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 electrodes. Fish cough by flexing their gills to get rid of unwanted particles, like grains of sand, from their breathing passages. If the fish shows signs of distress in response to something in the water by coughing or increased activity, the system automatically trips an alarm, takes samples, and summons authorities by email and pager so that they can investigate whether there is a threat to humans. The cost of the system is between $45,000 and $110,000.
ABOUT BLUEGILLS: The bluegill is a freshwater fish native to much of North America, from Quebec to northern Mexico, and is the state fish of Illinois. Its name comes from the bright blue-colored edging along its gills. Bluegills are popular game fish, chiefly caught at dawn and dusk. They subsist on small invertebrates and very small fish. The bluegill is able to elude predators by hiding in submerged tree stumps and to survive for weeks without food. Bluegills are also extremely sensitive to minute changes in the source water quality, and they are also quite sedentary, making them ideal candidates for the IAC 1090 system.
The American Water Works Association contributed to the information contained in the TV portion of this report.