Temporal variations in activity and biomass of the smaller benthic biota (size range: Bacteria up to small meiofaunal organisms) were investigated on the Goban Spur continental margin (NE Atlantic) within the framework of the multidisciplinary research programme OMEX ('Ocean Margin EXchange') sponsored by the European Union. Activities and biomasses were estimated analysing a series of biogenic sediment compounds (enzymes, adenylates, DNA, phospho-lipids, particulate proteins). In contrast to the very time-consuming sorting, enumeration and weighing of organisms, the determination of biochemical sediment parameters represents a useful method to obtain rapid information on ecological dynamics within benthic systems. Measurements of activity and biomass parameters on the Goban Spur continental margin showed a strong seasonal cycle with two peaks in spring (May) and autumn (September/October), and a rapid response within days and/or a few weeks of the most reactive part of the benthic community, i.e. bacteria and protozoans (flagellata, ciliata, amoeba, foraminifera), following episodic inputs of organic matter via phytodetritus sedimentation. In general, benthic activities and biomasses decrease with increasing water depth and distance from the shelf, and the seasonal signal fades with increasing depth. However, still high and sometimes even increasing values were found on a terrace in about 3600 m water depth (Pendragon Escarpment) and also on the continental rise, indicating the presence of deposition centres for a down-slope transport of organic material.