Monitoring river health

Rivers support cultural values, tourism, agriculture and development in the region.

To make sure they stay healthy, they're checked yearly in some areas of the Top End.

To assess the health of a river, different factors are considered.

A 'cause and effect' model is used to show how things are connected.

'Cause and effect'

The cause and effect model looks at 3 factors:

pressures - activities that people do that can hurt the environment
stressors - changes that happen to the environment because of these pressures
ecological responses - effects these changes have on plants and animals in the ecosystem.

For example, when people start farming in an area where there used to be natural land, this is a pressure.

Farming can cause more nutrients to get into a nearby creek, which is a stressor.

This stressor can lead to more algae growing in the creek, which is the ecological response.

Cause and effect model - as described above

Sometimes, more than one stressor affects plants and animals in the river.

For example, the growth of aquatic plants is influenced by 3 main factors:

All 3 of these need to be good for the plants and algae to grow well.

Venn diagram of what an algae need to grow - as explained above