Zooplankton Microscopic animals that are indicative of toxins, turbidity, and nutrient enrichment. Useful because these organisms have a brief life-cycle, providing a fast response. However, use has been limited by their patchy distribution and the inconvenience of their microscopic size. Good general indicators of overall water quality. They are invertebrates sensitive to water chemistry, hydrology, and geomorphology.
Various species have a distinct range of sensitivity to pollutants.
Thus, they are often used to indicate various degrees of environmental degradation. Fish Good indicators of the ecosystem since fish rely on the other categories for food. Thus, they reflect the overall health of the entire food chain. Their use is limited by their patchy distribution. Sampling device Good for use in the following situations Grab or scoop Devices that are designed to penetrate bottom sediment and samplers collect a sample in standing or flowing water.