To Attract Fish, Bring the Noise
Silence is not golden for many young fish: They prefer to call noisy reefs home.
Between shrimp clacking their claws, the grinding of teeth and other fishy sounds, reefs can be noisy places, and juvenile fish returning from the open ocean gravitate to the din, according to a study published in Friday’s issue of the journal Science.
After hatching on a reef, many fish drift out to sea, where they mature. Once they become strong swimmers, they return to reefs to live and breed.
A team of researchers led by Stephen D. Simpson of Edinburgh University in Scotland wanted to know how the fish find their way back.
Knowing that sound can travel for miles in water, they experimented to see if it attracted returning fish.
The researchers built 24 artificial reefs off the coast of Australia, leaving some silent and planting speakers in others to broadcast reef noise.
In the first test, reefs with sound collected 325 fish, compared with 108 in silent reefs. A second experiment had high-frequency noise, low-frequency noise and silent reefs. Reefs with high-frequency sounds attracted 1,118 fish, the low-frequency reefs 1,171 and the silent reefs 657.
The researchers say their finding raises the possibility there may be damaging effects from human-caused noise, such as that from shipping and drilling. In addition, however, the discovery may show fishery managers a new way to attract fish to restock depleted areas.
The research was funded by the British Ecological Society, Fisheries Society of the British Isles, Marsden Fund of New Zealand and Australian Institute of Marine Science.