Johnstone Estuary

The area of the Johnstone 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 5.4 km inland. The area includes numerous tributaries that drain into the main river channel.

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 Johnstone estuary area is dominated by residential and other urban developments and cropping. Urban development is associated with the town of Innisfail which overlays sections 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

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A water quality overall score and grade cannot be provided for the Johnstone estuary in 2014/15 due to insufficient data. Estuarine water quality monitoring for the Wet Tropics report card commenced 2016 in the Johnstone estuary and will be available for future report cards.

Habitat and hydrology

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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 Johnstone estuary in future report cards.

The mangrove and saltmarsh extent scored 54.4 (poor) with 13.7 per cent loss from pre-clear to 2013. 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 11.6 (very poor) with 77.3 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.