Inshore South

The northern boundary of the South inshore reporting zone extends due eastward from the mainland just south of the Moresby River at Double Point to the boundary of the offshore waters and includes enclosed coastal, open coastal and mid-shelf waters. The southern boundary of the South zone extends east from the North West bank of the Seaforth Channel mouth, just south of Hinchinbrook Island, to the offshore boundary.

The major rivers discharging into the South zone are the Tully River and the Murray River. The Hull River discharges to the north of the Tully River. Several smaller waterways drain sub catchments that are dominated by agricultural land use, for example Liverpool Creek and Maria Creek, which discharge into the South zone. Numerous smaller creeks discharge to the north of and within Hinchinbrook Channel.

Water quality in the South inshore zone is affected by plumes of sediments, nutrients and pesticides from rivers and creeks discharging directly into the zone but also from the plumes of southern rivers, particularly the Herbert and also the Burdekin located in the Dry Tropics NRM region.

The area includes the Barnard Island group some 7 km east of Cowley Beach, North and South Dunk Island some 7.5 km south east of Mission Beach, and the Bedarra Island group located several kilometres south of the Dunk Island group. The area also includes Hinchinbrook Island. These islands provide fringing shallow water environments that support coral reef ecosystems and intertidal and subtidal reef seagrass meadows. Extensive seagrass meadows fringe the northern and western coastal areas of Hinchinbrook Island. Intertidal coastal seagrass meadows also occur close to the mainland including Lugger Bay approximately 10 km south of Mission Beach.

The overall grade for the South zone in 2022-23 remained ‘moderate’ and the score increased from 53 to 55 since the previous year.

Key results

• The water quality grade in 2022-23 for the South inshore zone improved from ‘moderate’ to ‘good’ and scored 75, increasing from 60 in 2021-22.
• Improvement in grades since the previous year occurred for oxidised nitrogen (NOx), from ‘moderate’ to ‘good’ and particulate nitrogen (PN), from ‘very poor’ to ‘poor’.
• Pesticide monitoring and reporting re-commenced in 2022-23. High scores and a grade of ‘very good’ for pesticides, due to the very low pesticide toxicity risk, contributed to the increase of the water quality index score.
• In the South inshore zone the overall coral condition score declined from 60 in 2021-22 to 56 and the grade remained ‘moderate’.
• Coral cover change declined from ‘good’ to ‘moderate’, and the causes have been linked to higher levels of disease. Macroalgae improved from ‘poor’ to ‘moderate’, whilst juvenile coral score declined from 67 to 61. Densities of juveniles have declined due mostly to growth of corals out of the juvenile size class. 
• Seagrass condition in the South zone remained ‘poor’ with the score decreasing from 40 in the previous year to 36 in 2022-23.

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