The world is becoming too bright for bats. Baby oysters, too, are finding that sounds from us humans are causing them stress and is preventing them from moving away from “home” to settle into new environments, finds a new study. Noise pollution in seas may also be responsible in part to the proliferation of the oyster parasite multinucleate sphere X, or MSX, rendering oysters weak.
According to scientists at the University of Adelaide, oysters need specific sound cues to migrate and move around. Though they don’t swim, baby oysters do need to find the right habitat and ecosystem for them to live inside:
“The ocean’s natural sound is gradually hushing due to habitat loss, leading to a quieter natural environment increasingly drowned out by the crescendo of man-made noise pollution,” explained lead author Brittany Williams.
“Numerous marine larvae rely on natural sounds to navigate and select their dwellings, so this interference poses a problem for conservationists aiming to attract oysters to restored reefs using natural sounds.”
We know that shipping noises after whales and dolphins but marine noise pollution affects the less known creatures, some which are keystone species: “Noises from shipping, machinery and construction, for example, are pervasive and pose serious environmental change that affects both terrestrial and marine animals,” says Williams.
According to the research, published in Proceedings of the Royal Society B, marine organisms appear particularly vulnerable to the intensification of human-made or anthropogenic noise because they use sound for a range of activities, including to sense their surroundings, navigate, communicate, avoid predators, and find mates and food.
The teams have used a special kind of habitat “speaker” to help the oysters: But, “Our previous work demonstrated that novel acoustic technology can bolster oyster recruitment in habitat restoration projects, but this new research indicates potential limitations of this speaker technology,” said Dominic McAfee, who was part of the research team.
In environments where there is a lot of human noise pollution, the speakers did not increase larval recruitment.
Scientists all over the world have been playing specific seascape sounds using a loudspeaker to attract baby oysters. In the big scheme of things if the oysters are being attracted to harvesting islands where they are culled we can assume that natural selection will eventually wipe out the oysters who come for the call.
Oyster reef restorations are taking place in countries like America. This image shows surviving oyster reefs in Virginia. Aileen Devlin/Flickr, CC BY
“This suggests that noise pollution might cloak the intrinsic sounds of the ocean, potentially exerting profound ramifications on marine ecosystem vitality and resilience,” said co-author Professor Sean Connell, from the University of Adelaide and the Environment Institute.
While acoustic enrichment may be less effective along noisy metropolitan coastlines and urbanised waterways, the researchers are still optimistic about the application of the technique in less trafficked areas.
Another option: stop eating too much shellfish, and let the ocean dwellers take their own course.
