Rising CO2 is messing with fish's senses

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Rising CO2 is messing with fish's senses

October 31, 2016 - 19:33
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Research into the impact of rising CO2 has shown it can disrupt the senses of fish including their smell, hearing and vision and even make them swim towards predators, instead of away from them.

Somehow CO2 is disrupting the way fish brains process sensory signals.

Influx of CO2 is disrupting fishes' sense of smell, sight and hearing, marine biologists at the University of Exeter finds.

According to a paper just published in the journal Global Change Biology by Dr Robert Ellis and Dr Rod Wilson, abnormal behaviours have been linked to the effect of CO2 on how the brain processes signals from sensory organs.

How exactly isn't clear. What is clear, the problem is sure to get worse as the oceans' CO2 levels are expect to rise by a factor of 2.5 by the end of the century.

In their paper, Lessons from two high CO2 worlds: future oceans and intensive aquaculture, Dr. Ellis and Dr. Wilson, alongside a Chilean colleague Dr. Urbina, show that farmed fish often live in CO2 conditions 10 times higher than their wild cousins.


Captive fish farm populations living in high CO2 levels already amount to “a giant long-term laboratory experiment", the researchers note. The scientists believe that further study of farmed fish – which already provides as much seafood for human consumption as that caught in the wild – may be crucial for understanding how aquatic species will evolve to climate change.

"There is the enticing possibility that fish and shellfish previously grown in high CO2 aquaculture conditions over multiple generations can offer valuable insights regarding the potential for aquatic animals in the wild to adapt to the predicted further increases in CO2."
Robert Ellis, explained in a news release.

Many studies have demonstrated that elevated CO2 projected for end of this century can also impact physiology, and have substantial effects on behaviours linked to sensory stimuli (smell, hearing and vision) both having negative implications for fitness and survival.

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