In a new study, Jean-Charles Massabuau from University of Bordeaux and his colleagues investigated the impact of noise on 32 oysters in the laboratory, using a loudspeaker to play sounds underwater in a range of frequencies. The researchers found that oysters rapidly closed their shells at sound frequencies between 10 and 1000 hertz. Their maximum sensitivity was at low frequencies (between 10 and to 200 hertz).
The sounds and vibrations from breaking waves and currents are in the oysters’ sensitivity range, and the researchers propose that oysters may “hear” tidal cues that trigger appropriate behavior as the tide rises. In addition, most marine noise pollution is due to cargo boats, and most of the noise from shipping is at low frequencies that oysters “hear” best. Other sources of marine noise pollution also generatelow-frequency sounds, including explosions, seismic research, pile driving and wind turbines. All of these noises can thus muddle the normal oyster soundscape, and cause them to close their shells in response.
Research Article:
Charifi M, Sow M, Ciret P, Benomar S, Massabuau J-C (2017) The sense of hearing in the Pacific oyster, Magallana gigas. PLoS ONE 12(10): e0185353. https://doi.org/10.1371/journal.pone.0185353
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0185353
