Whales under pump
Fears noise may add to net threat
HUMPBACK whales may be bamboozled by underwater noise from a 111m sand-pumping barge, putting them at greater risk of becoming tangled in Gold Coast shark nets, according to a marine biologist.
James Cook University research fellow Geoff McPherson said noise from sand pumped on to beaches as part of a replenishment project is cancelling out sound from electronic warning “pingers” on the shark nets for whales and dolphins.
He said a baby whale killed in nets off Kurrawa Beach at the weekend as a barge worked nearby was an example of this.
“The whales could have no idea what’s going on and are running into the nets,” said Mr McPherson, an underwater acoustics specialist who worked with Fisheries Queensland for almost 40 years.
“We know noise from the sand-pumping jetty at The Spit can be heard up to 10km away, so when the barge is working (the sound) would be obliterating everything including warnings from the nets,” Mr McPherson said.
“It could have an impact of various species of marine life.”
The “pingers” were introduced off Queensland beaches in the 1990s to prevent whales from becoming entangled during their annual migration north to warmer water in winter months.
However, Humpbacks for High-Rises co-founder Dr Jan-Olaf Meynecke said studies had debunked the effectiveness of “pingers”, and called for the removal of nets from Gold Coast beaches.
He is petitioning Queensland Fisheries Minister Bill Byrne to remove nets prone to entanglements and has attracted more than 5500 supporters online.
“Studies have found pingers have no effect,” Dr Meynecke said. “We’re standing strong on removing some problem nets.
“Obviously, when the entanglement occurred 3km from the sand-pumping barge it gives us a bad feeling.”
But he said no one knew what effect the sand-pumping barge had on whales.
“We don’t know what effect the sound from sediment blast hitting the water has.”
A spokesman from Minister Byrne’s office said shark nets would not be removed because swimmers visit Gold Coast beaches at all times of the year.
“Shark nets can effect other marine life, but it’s about getting the balance right – which is why we use other measures to reduce entanglements of non-target species,” he said.
THE WHALES COULD HAVE NO IDEA WHAT’S GOING ON AND ARE RUNNING INTO THE NETS GEOFF MCPHERSON