In the Great Barrier Reef, Australia, a pair of Regal Angelfish (Pygoplites diacanthus), two Coral Rabbitfish (Siganus corallinus), and a Dot & Dash Butterflyfish (Chaetodon pelewensis) glide through the waters. The key to restoring the reef's health may lie in making it seem like a lively, welcoming place, as if the lights are on and the creatures are home. Jeff Hunter/Getty ImagesCoral reefs have suffered greatly over the last century. These fragile, intricate, and essential ecosystems have been deeply affected by pollution, ocean acidification, and the rising temperatures of our seas due to global climate change, resulting in weakened and diseased corals. Healthy coral reefs rely on a diverse range of fish species to survive, and in turn, fish need the reefs to thrive. Biodiversity is crucial for a reef's well-being, with various species playing specific roles — from eating algae and plankton to cleaning the reef. If key species leave due to deteriorating corals, others will follow, leading to a mass exodus that results in a reef's collapse.
However, a study published on Nov. 29, 2019, in the journal Nature Communications offers hope for coral reefs. It suggests that the answer to the large-scale departure of fish species may lie in playing the sounds of a healthy reef, enticing the fish to return.
"Healthy coral reefs are teeming with sounds – the crackle of snapping shrimp and the calls and grunts of fish combine to create a vibrant biological soundtrack," explained Steve Simpson, senior author and professor of Marine Biology & Global Change at the University of Exeter's Department of Biosciences, in a press release. "Juvenile fish are drawn to these sounds when searching for a new place to settle."
A loudspeaker placed on a coral reef to replicate the sounds of a healthy ecosystem and attract new marine life.
Tim Gordon, University of ExeterThe research team carried out their sound experiments on recently devastated areas of Australia's Great Barrier Reef. They broadcast recordings of a flourishing reef through loudspeakers in the rubble of a once-thriving reef habitat and discovered that twice as many fish were attracted to these degraded reefs as to similar environments where no sound was played. These fish stayed for the entire 40-day study, even after realizing the reef wasn't as lively as the sounds suggested.
Never underestimate the influence of a skilled DJ.
While attracting fish to the reef won't immediately revive it or resolve the root causes of the damage, enhancing the reef's soundscape could serve as an effective tool in revitalizing degraded reefs.
"Acoustic enrichment offers great potential as a local management strategy," said co-author Andy Radford, professor of behavioral ecology at the University of Bristol's School of Biological Sciences, in a press release. "When paired with habitat restoration and other conservation efforts, rebuilding fish populations in this way could accelerate ecosystem recovery. However, it remains crucial to address other significant threats such as climate change, overfishing, and water pollution to protect these delicate ecosystems."
A "barrier reef" like the one off the eastern coast of Australia gets its name because it acts as a barrier, shielding the shallow waters near the shore from the open sea, and offering a safe, calm environment for various organisms to thrive.
