Salmon farms follow stocking and fallowing cycles as part of regular operations with the aim to ensure ongoing health of the benthic environment within the lease. During the fallowing period, benthic communities partially recover, although rarely return to conditions observed pre-farming. In this study we examined change in benthic conditions within and around a salmon lease at a high energy, sandy site, both during active farming and subsequent decommissioning. Atlantic salmon (Salmo salar) were farmed in sea cages at this site for nearly five years, before farming finished on the lease in June 2019. Nine monitoring surveys were undertaken, two years during and five years post-production. Survey parameters included macrofaunal community structure, redox potential, sulphide levels, sediment organic content, particle size distribution, carbon and nitrogen isotopic ratios, and remotely operated vehicle footage (ROV). In addition, mesocosm incubations were undertaken to quantify sediment fluxes in oxygen and nutrients. Results show clear impacts to sediment condition during farming operations, that reduced with both distance and time. Macrofaunal community, ROV footage and oxygen flux rates were the most sensitive measures, with differences under cage sites detected after five years of fallowing compared to control data.