Dolphin Pingers work by emitting frequencies known to be audible to Whales, Dolphins and Porpoises. When Dolphin Pingers are placed on commercial fishing gear, Whales, Dolphins and Porpoises are alerted to the presence of the gear and entanglement can be avoided.
Scientific studies performed around the world over the past twenty years on different species and populations of Whales, Dolphins and Porpoises confirm that Pingers are highly effective in reducing incidental entanglement of these animals in fishing gear. The toothed Whales or Odontocetes (which includes Dolphin and Porpoise species) use an echo location system to help navigate their way in the oceans. By fitting Pingers to fishing gear, researchers believe that the Pings emitted stimulate Dolphins and Porpoise to echolocate, or send a signal to the Pingers and fishing gear, which is then returned to the cetaceans. The cetaceans are alerted to the gear the Pingers are attached to and entanglement is avoided. Porpoise Pinger was specifically designed to operate at 10 kHz which is the frequency with the longest track record of any signal for reducing Porpoise by-catch.
Dolphin Pingers & Porpoise Pingers incorporate a green LED inside the pinger. The LED allows fishermen to confirm if the Pinger is operating simply by observing if the Pingers are “blinking” This removes any uncertainty for fishermen and regulatory authorities who test if Pingers are operating. As we humans age, our hearing range decreases and for many people, hearing Pingers, is difficult. Added to that commercial fishing vessels can be very noisy, so the visual confirmation makes a lot of sense. We have used very small but powerful LED’s ensuring that the blinking light is visible even in broad daylight.
Future Oceans designed the LED to turn on for the first 15 cycles when the Pingers are immersed, and then they stop blinking and produce sonic pings only. Having Pingers blinking constantly in the water might be problematic as it may attract non target species to nets. When the Pingers are retrieved, the LED will immediately blink again for 15 cycles. If a fisherman wants to test Pingers when the nets are not in the water, it’s simply a matter of putting a Pinger in a container of salt water and if it blinks it is operating, if not, it’s time to change the batteries.
Whale Pingers incorporate a Red LED that when flashes indicates it is time to change the battery.
