~ 42 ~ International Journal of Fisheries and Aquatic Studies 2018; 6(2): 42-46 E-ISSN: 2347-5129 P-ISSN: 2394-0506 (ICV-Poland) Impact Value: 5.62 (GIF) Impact Factor: 0.549 IJFAS 2018; 6(2): 42-46 © 2018 IJFAS www.fisheriesjournal.com Received: 19-01-2018 Accepted: 20-02-2018 Nasrullah Bai Arifin Department of Aquaculture, Faculty of Fisheries and Marine Science, University of Brawijaya, Jl Veteran, Malang, Indonesia Muhammad Fakhri Laboratory of Biochemistry and Fish Nutrition, Faculty of Fisheries and Marine Science, University of Brawijaya, Jl Veteran, Malang, Indonesia Ating Yuniarti Laboratory of Biochemistry and Fish Nutrition, Faculty of Fisheries and Marine Science, University of Brawijaya, Jl Veteran, Malang, Indonesia Anik Martinah Hariati Laboratory of Biochemistry and Fish Nutrition, Faculty of Fisheries and Marine Science, University of Brawijaya, Jl Veteran, Malang, Indonesia Correspondence Nasrullah Bai Arifin Department of Aquaculture, Faculty of Fisheries and Marine Science, University of Brawijaya, Jl Veteran, Malang, Indonesia Phytoplankton community at intensive cultivation system of whiteleg shrimp, Litopenaeus vannamei in Probolinggo, East Java Nasrullah Bai Arifin, Muhammad Fakhri, Ating Yuniarti, and Anik Martinah Hariati Abstract Phytoplankton is a source of natural feed for shrimp cultivation in the pond. Phytoplankton productivity increases by the increasing nutrient content in the pond. Feed and metabolic waste is the sources of nutrient for phytoplankton growth. This study aimed to evaluate productivity and identify phytoplankton at intensive whiteleg shrimp, Litopenaeus vannamei cultivation system. This study was conducted at three intensive whiteleg shrimp located in Probolinggo, East Java. Samples were collected on the early and the late of culture period (day 17 and 87 after stocking). Four environmental parameters including total of ammonia nitrogen (TAN), nitrate, orthophosphate, total of suspended solid (TSS), and chlorophyll-a were measured. Identification and density of phytoplankton were also performed of each pond. The results showed that productivity of three ponds was 22,893.83 kg/ha to 23,600.61 kg/ha with an average size 12.74 g to 14.35 g. During culture period, the concentration of TAN, TSS and chlorophyll-a tended to increase. Meanwhile, the average of both nitrate and orthophosphate tended to decline. Several phytoplankton identified in this study were in the genus of Oocystis, Chlorella, Nannochloropsis, Chaetoceros, Stephanodiscus, Nitzschia, Coscinodiscus, Cyclotella and Ulothrix. Phytoplankton of the group Chlorophyta is predominance for pond 1 and 2, while pond 3 was dominated by phytoplankton in the group of Diatom/Baccillariophyta. This study indicated that the present of phytoplankton in the pond provide natural feed and good environmental condition for shrimp cultivation. Keywords: phytoplankton, intensive cultivation system, whiteleg shrimp, Litopenaeus vannamei Introduction Shrimp culture industry in Indonesia has been started at east java province in 1980 [1] , and became one of the most important of aquaculture activities untill today [2] . In 2002, whiteleg shrimp Litopenaeus vannamei was introduced and has been cultured around Indonesia, particularly in east java. In 2014, Indonesia government target shrimp production approximately 699.000 tons through intensification program [3] . Intensive shrimp culture is characterized by the use of qualified and quantified feed and also high stocking density in one pond [4] . In intensive shrimp culture, water exchange is the general method to reduce organic material accumulation both from uneaten feed and metabolic waste to improve water quality [5] . However, minimum or zero water exchange strategies have been practiced since 2001 in Indonesia [1] . Minimum or zero water exchange strategies in intensive shrimp culture frequently associated with biofloc technology. Biofloc is defined as macroaggregate consist of microalgae, feces, death organism, bacteria, protist and invertebrate [6] . The basic of biofloc technology is the application of nitrogen cycle in fish or shrimp culture in stagnant water by stimulating microbial growth assimilated nitrogen waste converted as natural feed for fish or shrimp [7] . Galvez et al. [8] demonstrated that in biofloc integrated system plankton communities changed with the decreasing of number of Cyanobacteria and increasing of number of Heterokontophyta and Chlorophyta. On the other hand, the number of protozoa decreased while Rotifera and Cladocera increased. The increasing of plankton of communities might stimulate growth of shrimp in biofloc system. Similar pattern was also demonstrated in the previous study that the pond contained high total suspended solid, TSS (1.413,6 mg/L) and without water exchange had low feed conversion ratio and higher productivity than that of the pond containing lower TSS (411 mg/L) [9] . The result demonstrated by Fakhri et al. [9]