University of Bristol: Underwater Sounds of Ponds

PHYS.ORG:

Old Sneed Park; credit: Dr Jack Greenhalgh

“Ponds are packed full of bizarre and mysterious sounds made by scratching aquatic insects, booming fish, and popping plants. It’s like an underwater disco,” explained lead author Dr. Jack Greenhalgh from Bristol’s School of Biological Sciences.

To better understand these mysterious soundscapes, the team collected 840 hours of underwater sound recordings from five ponds in the southwest of England using an underwater microphone (a hydrophone). In findings published in the journal Freshwater Biology, analysis of the audio files revealed clear daily acoustic activity cycles in each pond.

Typically, a nocturnal chorus is made by aquatic insects that compete to attract mates by producing strange scratching sounds as they rub their genitals against their abdomens. During the daytime, however, aquatic plants dominate the underwater orchestra with rhythmic whining and ticking sounds produced as tiny oxygen bubbles are released by plants respiring in the hot sun.