A team of researchers has found that rising levels of carbon dioxide interfere with the sensory systems of fish. As atmospheric carbon dioxide levels continue to increase exponentially, fish may become unable to avoid predators. The team used existing data from the aquaculture industry to study these effects. The details are in a paper that was just published in the journal Global Change Biology.
Carbon dioxide levels are rapidly rising due to the use of fossil fuels and other forms of pollution. As climate change worsens and these levels continue to rise, the physiology of some animals may be affected. Researchers from the University of Exeter decided to study the effects of high CO2 concentrations on fish, an important source of food and income for people.
The research team used fish farms to study the impacts of high CO2 levels on fish. The aquaculture industry has already farmed fish in these conditions for many years. Farmed fish are exposed to CO2 levels ten times higher than fish in the wild. Fish farms are excellent models for studying the future effects of climate change on aquatic animals.
The team has already observed a few effects in fish farms that may eventually occur in the wild. Farmed fish, exposed to extremely high levels of CO2, become impaired and can’t properly avoid predators. CO2 seems to affect their sensory systems and the researchers noted that the fish would swim towards a predator instead of away. They would also swim into dangerous areas that most wild fish would avoid. Previous climate change research has already showed the development of similar problems in other animals.
By using fish farms as models, researchers can gain insights into the long-term effects of climate change on fish populations. Farmed fish are already exposed to conditions similar to what wild fish are about to experience. The research will also aid the aquaculture industry by helping farmers learn how to best adjust water conditions to optimize fish growth and reproduction.
Ellis RP, Urbina MA, Wilson RW. Lessons from two high CO2 worlds – future oceans and intensive aquaculture. Global Change Biology (2016).