PHYTOPLANKTON GROWTH IN THE CONDITIONS OF MILKFISH POND CULTIVATION WITH APPLICATION OF PROBIOTICS IN EAST TEGAL DISTRICT OF TEGAL CITY, INDONESIA

Abstract

Milkfish is one of the leading aquaculture products. Shifting the demands of aquaculture production requires a probiotic mixture on feed, although the need for phytoplankton as natural food is still very much needed. This research method is a descriptive method. This study was conducted in April-June 2018 in milkfish ponds in East Tegal District, Tegal City, Indonesia. Retrieving water samples using a bottle size of 50 liters of water which is then filtered with plankton net, then the sample is preserved with 5% formalin and immediately taken to the laboratory for identification. The purpose of this study was to: (1) determine the growth of phytoplankton during the maintenance of milkfish, and (2) analyze the relationship between nutrient availability and phytoplankton abundance. The results showed that the growth of phytoplankton was quadratic, where the highest growth was achieved on day 31 of 3,135,150 individuals/milliliter, then decreased. The growth of functional phytoplankton is influenced by nitrate (NO3), phosphate (PO4) and total organic matter (TOM), which is indicated by the multiple regression equation Y = 3779627 + 29580113 NO3 - 1.1x10-8 PO4 - 24740.6 TOM (α <0.05).

Keywords

• Diversity
• phytoplankton
• milkfish ponds
• East Tegal