Bacteria and primary production

Abstract

Distribution of bacteria and bacterial activities in sediments in relation to primary production of overlying water at 10 stations in the backwaters and the adjoining mangrove forests (Pichavaram) were studied. Total nitrogen, total phosphorus and organic carbon of the sediments, and the nutrients and plant pigments of the water, were also estimated. Total bacterial population ranged from 1.48 x 10⁶ to 13.10 x 10⁶/g sediment. Phosphatase activity varied from 5.09 to 31.29 µ g phenol/g/hr. Phosphate solubilizing bacteria varied between 1.27 x 10⁶ and 10.26 x 10⁶/g sediment. Chlorophyll a, b and c varied from 3.68 to 31.88, 0 to 10.32 and 6.08 to 38.80 µu g/litre respectively, and carotenoids from 4.56 to 12.80 MSPU/m³. Gross production varied from 25. 21 to 336.12 mg C/m³/hr, and net production from 8.40 to 193.27 mg C/m³ /hr. Positive significant correlations were found between phosphatase producers and chl. a (<i>r</i> = 0.75), chl. <i>a</i> and net production <i>r</i> = 0.6) and phosphatase producers and phosphatase activity (<i>r</i> = 0.8). Similar relationships were also evident between the elements (nitrogen, phosphorus and carbon) and phosphatase producers, and the elements and phosphatase activity.