Rate of Photosynthesis of Phytoplankton Culture in Growth Phase

Abstract

When the rate of gross production (mg O₂/mg chi. a/h) is measured using light and dark bottle technique, especially in the case of phytoplankton culture, the incurred main error is due to the increase of newly formed phytoplankton and bacteria in the light bottle. It is, therefore, necessary to make a few corrections in the usual calculation.
This paper attempts to estimate the gross production rate using the average values of respiration rate and chlorophyll-a concentration during the incubation time. The estimated gross production is then analyzed from the light-photosynthesis relation (p_c-i curve) by using the Steele model.
Compared with the maximal gross production value (p'_m) obtained from usual formula, it would be unlikely that the respiration rate error in light bottle would exceed about 5 % of p_m value when calculated by method proposed in this paper. However, the p'_m value obtained from the initial chlorophyll-a concentration becomes 1.2-1.6 times higher than p_m value. The high p_mvalue is found in younger cells with high photosynthetic activity in the culture process of phytoplankton.