Date of Original Version
Metabolism in estuarine mesocosms was measured by total system oxygen and carbon dioxide and by C-14 bottle incubations to determine the effects of nutrient enrichment (6 levels) over a 9 mo period. These data provided an unprecedented opportunity for calculating metabolic ratios (photosynthetic quotient [P.Q.] and respiratory quotient [R.Q.]) based on the 3 measures of metabolism and determining the impact of other system processes. System metabolism ratios based on daily data varied from 0 to 5.0. System metabolism ratios of P.Q. and R Q. based on integrated data were highly correlated (r = 0.95 to 0.96) and similar to traditional ratios obtained in phytoplankton studies. A system photosynthetic quotient of 1.2 and a system respiratory quotient of 1.1 were calculated from the integrated data. These ratios were only slightly affected by carbon dioxide diffusion and 3 benthic processes: denitrification, sulfur metabolism and calcium carbonate dissolution. There was no trend for system metabolism ratios up the nutrient gradient. The C-14 estimations of productivity appeared nitrogen limited in the lower nutrient treatments and provided lower estimates than the 2 system measures of production.
Oviatt, C. A., Rudnick, S. T., Keller, A. A., Sampou, P. A., & Almquist, G. T. (1986). A comparison of system (O2 and CO2) and C-14 measurements of metabolism in estuarine mesocosms. Marine Ecology Progress Series, 28, 57-67. Retrieved from https://www.int-res.com/articles/meps/28/m028p057.pdf
Available at: https://www.int-res.com/articles/meps/28/m028p057.pdf