Ocean Acidification Makes Clownfish Go Deaf (Poor Nemo…)

Another Unforeseen Consequence of Global Warming
The planet’s oceans absorb a lot of CO2 from the atmosphere, slowly turning them more acidic than they would otherwise be. This can be a big problem for many species that haven’t evolved in these conditions, including coral reefs and, scientists have now found, the clownfish (popularized by Pixar’s Finding Nemo). Apparently, it’s the clownfish’s hearing that is most affected by acidification…

What Did You Say?
Indeed, researchers found that the clownfish appears to be losing its hearing in water only slightly more acidic than what is normal in the ocean.

Via BBC:

In this experiment, the fish could decide whether to swim towards or away from an underwater loudspeaker replaying the sounds of predators recorded on a reef, with shrimps and fish that would take a small clownfish.

But the clownfish in more acidic water showed no preference for moving away from the threatening sound, while those exposed to normal levels of acidity move away from the perceived danger source. This could seriously impact clownfish survival in the long term.

“Avoiding coral reefs during the day is very typical behaviour of fish in open water,” said researcher Steve Simpson from the School of Biological Sciences at the UK’s Bristol University. Indeed, coral reefs are home to many species that can feed on small clownfish.

“They do this by monitoring the sounds of animals on the reef, most of which are predators to something just a centimetre in length. But sounds are also important for mate detection, pack hunting, foraging – so if any or all of those capacities are gone, you’d have a very lost fish,” he told BBC News.

Not Sure Yet What is Causing the Impaired Hearing
The acidity doesn’t seem to physically damage the fish’s ears, so maybe the damage is neurological, or maybe they are “stressed by the higher acidity and do not behave as they otherwise would.”

Look at the Bigger Picture
But the bigger lesson here is that if this happens to clownfish, there are probably all kinds of other hard-to-foresee impacts on other species. We must get CO2 emissions under control and stop ocean acidification before marine ecosystems are more damaged than they already are…

This post was originally published by Treehugger.

Related Stories:

Oakland Lessons on Gender Diversity in Animal Kingdom Under Fire

Ocean Acidification: History Repeating Itself

How to Talk to a Global Warming Skeptic


Photo from Leszek Leszczynski via flickr
written by Michael Graham Richard, a Treehugger blogger


W. C
W. C5 months ago

Sad, thank you for the information.

William C
William C5 months ago


Fred Hoekstra
Fred Hoekstra5 years ago

Thank you Lindsay, for Sharing this!

Fiona T.
Past Member 5 years ago

Can we help to do something?

Diane L.
Diane L6 years ago

Randall, I have a clownfish in my aquarium, so I'm a bit familiar with their behavior, but first of all, fish don't have ears, so they are all totally deaf in the first place. They react to sight, smell and yes, vibrations. While it's possible that more acidic water could affect many things, it makes no sense to imply that the fishes sense of hearing would be affected when they don't "hear" to begin with.

Randall S.
Randy Stein6 years ago

Maybe the higher acidity of the water just makes them stupid not deaf??? Still doesn't explain Republican hearing problems. Less & less can they hear the taxpayers or the voice of reason---but they have NO problem hearing the sound of large checks entering their campaign accounts!!!

Janine Hofmann
Janine H6 years ago

Only when the last tree has been cut down; Only when the last river has been poisoned; Only when the last fish has been caught; Only then will you find that money cannot be eaten.
(Native American proverb)

"We have learned to fly the air like birds and swim the sea like fish, but we have not yet learned the simple art of living together as brothers." (Martin Luther King)

KrassiAWAY B.
Krasimira B6 years ago

Noted with sadness.

Lynne B.
Lynne Buckley6 years ago

What a shame. I hope they do more research on this to see if they can help them.