Abundance of Phytoplankton in Vannamei Shrimp (Litopenaeus vannamei) Farming Pond at the Center for Brackish Water Aquaculture Fisheries (BBPBAP) Jepara

Vannamei shrimp (Litopenaeus vannamei) is one of the commodities that is a priority in aquaculture development activities in Indonesia. The success of vannamei shrimp culture is influenced by various factors such as fry quality, feed quality, land carrying capacity, application of biosecurity and good water quality management. Water quality is closely related to the phytoplankton community contained in a waters. This study aims to analyze the abundance and dominance of plankton species found in pond waters. Monitoring the abundance of phytoplankton was carried out in 4 plots of vannamei shrimp aquaculture ponds at the Brackish Water Aquaculture Fisheries Center (BBPBAP) Jepara, namely plots A51, A51, A61 and A62. Identification and calculation of phytoplankton cells were carried out using a haemocytometer and Sedgwick. The results of the analysis showed that the highest abundance of phytoplankton was found in plots A61 at week 9 with a cell number of 36.73 x 106 cells/L, while plots A51, A52 and A62 decreased. Overall plot A62 had better water quality conditions when compared to plots A51, A52 and A61 indicated by the phytoplankton abundance value of 34.63 x 106 cells/L at week 9 and the dominance index of green algae, namely D > 0.5.