Impact of Nutrients and Suspended Particulate Matter on Phytoplankton Chlorophyll-a Biomass, in the Estuary of Kendal, Indonesia

Abstract

The Kendal River estuary receives nutrient input from various community activities from the surrounding waters and will indirectly affect the physical and biological quality parameters of the waters. Phytoplankton biomass is a parameter of biological quality, which can be measured based on the concentration of chlorophyll-a, while suspended particulate matter is a parameter of its physical quality. The purpose of this study was to determine the spatial distribution of nutrients and suspended particulate matter and their effect on chlorophyll-a in the Kendal River Estuary. This research was conducted in November 2017. Sampling was carried out at 12 stations representing river, coastal and high seas areas. Chlorophyll-a and nutrients N & P, were measured based on the spectrometric method and SPM using the gravimetric method. Spatial distribution of each parameter using kriging interpolation with ArcGIS. The results showed that chlorophyll-a, nitrate, phosphate, and SPM had a similar spatial distribution pattern, which was high in the estuary area and decreased in concentration towards the sea. The results of the multiple linear regression model analysis between chlorophyll-a on nutrients and SPM followed the formula [chl-a] = -11275 + 5.249 [NO3-] + 6.987 [PO42-] + 0.004 [TSS], with a coefficient of determination (R2) of 0.76 . The most influential water quality is phosphate, followed by nitrate and TSS. Based on the chlorophyll-a value, Muara Kendal is categorized as eutrophic.

Keywords

• chlorophyll a
• water quality
• kendal estuary