The Design of a Continuous Flow Biological Early
Warning System for Industrial Use
JOHN CAIRNS, JR., Research Professor and Director
RICHARD E. SPARKS, Research Associate
and
WILLIAM T. WALLER, Research Assistant
Department of Biology
and
Center for Environmental Studies
Virginia Polytechnic Institute and State University
Blacksburg, Virginia
INTRODUCTION
Management of aquatic ecosystems requires a clear understanding of the goals to be
achieved, the types of environmental information that are necessary, and development of
means to achieve the goals. As stated in the Water Quality Act of 1965, the national
management goal for most of our aquatic ecosystems is multiple use: use for public water
supplies, propagation of fish and wildlife, recreational purposes, and agricultural,
industrial, and other legitimate uses. Multiple use should not impair options for future
alternative uses, and quality control surveillance should be adequate to insure maintenance
of, or improvement to, desirable conditions. Precise control depends upon frequent or
continual feedback of information. Control measures applied to aquatic ecosystems, in the
absence of continuing information on the condition of the system, are apt to be
inappropriate and thus may overprotect the receiving system at times and underprotect it at
other times since the ability of ecosystems to receive wastes is not constant. The precision
and efficiency of environmental quality control and the lag time in the information
feedback loop are related. If the lag time is too great, the control measures may repeatedly
overshoot and undershoot the desired goal, as a thermostat with too slow a response will
cause first underheating, then overheating of a house.
Most commonly used techniques for measuring the responses of aquatic organisms and
communities require days or weeks. These techniques are useful in before-and-after studies
(before and after construction of an impoundment, a power plant, or an industry) or after
an environmental disaster (following an oil spill, a fish kill, etc.) to document the extent of
damage. In order to institute meaningful quality control of aquatic ecosystems and prevent
crises, however, we must have the means of assessing the condition and responses of aquatic
organisms and communities in hours or minutes, rather than in days or weeks.
These are two principal sources of delay in obtaining biological information: one
inherent in biological processes and one inherent in the technological means of gathering
and analyzing data. The response being assessed may not be elicited very rapidly because
of delayed uptake or because other preliminary events must occur. One can reduce lag
time by choosing a response that is more sensitive than the death response traditionally
used in the routine bioassay. If the response is also amenable to automated data collecting and analysis, then the technological delay can be reduced at the same time.
A biological monitoring system has been developed in our laboratory with the goal of
reducing biological response time and automating data collection and analysis as much as
possible. The system measures changes in the movement and breathing of fish in order to
provide an early warning of developing toxicity in the wastes of an industrial plant.
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