Teacher Guide: Human Impact on Estuaries, a Terrible Spill in Grand Bay
Contents
SUMMARY
In this activity developed by NOAA, students make a model of a pollution spill that occurred at Bangs Lake, a tidal lake within the Grand Bay NERR in Mississippi, in April 2005, and measure water quality parameters in their model. Students then study the actual spill, analyzing various forms of data to determine the date of the spill and identify how the spill changed water quality parameters in the estuary during and after the spill. They speculate on how various life forms in the estuary were affected. Finally, students produce a timeline of the spill event with recommendations to the state Department of Environmental Quality about how to prevent large-scale pollution spills like this in the future.
GOALS
Students will be able to:
- Describe how a chemical reaction affects water quality parameters of a sample of estuary water.
- Use their lab results to predict the effects of an actual pollution event on water quality and life forms in an estuary.
- Revise predictions based on new evidence.
- Analyze water quality and nutrient data to identify variables that are out of a typical range and that may be indicators of a disturbance to the estuary, such as a pollution event.
- Explain how estuarine species are threatened by drastic changes in water quality and nutrients.
- Explain how the water chemistry of an estuary affects the health of the estuarine ecosystem and how monitoring estuary water chemistry can account for and predict changes to the health of the ecosystem.
- Summarize data and develop a hypothesis to make a timeline that describes the spill and explains how it affected the chemistry of and life in an estuary.
- Suggest ways to prevent adverse human impacts on estuaries.
CONTEXT FOR USE
Teaching Time: 3 (55 minute) class sessions + homework
Organization of the Activity: This activity consists of 3 parts which help deepen understanding of estuarine systems:
- Modeling a Chemical Spill
- Learning More about the Spill
- Analyzing Data Before and After the Spill
Preparation:
- Collect or make enough brackish water (with a salinity of about 8 ppt) for each team of students. Each team should have a sample of about one to two liters. To make a water sample of this salinity, mix 8 grams of salt or Instant Ocean per liter of tap water, or dilute a seawater sample until it is 8 ppt —1.026 specific gravity on a hydrometer.
- Prepare one or multiple estuary models. Add the brackish water to the basin. Set it up so that you can pour the simulated wastewater.
