Environmental Condition Grades
The Environmental Condition Grade for each catchment is calculated by combining the results of a freshwater (biophysical and habitat), estuarine (water quality and habitat) and pollutant load assessment. Indicators are assessed against established guidelines and benchmarks, resulting in a single grade for each catchment or bay zone. The data used to calculate the grades is collected using an integration of computer modelling and field monitoring.
(A) Excellent: Conditions meet all guidelines. All key processes are functional and critical habitats are in near pristine condition.
(B) Good: Conditions meet guidelines for most of the reporting area. Most key processes are slightly impacted and most critical habitats are intact.
(C) Fair: Conditions are close to meeting guidelines in most of the reporting area. Key processes are impacted but still functional and critical habitats are impacted.
(D) Poor: Conditions meet few of the guidelines in most of the reporting area. Many key processes are not functional and most critical habitats are impacted.
(F) Fail: Conditions do not meet the set guidelines. Most key processes are not functional and most critical habitats are severely impacted.
Environmental Condition: Catchment Grades
There are 75 freshwater sites that are measured annually, and 138 estuarine sites measured eight times per year. Pollutant load data (sediment and nutrients) are collected during major rainfall events from six sites across South East Queensland. The following components are measured to form an overall grade for each South East Queensland catchment.
- Freshwater biophysical: Fish, aquatic macroinvertebrates, water quality, ecosystem processes
- Freshwater habitat: Riparian
- Estuarine Water Quality: Turbidity, chlorophyll a, Total nitrogen, total phosphorus, dissolved oxygen
- Estuarine Habitat: Mangroves, casuarina, saltmarsh
- Sediment load, nutrient loads (phosphorus and nitrogen).
Environmental Condition: Bay Zone Grades
The bay zone grades are calculated by combining a water quality, habitat and process assessments using the following indicators:
- Turbidity, chlorophyll a, total nitrogen, total phosphorus
- Seagrass distribution, mangroves, sediment
- Seagrass depth range