31Excessive transport of fine sediment, and its associated pollutants, can cause detrimental impacts in 32 aquatic environments. It is therefore important to perform accurate sediment source apportionment 33 to identify hotspots of soil erosion. Various tracers have been adopted, often in combination, to 34 identify sediment source type and its spatial origin, these include: fallout radionuclides, geochemical 35 tracers, mineral magnetic properties and bulk and compound-specific stable isotopes. In this review, 36 the applicability of these techniques to particular settings and their advantages and limitations are 37 reviewed. By synthesizing existing approaches, that make use of multiple tracers in combination 38 with measured changes of channel geomorphological attributes, an integrated analysis of tracer 39 profiles in deposited sediments in lakes and reservoirs can be made. Through a multi-scale approach 40 for fine sediment tracking, temporal changes in soil erosion and sediment load can be reconstructed 41 and the consequences of changing catchment practices evaluated. We recommend that long-term, 42 as well as short-term, monitoring of riverine fine sediment and corresponding surface and 43 subsurface sources at nested sites within a catchment are essential. Such monitoring will inform the 44 development and validation of models for predicting dynamics of fine sediment transport as a 45 function of hydro-climatic and geomorphological controls. We highlight, that the need for 46 monitoring is particularly important for hilly catchments with complex and changing land-use. We 47 recommend that research should be prioritized for sloping farmland-dominated catchments. 48 49

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