ENVIRONMENTAL
RESULTS
ABOUT THE ZONE
Rodds Bay is located to the south-east of the Outer Harbour zone. The eastern side of Rodds Bay includes a number of mangrove islands. The creeks that flow into the bay are mangrove-lined and contain large areas of salt pans.
WATER & SEDIMENT
Rodds Bay received an overall water quality score of 0.87 (A).
Sediment quality of Rodds Bay was very good with an overall score of 0.97 (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 the Rodds Bay zone (0.87) scored similarly to the 2023 report card, remaining a very good grade (A). 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, Rodds Bay received a score of 1.00 and a very good grade (A) for pH, indicating that the pH was within the guideline value range. This zone also received a very good grade (0.88, A) for turbidity, indicating that turbidity was below the guideline value range.
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Within the Nutrient sub-indicator group, total nitrogen (0.58) received a satisfactory grade (C) and chlorophyll-a (0.48) received a poor grade (D). Total phosphorus (0.99) received a very good grade (A), indicating that this measure was well below the guideline value.
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All six Dissolved metals received high scores (1.00) and very good grades (A), indicating that they were well below the water quality guideline values.
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For Sediment quality, Rodds Bay received an overall score of 0.97 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, six of the seven Metal and metalloid sub-indicator measures received very high scores (1.00) and very good grades (A), while one sub-indicator – arsenic – received a high score (0.82) and a good grade (B), indicating that they were below the guideline values for this zone.
HABITATS
SEAGRASS RESULTS
Meadow 94
Meadow 96
Meadow 104
There are three intertidal monitoring meadows in Rodds Bay: Meadows 94, 96 and 104.
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Recent improvements in overall seagrass health in Gladstone Harbour were largely driven by increases in biomass (Meadow 94: poor (0.37, D) in 2023 to very good (0.85, A) in 2024; Meadow 96: poor (0.46, D) in 2023 to good (0.78, B) in 2024) and area (Meadow 94: poor (0.30, D) in 2023 to good (0.74, B) in 2024; Meadow 104: poor (0.38, D) in 2023 to very good (0.93, A) in 2024) scores of the meadows at Rodds Bay. Species composition remained good to very good at all three meadows in this zone.
MANGROVE RESULTS
Rodds Bay has four Mangrove monitoring zones – Rodds Bay East, Rodds Bay West, Pancake Creek, and Hummock Hill. The overall grade for Mangroves at Rodds Bay improved to a good grade (B) in 2024 from a satisfactory (C) in 2019. In 2024, mangrove extent remained a good grade (B) at Rodds Bay. The grade for canopy condition at Rodds Bay remained a satisfactory (C) in 2024. Shoreline condition of mangroves at Rodds Bay was similar to 2019, staying stable with a good grade (B).
FISH & CRABS
FISH RECRUITMENT RESULTS
Fish recruitment was assessed for two species: Yellowfin bream Acanthopagrus australis and Pikey bream Acanthopagrus pacificus. In 2024, the fish recruitment score at Rodds Bay (0.60) was similar to the 2023 report card, remaining a satisfactory grade (C).
MUD CRAB RESULTS
Mud crabs at Rodds Bay received an overall zone score of 0.35, resulting in a poor grade (D), a decline in grade from good (B) in 2023. The 2024 results markedly declined in sex ratio in comparison to 2023. Abundance scores have been consistently low, and graded very poor (E) across years.