A healthy coral reef is a noisy place, with a cacophony of chatters, chirps, and clicks to match its rich visual displays. These sounds help young fish to identify appropriate habitat.
But a new study published this week in Proceedings of the National Academy of Sciences shows that damaged coral reefs have quieted down over recent years, making them less attractive to fish, which could have serious consequences for marine ecosystems.
The study found that three years of coral bleaching and the ravages of powerful cyclones have rendered areas of the Northern Great Barrier Reef less "acoustically diverse" than before. "It's heartbreaking to hear," said lead author Tim Gordon, a marine biologist at the University of Exeter, in a press release. "The symphony of the sea is being silenced."
Fish help to keep reefs healthy by removing algae and helping coral grow, and degraded reefs with healthy fish populations bounce back more quickly than reefs with fewer fish. "A reef without fish," explained Harry Harding, a co-author on the study from the University of Bristol, "is a reef that's in trouble."
This latest research comes alongside some decidedly more optimistic news for the Great Barrier Reef: The Australian government announced this week it is investing $377 million ($500 million Australian) in the reef, which it called "the planet's greatest living wonder." Much of the funding will go toward implementing restoration work, limiting pollution, and managing starfish that decimate reefs.
Such efforts may seem like an uphill battle in the face of global warming. But, Gordon urged, "it's still possible to protect some of the reefs that are left."