Bacterioplankton viability and production in the lower Cross River estuary, southeastern Nigeria. – E. E. Antai and A. D. Asitok
Temporal (12 months) and spatial dynamics of bacterioplankton abundance, production rate and viability based on cell integrity were determined in surface waters of the lower Cross River Estuary, South East Nigeria. Bacterial abundance was enumerated with epifluorescence microscopy, after staining with 4’ 6-diamidino-2-phenylindole (DAPI). Bacterial abundance showed temporal and spatial variation ranging from 4.84 to 16.49 x 109 cells l-1. Bacterial production based on multiplying bacterial growth grate and abundance varied from 3.16 to10.69 μgCl-1h-1. A coupled relationship between chl a and bacterial abundance (r2 = 0.906) is shown despite the in balance between bacteria and primary production. The proportion of viable bacterial cells varied from 52.4% to 77.3%, suggesting that bacteria in the Cross river estuary will constitute a significant active component of biological productivity.