In a new study from the ARC Centre of Excellence for Coral Reef Studies, scientists report that by leaving more big fish in the ocean, the amount of carbon dioxide (CO2) released into Earth’s atmosphere can be reduced.
“Contrary to most terrestrial organisms, which release their carbon into the atmosphere after death, carcasses of large marine fish sink and sequester carbon in the deep ocean. Yet, fisheries have extracted a massive amount of this ‘blue carbon,’ contributing to additional atmospheric CO2 emissions,” explained the study authors.
“Here, we focus on a previously underrecognized pathway of carbon sequestration by fish: their capacity to sequester carbon in the deep sea after their natural death. More precisely, we estimate how catching large fish from the ocean may have affected this carbon sequestration potential through the sinking of dead fish carcasses.”
When a fish dies in the ocean, it sinks to the seafloor along with all of the carbon it contains, where it is absorbed by oceanic sediments and stored as blue carbon.