Description: The Benthic Impact Experiment (BIE) is designed to address the effects of sediment redeposition prior to the commencement of commercial mining in the deep sea. The experiment is being conducted in collaboration with Russian scientists from the Yuzhmorgeologiya Association aboard the R/V YUZHMORGEOLOGIYA. Sediment resuspension and subsequent redeposition during manganese-nodule mining is predicted to be the primary impact on benthic communities living on the abyssal seafloor. Sediment redeposition could adversely affect abyssal benthic communities through entombment, spatio-temporal changes in recruitment patterns, or through starvation caused by food dilution and obstructed feeding. The Deep Sea Sediment Resuspension System was built by the National Oceanic and Atmospheric Administration (NOAA) to study the effects of sediment redeposition on the deep-sea benthos. Initial trials and experiments with the Deep Sea Sediment Resuspension System were conducted in 1991 and 1992. However the sediment redeposition results were not satisfactory; a second generation Deep Sea Sediment Resuspension System (Disturber) was manufactured and tested in 1993. The new Disturber fluidizes the sediments in the top layer, lifts the sediment slurry and discharges it 5 m above the seafloor. In July 1993 NOAA started the BIE with baseline studies which included deployment of a transponder net and current meters, and side scan sonar/camera surveys in the study area. In August 1993 the baseline current meters were recovered, baseline box core samples were randomly collected from the study area, and sediment traps and current meters with transmissometers were deployed. Following the baseline activities the 4900-m deep experimental area was blanketed with varying thicknesses of sediment using the Disturber. In the BIE, the Disturber was towed 49 times through a 150-m-x-3,000-m tow zone resuspending 4,000 m 3 of wet sediment. Northerly currents at the time of disturbance transported the bulk of resuspended sediment to the north as indicated by the sediment trap and transmissometer data. Results indicate that the discharged sediment did not travel far, settling quickly as a sediment-laden fluid flow.