Thursday, June 13, 2019

B-neutral certification recommended for sustainable fish farming

by Giulia Granato and Mauro Doimi, Marine biologists, D&D Consulting, Italy

Most of human activities emit carbon dioxide (CO2), which contains atmospheric carbon.
CO2, along with other emissions, have changed and is still changing global climate irremediably. What is not still well known is that our ocean, coasts and lagoons provide a natural way of reducing the impact of greenhouse gases on our atmosphere, through sequestration (or sinking) of this carbon.
 


83 percent of the global carbon cycle is circulated through the ocean. Coastal habitats cover less than two percent of the total ocean area, but account for approximately 50 percent of the total carbon sequestered in ocean sediments. The term used for carbon captured by marine ecosystems is called “Blue carbon”.

Carbon is taken by living organisms that store it in an organic form, like mud sediments or for building clam shells. Mangroves, salt marshes and seagrass “capture and hold” large quantities of carbon, acting as something called a “blue carbon sink”.

Fish farming is directly involved in the carbon cycle and can be positive in emissions or negative in the sink. Extensive aquaculture made in wetlands or in brackish lagoons proved to be an efficient blue carbon sink.

These ecosystems, strongly autotrophic, fix carbon dioxide photo-synthetically as organic matter and the excess of the CO2 is respired back by biota, thus removing CO2 from the atmosphere and storing it below the ground. The CO2 cycle is complex and begins from its capture in the water by atmosphere and photosynthesis due to the macro-micro algae.

The CO2 reacts with carbonate alkalinity in the brackish water and precipitates on the bottom. Moreover, the CO2 is captured by the mud due to the denitrification process and the chemical linkage with the cations and clay. It has been shown that the biomass production in brackish lagoons is higher than other blue ecosystems, like lakes or rivers, sequestering carbon at a much faster and bigger rate.


Read more HERE.

The Aquaculturists
This blog is maintained by The Aquaculturists staff and is supported by the
magazine International Aquafeed which is published by
Perendale Publishers Ltd

For additional daily news from aquaculture around the world: aquaculture-news

No comments:

Post a Comment