Dr. O'Keefe Gets Yet Another Environmental Assessment Contract.
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Dr. O'Keefe
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Different Types of Macroinvertebrates
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Dr. Sean O’Keefe, Associate Professor of Biology, has been awarded a
contract for $5,458 from Technical Water Laboratories, Inc. to conduct environmental
analyses of several streams in Tennessee.
The title of the award, “Assessment of Macroinvertebrate Biological
Integrity of Tackett Creek, Valley Creek, and Bennetts Fork, Claiborne County,
TN” indicates the nature of the grant. The
following excerpt (from the U.S. Environmental Protection Agency web site
explains the reasons why these studies are so important..
“In wadable streams (streams that can be easily walked across, with water no
deeper than about thigh-high), the three most common biological organisms
studied are fish, algae, and macroinvertebrates.
Macroinvertebrates
are organisms that are large (macro) enough to be seen with the naked eye and
lack a backbone (invertebrate). They inhabit all types of running waters, from
fast-flowing mountain streams to slowmoving muddy rivers. Examples of aquatic macroinvertebrates
include insects in their larval or nymph form, crayfish, clams, snails, and
worms. Most live part or most of their life cycle attached to submerged rocks,
logs, and vegetation.
Aquatic macroinvertebrates are good indicators of stream
quality because:
- They
are affected by the physical, chemical, and biological conditions of the
stream.
- They
can't escape pollution and show the effects of short- and long term
pollution events.
- They
may show the cumulative impacts of pollution.
- They
may show the impacts from habitat loss not detected by traditional water
quality assessments.
- They
are a critical part of the stream's food web.
- Some
are very intolerant of pollution.
- They
are relatively easy to sample and identify.
The basic principle behind the study
of macroinvertebrates is that some are more sensitive to pollution than others.
Therefore, if a stream site is inhabited by organisms that can tolerate
pollution and the more pollution-sensitive organisms are missing a pollution
problem is likely.
For example, stonefly nymphs aquatic insects that are very
sensitive to most pollutants cannot survive if a stream's dissolved oxygen
falls below a certain level. If a biosurvey shows that no stoneflies are
present in a stream that used to support them, a hypothesis might be that
dissolved oxygen has fallen to a point that keeps stoneflies from reproducing
or has killed them outright.”
Congratulations Dr. O’Keefe!!
