Table 1.
Elemental composition of fish pond water.
Figure 1.
pH and carbon availability of culture water.
a) Average maximum daily pH and b) total dissolved inorganic carbon available (CO2 and HCO3−) to Oedogonium cultures at five water exchange rates (0.1, 0.5, 1, 2.5 and 5 vol.day−1) using fish pond water with and without nitrogen (N) and carbon (CO2) supplementation. In graph b nitrogen treatments have been excluded as nitrogen had no significant effect on carbon availability.
Table 2.
Mixed model ANOVA results testing the effect of water exchange rates (0.1, 0.5, 1, 2.5 and 5 vol.day−1) and water treatment (Pond water with and without nitrogen and CO2 addition) on the pH of culture water over five replicate trials.
Figure 2.
Biomass production rates of Oedogonium cultured at 5 water exchange rates, 0.1, 0.5, 1, 2.5 and 5 vol.day−1, using fish pond water (PW) with and without nitrogen (N) and carbon (CO2) supplementation. Values are the means and SE of 5 replicate growth trials.
Table 3.
Mixed model ANOVA results testing the effect of water exchange rates (0.1, 0.5, 1, 2.5 and 5 vol.day−1) and water treatment (Pond water with and without nitrogen and CO2 addition) on the biomass productivity of Oedogonium cultured over five replicate trials.
Figure 3.
Nitrogen and phosphorous uptake rates and efficiencies.
Uptake rates (solid lines) and efficiency (dashed lines) of Oedogonium when cultured in pond water (grey lines) and pond water +CO2 (black lines) under increasing nutrient flux of a) nitrogen and b) phosphorous. For reference purposes the five water exchange rates that these nutrient fluxes correspond to have been added to the top x-axis.
Figure 4.
Mean (±SE) internal nitrogen content of Oedogonium cultured under 5 water exchange rates (0.1, 0.5, 1, 2.5 and 5 vol.day−1) using fish pond water (PW) with and without nitrogen (N) and carbon (CO2) supplementation. Note protein content of Oedogonium can be calculated by multiplying %N by 4.7 [28].