I really dig all parts of the ocean guys (even the nightmare parts like these). But y’all probably don’t know that I’m a total nerd for baby fish. More accurately called larval fish, it’s a super important life stage for the majority of species because not only is it when they’re most vulnerable, but those little guys are quite the travelers. Most fish produce planktonic larvae, meaning they’re subject to the whims of ocean currents and as such can travel tens, hundreds, or even thousands of kilometers from where their parents live. This connects distant populations, is vital for otherwise sedentary species (like reef fish), and is an extremely active area of scientific research.
Eventually, larval fish will “settle” – leaving their planktonic life behind and coming to spend the rest of their lives at a specific coral reef, for example. Fish that are ready to settle need to find suitable habitat in order to survive this transition and one of the ways they locate such habitat is by following auditory cues. Thriving coral reefs are noisy places, and scientists in the UK and Australia utilized this fact to influence where larval reef fish chose to settle. By playing the sounds of a healthy reef from underwater speakers, they were able to get twice as many little fishes to show up and make a reef home compared to where they didn’t play any sounds. Crucially, it didn’t matter if the reef was thriving or seriously degraded.
Since healthy fish populations are crucial to healthy reefs, – for example, fish clear away algae to make way for corals to have their own settlement – the idea is that engineering one will help to naturally restore the other. The scientists make it clear that this is no solution on its own, but combined with other methods of reef restoration, it may help to speed up the overall recovery process. I know you’re already aware that so many of the planet’s reefs are dead or dying – and it’s only getting worse. Any way we can give them a leg up on recovery is a frickin’ R.A.D. leg.