I read the paper with great interest and would like to ask this question :

I assume that the main carbon source in the slurry fed ponds was
atmospheric CO2 fixed by primary production. Please correct this assumption if it is incorrect.

You state that "most of the energy in chicken manure applied to the
fishpond turned into methane."  Does this mean that the
manure fed ponds also relied primarily on atmospheric CO2 as the carbon source?

Thank you,
Regards,

Sam Levy
Eilat, Israel