[Numerical dynamics of sediment bacteria in shrimp polycultural ecosystems]

The numerical dynamics of sediment bacteria was studied from May to September 1997, in the Shrimp Farm of Huanghai Fisheries Group Corporation with five experimental enclosures. It shows that the numbers of sediment bacteria ranged from 4.10 x 10(8) to 12.36 x 10(8) cells.g-1, averaged 8.09 x 10(8) +/- 2.17 x 10(8) cells.g-1, and increased gradually with increasing cultural time. The maximum was in 0-1 cm layer, and decreased obviously bellow 2-3 cm layer.