Food and sex: this is what fish are chatting about, say scientists

It turns out that fish love to chat.

A team led by Cornell University in the United States found that fish use sound to communicate to a much greater extent than had previously been realised. They also found evidence that some fish have been chatting for a very long time - 155 million years to be precise.

The team studied sounds produced by 34,000 fish species, and lead study author Aaron Rice told The Guardian that the sounds were best described as “boops”, “honks” and “hoots”.

The study revealed that sound was “a major mode of communication among fish,” Rice told the British newspaper, adding that the topics the fish were chatting about were mainly food and sex. “We see more elaborate sounds being produced in reproductive contexts,” he added.

Some fish make sounds by vibrating their swim bladders, while others rub their bones together to make noise, the researchers say, while the habit of chatting using swim bladder vibration can be traced back to early sturgeon 155 million years ago.

Today’s fish use sounds to warn others about predators, indicate the presence of food, keep the shoal together and identify individuals. The researchers also say that evolution has favoured fish with the ability to communicate with sound.

Rice told The Guardian it was vital to reduce ocean noise pollution. “If you have literally millions of individual fish that are relying on communication sounds for the success of their populations, perturbing their acoustic environment may have real consequences,” he said.

Previous research found fish have “regional accents” depending on where in the ocean they live. A team from the UK’s Exeter University found American codfish make a “bop bop bop sound” while their European cousins use a “deep, rumbling growling”.

Publication of the Cornell-led research coincides with a call from the Co-Chair of Friends of Ocean Action, UN Ocean Ambassador Peter Thomson, to make 2022 the year we halt the decline in the health of the world's ocean.

“Simply put, there can be no healthy planet without a healthy ocean, and the ocean’s health is measurably in decline. Therefore, we must not squander the confluence of game-changing opportunities for ocean health that 2022 presents,” he said.

Six major conferences on the state of the seas are planned in 2022, including the UN Oceans Conference in Lisbon, Portugal which opens at the end of June.

2022 is also the International Year of Artisanal Fisheries and Aquaculture. “This year holds key opportunities for advancing ocean action, from securing a deal to end plastic pollution and eliminating harmful fisheries subsidies to prioritizing the ocean’s role in tackling climate change and in providing healthy, sustainable, equitable, affordable food for a growing population,” said Gemma Parkes, Communications Lead for Friends of Ocean Action at the World Economic Forum.