Spectrophotometric determination and multivariate analysis of nutrients in the Zrmanja estuary
Maša Buljac; Goran Olujić (HHI); Marija Bralić; Nenad Periš; Mirjana Čurlin;
In this work are presents, for the first time, spectrophotometric determination and detailed analysis of spatial and seasonal distribution of nutrients in the Zrmanja estuary. For the study period were obtained the average concentrations of nutrients: for orthosilicate from 7.98-12.35 mmol/m3, for nitrites 0.11-0.12 mmol/m3, for nitrates 5.81-11.27 mmol/m3, for ammonia 0.75-1.57 mmol/m3 and for orthophosphate 0.03-0.07 mmol/m3. The highest concentrations of orthosilicate and nitrate were recorded during the increased river flow. Phosphorous was the limiting element in the Zrmanja estuary, while the concentrations of orthophosphate through all four seasons were lower than 0.1 mmol/m3. The relationship between determined parameters was established using the multivariate analysis (Spearman's correlation coefficient and Cluster analysis). The purpose of this study is to demonstrate the influence of the sea on the distribution of the determined parameters and their impact on the ecosystem in oligotrophic estuary.