Flipper the Aquatic Lassie
Written by: Tony Harris, December 2, 2015
According to studies released in 2003 by American and Scottish Biologist over 300,000 whales, dolphins and porpoises were killed unintentionally in fishermen’s hauls in 2002. This is just a statistic and statistics are just numbers, unless of course they are about someone you knew. What if it was about Flipper!
So called ‘drift out nets’ used in the Baltic seas have long been banned in other waters due to the danger to marine life. So how can we catch fish economically and yet preserve marine life. Ultrasound provides a solution, in what is called a ‘pinger’.
There are different types of pinger but we are interested in the ADD or Acoustic Deterrent Device. An ADD is a device with a low intensity that emits signal of about 10 KHz with higher harmonic frequencies. Pingers use ultrasound to keep the dolphins away from the fishing nets.
Before it introduced its own pinger program in 2000, Denmark estimated up to 6,000 porpoises were caught annually in its waters alone. The use of pingers continues to reduce the number of porpoises caught in nets up to 4 km, and compliance in pinger use has improved. Of course pingers introduce noise into the marine environment, and so are not without potential impacts themselves, but perhaps they are the lesser of two evils.
E&I supplies amplifiers to companies that manufacture pingers. The usefulness of ultrasound appears boundless. And we like to think that we can help keep Flipper out of the statistics.
For more info see here: