Ecosystem health technical description

This refers to the extent to which a Freshwater Management Unit (FMU) or part of an FMU supports an ecosystem appropriate to the type of water body (for example, river, lake, wetland, or aquifer).

There are five biophysical components that contribute to freshwater ecosystem health, and it is necessary that all of them are managed. They are:

Water quality – the physical and chemical measures of the water, such as temperature, dissolved oxygen, pH, suspended sediment, nutrients, and toxicants.

Water quantity – the extent and variability in the level or flow of water

Habitat – the physical form, structure, and extent of the water body, its bed, banks, and margins; its riparian vegetation; and its connections to the floodplain and to groundwater.

Aquatic life – the abundance and diversity of biota including microbes, invertebrates, plants, fish, and birds

Ecological processes – the interactions among biota and their physical and chemical environment such as primary production, decomposition, nutrient cycling, and trophic connectivity.

In a healthy freshwater ecosystem, all five biophysical components are suitable to sustain the indigenous aquatic life expected in the absence of human disturbance or alteration (before providing for other values).