Most aquatic organisms are ectothermic (poikilothermic) - body temperature varies with the environment, so they are sensitive to temperature changes in the environment.

Human activity can result in warming of aquatic ecosystems - thermal pollution.

Oxygen levels in water decreases as temperature increases: see Table 8.1-1.

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• PART A - THERMAL POLLUTION EXPERIMENT p. 204

  Observe goldfish breathing rate - keep fish calm, look at opercula (gill covers), not the mouth.
  

  Establish a basal rate, then at 3 different water temperatures, 3 trials each.

  Note that goldfish can tolerate temperatures up to 106°F (41°C), see Table 8.1-2.

  DO NOT use temperatures near 40°C or 0°C: do not COOK or FREEZE the fish!

  Add cold or hot water slowly down the sides of the beaker; do not dump right into the beaker and disturb the fish!

  State your hypothesis on the effect of water temperature on breathing rate?

• PART B - QUESTIONS