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Water: Middle School

Exercise IV. Nutrients in the Water

Although no scientific documentation has confirmed exactly what triggers Pfiesteria to become toxic, one thing that is well established by researchers: that the vast majority of Pfiesteria outbreaks are associated with waterways that have been heavily polluted with high levels of nutrients, such as nitrogen and phosphorus. Areas of highly concentrated animal agriculture have become the prime source of concern as a possible link between Pfiesteria and nutrients.

Large numbers of poultry farms are located on the coastal areas around the Chesapeake Bay. They produce manure that finds its way into the waterways. The manure is commonly used as fertilizer on farmlands, which washes off into the ditches, streams, and rivers that lead into the bay. Here, in the estuary environment, the water slows down and all the nutrients it is carrying, for example, on particles of sediment tend to settle out and concentrate.

Do we contribute Nitrogen and Phosphorus loadings into our Bays and estuaries?

Step 1: How much do you contribute?

The average homeowner can contribute to the nutrient enrichment problem in the Bay. Many everyday activities and facilities used are sources of nitrogen. Read the handout called Know Your Nitrogen. Then do the "Know Your Nitrogen" worksheet, on nitrogen generated by an average household on a yearly basis by activity.

Download the Know Your Nitrogen Worksheet (PDF)(4 pp, 174K). Exit EPA Disclaimer

Step 2: Real time monitoring

Scientists monitoring this environmental pollution problem need more data to establish more firmly what particular conditions spawn the Pfiesteria outbreaks. They are particularly interested in monitoring water temperature, dissolved Oxygen and other parameters that have proved significant when Pfiesteria has in the recent past caused fish kills.

Look at "Real Time Data" being downloaded via the web to Web site 8: "Neuse Estuary Monitoring Project". Exit EPA Disclaimer

The Neuse River estuary in North Carolina is being monitored at various locations. Click on one of the red locations. Look at temperature, pH, and Dissolved Oxygen. Describe EACH.



Dissolved Oxygen

Look at Web site 9: "Water Quality Parameters".

Read each of the descriptions under Temperature, pH and Dissolved Oxygen.

Do you think the Dissolved Oxygen conditions are alright for fish? What about pH conditions? (Back up your answers with the numbers from the real-time monitored data above.)

Dissolved Oxygen


Look at the real-time data over the web at the location on the Neuse River that you chose earlier. Scroll down with your mouse, and find Links to Historical Data. Click on the blue box for Hydrologic Data.

Find the span of days for which data is recorded.


Find two graphs: one showing Dissolved Oxygen and one showing Temperature. What are the units of measurement for Dissolved Oxygen and for Temperature?


Describe how the dips and peaks on each graph correspond to each other.


Can you tell if conditions are right for another Pfiesteria break out?


Do you need more data on water quality? What data would you request?



Middle Schools  |  Hysteria Over Pfiesteria  |  Exercises: I  |  II  |  III  |  IV  |  Top

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