The Relationship of P and N Nutrient Contents with Chlorophyll-a Concentration in Tarakan Island Waters

Abstract

Water productivity is related to nutrient availability. One of the factors related to nutrient availability is a chlorophyll-a concentration in these waters. This study analyses the relationship between chlorophyll-a concentration and nutrient content in Tarakan Island waters. The water samples taking on 18 points of observation locations used a water sampler Horiba U51. The chlorophyll-a assay using a spectrophotometer method. The phosphate and nitrate levels are measured based on APHA phosphate concentration with the ascorbic acid method using a spectrophotometer at a wavelength (λ) = 880 nm. Nitrate samples were analysed using the Brucine method using a spectrophotometer at a wavelength (λ) = 410 nm. The analysis of the chlorophyll-a does with the acetone extraction method. Nutrient content and chlorophyll-a data were obtained and processed using Microsoft Office Excel 2010 and Sigmaplot. The results showed the highest nutrient content of phosphate (0.11-0.19 mg/l), while for nitrate (0.03-0.16 mg/l) and chlorophyll-a content ranged from 0.13-4, 56 mg/m3 and dissolved oxygen content (5, 48-8.39 mg/l). The results showed that the nitrate content had a significant relationship with the chlorophyll-a concentration, but not for phosphate nutrients.