Marine – What’s in a Grade?

Our results aren‘t simply pulled out of the sky, they have been prepared using a set of formulas and scores that are applied from the indicator level all the way to the Basin grade. All of these steps and their application are based on best available science along with the expert knowledge and guidance of our science panel.

Marine Zone

The marine reporting area utilises data provided from the Marine Monitoring Program and the scoring of these indicators aligns with Reef Plan reporting.


Freshwater catchments and Estuary

The freshwater and estuary reporting areas are assessed with a different rating system to the marine reporting area, using indicators, grades, thresholds and a normalising formula.

Marine Indicator Categories

The marine area has different indicator categories to the other reporting areas: Water Quality, Seagrass and Coral. These contribute evenly (33.3% each) to the overall marine score.

The Water Quality category consists of:

  • Chlorophyll a, and
  • Total Suspended Solids

The Seagrass category consists of:

  • Abundance
  • Reproductive Effort, and
  • Nutrient Status

The Coral category consists of:

  • Coral cover
  • Change in hard coral cover
  • Macroalgae cover, and
  • Juvenile density

The indicator scores are evenly weighted within their categories to give the category scores, which are averaged to calculate the overall marine score.