Fish measures water cleaning

1996/09/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Ingurumena

The Apteronotus albifron of fresh water from South America emits electric pulses to analyze its environment. When water is clean, the pulse rate is approximately 1 kilohercilla (1000 pulses per second). However, when water is of poor quality, it changes the frequency of electric pulses.

The French city of Nancy has taken advantage of this fish feature to measure the contamination of drinking water. For this purpose they have prepared an apparatus called Gymnotox. It is a container basically full of water and inside it has a glass tube. The fish is usually in the stone holes, so it goes inside the glass tube and remains practically immobile.

At the ends of the tube there is an electrode that sends the electrical pulses received to the computer, which constantly analyzes its rhythm and shape. In case the water presents some type of pollution, even if it is very small, it is detected immediately.