UCSB researchers discover fishing leads to high carbon emissions
Study co-authors, Steve Gaines, at left, and Juan Mayorga.
A group of scientists have discovered that carbon emissions from fishing are 25% higher than what was considered from fuel consumption.
Carbon is a large component in living tissue molecules, and when fish die naturally in the ocean, they take all the carbon with them and it’s sequestered for thousands or even million years.
This natural phenomenon is called a “blue carbon” pump.
Harvesting large fish, like yellowfin tuna, prevents the carbon in their bodies from sinking to the seafloor when they die.
However, according to a recent study published in “Science Advances,” researchers found that industrial fishing disrupts that sequestration.
Furthermore, they found that industrial fishing emits a double amount of CO2 into the atmosphere, both from the boats’ greenhouse gas emission by consuming fuel oil and by releasing CO2 from extracting fish from the sea, which would have otherwise remained in the ocean.
In a press release from the Current, UCSB marine data scientist and co-author of the study, Juan Mayorga, said, “This is a step forward toward more holistic, science-based assessments of the status of fisheries management and opens the door to innovative financing models including tapping into carbon markets.”
The scientists used historial catches and fuel consumption to show that ocean fisheries have released a minimum of 0.73 billion metric tons of CO2 in the atmosphere over the course of 70 years.
In the study, they called for limiting blue carbon extraction by fisheries, specifically in unprofitable areas.
“We raise the issue of rapidly assessing the effect of measures promoting the recovery of fish stocks, on the reactivation of the natural capacity of large fish to sequester carbon through the sinking of their carcasses or through their potential indirect effect on the sequestration of carbon by other living compartments,” the authors wrote in the study. “This would improve estimates to assess whether rebuilding fish stocks can be considered an additional nature-based solution to climate change that has been ignored so far.”
Overall, the scientists believe fisherfolks just need to fish better, avoiding remote areas that cause fuel consumption and avoiding the large fish that contain much of the blue carbon that scientists don’t want extracted.
“We do not have to stop fishing to regain many of these carbon sequestration benefits,” Steve Gaines, another coauthor and the director of UCSB’s Bren School of Environmental Science and Management, said in a statement to the Current. “If we fish in the right places and at sustainable rates, we can rebuild a significant amount of this natural blue carbon sink.”
The study, titled, “Let more big fish sink: Fisheries prevent blue carbon sequestration—half in unprofitable areas,” can be viewed at https://advances.sciencemag.org/content/6/44/eabb4848.
email: gmccormick@newspress.com
