Phytoplankton composition of the River Thames in relation to certain environmental variables
Ruse, L. P.; Hutchings, A. J.
Phytoplankton and associated environmental data collected fortnightly over one year were analysed to prepare predictive models of the effects of proposed regulation schemes on the River Thames. About 80% of the variation in phytoplankton taxa composition could not be explained by the environmental data. The most important predictive variables measured were temperature, ortho-phosphate, silica, total organic nitrogen and discharge. Less than 2% of phytoplankton variation was attributable to sample location. 90% of explained variation was temporal. Indicator taxa for specific physical and chemical influences have been identified. Their reactions can be modelled but the high percentage of unexplained variation makes prediction unsafe. Future monitoring should additionally include measurements of solar radiation, ammonia concentrations and light transmission in water.