Hydrobiology experts have been providing on-ground support to BHP on a regular basis since dam failure in late 2015. This has involved impact characterisation related to: aquatic ecology, marine and fresh water quality, and geomorphology. Support has involved regular site visits as well as remote data analysis in Australia. In conjunction with Brazilian scientists, Hydrobiology has designed and led several primary data collection efforts including hydroacoustics to quantify fish stocks and habitat in the Rio Doce system, and will soon commence an electrofishing program amongst impacted and reference upstream catchments.