The coastal zone
The coastal zone is the focal point for human-environment interactions in Queensland. While it contains many sensitive ecosystems, it is home to most of the state's population and the site of many intensive economic activities. Queensland's coastal waters are the ultimate sink for many stormwater, waste and nutrient discharges. Growing populations and rising levels of economic activity are placing increasing pressures on the coastal zone. In particular:
- Queensland's coastal zone is home to around 85% of the state's population.
- More than 5000 ships (moving 180 million tonnes of cargo and 130 million tonnes of petroleum products) visit Queensland ports each year.
- Approximately 16 000 000 people visit coastal regions in Queensland each year; these include 1 600 000 tourists visiting the Great Barrier Reef.
- There were an average of 75 oils spills a year in Queensland waters in 1997-2002, 99% were not significant.
- A total of 6 144 865 tonnes of extractive materials was dredged from 86 sites between July 1999 and June 2002.
- Of 29 important fish stocks in Queensland, 12 have a low risk of being fished unsustainably, 14 have a medium risk and 3 (shark, snapper and grey mackerel in the Gulf of Carpentaria) have a high risk.
- Queensland had 1088 ha of aquaculture ponded areas in 2001, including 665 ha of prawns, 182 ha of barramundi and 140 ha of crayfish.
- Nutrient discharged via wastewater accounts for approximately 40% of the total nitrogen and 60% of the total phosphorus released to coastal and estuarine waters in south-east Queensland; levels are typically below 10% elsewhere in the state.
- Diffuse runoff from cropping and grazing lands contributes more than 90% of nutrient loads in catchments north of Bundaberg.
- Water quality sampling in east coast waterways found less than 9% in the Wet Tropics in poor condition. In the Burdekin Dry Tropics, more than 35% of sites were rated as being in poor condition, as were 23% in the Mackay-Whitsunday region, 17% in the Fitzroy, 13% in the Burnett-Mary region, and 22% in south-east Queensland.
- Pesticide sampling of marine organisms found elevated levels of atrazine, diuron, dieldrin, dioxins and organochlorines in a number of coastal waterways and seas.
- Recreational water quality at both beach and river sites in south-east Queensland has generally improved, river sites increasing from 44% to 83% compliance between 1998-99 and 2000-01.
- While the majority of the state's estuaries are in good condition, almost all the estuaries in south-east Queensland are in poor to moderate condition.
- Ten of the twenty listed weeds of national significance occur in coastal areas of Queensland.
- There have been increasing reports of outbreaks of Lyngbya blooms in Deception Bay since 1990, in other parts of Moreton Bay since 1997, and in five areas along the Queensland coast at the end of 2002.
- There were significant outbreaks of crown-of-thorns starfish on the Great Barrier Reef in 1999 and 2000.
- The worst recorded coral bleaching episode was experienced in the Great Barrier Reef in 2002, when almost 60% of 641 reefs surveyed showed evidence of bleaching.
- Fifteen known introductions and nine possible introductions of marine pests threaten Queensland's marine biodiversity
- There are 83 endangered regional ecosystems in the coastal zone; 30% of these are along the Central Queensland Coast.
- A 10-year study on Milman Island showed an annual rate of decline of 3-4% in the nesting population of hawksbill turtles (approximately 4000 are estimated to nest in Queensland). The number of loggerhead turtles nesting in Queensland has declined to fewer than 3000 from an estimated population of 3500 in 1976-77. Both populations of green turtles on the Great Barrier Reef (total of about 38 000 nesting turtles) appear to be in the early stages of decline.
- Two species of marine fish are classified as critically endangered, three are classified as endangered and five are classified as vulnerable.
- Seagrass communities in Queensland have remained relatively stable over the past three years.
Last updated: 19 May 2004