Moresby Estuary

The area of the Moresby 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 3.3 km north and 2 km south of the river mouth along the coastline and extends approximately 12 km inland. The area includes numerous tributaries that drain into the main river channel.

Land use within the Moresby estuary area is dominated by cropping and pond aquaculture with some residential development. The Moresby locality is on the western fringe of the estuary area. The Port of Mourilyan is located near the mouth of the estuary and exports raw sugar and molasses from a loader, wharf and handling facility.

Key results

The Moresby estuary grade improved from ‘moderate’ to ‘good’ in 2024-25, with the score increasing from 55 to 63.

• Water quality improved from ‘moderate’ to ‘good’ with the score increasing from 55 to 71.
• Turbidity improved from ‘good’ to ‘very good’.
• Chlorophyll a improved from ‘very poor’ to ‘moderate’.
• Mangrove and saltmarsh extent remained ‘very good’ with no recorded habitat loss since 2019.
• Shoreline mangrove habitat condition remained ‘very good’ since the 2023-24 survey.
• Riparian vegetation extent remained ‘good’ with no recorded habitat loss since 2019.
• Seagrass condition grade of ‘very poor’ was unchanged whilst the score declined from 9 to 3, with biomass and meadow extent below long-term averages.

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