Alarms warn dolphins of nets
NEW acoustic alarms are being trialled at Rainbow Beach to help reduce the number of dolphins caught in shark control equipment.
The alarms, known as pingers, have been attached to two of the three nets at Rainbow Beach and six of the 11 shark nets on the Gold Coast.
Last year two dolphins were caught in the nets at Rainbow Beach.
Both were released alive.
Shark control program manager Jeff Krause, from the Queensland Boating and Fisheries Patrol, said no dolphins had been caught in the nets since the new pingers were established in April this year.
"As with any trial of this nature the pingers will be in place for some time so we can properly determine their effectiveness, but these early results are promising," Mr Krause said.
"In the past we've had some success with other types of pingers in reducing the number of dolphin entanglements, but we're hoping these new pingers will be even more successful.
"If these pingers are as effective as we hope they will be, we'll then look at installing them at other beaches with shark nets in place along the Queensland coast."
The alarms are developed by Fumunda Marine, a Sunshine Coast-based specialist marine mammal acoustic pinger manufacturer.
Fumunda Marine director James Turner said earlier pingers were designed to target harbour porpoises, prevalent in the northern hemisphere.
"These new pingers work differently to the porpoise pingers and are designed specifically to alert dolphins to the presence of the shark nets.
"The earlier porpoise pingers do work on some dolphin species but these new pingers are more powerful and deliver a louder signal, as dolphin species are larger and more robust than porpoises.
"The pingers operate at 70 kHz, which sits right in the best known middle hearing range of bottlenose and common dolphins, both of which are found in Queensland.
"This frequency is far higher than the 10 kHz used in the earlier porpoise pingers."
Mr Krause said while the main priority of the shark control program was to improve safety for beachgoers, a range of measures were in place to reduce the number of marine animal entanglements.
"Whale pingers have been used on shark control nets since 1993 and since then research and development has continued and a new type of whale pinger was most recently introduced in 2010," he Ssaid.
"Given we're expecting to see up to 16,000 whales migrating along the coast this season, it's important we continue to take preventative measures to help them avoid entanglements. A volunteer whale observer program is in place on the Gold Coast and Sunshine Coast, whereby people living in high-rise buildings are trained to identify whale entanglements in shark control gear if they occur."