NASA says climate change could decimate coral reefs by by 2050. And recent study in the journal Science Advances finds that clown fish in Papua New Guinea is shrinking in response to heat stress.
A MARTÍNEZ, HOST:
A few animal species have tried to adapt to man-made climate change by changing things such as their migration patterns and feeding habits. Recently, though, scientists found an animal that seems to be able to change its body to better survive. The clown fish – that’s right, that’s the fish featured in Disney’s “Finding Nemo” – is the latest animal to have been observed shrinking in response to heat stress.
MELISSA VERSTEEG: First time I started noting the shrinking, I thought, oh, (laughter) something really weird is happening.
STEVE INSKEEP, HOST:
Melissa Versteeg is a Ph.D. student, a marine scientists at Newcastle University and coauthor of a paper recently published in the journal Science Advances.
VERSTEEG: I had a bit of a panic. It’s usually assumed that growth is relatively one way, so it’s favorable to be a bit bigger. And we’ve not really seen before that they actually have this capacity or ability to shrink.
INSKEEP: She was interested in clown fish because they are coral reef fish, and coral reefs are under threat from warming oceans. Versteeg’s team studied clown fish along reefs in Papua New Guinea for five months during a heat wave, when temperatures rose around 7 degrees Fahrenheit. They found that some clown fish, which are only 3 inches long on average, shrank as the water’s temperature increased.
VERSTEEG: When they shrink, it’s about 1% or 2% of their body size. So really small length reductions of just, like, between 1 or 2 millimeters.
MARTÍNEZ: Versteeg says it’s not yet clear how the fish are shrinking or why they were significantly more likely to survive the heat wave. But the research team speculates that literally being smaller means needing less food and makes their metabolism more efficient.
VERSTEEG: Something about these shrinking fish was giving them a better opportunity to survive the heat wave compared to the ones that kept growing bigger in size.
MARTÍNEZ: Versteeg says the fish grew again when water conditions improved.
INSKEEP: Oh, and now we have a story of togetherness because researchers noticed that the clown fish in breeding pairs shrink together.
VERSTEEG: It’s a beautiful example of really cooperating and working together in that sense to try and make sure that you come out unscathed at the other end.
INSKEEP: It really is kind of sweet.
MARTÍNEZ: (Laughter).
INSKEEP: Although, the motivation is to try to outcompete other clown fish, we’re told. Still, Versteeg says the discovery means that if clown fish can shrink, there’s a chance that many other coral reef fish can do this to survive also.
MARTÍNEZ: Let’s, you and I, shrink together, Steve.
INSKEEP: No. No. But I’m happy to broadcast with you.
MARTÍNEZ: (Laughter) Aw, come on.
(SOUNDBITE OF SONG, “BEYOND THE SEA”)
BOBBY DARIN: (Singing) Somewhere beyond the sea, she’s there, watching…
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