Small fish make good reservoir water guards

Bluegills used as early warning sensors for NYC reservoirs

By FRITZ MAYER

NEW YORK STATE — If a terrorist manages to poison the reservoirs or a chemical spill threatens water quality, chances are officials will first learn about it from a bluegill fish. Bluegill fish emit tiny electrical impulses, much the same as the electrical impulses produced by a human heart, and those impulses are being measured, read and used to detect dangers in the water supply.

The New York City Department of Environmental Preservation (DEP) has been using bluegills to monitor water quality in the reservoirs for about four years. DEP spokesman Ian Michaels said the agency was not really looking to publicize the program, but Intelligent Automation Corp (AIC), the company that developed the fish sensor technology in conjunction with the U.S. Army, has issued a press release about their work, and now it is public knowledge.

Bill Lawler, a spokesperson for AIC, explained the way the system works. A bluegill is kept in an aquarium tank. Water from the reservoir is piped through the aquarium at a constant rate, and electrical sensors on the tank measure the fish’s electrical output. The fish, said Lawler, are extremely sensitive to the slightest changes in the water.

Lawler said a bluegill alerted officials to a spill of diesel fuel two hours before they learned of it through any other means. Just a few drops of any contaminant in the reservoir sparks a major reaction in the fish.

Lawler said each fish is kept in the aquarium for about two weeks. They could be kept in the tank for much longer, because after a good feeding bluegills can live up to eight weeks without more. But, said Lawler, the whole idea is “to keep the fish happy.” The electrical impulses emitted by bluegill remain constant when they are happy, but change when the fish are upset. For instance, said Lawler, early on the fish were setting off alarms in the middle of the night. It turned out that maintenance workers were checking in on the fish, and the fish became upset. The practice was stopped.

Because of security concerns, Lawler and the DEP won’t divulge the location of the tank, but everyone is pleased enough with the results that the DEP has plans to purchase four more bluegill set-ups at a cost of about $250,000.

Lawler pointed out that the fish are unique because, while there are sensors that can detect a single contaminant, there are no other sensors that can detect the wide range of contaminants that the bluegill can.

Michaels of the DEC said the fish represent “another layer” of security for the water supply for New York City. He said the agency conducts hundreds of tests daily on the reservoir water and the 6,000 miles of water mains in the city.

The system is also being used to protect the municipal water supply in San Francisco. A press release from IAC, which is now marketing the system, reads: “The IAC 1090 intelligent Aquatic BioMonitoring System (iABS), is an automated, intelligent system that uses fish (bluegills) as biosensors to continuously monitor the water supply and rapidly identify toxic conditions caused by a wide range of chemicals or chemical mixtures. The IAC 1090 monitors fish behavior and water quality parameters to determine toxic conditions.”