Climate change impairs survival instincts of fish and can make them swim towards predators

October 21, 2016, University of Exeter

Climate change is disrupting the sensory systems of fish and can even make them swim towards predators, instead of away from them, a paper by marine biologists at the University of Exeter says.

Research into the impact of rising CO2 has shown it can disrupt the senses of fish including their smell, hearing and vision.

High CO2 levels can impair the way they behave, including making them swim towards predator smells instead of away and even ignoring the sounds that normally deter them from risky habitats.

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

CO2 levels are predicted to be 2.5 times higher in the oceans by the end of this century.

The report's authors Dr Robert Ellis and Dr Rod Wilson believe that fish farms, may be the key to establishing the long-term impact of CO2 on marine life.

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

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.

The captive fish farm populations living in high CO2 levels already amount to "a giant long-term laboratory experiment".

"Aquaculture may provide an 'accidental' long-term experiment that can help climate-change predictions," said Dr. Ellis. "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."

The aquaculture industry may also benefit from what the scientists study too. The abnormal behaviour seen in wild fish may not matter in farmed fish, as they are provided with abundant food and shelter and they have no predators to avoid. But while extremely high CO2 can reduce digestion efficiency in cod, recent research suggests that relatively small increases in CO2 may actually act as a growth stimulant in some fish.

Dr. Rod Wilson said: "Our research will allow fish farmers to optimise conditions, and specifically CO2 levels, to improve growth and health of their fish, profitability and the long-term sustainability of the industry. This is really important given that aquaculture is the only way we will increase seafood production to feed the growing human population, particularly given wild fish stocks are overexploited".

Explore further: Transmission of new virus believed to occur between farmed and wild fish

More information: Robert P. Ellis et al, Lessons from two high COworlds - future oceans and intensive aquaculture, Global Change Biology (2016). DOI: 10.1111/gcb.13515

Related Stories

Can farmed fish feed the world sustainably?

September 14, 2016

The world's population is expected to soar by 2.5 billion people by 2050, bringing a host of global challenges – including how to feed so many hungry mouths.

Salmon sickness detected in farmed Canadian fish

May 20, 2016

Researchers led by a Canadian government scientist have diagnosed potential heart and skeletal muscle inflammation in farmed salmon from British Columbia province, the Canadian fisheries ministry announced Friday.

Action needed to keep fish on the menu in 2050

April 23, 2012

The latest study suggests we may still be able to eat as much fish as we do today 40 years from now. But for that to happen, we'll have to change our ways, say scientists.

Recommended for you

Not all stem cells are created equal, study reveals

March 22, 2019

Researchers from the University of Toronto's Institute for Biomaterials and Biomedical Engineering (IBBME) and the Donnelly Centre have discovered a population of cells – dubbed to be "elite" – that play a key role in ...

Ancient birds out of the egg running

March 22, 2019

The ~125 million-year-old Early Cretaceous fossil beds of Los Hoyas, Spain, have long been known for producing thousands of petrified fish and reptiles (Fig. 1). However, researchers have uncovered an extremely rare, nearly ...

Making solar cells is like buttering bread

March 22, 2019

Formamidinium lead iodide is a very good material for photovoltaic cells, but getting the correct stable crystal structure is a challenge. The techniques developed so far have produced poor results. However, University of ...

7 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

SamB
1 / 5 (2) Oct 21, 2016
I guess Darwin was not talking about these fish when he mentioned 'survival of the fittest.'
antigoracle
2.3 / 5 (6) Oct 21, 2016
Climate change obviously impairs, the already very limited "intelligence" of the Chicken Littles and makes them hunger for the AGW Cult's Pathological Lies wrapped in their Pathological "Science".
gkam
1.6 / 5 (7) Oct 22, 2016
We have just seen it affect the weaker members of our species in politics as well, as the losers are attracted to the predator.
TheGhostofOtto1923
3.4 / 5 (5) Oct 22, 2016
We have just seen it affect the weaker members of our species in politics as well, as the losers are attracted to the predator
Stoned again eh george?
Shootist
1.8 / 5 (5) Oct 23, 2016
Climate change impairs survival instincts of fish and can make them swim towards predators


Cats will lay with dogs. The lion shall lie down with the lamb.

Climate change© Is there nothing it cannot do?

Climate change© Global Warming© and Nuclear Winter© are copyright 1976, 1977, . . ., 2015, 2016, House of Gaia Socialist Universalist Church. All Rights Reserved
BackBurner
1 / 5 (2) Oct 23, 2016
"Climate change is disrupting the sensory systems of fish and can even make them swim towards predators, instead of away from them, a paper by marine biologists at the University of Exeter says."

The paper says nothing of the sort. Nowhere does it say CO2 cause fish to swim towards predators. The study is of farmed fish, there are no predators. It was done at levels of CO2 that could never occur in an open system.

This is alarmist garbage. You've claimed something that isn't in the paper and isn't even suggested in it.
TheGhostofOtto1923
1 / 5 (1) Oct 24, 2016
Climate change impairs survival instincts of fish and can make them swim towards predators


Cats will lay with dogs. The lion shall lie down with the lamb
Maybe climate change is causing them to be infected with toxoplasma somehow.

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.