As soon as they start life, it's all about survival for juvenile young fish. They must learn to catch prey and to escape enemies. Additionally, at this stage of their lives they are highly sensitive to environmental factors such as temperature, oxygen and the pH of the water. Exactly these factors are currently changing on a global scale: temperature is rising, the oxygen content of the ocean is decreasing and more and more carbon dioxide (CO2) from the atmosphere dissolves in the seawater, where it forms carbonic acid and lowers the pH level. But not only directly, also indirectly elevated CO2 affects the survival of fish larvae, because it can change their food supply.
As soon as they start life, it's all about survival for juvenile young fish. They must learn to catch prey and to escape enemies. Additionally, at this stage of their lives they are highly sensitive to environmental factors such as temperature, oxygen and the pH of the water. Exactly these factors are currently changing on a global scale: temperature is rising, the oxygen content of the ocean is decreasing and more and more carbon dioxide (CO2) from the atmosphere dissolves in the seawater, where it forms carbonic acid and lowers the pH level. But not only directly, also indirectly elevated CO2 affects the survival of fish larvae, because it can change their food supply.
Scientists from Germany, Sweden and Norway, led by the GEOMAR Helmholtz Centre for Ocean Research Kiel, have now investigated how the combination of these two effects of ocean acidification can affect the survival and growth of herring larvae. As they have published today in the international journal Nature Ecology and Evolution, the experiment revealed that herring could benefit from an ocean acidification induced change in the food web. “It appears that the herring will have an advantage over other more sensitive species in a future acidified ocean,” states Dr. Michael Sswat from GEOMAR, lead author of the study.
Read more at GEOMAR - Helmholtz Centre for Ocean Research Kiel
Photo: The scientists tested the response of young herring to ocean acidification by rearing them in a complete food web under present and future CO2 conditions in the KOSMOS mesocosms.
CREDITS: Maike Nicolai (CC BY 4.0)
