A dynamic growth model of macroalgae: Application in an estuary recovering from treated wastewater and earthquake-driven eutrophication

摘要: Abstract A dynamic growth model of macroalgae was developed to predict the green macroalga Ulva sp. in response changes environmental variables. The is based on common physiological behaviour and hence has general applicability macroalgae. Three state variables (nitrogen, carbon phosphorus) were used describe processes functional differences between nutrient uptakes. Carbon uptake modelled as a function temperature, light, algal internal water current, while depends state, temperature level. Growth can only occur when nutrients environment storage pools (N-quota P-quota) reach threshold levels. Physiological rates follow Arrhenius relationship increase exponentially with increasing within tolerance range species. When parameterised applied eutrophic Avon-Heathcote Estuary, New Zealand, generally reproduced field observations abundance. followed clear seasonal cycle biomass from early-middle summer, reaching peak values early autumn then decreasing. Conversely, N-quotient levels maximal during winter months, declining summer growth. These patterns collectively driven by light intensity nutrients. captured N-quota responses N-reduction arising diversion treated wastewater Estuary an offshore outfall 2010, raw sewage N-discharges resulting infrastructure damage caused Canterbury earthquakes 2011. Sensitivity analyses revealed that temperature-related parameters maximum rate C among most sensitive predicting biomass. In addition, earthquake-derived reduction immersion time decrease start prior blooms shown drive considerable declines