Analisis Nilai Konsentrasi Klorofil-a dan Tingkat Produktivitas Primer di Teluk Tapian Nauli, Kabupaten Tapanuli Tengah, Provinsi Sumatera Utara

Abstract

This research aims to determine the concentration of chlorophyll-a and analyze its relationship with primary productivity levels in the waters of Tapian Nauli Bay, a coastal area with high marine ecosystem potential. Chlorophyll-a is the main photosynthetic pigment in phytoplankton and serves as a key indicator of marine fertility. The research employed a quantitative approach through in situ sampling at five observation stations at two different depths, combined with secondary data from Aqua MODIS satellite imagery. Primary productivity was estimated using the Vertically Generalized Production Model (VGPM), which incorporates parameters such as chlorophyll-a concentration, sea surface temperature (SST), Photosynthetically Active Radiation (PAR), and euphotic depth. The results showed that in situ chlorophyll-a concentrations ranged from 0.2054 to 0.41 mg/m³, while satellite-derived values ranged from 0.49 to 1.31 mg/m³. Primary productivity values estimated using the VGPM ranged from 798.546 to 839.35 mgC/m²/day. Simple linear regression analysis revealed a very strong relationship between chlorophyll-a and primary productivity, with a correlation coefficient (r) of 0.98 and an RMSE of 0.21, indicating a high level of agreement between satellite and field data. These findings demonstrate that chlorophyll-a is an effective indicator for estimating primary productivity and assessing water fertility, while also supporting the application of remote sensing technology for sustainable marine resource management, particularly in the Tapian Nauli Bay area