An assessment of manganese and iron in Kentucky Lake using Tubifex tubifex (Oligochaeta:Tubificidae)

The sediment reworking rates of Tubifex tubifex were measured in various Kentucky Lake sediments using a 137cesium marker layer in natural sediments and in sediments with various iron and manganese levels and a gamma-scan biomonitoring system to assess the suitability of Kentucky Lake benthic habitats with respect to burrowing organisms. The gamma-scan experiment indicated that burrowing organisms cannot inhabit the sediments from the eastern side of the lake. Worm activity rates decreased as manganese concentrations were increased.. However, when iron was added to sediments at three levels (20.2, 60.0, and 100 mg/L) the worm activity rates did not correspond with increasing concentrations.