Concert of sound under water
DANIEL BATEMAN SINGING fish and insect orchestras have been recorded in a Far Northern river, in a world-first study documenting the biological sounds from a fresh water environment.
Griffith University researchers Dr Simon Linke and Emilia Decker led the acoustic research into river health monitoring, recording underwater sounds continuously over seven days in two waterholes in the Einasleigh River, in the state’s northwest.
The researchers identified more than 8000 sounds during the study.
It is the first time in the world that all biological sounds from fish and aquatic insects in an underwater location were identified.
Dr Simon Linke said the study demonstrated a new way to log ecosystem health autonomously 24/7.
“This is the first time that we have performed this work systematically,” he said.
“When we started doing this work 4-5 years ago, we would put a microphone in the water at general times and intervals but never got a conclusive result,” he said.
“What we have found is that, just like above water, sounds vary during the day.
“If you arrive somewhere at a certain time of day, you might miss what you’re interested in hearing, whether that’s fish or insects or change in waterflow.
“By recording 24/7 you get an encompassing overview of life underwater.”
Ms Decker said they found fish were active throughout the day, but most detectable during the morning.
“This is just like daily rhythms above water, with bird morning choruses and evening cicadas,” she said. “So it’s basically a fish chorus for breakfast, creekflow for lunch, and an insect orchestra for dinner.”
It was conducted on the land of the Ewamian Aboriginal Corporation.