108
11. Terrestrial Runoff to the Great
Barrier Reef and the Implications
for Its Long Term Ecological Status
J. Brodie and K. Fabricius
The Great Barrier Reef (GBR) region with its two layers
of protected areas (the GBR Marine Park and the GBR
World Heritage Area) is a large marine ecosystem adjacent to the north-east Australian coast. The land adjacent
to the GBR forms the GBR Catchment Area (GBRCA)
(Fig. 11.1) from which many rivers and streams discharge into the GBR. As the GBRCA has been developed
for agricultural, industrial and residential use over the
last 150 years, waters discharged from GBRCA rivers
have contained increasing amounts of nutrients, sediments and other pollutants.
Discharges of suspended sediments from the GBRCA
to the GBR, estimated from monitoring and modelling
studies, have increased by approximately five times, nitrogen exports by four times and phosphorus exports
by 10 times. Some pesticides are now also being discharged to the GBR at potentially ecologically relevant
concentrations. The sources of these pollutants are the
principal land uses on the GBRCA: sediments and nutrients from beef grazing, primarily through increased
soil erosion; sediments, nutrients and pesticides (currently mainly herbicides) from cropping (sugarcane, banana and other horticulture, cotton, and grain crops)
associated with soil erosion, fertiliser use and pesticide
Endeavour
Jacky Jacky
Olive-Pascoe
Stewart
Daintree
Mossman
Mulgrave-Russell
Johnstone
Tully
Don
Haughton
Normanby
Herbert
Ross
Burdekin
Pioneer
Fitzroy
Boyne
Burnett
Kolan
Calliope
O’Connell
Lockhart
Jeannie
Endeavour
Murray
Hinchinbrook Island
Whitsunday Islands
Plane
Shoalwater
Waterpark
Curtis Island
Baffle
Fraser Island
Noosa
Mary
Burrum
Styx
Black
Barron
Proserpine
Cooktown
Port
Douglas
Cairns
Innisfail
Cardwell
Townsville
Bowen
Proserpine
Gladstone
Rockhampton
Mackay
The Great Barrier
Reef Lagoon
Australia – Major
Drainage Divisions
The Great
Barrier
Reef World
Heritage
Area
Figure 11.1 The Great Barrier Reef (GBR) and the Catchment Area (GBRCA). (Data source: Auslig Australia PL.)
11. Terrestrial Runoff to the Great
Barrier Reef and the Implications
for Its Long Term Ecological Status
J. Brodie and K. Fabricius
The Great Barrier Reef (GBR) region with its two layers
of protected areas (the GBR Marine Park and the GBR
World Heritage Area) is a large marine ecosystem adjacent to the north-east Australian coast. The land adjacent
to the GBR forms the GBR Catchment Area (GBRCA)
(Fig. 11.1) from which many rivers and streams discharge into the GBR. As the GBRCA has been developed
for agricultural, industrial and residential use over the
last 150 years, waters discharged from GBRCA rivers
have contained increasing amounts of nutrients, sediments and other pollutants.
Discharges of suspended sediments from the GBRCA
to the GBR, estimated from monitoring and modelling
studies, have increased by approximately five times, nitrogen exports by four times and phosphorus exports
by 10 times. Some pesticides are now also being discharged to the GBR at potentially ecologically relevant
concentrations. The sources of these pollutants are the
principal land uses on the GBRCA: sediments and nutrients from beef grazing, primarily through increased
soil erosion; sediments, nutrients and pesticides (currently mainly herbicides) from cropping (sugarcane, banana and other horticulture, cotton, and grain crops)
associated with soil erosion, fertiliser use and pesticide
Endeavour
Jacky Jacky
Olive-Pascoe
Stewart
Daintree
Mossman
Mulgrave-Russell
Johnstone
Tully
Don
Haughton
Normanby
Herbert
Ross
Burdekin
Pioneer
Fitzroy
Boyne
Burnett
Kolan
Calliope
O’Connell
Lockhart
Jeannie
Endeavour
Murray
Hinchinbrook Island
Whitsunday Islands
Plane
Shoalwater
Waterpark
Curtis Island
Baffle
Fraser Island
Noosa
Mary
Burrum
Styx
Black
Barron
Proserpine
Cooktown
Port
Douglas
Cairns
Innisfail
Cardwell
Townsville
Bowen
Proserpine
Gladstone
Rockhampton
Mackay
The Great Barrier
Reef Lagoon
Australia – Major
Drainage Divisions
The Great
Barrier
Reef World
Heritage
Area
Figure 11.1 The Great Barrier Reef (GBR) and the Catchment Area (GBRCA). (Data source: Auslig Australia PL.)