Does Water Quality Affect the Plankton Dynamics and the Specific Growth Rate of <i>Litopenaeus vannamei</i>?

The whiteleg shrimp Litopenaeus vannamei is one of the most cultured penaeid species in Indonesia. However, a good standard of environment such as water quality characteristics for aquaculture must be met to avoid commercial loss. The aims of the study were to analyze the water quality in the aquaculture pond and their relationship with plankton dynamics and specific growth rate (SGR) of L. vannamei. A descriptive method with the analysis on the primary and the secondary data was performed to determine the effect of water quality on the abundance of plankton and the SGR of the whiteleg shrimp in the intensive pond. The results showed that the plankton abundance indicates that the pond is eutrophic and the water quality affects the plankton abundance. The regression analysis demonstrated that the abundance of phytoplankton was influenced (from the highest to the lowest regression coefficient) by the salinity (94.7%), orthophosphate (94.1%), temperature (91.8 %), CO2 (80.3%), turbidity (66.1%), total organic matter (TOM, 35.2%) and ammonia (16.4%). On the other hand, the zooplankton abundance was significantly affected by the temperature (44.7%), turbidity (41.9%), dissolved oxygen (DO, 26.2%), salinity (14.9%) and TOM (7.2%). The parameters of water quality that affect SGR L. vannamei were ammonia (87.3%), zooplankton abundance (81.2%), TOM (74.9%), DO (63.1%), pH (48.9%), temperature (41%), turbidity (25.8%), salinity (19.4%), orthophosphate (13.2%), and phytoplankton abundance (1.1%). The PCA analyses performed the relation between plankton abundance and water quality parameters.