Monitoring of Phytoplankton Abundance and Chlorophyll-a Content in the Estuary of Banjar Kemuning River, Sidoarjo Regency, East Java

Estuaries are coastal areas that have a fairly high fertility rate. This region can be said to be fertile because it is‎influenced by such physical factors as temperature, turbidity, light, and current as well as such chemical factors‎as salinity, dissolved oxygen, pH, and nutrient content. The estuary of the Banjar Kemuning River is a coastal‎area with a lot of human activities, and it is close to the mainland, causing the change in the nutrient content in‎the waters. The nutrient content in the waters is closely related to the phytoplankton abundance, as the higher the‎nutrient content in the waters, the greater the phytoplankton abundance and the chlorophyll-a content. The level of‎chlorophyll-a content in the waters can indirectly be used as an indicator of the phytoplankton abundance, which‎can determine the level of fertility of these waters. The purpose of this study was to determine the relationship‎between the phytoplankton abundance and the chlorophyll-a content in the estuary of the Banjar Kemuning River.‎This study is observational research with data analysis using linear regression, simple correlation (Pearson), and‎ANOVA. In addition, the data collection was carried out by purposive random sampling at predetermined points‎of stations. The results of this study indicated that the phytoplankton abundance and the chlorophyll-a content at‎the estuary of Banjar Kemuning River during different months were significantly different (P<0.05). The averaverage age phytoplankton abundance during the study was 19,256 cells/L, 19,044 cells/L, and 22,613 cells/L, while the ‎chlorophyll-a content during the study was 0.958 μg/L, 0.998 μg/L, and 1.167 μg/L. The conclusion was‎drawn that there is a difference between the phytoplankton abundance and the chlorophyll-a content each month‎and classified into high correlation.