<
https://www.newscientist.com/article/2412752-seabed-trawling-found-to-be-a-major-source-of-global-co2-emissions/>
"Bottom trawling releases around 340 million tonnes of carbon dioxide into the
atmosphere each year, according to the first study to estimate these emissions.
That is nearly 1 per cent of all global CO2 emissions, a major contribution
that has been overlooked until now.
Trawling involves dragging weighted nets across the seafloor to catch
bottom-dwelling fish, crustaceans and shellfish. This practice is widely used
around the world, but it is controversial because the fishing gear damages
seafloor environments such as cold water reefs, where some corals may be
thousands of years old.
“Bottom trawling is an extremely destructive form of fishing as the nets and
weights dragged along the bottom destroy marine habitats that can take many
years to re-establish and recover,” says Mika Peck at the University of Sussex,
UK, who wasn’t involved in the research.
It also stirs up sediments, providing the oxygen that microbes need to break
down organic matter into carbon dioxide. Those sediments might otherwise
continue to build up for many millennia, with the organic matter in them
preserved by low-oxygen conditions – meaning the carbon is effectively locked
away.
In 2021, Trisha Atwood at Utah State University in Logan and her colleagues
combined studies looking at how much CO2 may be released during trawling with
data on the extent of trawling worldwide from an organisation called Global
Fishing Watch. The team concluded that massive amounts were released into the
seawater.
But the big unanswered question was how much of the CO2 released from sediments
ends up in the atmosphere."
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
