(Scientific American) The team found that the sound waves produced by the sharks also caused the tiny, gelatinous algae that grow on the coral to grow and enlarge. When they released one of these larvae on the coral, the coral grew new, larger coral. [New study demonstrates benefits for coral reefs] (WLRN) “We don’t know whether the larvae can produce new colonies or whether a single adult is enough to control coral population dynamics,” study lead author Michael J. Reilley, a graduate student at the Scripps Institution of Oceanography at Monterey, said in a news release. “What is clear from our findings is, however, that the sound is an effective way of encouraging coral reproduction, which can reduce the effects of coral bleaching and sea-level rise.”
The technique is an “inert” control on the coral, using the sound wave as the trigger, to attract the algae that ultimately grow and create new corals.
The sound of the sharks’ clicks on the coral produced the desired effect, allowing the bacteria to consume more material - a change in the coral’s natural behavior that will ensure survival in future events like climate change.
The study also explains that corals have a complex ability to identify and avoid particular “favored” algae, thanks to a process called “acoustic cues,” which allows specific cells, or bacteria, to detect the specific tone that one of the shark’s clicks give off.
“Acoustically, the coral is making an individual call with its acoustically sensitive cells. If it has a sound alarm, then the plant has a sound alarm,” Reilley explained in the press release.
To be clear, these findings are only a glimpse into what the team may uncover in the future - the technology may get refined, and potentially even better, as scientists learn to control the sound of multiple tiny animals or in combination.
Scientists studying the sound of the sharks’ clicks on coral at the Royal Society
However, Reilley explained that some of the advantages of their idea could be realized on a microscopic scale this year. The team’s proposed method is capable of being implemented on, say, very small species of algae that can grow on every stage of a reef - at the base of the coral, on the surface, in the water - in just a few weeks, with little added effort.