Water and sediment
Water and sediment quality data is a key diagnostic tool in the SWIRC, used to infer both the effect of various pressures on the system (for example, land use and hydrological change can influence water quality) and as a direct stressor to aquatic communities (for example, water quality changes can have direct impacts to aquatic animals).
There is a wide range of chemical and physical attributes of water that can be included in this theme, which can help to indicate the status of catchment and riverine transport and biochemical processes, and interpret any changes seen in biological communities (based on the tolerance of each species).
However, most assessments are limited to factors relevant to all south-west systems (and those that are relatively quick and cheap to collect), such as temperature, dissolved oxygen and salinity.
Data for other contaminants is collected as required based on site-specific risk assessment and compared to established guidelines, for example ANZG 2018.