Quantification of sediment reworking rates in bioturbation research: a review

This review lists and discusses the different methods currently available to assess sediment reworkingby benthic infauna. Direct methods are used to estimate the amount of sediment transported by infauna at the sediment-water interfaceduring a given period of time. Particle-tracer methods are used to quantify the vertical distribution of particle tracers within the sediment column. Tracers are classified based on their mode of introduction at the sediment-water interface(i.e. whether they occur naturally or are deliberately introduced at the onset of the experiment). The main characteristics of each method, in- cluding modelling aspects, are presented, and their respective advantages and drawbacks are outlined with a particular emphasis on their accuracy, spatial (i.e. both horizontal and vertical) and temporal resolutions. Direct and particle-tracer methods assess different components of sediment reworking. Se- lection of the most appropriate approach depends on the specific question(s) to be answered, as well as other factors, including the behaviour of the organisms studied, the spatial and temporal scalescon- sidered, and whether the experiments are carried out in situ or under controlled laboratory conditions.