Certain Marine Fish Can Live With Higher Carbon Dioxide Levels

Study subjects cinnamon anemonefish fry to varying C02 levels with interesting results.

July 5, 2012

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The Cinnamon anemonefish (Amphiprion melanopus) was the subject of a CO2 study that found that offspring can cope with higher CO2 levels provided the parents were also exposed to higher levels of CO2. Photo credit: Nick Hobgood

According to a paper published in Nature Climate Change, certain marine fish are able to cope with increasing carbon dioxide levels in their waters if their parents were also exposed to similar CO2 levels. Researchers at the ARC Centre of Excellence for Coral Reef Studies (CoECRS) exposed breeding pairs of cinnamon anemonefish (Amphiprion melanopus) to three levels of carbon dioxide.

The different levels help mimic varying climate change events ranging from current levels to moderate levels and high levels of CO2, which are predicted by the end of the century. The study also included a rise in water temperature of 1.5 degrees to 3 degrees Celcius, which are the projected increases by the end of the century. Fry from the breeding pairs that were exposed to the same levels of CO2 as their parents showed no adverse effects, while those fry subjected to more dense CO2 levels and warmer water had negative impacts on growth rate, as well as the survival of the juvenile fish.

“There has been a lot of concern around the world about recent findings that baby fish are highly vulnerable to small increases in acidity, as more CO2 released by human activities dissolves into the oceans,” says co-researcher Dr. Gabi Miller of CoECRS and James Cook University. “Our work with anemonefish shows that their babies, at least, can adjust to the changes we expect to occur in the oceans by 2100, provided their parents are also raised in more acidic water.”

What is not yet known is how the fish pass on the capability to adapt to changing CO2 levels. The study will help to assess how the world's fish stocks will react to changes that are occurring every day to the ocean's chemistry.

The authors will present a paper on their study at the International Coral Reef Symposium on July 13, 2012, in Cairns, Australia.