Study of Factors Affecting Phytoplankton Primary Productivity in a Pond of Patna, Bihar, India

摘要

The rate of carbon fixation at the primary level currently provides the best assessment of the result ofphysical, chemical and biological interactions determining the actual fertility of any environment. Phytoplanktonprimary productivity and its regulating factors were studied in a pond in Patna, Bihar, India month-wiseperiodically from April 2011 to March 2013. Primary productivity was determined by light and dark bottlemethod. Physicochemical factors, i.e. water temperature, light penetration depth, pH, DO, alkalinity, hardness,TSS, TDS, nitrate, phosphate and phytoplankton density were determined following standard methods.Phytoplankton primary productivity (gross primary productivity) was estimated as 5.496 gC/m 2 /day to 9.964gC/m 2 /day with mean value of 7.73 gC/m 2 /day. It indicates eutrophic nature of the pond. Higher values ofprimary productivity were found in the post monsoon season and monsoon season. Mean value of primaryproductivity was lower in summer and winter season. Phosphate, TSS and phytoplankton density werefound to be highly correlated positively with phytoplankton primary productivity while light penetration depth,alkalinity and hardness were highly correlated negatively. Phytoplankton primary productivity was found to bemoderately correlated with temperature.