A familiar racket helps fish find a suitable home

Noisy neighbours can be desirable – at least if you're a young reef fish trying to choose a home. New research from the Universities of Auckland and Bristol found that juvenile fish listen to the sounds made by local residents – such as other fish, shrimps and lobsters – before heading for the reef that suits them best.

Working on the Great Barrier Reef, an international team of marine biologists played recordings from different types of habitats next to artificial reefs, and discovered that juvenile fish arrived preferentially at reefs supplemented with noises from their naturally favoured habitat.

This shows that fish can use acoustic cues to distinguish between different communities and employ this information to select a suitable home.

The shallow waters around coral reefs are very loud: the combination of clicks, pops, chirps and scrapes produced by resident fish, snapping shrimp, lobsters and urchins can be detected with the aid of underwater microphones (hydrophones) many kilometres away.

This biological symphony varies depending on which animals make up the local community and, as a result, signature sounds give a strong indication of the type of habitat.

For each night of a new moon phase during the Australian summer, the team working at Lizard Island Research Station moored underwater sound systems next to artificial reefs they had built on sand flats, then early the following morning, scuba divers collected the juvenile fish which had arrived over night.