An Associated Press report explains: “The fish are kept in tanks constantly replenished with water from the municipal supply, and sensors work around the clock to register changes in the breathing, heartbeat and swimming patterns of the bluegills that occur in the presence of toxins. ”
Кога во водата има отровни материи, кај рибите доаѓа до промени во дишењето, во чукањето на срцето и во пливањето.