Oregon State University scientist Joe Haxel recorded hours of underwater sound, tracking whales and boat noise.
“We brought the data back and started looking through it, and we found an area where there wasn’t a lot of boat traffic and we knew there wasn’t a lot of weather, we had this really loud signal happening,” he said.
Haxel heard a sound that can be described as similar to rain falling on Pop Rocks. There’s a popping static created by thousands of shrimp claws pushing out jets of water at extremely high speed. The speed and disturbance create a tiny bubble that immediately collapses, creating a noise so loud and strong it can to stun prey a few inches away.
Haxel says he noticed the rocky areas where the shrimp live are also home to swarms of tiny zooplankton that whales love. And that left him wondering if Northwest whales could be using the shrimp as a tool.
“We’re starting to explore the idea that maybe the snapping shrimp could provide an acoustic cue for the gray whales as they’re foraging. That this may be an area of more prey.”
Whales rely heavily on sound to communicate, navigate and find prey.
Haxel says more underwater recording this summer could help determine if whales are using shrimp sounds to seek out food.
It would add a layer to an already complex picture of how whales are using sound in the water – and the potential consequences when those natural sounds they rely on are drowned out by human-created noise. As it is, Haxel says the sound of passing boats is one of the only things loud enough to drown out the snapping of the shrimp.
The discovery of the shrimp off Oregon’s coast was presented this week at the Ocean Sciences meeting in Portland.