Gully erosion is a major sediment source to the Great Barrier Reef (GBR). Nutrients are exported in association with sediment erosion in various forms (e.g., dissolved and particulate). Some of these nutrient forms are or become bioavailable (e.g., dissolved inorganic nitrogen (DIN)) as they are transported, along with suspended sediment, through catchments and eventually into marine fine sediment plumes (Garzon-Garcia et al., 2021, 2018, in prep). An increase of bioavailable nutrients and sediment delivered to the coastal environments of the GBR since the arrival of Europeans has been associated with a range of damaging effects to the GBR.