Russell-Mulgrave Estuary

The area of the Russell-Mulgrave estuary reporting zone can be defined by the pre-cleared extent of mangrove and saltmarsh remnant vegetation which is characterised by species that require periodic inundation of sea water.

This area extends approximately 1.5 km north and 2 km south of the river mouth along the coastline and extends approximately 5.2 km inland. The area includes the confluence of the Russell River and Mulgrave River and several coastal tributaries that drain into the main river channels.

The assessment area of riparian extent extends further up the river than the mangrove and salt marsh communities to the upper tidal limit and includes vegetation types that are more typical of freshwater environments.

Land use within and adjacent to the Russell-Mulgrave estuary area is dominated by grazing in native vegetation in the downstream reaches with cropping more dominant upstream of the confluence on both the Russell and Mulgrave rivers, with some residential development. The localities of Deeral and Bellenden Ker are just west of the estuary area.

Key results for 2024-25

The Russell-Mulgrave estuary grade has remained ‘good’ with the score increasing from 66 to 71.

• Water quality remained ‘good’, with the score increasing from 71 to 73.
• Pesticide risk remained low, the grade remained ‘good’.
• Dissolved oxygen declined from ‘good’ to ‘moderate’.
• Dissolved inorganic nitrogen (DIN) improved from ‘poor’ to ‘moderate’.
• Filterable reactive phosphorus (FRP) increased from 61 to 80, the grade remained ‘good’.
• The habitat and hydrology index improved from ‘moderate’ to ‘good’.
• Mangrove and saltmarsh extent remained ‘very good’ with no recorded habitat loss since 2019.
• Riparian vegetation extent remained ‘poor’ with a 0.2 km2 of habitat increase recorded since 2019.
• The flow indicator improved from ‘moderate’ to ‘very good’ due to the return of a more typical rainfall pattern for the region. Poorer scores in 2023-24 were influenced Severe Tropical Cyclone Jasper (TC Jasper) and the early onset of the wet season and intense rainfall and flood events from mid-December. 

The diagram below shows the detailed results for each indicator by year. Click on the timeslider to see data from previous years.