Drivers of change, pressures and impacts on the Great Barrier Reef

Drivers are overarching causes that can drive change in the environment (State of the Environment, 2011; Strategic Assessment Report, 2014) and have also been referred to as underlying causes of change in the environment (Outlook Report, 2014).  For the purposes of the Reef 2050 draft Cumulative Impact Management and Net Benefit policies and the Reef 2050 Integrated Monitoring and Reporting Program, it is proposed to adopt six drivers of change for the Great Barrier Reef system:

  1. Climate change
  2. Population growth
  3. Economic growth
  4. Technological developments
  5. Societal attitudes
  6. Governance systems

Pressures and impacts are mechanisms that exert a change force (either positive or negative) on a value.  Put another way, pressures and impacts are the change mechanisms (e.g. processes or activities) that result from drivers. For the purposes of this policy, pressures are defined consistent with the Outlook Report ‘threats’ (2014) and the Strategic Assessment Report ‘impacts’ (2014).

Pressures and impacts


Acid sulphate soils

Exposure and subsequent oxidation of potential acid sulphate soils.

Altered ocean currents

Altered ocean currents due to climate change or anomalies related to the El Niño-Southern Oscillation, and altered coastal water movement at a local scale.

Artificial light

Artificial lighting including from resorts, industrial infrastructure, mainland beaches and coastlines, vessels and ships.

Atmospheric pollution

Pollution of the atmosphere related to domestic, industrial and business activities in both the Region and adjacent areas. The contribution of gases such as carbon dioxide to climate change is not included as this is encompassed under threats such as sea temperature increase and ocean acidification.

Artificial barriers to flow

Artificial barriers to riverine and estuarine flow including breakwalls, weirs, dams, gates, ponded pastures, and weeds causing changes to hydrology, groundwater and ecological connectivity.

Coastal reclamation

Coastal land reclamation, including for ports and groynes.

Cyclone activity

Cyclone activity.

Damage to reef structure

Physical damage to reef benthos (reef structure) through actions such as snorkelling, diving, anchoring and fishing, but not vessel grounding.

Damage to seafloor

Physical damage to non-reef benthos (seafloor) through actions such as trawling and anchoring, but not vessel grounding.

Disposal and resuspension of dredge material

Sea dumping of dredge material including smothering, loss and modification of seabed habitats and resuspension.


Dredging of the seafloor.

Exotic species and diseases

Introduction of exotic species and diseases from aquaculture operations, hull fouling, ballast release, imported bait and release of aquarium specimens to the Region, plus the introduction of weeds and feral animals to islands.

Extraction – discarded catch

Immediate or post-release effects (such as death, injury, reduced reproductive success) on discarded species as a result of interactions with fishing gear. Does not include species of conservation concern.

Extraction — fishing in spawning aggregations

Retained take (extraction) of fish from unidentified or unprotected spawning aggregations.

Extraction – herbivores

Retained take (extraction) of herbivores (e.g. some fish, molluscs, dugongs, green turtles) through commercial and non-commercial uses.

Extraction – incidental catch of species of conservation concern

Immediate or post-release effects (such as death, injury, reduced reproductive success) of interactions of species of conservation concern with fishing gear.

Extraction — lower order predators

Retained take (extraction) of lower order predators (e.g. coral trout and snapper) through commercial, recreational and traditional fishing.

Extraction — lower trophic orders

Retained take (extraction) of lower trophic orders (e.g. scallops, sea cucumbers and prawns) through commercial, recreational and traditional fishing.

Extraction — top order predators

Retained take (extraction) of top order predators (e.g. sharks) through commercial, recreational and traditional fishing and the Queensland Shark Control Program.

Grounding large vessel

Grounding of large vessels (>50m) including physical damage and the dislodging of antifoulants.

Grounding small vessel

Grounding of small vessels (<50m) including physical damage and the dislodging of antifoulants.

Illegal activities — other

Illegal activities such as entering a protected or restricted area, illegal release of industrial discharge, shipping outside of designated shipping areas.

Illegal fishing and poaching

Illegal fishing, collecting and poaching (foreign or domestic) including of species of conservation concern.

Incompatible uses

Activities undertaken within the Region that disturb or exclude other users, such as recreational use in areas important for cultural activities.

Increased freshwater inflow

Increased freshwater inflow from prolonged or heavy rainfall including flood events, and from changes to catchment ecosystems; resulting in reduced salinity.

Marine debris

Manufactured material discarded, disposed of or abandoned in the marine and coastal environment (including discarded fishing gear and plastics).

Modifying supporting terrestrial habitats

Clearing or modifying supporting terrestrial habitats such as wetlands, saltmarshes, mangroves and sand dunes — this also includes trampling and damage from recreational vehicle use.

Noise pollution

Noise from human activities, both below and above water.

Nutrients from catchment run-off

Nutrients entering the Region in run-off from the catchment.

Ocean acidification

Increasing acidity of the Region’s waters.

Outbreak or bloom of other species

Outbreak of naturally occurring or native species, excluding crown-of-thorns starfish.

Outbreak of crown-of-thorns starfish

Outbreak of crown-of-thorns starfish (i.e. when the density exceeds about 30 starfish per hectare).

Outbreak of disease

Outbreak of disease, both naturally occurring and introduced.

Pesticides from catchment run-off

Pesticides (including herbicides, insecticides, fungicides) entering the Region in run-off from the catchment.

Rising sea level

Rising sea level.

Sea temperature increase

Increasing sea temperature.

Sediments from catchment run-off

Sediments entering the Region in run-off from the catchment.

Spill — large chemical

Chemical spill that triggers a national or regional response or is more than 10 tonnes.

Spill — large oil

Oil spill that triggers a national or regional response or is more than 10 tonnes.

Spill — small chemical and oil

Chemical or oil spill that does not trigger a national or regional response and is less than 10 tonnes

Urban and industrial discharge

Point and diffuse-source land-based discharge of pollutants from urban and industrial land use and mining, including polluted water, sewage, wastewater and stormwater.

Vessel strike on wildlife

Death or injury to wildlife as a result of being struck by a vessel of any type or size.

Waste discharge from a vessel

Waste discharged from a vessel into the marine environment.

Wildlife disturbance

Disturbance to wildlife including from snorkelling, diving, fish feeding, walking on islands and beaches, and the presence of boats; not including noise pollution.