Abstract
It is important to assess the recovery potential of algal population after the temporal pesticide exposure in natural aquatic environment. In this study, we investigated the temporal variability of delayed fluorescence（DF）of chlorophyll as the indicator of algal physiological state during the exposure period and the subsequent recovery period. The tested substance was 3,5-dichlorophenol（DCP）and the test species were a green alga Pseudokirchneriella subcapitata and a diatom Navicula pelliculosa. After the 72-h DCP exposure period, algal cells were inoculated into a clean medium and then the algal growth was monitored for around 10-d. The DF intensity per biomass（DF/biomass） decreased with increasing DCP concentration during the exposure period. In the recovery period, algal growth rate recovered with the recovery of DF/biomass. The values of DF/biomass were well-correlated with the algal growth rates, and the correlations during the exposure and the recovery periods showed similar pattern. This indicates the potential use of DF/biomass as the indicator of population recovery status.
