Te. Murray et Ph. Rich, RESPIRATORY QUOTIENTS PREDICT INCREASES IN REDUCING PRODUCTS IN THE HYPOLIMNION OF A STRATIFIED LAKE, Canadian journal of fisheries and aquatic sciences, 52(6), 1995, pp. 1183-1189
The benthic respiration of Crystal Lake, Connecticut, was modeled with
two respiratory quotients, the volumetric respiratory quotient (VRQ)
and the fundamental respiratory quotient (FRQ). The VRQ is defined as
the quotient of the increase in dissolved inorganic carbon (DIG) and t
he decrease in dissolved oxygen (DO) resulting from respiration at a g
iven depth. Those changes are relative to concentrations determined ea
rly in spring. The FRQ is the slope of the regression of DIC against D
O at all depths not chronically anoxic. Respiratory quotients describe
the predominance of anaerobic over aerobic metabolism and should, the
refore, predict the accumulation of the products of anaerobic metaboli
sm (i.e., Fe2+, H2S). VRQs successfully predicted the increase in redu
ced products in the hypolimnion of Crystal Lake. FRQs successfully pre
dicted the rate of increase of reduced products early in stratificatio
n. FRQ was unsuccessful in predicting the continued accumulation of re
ducing products later in the summer, which may reflect a steady state
between the production of DIC and reduced products and the diffusion o
f oxygen across the thermocline, or may reflect methodological constra
ints imposed by the calculation of FRQ. Both models were successful to
a limited extent in predicting the accumulation of the products of an
aerobic metabolism.