Fish swimming off the British coastline have been found not only to speak to each other, but to do so in many regional accents, according to scientists.
Research shows communication between cod is vital to their survival and is used to attract mates, warn others of danger and establish territories.
Now scientists are investigating whether fish in British waters have regional accents, having already discovered distinct differences between European cod and their American cousins.
Professor Steve Simpson, of the University of Exeter, believes the research is essential to the future of fish stocks, which are already under stress due to marine traffic and warming waters.
“We are interested in cod, partly because they are an iconic European species; partly because they have elaborate mechanisms of making sounds through vibrating their swim bladder, and partly because they have a wide vocal repertoire with opportunity to diversify their song,” Simpson told Wired magazine.
“The American sounds are deeper, short thumping sounds, while the European ones are higher in frequency and the growls are more prolonged. This suggests that regional dialects may exist, such as are seen in birds and mammals – including humans!”
Simpson predicts that as climate change drives cold-water species north, fish with different ‘accents’ could be forced together, where they may struggle to integrate, share territory and breed.
Increasing noise from marine traffic is also cause for concern, as the sound of motorboats threatens to drown out fish ‘chat’.
“This is now a dominant component of many marine soundscapes, and much of the work of my group and I looks at how human noise is drowning out natural sounds, and even causing stress and behavioral changes in fish,” he told Wired.
“Seawater is hundreds of times denser than air, so sounds travel much faster and further.
“We have found that fish on coral reefs are susceptible to noise pollution but we are yet to study the effects in our own waters, which are some of the busiest in the world,” he added.
New research vessels such as the RRS Sir David Attenborough – which narrowly avoided being christened ‘Boaty McBoatface’ – are designed to be quiet so as not to disturb fish.
Simpson is discussing his research on Wednesday at the Natural Environment Research Council’s ‘Into the Blue’ event in Liverpool, England.