order to answer the questions.

Evergreen State College