Those tucking into a steaming bowl of moules mariniere on their summer holidays may be alarmed to hear that a shortage could be on horizon, as scientists have found that increasing noise could potentially cause a shortage.
A team of marine scientists from Napier University and Heriot Watt University, both in Edinburgh, have found that a decline in mussel banks in some areas of the UK could be because excessive noise causes stress for the bivalves.
The researchers collected mussels from the shore at Musselburgh, outside Edinburgh, and tested their response to noise in a lab at the St Abbs Marine Station near Eyemouth – a charity dedicated to marine science, conservation and education.
Scientists played the sound of a ship’s motor to a sample of blue mussels in a controlled setting, and measured biochemical and behavioural changes in the mussels.
The study found that mussels that had been exposed to noise consumed 12 per cent less oxygen than their counterparts in more peaceful waters, which ould lead to increased energy use and potentially slower growth.
Even though the creatures do not have ears, the study found they can detect changing sound levels in their environment.
Matt Wale, from Edinburgh Napier University, explained: “The filtration rate, or how much algae they consume, decreased by over 80% and there was a 60% increase in valve gape, which means the mussels are spending more time vulnerable to predators.”
Another member of the team, Mark Hartl from Heriot-Watt University, added: “Given the wide distribution of mussels in areas where they may be exposed to noise, the impact of noise does not appear to be fatal or immediately dangerous for mussels.
“However, this doesn’t mean it isn’t having a long-term effect on mussel populations in high noise areas, it could be affecting their growth, reproductivity and may help explain the decline of mussel banks in some areas of the UK.”
Karen Diele, from Edinburgh Napier University, the co-director of research at the marine station, said: “The blue mussel is an extremely important invertebrate in the UK: it is commercially valuable and it plays an essential ecological role as a reef builder and a filter-feeder that keeps the water clean.”
“For the first time in a marine species, we detected noise-induced changes in DNA integrity, indicating an underlying source of stress.”
The research was supported with funding from the Marine Alliance for Science and Technology for Scotland. The team is also looking at how Norway lobsters, squid and native oysters respond to underwater noise.