Alert! Fish to Lose Sight, Hearing, Smell Due to Increased Carbon Dioxide

Being one of the culprits of global warming and climate change, carbon dioxide is again creating another strain of problem to the marine ecosystem, specifically to the fish. But this time, it's not about warming the seas but impairing their sense that can eventually lead them swimming toward their predators.

A recently published paper in the journal Global Change Biology led by Exeter University has shown how carbon dioxide affects the capabilities of fish through disrupting their main senses used to survive from predation. This is due to the acidification brought by the increased CO2 found on the marine waters. Carbon dioxide in water can produce carbonic acid, increasing water's pH. Once the acidity increases, the quality of water then starts to hamper the development of sensory stimuli, making fish behave differently.

To further understand the scenario, authors Dr. Robert Ellis and Dr. Rod Wilson and a counterpart from Chile, Dr. Maricio Urbina, tried to maximize the fish farms in studying potential reactions of fish exposed to higher CO2 concentrations.

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

Read here: Lessons from two high CO2 worlds - future oceans and intensive aquaculture.

Since the projection of carbon dioxide content in oceans by the end of the century is already the usual status of aquaculture farms, using them as the "laboratory" itself to foresee fish responses to the future is one of their best options. As stated in a press release, it could even be a key to help understand the potential species' adaptation through climate change.

"Our research will allow fish farmers to optimize 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," Dr. Wilson explained in ScienceDaily.