Shrimp make more noise due to rising temperatures

Aug. 19 () –

In a warming ocean, snapping shrimp could be like the canary that warned that something was wrong in the old coal mines.

Research published by scientists at the Woods Hole Oceanographic Institution (WHOI) in Frontiers in Marine Science confirmed their earlier observations that rising temperatures increase the sound of snapping shrimp, a small crustacean found in temperate and tropical coastal marine environments around the world.

In the first study of its kind, WHOI marine ecologists Ashlee Lillis and T. Aran Mooney established a clear relationship between rising temperatures and the frequency and volume of sound emitted by two species of snapping shrimp, with implications for underwater navigation and communication for both humans and animals.

The continuous clicking sounds produced by the shrimp, reminiscent of the sound of sizzling bacon, are so loud and cover such a wide acoustic range that they interfere with boat sonar and fish finders. Research shows that whales and dolphins may rely on the sound of shrimp to orient themselves along the shoreline, and diverse soundscapes help attract fish, shellfish, and coral larvae to appropriate settlement sites.

“These shrimp are the most ubiquitous sound producers in the ocean, and we now have evidence that temperature has a huge impact on their behavior and the soundscape in general,” said Lillis, WHOI visiting scholar and Sound Ocean principal scientist. Science. “That’s relevant to everything from migrating whales to larvae trying to use the soundscape, or the humans who use the sea for extractive or military purposes”.

Lillis analyzed recordings of snapping shrimp from an oyster reef off the coast of North Carolina and found an increase of 1 to 2 decibels, as well as a 15 to 60 percent increase in click frequency, for each degree Celsius of increase. temperature increase. Testing in a controlled laboratory environment, Lillis found that the frequency of the clicks doubled with water temperatures between 68F (20C) and 86F (30C), with some differences depending on the season or the social group of the shrimp.

The experiments simulated the effects of a short-term heat wave, so it’s not yet clear whether the shrimp will eventually adapt or how the increased snapping might affect their physiology or the ecosystem over time. While temperature has long been understood to influence crustacean behavior, the effects of warming water on the broader sea soundscape are a crucial — and often overlooked — offshoot of climate change, says Mooney.

“Climate change is affecting the marine soundscape in fundamental ways,” Mooney said. it’s a statement. “Warming waters may influence how animals can physically communicate and use sound to reproduce and attract mates. We don’t yet know what happens to the ecosystem when background noise levels are higher, but there are implications.” powerful.”