Improving our knowledge of marine waters in the Southern inshore zone

The Southern Inshore Marine Zone extends from Cape Palmerston, south of Sarina, to Clairview Bluff and is one of four inshore marine zones included in the Report Card. The Southern Inshore Marine Zone is considered an important habitat for protected dugongs and green sea turtles which graze on seagrass beds found throughout the zone.

From 2014 to 2017 there was no data available for the Southern Inshore Marine Zone and the Partnership worked to establish a monitoring program as a priority to collect data on seagrass, coral and water quality including pesticides.

Our partner, Dalrymple Bay Coal Terminal Pty Ltd (DBCT P/L) funded the program in its entirety between 2017 and 2019, with Dalrymple Bay Infrastructure coming on board as a funding partner in 2019. Both DBCT P/L and DBI recently signed on to continue funding the project, securing the data collection until at least 2026. Their strong commitment to the program will ensure our understanding of waterway health in the Mackay-Whitsunday-Isaac Region continues to grow.

What is the data telling us?

With continued investment from both DBCT P/L and DBI, the Southern Inshore Monitoring Program is now well established with all indicators assessed across multiple years. We’ve summarised the key findings about coral, seagrass and water quality from the program to date in our Community Summary. More scientific detail about these findings is available in the Southern Inshore Monitoring Program Technical Report 2017-22.

A Map showing the reporting zones of the Mackay Whitsunday Isaac Healthy Rivers to Reef Partnership
A map of the reporting region of the Mackay Whitsunday Isaac Healthy Rivers to Reef Partnership.
Southern Inshore Monitoring Program Community Summary 2017-2022
Southern Inshore Monitoring Program Technical Results Summary 2017 - 2022
Seagrass in the Southern Inshore Zone
Seagrass beds in the Southern Inshore Marine Zone, October 2021. Credit: TropWater, James Cook University.
Man on boat.
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LATEST RESULTS

The 2024 Report Card grade for the Southern Inshore Marine Zone

(released in July 2024, based on data collected June 2022 and July 2023)

Water quality

  • Water quality declined from ‘moderate’ to ‘poor’ due to increased concentrations of chl-a and nutrients.
  • The change in nutrients was influenced by declines in particulate nitrogen and particulate phosphorus grades.
  • Chl-a declined at all sites with the Southern Inshore Marine Zone, most noticeably at Fanning Shoal.
  • Pesticide scores were ‘very good’ in line with other monitored inshore marine zones.

Coral

  • Coral scores in the Southern Inshore Marine Zone remained, ‘poor’, despite favourable conditions and a lack of disturbances. Resilience of these ecologically isolated coral communities continues to be challenged by high cover of macroalgae and low density of juvenile hard corals, where persistent algae coral impedes hard coral recruitment.
  • Henderson Island, with less macroalgae cover, is the only reef demonstrating continued recovery following the bleaching event in 2020.

Seagrass

  • Meadows in the Southern Inshore Marine Zone continued to show evidence of high usage of dugongs and turtles, with numerous feeding trails and animal presence detected during surveys.