Baby fish will be lost at sea in acidified oceans

December 15, 2015, University of Adelaide
ocean

The ability of baby fish to find a home, or other safe haven, to grow into adulthood will be severely impacted under predicted ocean acidification, University of Adelaide research has found.

Published today in the journal Proceedings of the Royal Society B, the researchers report the interpretation of normal ocean sound cues which help find an appropriate home is completely confused under the levels of CO2 predicted to be found in oceans by the end of the century.

"Locating appropriate homes is a crucial step in the life cycle of fish," says Tullio Rossi, PhD candidate with the University's Environment Institute. "After hatching in the open ocean, baby fish travel to reefs or mangroves as safe havens to feed and grow into adults.

"Baby fish can find those places through ocean noise: snapping shrimps and other creatures produce sounds that the baby fish follow.

"But when acidity increases due to increased CO2, the neurological pathways in their brain are affected and, instead of heading towards those sounds, they turn tail and swim away."

Mr Rossi conducted experiments with barramundi hatchlings, an important fisheries species. The study was in collaboration with other researchers including Professor Sean Connell (University of Adelaide), Dr Stephen Simpson (University of Exeter) and Professor Philip Munday (James Cook University).

He and his collaborators also found that high CO2 makes baby fish move slower and show more hiding behaviour compared to normal fish. This could make it more difficult for them to find food or habitat and to avoid predators.

Research leader Associate Professor Ivan Nagelkerken says marine researchers know that can change fish behaviours. But it hasn't been known how high CO2 would affect such crucial hearing behaviour as finding somewhere to settle.

"Such misinterpretation of sound cues and changes in other behaviours could severely impact fish populations, with the number of young fish finding safe habitats dramatically reduced through their increased vulnerability to predators and reduced ability to find food," Associate Professor Nagelkerken says.

There is still time to turn around this scenario, Mr Rossi says. "We have the capacity to steer away from that worst-case scenario by reducing CO2 emissions," he says. "Business as usual, however, will mean a profound impact on and the industries they support."

Explore further: Sharks' hunting ability destroyed under climate change

More information: Ocean acidification boosts larval fish development but reduces the window of opportunity for successful settlement, Proceedings of the Royal Society B: Biological Sciences, rspb.royalsocietypublishing.or … .1098/rspb.2015.1954

Related Stories

Volcanic vents preview future ocean habitats

August 10, 2015

A world-first underwater study of fish in their natural environment by University of Adelaide marine ecologists has shown how predicted ocean acidification from climate change will devastate temperate marine habitats and ...

Ocean acidification leaving fish in the dark

January 30, 2014

Increasing carbon dioxide in the world's oceans could hamper fishes' eyesight, slowing their reaction times and leaving them vulnerable to predators or unable to hunt, new research has shown.

Carbon dioxide affecting fish brains: study

January 16, 2012

Rising human carbon dioxide emissions may be affecting the brains and central nervous systems of sea fish, with serious consequences for their survival, according to new research.

Ocean acidification leaves clownfish deaf to predators

June 1, 2011

(PhysOrg.com) -- Since the Industrial Revolution, over half of all the CO2 produced by burning fossil fuels has been absorbed by the ocean, making pH drop faster than any time in the last 650,000 years and resulting in ocean ...

Recommended for you

Microbial dark matter dominates Earth's environments

September 26, 2018

Uncultured microbes—those whose characteristics have never been described because they have not yet been grown in a lab culture—could be dominating nearly all the environments on Earth except for the human body, according ...

Team names world's largest ever bird—Vorombe titan

September 25, 2018

After decades of conflicting evidence and numerous publications, scientists at international conservation charity ZSL's (Zoological Society of London) Institute of Zoology, have finally put the 'world's largest bird' debate ...

The grim, final days of a mother octopus

September 25, 2018

Octopuses are the undisputed darlings of the science internet, and for good reason. They're incredibly intelligent problem-solvers and devious escape artists with large, complex nervous systems. They have near-magical abilities ...

Climate change not main driver of amphibian decline

September 25, 2018

While a warming climate in recent decades may be a factor in the waning of some local populations of frogs, toads, newts and salamanders, it cannot explain the overall steep decline of amphibians, according to researchers.

Team discovers new species of dazzling, neon-colored fish

September 25, 2018

On a recent expedition to the remote Brazilian archipelago of St. Paul's Rocks, a new species of reef fish—striped a vivid pink and yellow—enchanted its diving discoverers from the California Academy of Sciences. First ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.