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Research Theme: Bioassessment

Biological assessment or “bioassessment” measures the health of an ecosystem by examining the organisms that live within it. Examples of organisms include aquatic insects, snails, worms, crustaceans, fish, or periphyton. Biological indicators provide a direct measure of the health of the local aquatic life. In contrast, chemical monitoring simply predicts the potential for harmful ecosystem effects based on the levels of contaminants that organisms are exposed to. Although more complex to interpret, monitoring living organisms in conjunction with traditional chemical measures often yields richer data than measuring chemical or physical parameters alone. This is because biological organisms integrate exposure to many different types of contaminants over time. Living organisms may be subject to a variety of stressors, such as low dissolved oxygen, presence of toxic substances, extreme temperature changes, and excess sediment loading. The combined effects of ecosystem stressors become apparent when observing the biological community structure. Tracking organism community assemblages allows early detection of potential environmental degradation, even when the contaminant at fault is unknown.

Scientists sort benthic invertebrates and detritus collected from a stream bottom with a net.

SCCWRP Research

SCCWRP research in this area is based largely on developing and testing assessment tools for interpreting biological monitoring data. Many of these assessment tools take complex biological community data and simplify them into a single index or number matched to the degree of environmental impact. The results are very effective for communicating risk to managers and the public. Other bioassessment tools look at the response of individual organisms using new molecular techniques. Once they are sufficiently vetted and tested, biological assessment tools can provide a foundation for establishment of regulatory biological criteria or “biocriteria.” These are often in combination with other monitoring techniques to assess environmental condition.


Highlighted Research Projects

Completed Research Projects

For more information on Bioassessment, contact Ken Schiff at kens@sccwrp.org (714) 755-3202.
This page was last updated on: 7/23/2014