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Water: Middle School

Activities: "Hysteria Over Pfiesteria"

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For Grades 6 - 8

Hysteria over Pfiesteria (Full Article)(PDF) (2 pp, 1.5MB)

Hysteria over Pfiesteria (Activity Sheets)(PDF) (9 pp, 850K)


Exercise I. Draw Your Own Pfiesteria

Exercise II. Locating Pfiesteria

Exercise III. File Your Own Pfiesteria Kill Column

Exercise IV. Nutrients in the Water


Students will be guided through an investigation of the Pfiesteria outbreaks through a variety of approaches employing writing, math, drawing, summarizing and deductive skills. As students assimilate details of the Pfiesteria problem, they will begin to develop a multifaceted understanding of the issue and its potential links to nonpoint source pollution. In Exercise II, they study the spatial and temporal distribution of Pfiesteria outbreaks in an effort to explore reasons for the connection between nonpoint source nutrient pollution and the occurrence of Pfiesteria outbreaks. This will lead them into an exercise investigating their own households as sources of nonpoint source nutrient pollution. Finally students look at real-time data collection efforts to make the connection between the science they read about and actual data interpretation from science labs studying Pfiesteria in North Carolina's rivers.

Time Required:

Individual exercises are designed to be approximately ½ hour to 45 minutes long. The time to complete an exercise can be longer if the optional links to related Web sites are explored for a deeper examination of the subject. All exercises are well-suited for in-class lessons. Exercise IV has two steps, each of which can stand alone.

Curricular Standards and Skills:

  • measurement
  • scientific method
  • biological terminology
  • life form classification
Thinking Skills:
  • deductive reasoning
Language Arts:
  • reading comprehension
  • essay writing
Social Sciences:
  • spatial understanding:


Nutrients: Substances that all living organisms need for growth and reproduction. Two major nutrients, nitrogen and phosphorus, occur naturally in water, soil, and air. Nutrients are present in animal and human waste and chemical fertilizers. All organic material such as leaves and grass clippings contains nutrients.

Nutrient Loading: adding nutrients to a system. In particular, nitrates and phosphates added to aquatic systems can often cause microorganisms such as algae to undergo a population explosion.

Algae: aquatic photosynthetic organisms which are not true plants, but close relatives, often microscopic. Small algal populations are normal; overpopulation (green turbid blooms) indicate nutrient pollution.

Bloom: a severe overpopulation of aquatic algae, characterized by serious green turgidity. Can lead to anoxic conditions.

Eutrophication: the result of overloading an aquatic system with nutrients (sewage, phosphate), producing an overgrowth of algae, low dissolved oxygen, and little aquatic life.

Toxic: a substance is said to be toxic if it harms or kills plants or animals by direct action.

Toxin: any poisonous product of animal or vegetable cells. The toxins produced by harmful bacteria cause the symptoms of many diseases.

Cyst: a protective outer membrane formed around an organism, such as a protozoan, during reproduction or in response to unfavorable environmental conditions.

Dinoflagellates: a unicellular biflagellate, typically marine, algae that is an important component of plankton; usually photosynthetic.

Flagella: long whip-like moveable structure or tail extending from the cell and used in locomotion.

Pfiesteria: a microscopic, single-cell organism that has the ability to behave like an animal under certain conditions. It belongs to a group of phytoplankton known as dinoflagellates.

Tributary: a branch (smaller stream) bringing water into a stream, river, etc.

Phytoplankton: minute, floating aquatic plants; algae

Hydrology: a science dealing with the properties, distribution, and circulation of water on and below the earth's surface and in the atmosphere.


  1. Know Your Nitrogen exercise (Source: the Chesapeake Bay Foundation / State of Pennsylvania DEP.) Know Your Nitrogen: A Guide to Reducing Nitrogen Pollution at Home (PDF) (4 pp, 175K)  Exit EPA Disclaimer
  2. Draw your own Pfiesteria worksheet.
  3. Trigger Test (PDF) (1 pp, 507K)

Internet sites referenced:

Web site 1: "Background Information on Pfiesteria" [broken link]  Exit EPA Disclaimer

Web site 2: "Life Cycles of Pfiesteria pescicida" [broken link]  Exit EPA Disclaimer

Web site 3: "Images of Pfiesteria" [broken link]  Exit EPA Disclaimer

Web site 4: "Dinoflagellates, Protists and Pfiesteria"  Exit EPA Disclaimer

Web site 5: "Pfiesteria piscicida and Pfiesteria-like Organisms"  Exit EPA Disclaimer

Web site 6: "Pfiesteria piscicida, Fact Sheet" [broken link]

Web site 7: "Alien in Our Midst? Phantom Algae Suspected in Bay"  Exit EPA Disclaimer

Web site 8: "Neuse Estuary Monitoring Project" [broken link]  Exit EPA Disclaimer

Web site 9: "Water Quality Parameters" [broken link]  Exit EPA Disclaimer


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

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