Scientists are investigating whether cod in British waters have regional accents that could interfere with their mating as they move further north due to rising sea temperatures.
Lead researcher Professor Steve Simpson said there is already a precedent for this, with recordings of American cod very different to those from their European cousins.
"This species is highly vocal with traditional breeding grounds established over hundreds or thousands of years, so the potential for regionalism is there," he added.
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"Seawater is hundreds of times denser than air, so sounds travel much faster and further."
Cod make sounds with their swim bladders to attract mates and could struggle to integrate, share territory and breed if they do not understand each other as they migrate north from Cornwall to Liverpool in search of cooler waters, scientists warn.
"If we value our fish stocks - or our Friday night fish supper - we need to understand this," Simpson said.
The fish are also threatened by noise pollution, which interferes with their ability to communicate. Efforts are being made to make fishing boats quieter and more environmentally friendly and for fishermen to avoid key breeding grounds during mating season.
Cod aren't the only fish to use sound to attract potential mates, according to Sky News. "Clownfish in colonies make a popping sound to show dominance and purr to show submission, while the male midshipman hums to attract female companions," it says.