Great barrier reef

length and area of GBR

2300km long, 348000km2

area of Coral Triangle

6 million square km

how many individual reefs in GBR

2900

what percentage of global reefs does the GBR make up

10%

types of coral reefs found in GBR

fringing, barrier, patch, atolls, and coral cays

latitude and longitude range of Coral Triangle +major circle of latitude

23N-13S, 115E-165E, tropics and equatorial

latitude and longitude range of GBR + major circle of latitude

8S-24S, 142E-154E, tropics

6 major countries that Coral Triangle surrounds?

surrounds Indonesia, Malaysia, Papua New Guinea, Philippines, Solomon Islands, and Timor-Leste

where is GBR located in the world

East coast of North Queensland

amount of hard coral and fish species at Coral Triangle

600 coral with 15 endemic, 2000 fish

amount of hard coral and fish species at GBR

400 coral, 1500 fish

ecological functioning: CaCO3 nutrient cycle

hard corals use CaCO3 to build limestone, when dead new coral grow or weathered to form new landforms like coral cays

ecological disturbances: nutrient overload

5x phosphorous, 3x nitrogen being delivered to GBR due to agricultural pesticides and fertilisers, leads to algae blooms which depletes CO2 and kills fish

ecological disturbances: excess sediment

turbidity means no photosynthesis for polyps so coral dies

ecological disturbances: cyclones

Cyclone Debbie 2017, heavy rain led to erosion and increased turbidity, AIMS found up to 95% coral destroyed in some Whitsunday reefs

vulnerability and resilience of GBR

location in warm coral sea makes vulnerable to tropical cyclones and human settlements, size and biodiversity increase resilience

GBR ecological disturbances: crown of thorn starfish

consumes up to 10m2 coral a year, 4 major outbreaks in past 60 years, quick to repopulate at age 2, reefs lose up to 90% of hard coral

GBR ecological disturbances: increased survival of crown of thorn starfish

increase in nutrient = increase of plankton = more survive to breeding age, reduction in predators eg coral trout and rock cod which are fished

GBR human induced modifications: recreational/commercial sea vessels general impact

source of pollution through oil spills and rubbish

GBR human induced modifications: recreational/commercial sea vessels ballast water

small animals and plant species transported, estimated 250 species with 15 confirmed

GBR human induced modifications: recreational/commercial sea vessels movements

estimated 11 000 large ship movements annually, potential for major spill

GBR human induced modifications: bleaching in 2024

surveyed reefs 2024 from AIMS: 21% had 30-60% coral cover bleached, 31% had 60-90%, and 8% had >90%

GBR human induced modifications: agricultural and aquaculture

chemical fertilisers can increase nutrients leading to algal growth, major source of soil erosion

GBR response to maintain ecosystem: overview of reducing nitrogen and soil erosion + initiator

Part of the Reef 2050 water quality improvement plan, 80% reduction in dissolved inorganic nitrogen and 50% reduction in soil erosion from catchments, initiated by GBRMPA

GBR response to maintain ecosystem: progress towards dissolved inorganic nitrogen, sediment, particulate phosphorus and nitrogen in 2021-22

very poor progress to inorganic nitrogen, poor progress to sediment, very good progress to particulate phosphorus and moderate progress towards nitrogen

GBR response to maintain ecosystem: regions with greatest reduction in dissolved nitrogen and sediment + why

Burdekin catchment dec by 3% due to improved sugarcane practises, Murray and Endeavour catchment dec 5.3% due to streambank repair projects and improved grazing land management

GBR response to maintain ecosystem: overview of mooring/anchoring + initiator

Reducing impacts of heavy metal anchors damaging the coral formations and dredging up seagrass beds, initiated by GBRMPA and Queensland Government

GBR response to maintain ecosystem: zoning of allowed mooring/anchoring areas

Zoning areas of the reef as 'no anchor' to protect fragile ecosystem, also supported by floating markers for visibility

GBR response to maintain ecosystem: public mooring + money invested + amount

Public moorings which are permanently fixed to the seabed which allows boatskippers to secure boat without anchors, $3.9 million Reef Trails project with 1234 total public moorings

GBR response to maintain ecosystem: overview of shipping regulations + initiator

Reduce the impacts of large ships colliding with coral and damaging reef structure, along with oil, chemical, and natural gas spill, initiated by Australian Government in 1991

GBR response to maintain ecosystem: details of shipping regulations (sea pilot and entry points)

Ships longer than 70m and/or carrying cargo of oil, chemicals, or liquefied natural gas require a sea pilot, 6 main channels which ships are allowed to pass through to enter the reef

GBR response to maintain ecosystem: evidence of shipping regulation effectiveness

Before 1991 it averaged 2.85 collisions a year, the years after average 1.18 collisions a year

economic differences in management: GBR

13th largest economy in 2023, management strategies do not impact greatly on coastal communities

economic differences in management: Coral Triangle

Disparities in economic development between countries, food insecurity and high incidence of poverty, 120 million dependence on marine resources for income and food

political differences in management: Coral Triangle

6 member countries, international organisations, national departments, and NGOS, regions may operate under different laws and customs

political differences in management: GBR

State and national government departments, bodies, and multiple NGOs

socio-cultural differences in management: Coral Triangle

Wide range of Indigenous and cultural groups means different tenure systems, beliefs, and customs, linguistic complexity and remote communities make communication difficult

socio-cultural differences in management: GBR

80% of Queenslanders spoke only English at home, Indigenous and Torres Strait Islander peoples, made up 4.6% pop. of Queensland and are entitled to undertake activities related to customs and traditions