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

Scroll down for further detailed results for each indicator group.

Grading

gradesa1

very good

gradesb1

good

gradesc1

moderate

gradesd1

poor

gradese1

very poor

gradesnd1

insufficient data

gradesna1

not applicable

Confidence surrounding the data used in the circle diagrams has been assessed using a multi-criteria framework.

confidence

Water quality

Hover over each segment for indicator scores and data confidence.

The overall water quality grade in 2014/15 for the Russell-Mulgrave estuary is ‘moderate’. Water quality grades are based on aquatic ecosystem guidelines for protection of estuarine waters, and are not based on load reduction targets for the marine environment. The results are derived from a single monitoring site at the confluence of the Mulgrave River and Russell River.

The physical and chemical score of 100 (very good) is comprised of a dissolved oxygen (DO) score of 100 (very good) indicating that the annual median and 80 per cent of the monthly medians of DO comply with guideline values.

Nutrients scored 87.9 (moderate) in the Russell-Mulgrave estuary, comprising of a DIN (dissolved inorganic nitrogen) score of 75.8 (moderate) and FRP (filterable reactive phosphorus) score of 100 (very good) indicating that the annual median and 80 per cent of the monthly medians of FRP comply with guideline values.

The chlorophyll a score in the Russell-Mulgrave estuary was 100 (very good) indicating that the annual median and 80 per cent of the monthly medians of chlorophyll a comply with guideline values.

Using the ms-PAF method, contaminants received a moderate risk category with 5.6 per cent of species affected in the waterways of the Russell-Mulgrave estuary. This resulted in a contaminant grade of moderate for the estuary.

Habitat and hydrology

Hover over each segment for indicator scores and data confidence.

The overall habitat and hydrology grade for the Russell-Mulgrave estuary could not be determined due to insufficient data. The development of the flow and fish barrier indicators will provide sufficient data for habitat and hydrology to be reported for the Russell-Mulgrave estuary in future report cards.

The mangrove and saltmarsh extent scored 100 (very good) with 0.5 per cent loss from pre-clear to 2013. These results reflect a low level of development within the estuary area.

Riparian extent is assessed to the upper tidal limit of the river which extends upstream of the estuary area that is characterised by mangroves and saltmarsh. Thus riparian assessment includes areas that have been cleared for agriculture and other developments.
The riparian extent scored 27.2 (very poor) with 46.8 per cent loss from pre-clear to 2013.
Estuary riparian extent and mangrove and saltmarsh extent are updated every four years and the figures in the pilot report card are the most current. The data for both are due to be updated in 2017/18.

The methods for the flow and fish barrier indicators are currently under development and will be available for future report cards

Fish

Hover over each segment for indicator scores and data confidence.

The fish index is currently under development and will be available in future report cards.

Further information on the methods used to produce the scores and grades and detailed results can be found here.