The race to understand how kelp forests dampen ocean noise — before it’s too late
- Media Manager
- Mar 23, 2023
- 2 min read
The Narwhal
Written By: Ainslie Cruickshank
Published: March 24th, 2023
The sea is calm and, for the moment, relatively quiet. But marine ecologist Kieran Cox is about to change that. He hits play and suddenly the deep hum of a large ship surging through ocean swells emanates from a waterproof speaker. Sound waves ripple toward a lush underwater forest off the west coast of Vancouver Island.
Cox, a postdoctoral fellow at Simon Fraser University, has a theory that kelp forests may offer sea creatures a quiet refuge from a growing barrage of ocean noise. As they disappear, destroyed by hungry urchins and thinned out by warming seas, he and other scientists are racing to understand what could soon be lost. “We’re losing kelp forests at a pretty alarming rate in some places,” Cox said.
It’s early September and nearing the end of Cox’s field season in Barkley Sound. Today is a demonstration of the noise experiments he’s been running all summer, usually with underwater recorders to measure any shifts in volume as the sound travels through the stand of giant algae. Suddenly, a seal pops its head above water, and Cox, wanting to protect it from the noise, halts the experiment. “Oh no, let’s pull that up,” he says, and the speaker is lifted from the water.
Seals, like whales and other mammals, are particularly sensitive to sound, but all kinds of sea creatures hear. They rely on sound to find mates or alert them to danger. But a cacophony of human made noise is drowning out the sounds of nature — and it’s only getting louder.
If Cox’s hypothesis proves true, it could further underscore the need to protect and restore an ecosystem that serves as a nursery for herring and other forage fish. Herring are food for salmon, which are in turn eaten by endangered southern resident killer whales. The research is timely for another reason too. Canada is currently developing a strategy to reduce the harm from ocean noise. Maybe kelp could be part of the solution.
