ENVIRONMENTAL
RESULTS
ABOUT THE ZONE
Calliope Estuary is fed by Gladstone Harbour’s largest freshwater catchment. The main tributaries of the Calliope River include Oakey, Paddock, Double and Larcom Creeks.
WATER & SEDIMENT
Calliope Estuary received an overall water quality score of 0.86 (A).
Sediment quality of Calliope Estuary was very good with an overall score of 0.99 (A).
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The following graphs compare the Water and Sediment scores reported for 2024 (top line) to those from 2023.
WATER
SEDIMENT
Very good (0.85-1.00)
Poor (0.25-0.49)
Good (0.65-0.84)
Satisfactory (0.5-0.64)
Very Poor (0.00-0.24)
No data available
Overall, Water quality in Calliope Estuary scored 0.86 and received a very good grade (A), improving a grade from the 2023 report card. This score was calculated by aggregating the three sub-indicator and associated measure scores (Physicochemical – pH and turbidity, Nutrients – total nitrogen, total phosphorus and dissolved metals, and dissolved metals – aluminium, copper, lead, manganese, nickel and zinc).
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Within the Physicochemical sub-indicator, Calliope Estuary received a score of 1.00 and a very good grade (A) for pH, indicating that the average pH was within the guideline value range. This zone received a score of 0.50 and satisfactory grade (C) for turbidity, indicating that average turbidity was within the guideline value range.
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Within the Nutrient sub-indicator group, total nitrogen (0.51) received a satisfactory grade (C), indicating that total nitrogen was below the guideline value. Total phosphorus (0.79) and chlorophyll-a (0.81) both received good (B) grades, indicating that average concentrations for these measures were below the guideline values.
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All six Dissolved metals received high scores (1.00) and very good grades (A), indicating that concentrations were well below the water quality guideline values.
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For Sediment quality, Calliope Estuary received an overall score of 0.99 and a very good grade (A), a similar result to the previous year. This score was calculated by aggregating measure scores (Metal and metalloids – arsenic, cadmium, copper, lead, mercury, nickel and zinc).
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In 2024, all seven Metal and metalloid sub-indicator measures received very high scores (0.91-1.00) and very good grades (A) indicating that metal concentrations were well below guideline values.
HABITATS
MANGROVE RESULTS
Overall in 2024, Mangroves at Calliope Estuary improved from a satisfactory grade (C) in 2019 to a good grade (B). Mangrove extent improved from a good grade (B) at Calliope Estuary in 2019 to a very good grade (A) in 2024. The grade for canopy condition at Calliope Estuary improved from a poor (D) in 2019 to a good (B) in 2024. Shoreline condition of mangroves at Calliope Estuary improved in grade from a poor (D) in 2019 to a satisfactory (C) in 2024.
FISH & CRABS
FISH RECRUITMENT RESULTS
Fish recruitment was assessed for two species: Yellowfin bream Acanthopagrus australis and Pikey bream Acanthopagrus pacificus. The overall grade for Fish recruitment at Calliope Estuary improved from a poor (D) in 2023 to a satisfactory (C) in 2024.
MUD CRAB RESULTS
The overall zone score for Mud crabs at Calliope Estuary in 2024 was 0.38, resulting in a poor grade (D), a decline in grade from the previous year (0.54, C). The scores for abundance and prevalence of rust lesions remained consistent and indicate low catch rates and low prevalence of rust lesions.