Inshore Central

The northern boundary of the Central inshore reporting zone area extends north-east from Cape Grafton just south of Cairns to the offshore boundary and includes enclosed coastal, open coastal and mid-shelf waters. The southern boundary of the Central zone extends due eastward from the mainland just south of the Moresby River at Double Point to the boundary of the offshore waters.

The major rivers discharging into the central zone are the Mulgrave River the Russell River and Johnstone River. The Moresby River discharges into the southern coastal area of the Central zone. Numerous smaller waterways drain coastal sub catchments that discharge into the Central zone.

Water quality in the Central zone is affected by plumes of sediments, nutrients and pesticides from rivers discharging directly into the zone but also from the plumes of southern rivers, particularly the Tully/Murray, which are carried north by prevailing currents.

The area includes Fitzroy Island to the north, the High Island Group some 12km north-east of Deeral, the Frankland Island group approximately 16 km due east of Deeral and Normanby Island located between the High Island group and the Frankland Island group. These islands provide fringing shallow water environments that support coral reef ecosystems.

Scroll down for further detailed results for each indicator group.



very good








very poor


insufficient data


not applicable

Confidence surrounding the data used in the circle diagrams has been assessed using a multi-criteria framework.


Water quality

Hover over each segment for indicator scores and data confidence.

The overall water quality grade in 2014/15 for the Central inshore zone is ‘good’ (67.6).

Water quality grades are based on water quality guideline trigger values established for the waters of the Great Barrier Reef Marine Park that, if exceeded, identify the need for management responses. The guidelines are not targets and are not an assessments of pollutant loads entering the marine environment.

The results are derived from in-situ water samples taken at eight locations and from water quality loggers at three locations from inshore waters extending from sites at Fitzroy Island in the north to sites at the Frankland Island Group in the south. In addition passive contaminant samplers are located at Fitzroy Island and Normanby Island.

The water clarity score of 55.6 (moderate) in the Central zone is comprised of total suspended solids (moderate) and turbidity (good).

Nutrients scored 57.2 (moderate) in the Central zone, comprising of ‘moderate’ for oxidised nitrogen (NOx), a ‘moderate’ for particulate nitrogen (PN) and a ‘good’ for particulate phosphorus (PP).

The chlorophyll a score in the Central zone 62.6 (good).

Using the Photosystem II herbicide equivalent concentrations method, contaminants received a score of 95.0 (very good).


Hover over each segment for indicator scores and data confidence.

The overall coral grade in 2014/15 for the Central inshore zone is 59.2 (moderate).

The coral grade is comprised of the density of juvenile hard corals score of 48 (moderate), the macroalgae cover score of 75 (good), the coral cover score of 62 (good), the change in coral cover score of 57 (moderate), and the coral community composition score of 54 (moderate).

Physical damage including loss of coral cover occurred at most reefs in the Central zone during a sequence of tropical cyclones since 2006. In addition to the loss of coral cover was an increase in the cover of macroalgae at several reefs despite the water quality being scored as “good”.

In the Central zone, in the absence of any acute disturbance events since 2014, scores for the majority of coral indicators have improved over the last two years. Improvement across a range of indicators provides a positive indication of coral community resilience.

This explanatory information of coral condition in the Central zone is based on the Marine Monitoring Program report by Thompson et al. (2016).


Hover over each segment for indicator scores and data confidence.

There is no current seagrass monitoring undertaken in the Central zone and consequently there is no seagrass grade available for the pilot report card in the Central zone


Hover over each segment for indicator scores and data confidence.

The fish index is currently under development and will be available in future report cards.

Further information on the methods used to produce the scores and grades and detailed results can be found here.