You are here

Scientific progress

03 - 04 - 2018

CO2 increase may not be bad news ... for herrings

A study at sea indicates that ocean acidification would increase the survival of herring fry.



According to laboratory studies, ocean acidification associated with increased CO2 concentration would reduce the survival of fish in the early stages of life, with negative impacts on populations.


These studies were not conducted in the wild, eliminating interactions with the food chain. A team of researchers from a Norwegian university has just published the results of a study carried out at sea on Atlantic herring.


They reproduced for 113 days, in a 19 meters long tube with 2.8 meters in diameter and with herring eggs in it, the CO2 level corresponding to the expected levels at the end of the century. A control tube without added CO2 was studied in parallel.




In contrast to what was found in the laboratory, the survival of herring fry in the CO2-enriched tube was increased by 19% compared to the control tube.


The analysis of the surrounding plankton suggests that the algae benefited from increased CO2 input, which benefited zooplankton and ultimately herring fry.


This result is not directly applicable to other fish species. Further studies in the wild will be necessary if we want to predict the effect of ocean acidification on fish populations.