ENVIRONMENTAL EFFECTS ON THE GROWTH AND PHOTOSYNTHETIC ACTIVITY OF LASPINEMA SP. IN SIMULATED WATER CONVEYANCE OPEN CHANNEL

In order to explore the physiological and ecological adaptability of harmful periphytic algae in water conveyance open channels, a small runway pool was used indoors to simulate the environment. Specifically, periphytic algae (Laspinema sp. APE171) were selected. The chlorophyll a content and chlorophyll fluorescence parameters of Laspinema sp. APE171 were selected for examination. The study assessed the chlorophyll a content and chlorophyll fluorescence parameters of Laspinema sp. APE171 under different environmental conditions such as flow rate, light intensity, UV-A intensity, and turbidity. Furthermore, distinctions in the physiological state of Laspinema sp. APE171 in the water-air interface and benthic habitats were compared. The results showed that when the flow rate V > 0.23 m/s, the growth of Laspinema sp. APE171 was inhibited in the water-air interface habitat. Moreover, UV-A intensity at 440 μW/m² induced stress on the photosynthesis of Laspinema sp. APE171 in water-air interface habitat. Additionally, when the turbidity was 100 NUT, the photosynthetic activity of Laspinema sp. APE171 in the water-air interface habitat was the lowest, and Laspinema sp. APE171 was more sensitive to changes of environmental factors in the water-air interface habitat. Therefore, the effects of flow velocity, UV-A intensity, and turbidity on cyanobacterial growth in different habitats necessitate thorough consideration in the monitoring and management strategies aimed at controlling Laspinema sp. in open water conveyance channels.