Highlights
- • Phosphate exhibits a non-conservative behavior within the Jiulong River Estuary
- • The buffer-biological coupling model captures the spatial phosphates dynamics
- • The dominant model factor can be influenced by season and estuary attributes
Abstract
Phosphorus is one of the most important estuary-received nutrients and constitutes a significant component of estuarine biogeochemical research. Estuarine phosphates typically exhibit a non-conservative behavior: concentrations increase with the increment of salinity along the riverine end, reaching a critical point, after which decrease due to the dilution upon freshwater-seawater mixing. The primary controlling factors altering the phosphate dynamics are the buffering effect and biological activities. The buffering effect maintains the relative stability of phosphate levels through the dissolution of phosphorus-containing sediments and the adsorption of suspended particulate matter (SPM), while biological activity alters the phosphorus concentration level through uptake and biodegradation. The dual effects could be elucidated through a buffer-biological coupling model, where biological processes primarily determine phosphate distribution when phosphate correlate positively with the SPM concentration; conversely, the buffering effect dominant the phosphate concentration within the estuary in cases of reversed or weak correlated phosphate-SPM relationships. The key controlling factor may vary with seasons and specific estuarine regional conditions.
Keywords Phosphate; non-conservative; buffer-biological coupling model; estuary
Publication Professional Experiment of Marine Chemistry Forum