min_flow {respirometry}

Minimum flow rate to support MO2

Description

Calculates the minimum flow rate into a respirometer required to maintain a high pO2. Useful for ensuring an acclimating animal maintains a normoxic environment. It can also be used to estimate the flow rate needed for a given pO2 decrease desired for flow-through respirometry.

Usage

min_flow(
  MO2,
  min_pO2 = 90,
  pO2_in = 100,
  temp = 25,
  sal = 35,
  atm_pres = 1013.25
)

Arguments

MO2

whole-animal oxygen consumption rate (umol / hour).

min_pO2

minimum pO2 acceptable in respirometer (% air saturation). Default is 90% air saturation.

pO2_in

pO2 of water entering respirometer (% air saturation). Default is 100% air saturation.

temp

temperature (°C). Default is 25 °C.

sal

salinity (psu). Default is 35 psu.

atm_pres

atmospheric pressure (mbar). Default is 1013.25 mbar.

Value

The flow rate (liters / min) into the respirometer required for the steady state pO2 to be min_pO2.

Note

Keep in mind that most organisms are very stressed upon being placed in a respirometer and their MO2 may be much higher than basal MO2.

Author(s)

Matthew A. Birk, [e-mail]

References

Steffensen JF. 1989. Some errors in respirometry of aquatic breathers: How to avoid and correct for them. Fish Physiol Biochem. 6:49–59. Equation 8.

See Also

max_MO2, flush_water

Examples

min_flow(MO2 = 1000)

# What is the minimum flow rate required to maintain at least 75% air saturation in a
# respirometer with an organism(s) with an oxygen consumption rate of 1000 umol/h
# when the intake fresh water is 10 °C and 90% air saturated?
min_flow(MO2 = 1000, min_pO2 = 75, pO2_in = 90, temp = 10, sal = 0)