BACKGROUND: Bluegill fish are keeping vigil over the Washington
region's water supplies, and might be able to save millions of
lives in the event of a terrorist attack. They are a key
component of a new early-warning water-monitoring device that
electronically analyzes the behavior of eight captive bluegills
to detect the presence of chemical toxins or other contaminants.
The system, called IAC 1090 Intelligent Aquatic Biomonitoring
System, is also being used in New York City and San Francisco.
HOW IT WORKS: The biomonitoring system resembles a luggage trunk
outfitted with cables and tubes, and hooked up to a monitor.
Eight juvenile bluegills swim in a row of solitary compartments,
submerged in piped-in water and separated from the others by a
pane of frosted glass. Electrodes attached to each compartment
convey data about the fish's movements and breathing patterns to
a computer. When the fish use muscles to breathe, the action
sends a low-level electrical pulse through the water that can be
detected by the