Ecosystem Health Report
- Additional Information
Summary Of results: 2011-2012
Most reporting areas remained stable or improved in 2011-12, with the exception of the Connors and Marine zone and this led to the Fitzroy Basin retaining an overall C grade. All reporting areas retained their grading from the previous year, except the Lower Dawson, which moved to a B.
It was a less extreme wet season compared to the previous year. Generally there was an improvement in turbidity, metal and nutrient results and a decline in salt and sulfate scores.
Factors that influenced the scores in this report card included less intense rainfall and flow than the previous year resulting in less catchment runoff as well as prolonged river flow in the second half of 2011 fed by higher groundwater levels.
In 2011-12 the Marine zone was again found to be in poor condition. This is likely attributable to continuing impacts from the 2011 floods resulting in larger sediment and nutrient loads reaching the marine area, as well as physical disturbance from storms during that period.
Adequate data exists for most water quality indicators in some reporting areas. Major data gaps remain for many some indicators, particularly indicators in the ecology category . Preliminary work is currently underway to help address the issue of monitoring gaps and associated data deficiency in the longer term.
The current report focuses on aquatic ecosystem health. Drinking water reporting for Rockhampton Regional and Central Highlands Regional Councils will be released in the near future.
Facts about the Fitzroy Basin
At 142 600 km2 the Fitzroy Basin is the largest catchment on the eastern seaboard. It covers more than a third of the land that catches water and drains to the Great Barrier Reef. Named after New South Wales (NSW) Governor, Sir FitzRoy, the basin is dissected by the Tropic of Capricorn and is characterised by a humid coastal and semi-arid inland subtropical climate.
The basin is separated into six major river catchments: Isaac/Connors, Nogoa, Comet, Mackenzie, Dawson and Fitzroy, which flows into the ocean at Keppel Bay. This has been further separated into 11 waterway reporting catchments.
Seasonal irregularity is a defining feature of the basin, with long dry spells often followed by intense wet season rainfalls. Mean annual rainfall varies from 600 mm in the west, to 800 mm in the east, peaking at 1000 mm in northern coastal area. Due to its extreme size and fan like shape, the Fitzroy Basin is capable of producing large flooding. The highest recorded flood occurred in 1918.
Around 120,000 people live in the basin, with most living in the urban centre of Rockhampton. Current land use across the basin is 81% for grazing; 6% for cropping; 6% for conservation; 5% for forestry; 1% for urban; 0.5% for mining and 0.5% for irrigation.
The Fitzroy Basin is home to a number of rare and threatened species, and internationally significant wetlands. It has the greatest diversity of native freshwater fish in Australia and supports commercial and recreational fisheries significant to Queensland.
The Fitzroy River mouth marks the beginning of waters described as the Great Barrier Reef World Heritage Area. Flood plumes discharged from large floods extend east across the Capricorn Bunker Group and north of Townsend Island, covering an area greater than 10 000 km2.
Plumes from average floods inundate Keppel Bay. Keppel Bay is home to reefs with some of the highest coral cover of any within the Great Barrier Reef. These inshore reefs are at risk from the impacts of sediment, nutrients, and chemicals, and this risk is exacerbated by climate change.