161-574: The Great Barrier Reef is the world's largest coral reef system, composed of over 2,900 individual reefs and 900 islands stretching for over 2,300 kilometres (1,400 mi) over an area of approximately 344,400 square kilometres (133,000 sq mi). The reef is located in the Coral Sea , off the coast of Queensland , Australia , separated from the coast by a channel 160 kilometres (100 mi) wide in places and over 61 metres (200 ft) deep. The Great Barrier Reef can be seen from outer space and
322-505: A Cooperative Research Centre , has found coral 'skeleton' deposits that date back half a million years. The Great Barrier Reef Marine Park Authority (GBRMPA) considers the earliest evidence of complete reef structures to have been 600,000 years ago. According to the GBRMPA, the current, living reef structure is believed to have begun growing on the older platform about 20,000 years ago. The Australian Institute of Marine Science agrees, placing
483-730: A Darwin Point is reached. One such point exists at the northwestern end of the Hawaiian Archipelago; see Evolution of Hawaiian volcanoes#Coral atoll stage . However, reefs in the Persian Gulf have adapted to temperatures of 13 °C (55 °F) in winter and 38 °C (100 °F) in summer. 37 species of scleractinian corals inhabit such an environment around Larak Island . Deep-water coral inhabits greater depths and colder temperatures at much higher latitudes, as far north as Norway. Although deep water corals can form reefs, little
644-587: A Holocene hunter-gatherer sample ("Leang Panninge") from South Sulawesi , which shares high amounts of genetic drift with Aboriginal Australians and Papuans. This suggests that a population split from the common ancestor of Aboriginal Australians and Papuans. The sample also shows genetic affinity with East Asians and the Andamanese people of South Asia. The authors note that this hunter-gatherer sample can be modelled with ~50% Papuan-related ancestry and either with ~50% East Asian or Andamanese Onge ancestry, highlighting
805-505: A "shark control" program ( shark culling ) that deliberately kills sharks throughout Queensland, including in the Great Barrier Reef. Environmentalists and scientists say that this program harms the marine ecosystem ; they also say it is "outdated, cruel and ineffective". The Queensland "shark control" program uses shark nets and drum lines with baited hooks to kill sharks in the Great Barrier Reef – there are 173 lethal drum lines in
966-644: A continental shelf, and not around a volcanic island, Darwin's principles apply. Development stopped at the barrier reef stage, since Australia is not about to submerge. It formed the world's largest barrier reef, 300–1,000 m (980–3,280 ft) from shore, stretching for 2,000 km (1,200 mi). Healthy tropical coral reefs grow horizontally from 1 to 3 cm (0.39 to 1.18 in) per year, and grow vertically anywhere from 1 to 25 cm (0.39 to 9.84 in) per year; however, they grow only at depths shallower than 150 m (490 ft) because of their need for sunlight, and cannot grow above sea level. As
1127-578: A depth of 150 metres (490 ft) due to their need for sunlight, and cannot grow above sea level. When Queensland edged into tropical waters 24 million years ago, some coral grew, but a sedimentation regime quickly developed with erosion of the Great Dividing Range ; creating river deltas , oozes and turbidites , unsuitable conditions for coral growth. 10 million years ago, the sea level significantly lowered, which further enabled sedimentation. The reef's substrate may have needed to build up from
1288-504: A disease of bony corals caused by the protozoan Halofolliculina corallasia , affects 31 coral species. According to a 2012 study by the National Academy of Sciences , since 1985, the Great Barrier Reef has lost more than half of its corals with two-thirds of the loss occurring from 1998 due to the factors listed before. In 2022, the northern and central parts of the reef had the highest amount of coral cover since monitoring began, but
1449-545: A draft decision, expressing serious concern about the impact of coral bleaching on the Great Barrier Reef. The draft decision also warned Australia that it will not meet the targets of the Reef 2050 report without considerable work to improve water quality. Climate change has implications for other forms of reef life – some fish's preferred temperature range leads them to seek new habitat, thus increasing chick mortality in predatory seabirds. Climate change will also affect
1610-593: A gene flow from India to Australia: firstly, signs of South Asian components in Aboriginal Australian genomes, reported on the basis of genome-wide SNP data; and secondly, the existence of a Y chromosome (male) lineage, designated haplogroup C∗, with the most recent common ancestor about 5,000 years ago. The first type of evidence comes from a 2013 study by the Max Planck Institute for Evolutionary Anthropology using large-scale genotyping data from
1771-485: A lawsuit against the government of Queensland to stop shark culling in the Great Barrier Reef. In March 2015, the Australian and Queensland's governments formed a plan for the protection and preservation of the reef's universal heritage until 2050. This 35 years plan, titled "Reef 2050 Plan" is a document proposing possible measures for the long-term management of the pollution, climate change and other issues that threaten
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#17328376105301932-731: A person as Indigenous. (Torres Strait Islanders are ethnically and culturally distinct, despite extensive cultural exchange with some of the Aboriginal groups, and the Torres Strait Islands are mostly part of Queensland but have a separate governmental status .) Some Aboriginal people object to being labelled Indigenous , as an artificial and denialist term, because some non-Aboriginal people have referred to themselves as indigenous because they were born in Australia. Australian Indigenous people have beliefs unique to each mob ( tribe ) and have
2093-412: A pinhead to 12 inches (30 cm) across. Reef-building or hermatypic corals live only in the photic zone (above 70 m), the depth to which sufficient sunlight penetrates the water. Coral polyps do not photosynthesize, but have a symbiotic relationship with microscopic algae ( dinoflagellates ) of the genus Symbiodinium , commonly referred to as zooxanthellae . These organisms live within
2254-588: A pool of Aboriginal Australians, New Guineans, island Southeast Asians, and Indians. It found that the New Guinea and Mamanwa (Philippines area) groups diverged from the Aboriginal about 36,000 years ago (there is supporting evidence that these populations are descended from migrants taking an early "southern route" out of Africa, before other groups in the area). Also the Indian and Australian populations mixed long before European contact, with this gene flow occurring during
2415-615: A profound spiritual connection. Over the millennia, Aboriginal people developed complex trade networks, inter-cultural relationships, law and religions. Contemporary Aboriginal beliefs are a complex mixture, varying by region and individual across the continent. They are shaped by traditional beliefs, the disruption of colonisation, religions brought to the continent by Europeans, and contemporary issues. Traditional cultural beliefs are passed down and shared through dancing , stories , songlines , and art that collectively weave an ontology of modern daily life and ancient creation known as
2576-490: A pseudo-atoll. These can be distinguished from real atolls only by detailed investigation, possibly including core drilling. Some platform reefs of the Laccadives are U-shaped, due to wind and water flow. Atolls or atoll reefs are a more or less circular or continuous barrier reef that extends all the way around a lagoon without a central island. They are usually formed from fringing reefs around volcanic islands. Over time,
2737-433: A rapidly subsiding bottom can overwhelm coral growth, killing the coral and the reef, due to what is called coral drowning . Corals that rely on zooxanthellae can die when the water becomes too deep for their symbionts to adequately photosynthesize , due to decreased light exposure. The two main variables determining the geomorphology , or shape, of coral reefs are the nature of the substrate on which they rest, and
2898-408: A rate of about 0.1 per decade this century. The acidic water breaks down the materials that coral and shell building creatures need to grow. Another key threat faced by the Great Barrier Reef is pollution and declining water quality . The rivers of north-eastern Australia pollute the Reef during tropical flood events. Over 90% of this pollution comes from farm runoff . 80% of the land adjacent to
3059-483: A single group. Aboriginal identity has changed over time and place, with family lineage, self-identification, and community acceptance all of varying importance. In the 2021 census , Indigenous Australians comprised 3.8% of Australia's population. Most Aboriginal people today speak English and live in cities. Some may use Aboriginal phrases and words in Australian Aboriginal English (which also has
3220-411: A spirit creates the earth then tells the humans to treat the animals and the earth in a way which is respectful to land. In Northern Territory this is commonly said to be a huge snake or snakes that weaved its way through the earth and sky making the mountains and oceans. But in other places the spirits who created the world are known as wandjina rain and water spirits. Major ancestral spirits include
3381-487: A state icon of Queensland in 2006. A large part of the reef is protected by the Great Barrier Reef Marine Park , which helps to limit the impact of human use, such as fishing and tourism. Other environmental pressures on the reef and its ecosystem include runoff of humanmade pollutants, climate change accompanied by mass coral bleaching , dumping of dredging sludge and cyclic population outbreaks of
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#17328376105303542-470: A strong connection to the land. Contemporary Indigenous Australian beliefs are a complex mixture, varying by region and individual across the continent. They are shaped by traditional beliefs, the disruption of colonisation, religions brought to the continent by Europeans, and contemporary issues. Traditional cultural beliefs are passed down and shared by dancing , stories , songlines and art —especially Papunya Tula (dot painting)—collectively telling
3703-427: A tangible influence of Aboriginal languages in the phonology and grammatical structure ). Many but not all also speak the various traditional languages of their clans and peoples. Aboriginal people, along with Torres Strait Islander people, have a number of severe health and economic deprivations in comparison with the wider Australian community. DNA studies have confirmed that "Aboriginal Australians are one of
3864-423: A zone extending from approximately 30° N to 30° S of the equator. Tropical corals do not grow at depths of over 50 meters (160 ft). The optimum temperature for most coral reefs is 26–27 °C (79–81 °F), and few reefs exist in waters below 18 °C (64 °F). When the net production by reef building corals no longer keeps pace with relative sea level and the reef structure permanently drowns
4025-750: Is an increase in allele sharing between the Denisovan and Aboriginal Australian genomes, compared to other Eurasians or Africans. Examining DNA from a finger bone excavated in Siberia , researchers concluded that the Denisovans migrated from Siberia to tropical parts of Asia and that they interbred with modern humans in Southeast Asia 44,000 years BP, before Australia separated from New Guinea approximately 11,700 years BP. They contributed DNA to Aboriginal Australians and to present-day New Guineans and an indigenous tribe in
4186-471: Is based on the Aboriginal peoples' geographical isolation, with little or no interaction with outside cultures before some contact with Makassan fishermen and Dutch explorers up to 500 years ago. The Rasmussen study also found evidence that Aboriginal peoples carry some genes associated with the Denisovans (a species of human related to but distinct from Neanderthals ) of Asia; the study suggests that there
4347-578: Is constantly changing. Each reef is made up of irregular patches of algae, sessile invertebrates, and bare rock and sand. The size, shape and relative abundance of these patches change from year to year in response to the various factors that favor one type of patch over another. Growing coral, for example, produces constant change in the fine structure of reefs. On a larger scale, tropical storms may knock out large sections of reef and cause boulders on sandy areas to move. Coral reefs are estimated to cover 284,300 km (109,800 sq mi), just under 0.1% of
4508-445: Is directly attached to a shore, or borders it with an intervening narrow, shallow channel or lagoon. It is the most common reef type. Fringing reefs follow coastlines and can extend for many kilometres. They are usually less than 100 metres wide, but some are hundreds of metres wide. Fringing reefs are initially formed on the shore at the low water level and expand seawards as they grow in size. The final width depends on where
4669-456: Is expected to become an annual occurrence. In 2020, a study found that the Great Barrier Reef has lost more than half of its corals since 1995 due to warmer seas driven by climate change. As global warming continues, corals will not be able to keep up with increasing ocean temperatures. Coral bleaching events lead to increased disease susceptibility, which causes detrimental ecological effects for reef communities. In July 2017 UNESCO published in
4830-563: Is how they've collected much of their data regarding threats to the Great Barrier Reef. In addition, the Reef 2050 Water Quality Improvement Plan was announced in 2018 in order to help transition local communities, agricultural organizations and industries to more sustainable practices. This plan will join the Queensland government and the Great Barrier Reef Marine Park Authority to manage the amounts of runoff that reach
4991-513: Is known about them. The northernmost coral reef on Earth is located near Eilat , Israel . Coral reefs are rare along the west coasts of the Americas and Africa , due primarily to upwelling and strong cold coastal currents that reduce water temperatures in these areas (the Humboldt , Benguela , and Canary Currents , respectively). Corals are seldom found along the coastline of South Asia —from
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5152-480: Is no evidence for South Asian gene flow to Australia .... Despite Sahul being a single connected landmass until [8,000 years ago], different groups across Australia are nearly equally related to Papuans, and vice versa, and the two appear to have separated genetically already [about 30,000 years ago]." Aboriginal Australians possess inherited abilities to adapt to a wide range of environmental temperatures in various ways. A study in 1958 comparing cold adaptation in
5313-418: Is often the reef's most diverse area. Coral and calcareous algae provide complex habitats and areas that offer protection, such as cracks and crevices. Invertebrates and epiphytic algae provide much of the food for other organisms. A common feature on this forereef zone is spur and groove formations that serve to transport sediment downslope. The reef flat is the sandy-bottomed flat, which can be behind
5474-453: Is only in the last two hundred years that they have been defined and started to self-identify as a single group, socio-politically. While some preferred the term Aborigine to Aboriginal in the past, as the latter was seen to have more directly discriminatory legal origins, use of the term Aborigine has declined in recent decades, as many consider the term an offensive and racist hangover from Australia's colonial era. The definition of
5635-497: Is that the desert people are able to have a higher body temperature without accelerating the activity of the whole of the body, which can be especially detrimental in childhood diseases. This helps protect people to survive the side-effects of infection. Aboriginal people have lived for tens of thousands of years on the continent of Australia , through its various changes in landmass. The area within Australia 's borders today includes
5796-549: Is the world's biggest single structure made by living organisms. This reef structure is composed of and built by billions of tiny organisms, known as coral polyps . It supports a wide diversity of life and was selected as a World Heritage Site in 1981. CNN labelled it one of the Seven Natural Wonders of the World in 1997. Australian World Heritage places included it in its list in 2007. The Queensland National Trust named it
5957-418: Is thought that the poor water quality is due to increased light and oxygen competition from algae . Farming fertiliser runoff release nitrogen , phosphorus , and potassium into the oceanic ecosystem, and these limiting nutrients cause massive algal growth which eventually leads to a reduction in oxygen available for other creatures in a process called eutrophication . This decreases the biodiversity in
6118-551: The Aboriginal Australian and Torres Strait Islander peoples, and is an important part of local groups' cultures and spirituality. The reef is a very popular destination for tourists, especially in the Whitsunday Islands and Cairns regions. Tourism is an important economic activity for the region, generating over AUD$ 3 billion per year. In November 2014, Google launched Google Underwater Street View in 3D of
6279-530: The Australian mainland and many of its islands, excluding the ethnically distinct people of the Torres Strait Islands . Humans first migrated to Australia at least 65,000 years ago, and over time formed as many as 500 language-based groups . In the past, Aboriginal people lived over large sections of the continental shelf . They were isolated on many of the smaller offshore islands and Tasmania when
6440-486: The CSIRO stressed the importance of taking a demand-driven approach to services in desert settlements, and concluded that "if top-down solutions continue to be imposed without appreciating the fundamental drivers of settlement in desert regions, then those solutions will continue to be partial, and ineffective in the long term." [REDACTED] This article incorporates text by Anders Bergström et al. available under
6601-617: The Cenozoic . Eastern Australia experienced a period of tectonic uplift , which moved the drainage divide in Queensland 400 km (250 mi) inland. Also during this time, Queensland experienced volcanic eruptions leading to central and shield volcanoes and basalt flows. Some of these became volcanic islands . After the Coral Sea Basin formed, coral reefs began to grow in the Basin, but until about 25 million years ago, northern Queensland
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6762-520: The Great Barrier Reef Foundation in 2018. The announcement of the grant was subject to backlash as the grant had avoided proper tender and transparency processes. The Great Barrier Reef contributes to the overall wellbeing of the marine biome. Numerous species of aquatic plants, fish and megafauna use the reef for feeding, shelter and mating. Threats such as ocean acidification , pollution runoff and outbreaks of destructive species like
6923-573: The Initial Upper Paleolithic . They are most closely related to other Oceanians , such as Melanesians . The Aboriginal Australians also show affinity to other Australasian populations, such as Negritos , as well as to East Asian peoples . Phylogenetic data suggests that an early initial eastern lineage (ENA) trifurcated somewhere in South Asia , and gave rise to Australasians (Oceanians), Ancient Ancestral South Indian (AASI), Andamanese and
7084-688: The Kimberley region in what is now Western Australia about 60,000 years ago. They migrated across the continent within 6,000 years. A 2018 study using archaeobotany dated evidence of continuous human habitation at Karnatukul (Serpent's Glen) in the Carnarvon Range in the Little Sandy Desert in WA from around 50,000 years ago. Genetic studies have revealed that Aboriginal Australians largely descended from an Eastern Eurasian population wave during
7245-468: The Late Cretaceous (100–66 Ma), when reefs formed by a group of bivalves called rudists existed; one of the valves formed the main conical structure and the other, much smaller valve acted as a cap. Measurements of the oxygen isotopic composition of the aragonitic skeleton of coral reefs, such as Porites , can indicate changes in sea surface temperature and sea surface salinity conditions during
7406-699: The Mesoamerican Barrier Reef System and the New Caledonian Barrier Reef . Barrier reefs are also found on the coasts of Providencia , Mayotte , the Gambier Islands , on the southeast coast of Kalimantan , on parts of the coast of Sulawesi , southeastern New Guinea and the south coast of the Louisiade Archipelago . Platform reefs, variously called bank or table reefs, can form on the continental shelf , as well as in
7567-578: The Middle Cambrian (513–501 Ma ), Devonian (416–359 Ma) and Carboniferous (359–299 Ma), owing to extinct order Rugosa corals, and Late Cretaceous (100–66 Ma) and Neogene (23 Ma–present), owing to order Scleractinia corals. Not all reefs in the past were formed by corals: those in the Early Cambrian (542–513 Ma) resulted from calcareous algae and archaeocyathids (small animals with conical shape, probably related to sponges ) and in
7728-657: The Northern Territory to study their genetic makeup (which is not representative of all Aboriginal peoples in Australia). The study concluded that the Warlpiri are descended from ancient Asians whose DNA is still somewhat present in Southeastern Asian groups, although greatly diminished. The Warlpiri DNA lacks certain information found in modern Asian genomes, and carries information not found in other genomes. This reinforces
7889-576: The Ok Tedi Mine in Papua New Guinea are a potential pollution risk for the far northern Great Barrier Reef and Torres Strait regions. Some 67% of corals died in the reef's worst-hit northern section, the ARC Centre of Excellence for Coral Reef Studies report said. The runoff problem is exacerbated by the loss of coastal wetlands which act as a natural filter for toxins and help deposit sediment. It
8050-453: The Pleistocene epoch and lived over large sections of the Australian continental shelf when the sea levels were lower. At that time, Australia, Tasmania and New Guinea were part of the same landmass, known as Sahul . As sea levels rose, the people on the Australian mainland and nearby islands became increasingly isolated, some on Tasmania and some of the smaller offshore islands when
8211-611: The Rainbow Serpent , Baiame , Dirawong and Bunjil . Similarly, the Arrernte people of central Australia believed that humanity originated from great superhuman ancestors who brought the sun, wind and rain as a result of breaking through the surface of the Earth when waking from their slumber. Taken as a whole, Aboriginal Australians, along with Torres Strait Islander people, have a number of health and economic deprivations in comparison with
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#17328376105308372-573: The crown-of-thorns starfish have brought about the decline of this ecosystem. These threats to the reef are not only a danger to the organisms inhabiting it, but also the economy of this region, a large part of which relies on revenue from ecotourism of the Great Barrier Reef. The Australian government has had the goal of protecting this World Heritage Site since 1972 when they created The Australian Institute of Marine Science. The Australian and Queensland governments have contributed about $ 142.5 million to their National Environmental Science Program which
8533-620: The crown-of-thorns starfish . According to a study published in October 2012 by the Proceedings of the National Academy of Sciences , the reef has lost more than half its coral cover since 1985, a finding reaffirmed by a 2020 study which found over half of the reef's coral cover to have been lost between 1995 and 2017, with the effects of a widespread 2020 bleaching event not yet quantified. The Great Barrier Reef has long been known to and used by
8694-423: The olive ridley . The green sea turtles on the Great Barrier Reef have two genetically distinct populations , one in the northern part of the reef and the other in the southern part. Fifteen species of seagrass in beds attract the dugongs and turtles, and provide fish habitat. The most common genera of seagrasses are Halophila and Halodule . Saltwater crocodiles live in mangrove and salt marshes on
8855-417: The tropics where the water is agitated, but can only live within a limited depth range, starting just below low tide . Where the level of the underlying earth allows, the corals grow around the coast to form fringing reefs, and can eventually grow to become a barrier reef. Where the bottom is rising, fringing reefs can grow around the coast, but coral raised above sea level dies. If the land subsides slowly,
9016-774: The 1970s and 1980s, when Aboriginal people moved to tiny remote settlements on traditional land, brought health benefits, but funding them proved expensive, training and employment opportunities were not provided in many cases, and support from governments dwindled in the 2000s, particularly in the era of the Howard government . Indigenous communities in remote Australia are often small, isolated towns with basic facilities, on traditionally owned land . These communities have between 20 and 300 inhabitants and are often closed to outsiders for cultural reasons. The long-term viability and resilience of Aboriginal communities in desert areas has been discussed by scholars and policy-makers. A 2007 report by
9177-655: The 19th century. Scholars believe that most Aboriginal Australians originated from Southeast Asia. If this is the case, Aboriginal Australians were among the first in the world to have completed sea voyages. A 2017 paper in Nature evaluated artefacts in Kakadu . Its authors concluded "Human occupation began around 65,000 years ago." A 2021 study by researchers at the Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage has mapped
9338-412: The 2022 report showed the greatest recovery in 36 years. It is mainly due to the regrowth of two-thirds of the reef by the fast-growing Acropora coral, which is the dominant coral there. The Great Barrier Reef has long been known to and used by the Aboriginal Australian and Torres Strait Islander peoples, and is an important part of local groups' cultures and spirituality. The first European to sight
9499-491: The Dreaming . Studies of Aboriginal groups' genetic makeup are ongoing, but evidence suggests that they have genetic inheritance from ancient Asian but not more modern peoples. They share some similarities with Papuans , but have been isolated from Southeast Asia for a very long time. They have a broadly shared, complex genetic history, but only in the last 200 years were they defined by others as, and started to self-identify as,
9660-599: The East/Southeast Asian lineage, including ancestors of the Native Americans . Papuans may have received approximately 2% of their geneflow from an earlier group (xOOA) as well, next to additional archaic admixture in the Sahul region. Aboriginal people are genetically most similar to the indigenous populations of Papua New Guinea , and more distantly related to groups from East Indonesia. They are more distinct from
9821-414: The Great Barrier Reef as well as mitigating crown-of-thorns starfish population flare-ups. Coral reef A coral reef is an underwater ecosystem characterized by reef-building corals . Reefs are formed of colonies of coral polyps held together by calcium carbonate . Most coral reefs are built from stony corals , whose polyps cluster in groups. Coral belongs to the class Anthozoa in
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#17328376105309982-477: The Great Barrier Reef can be found in The Kimberley , Western Australia. The Great Barrier Reef World Heritage Area has been divided into 70 bioregions , of which 30 are reef bioregions. In the northern part of the Great Barrier Reef, ribbon reefs and deltaic reefs have formed; these structures are not found in the rest of the reef system. A previously undiscovered reef, 500 metres tall and 1.5 km wide at
10143-489: The Great Barrier Reef in warm waters up to 50 metres (160 ft) deep and are more common in the southern than in the northern section. None found in the Great Barrier Reef World Heritage Area are endemic, nor are any endangered. Six species of sea turtles come to the reef to breed: the green sea turtle , leatherback sea turtle , hawksbill turtle , loggerhead sea turtle , flatback turtle , and
10304-403: The Great Barrier Reef is the rising levels of ocean acidification in the ocean. Ocean acidification occurs when excess atmospheric carbon dioxide gets absorbed into the ocean. This causes a decrease in the pH and this alters the chemistry of the ocean's water. This reduces the amount of aragonite, a key mineral for coral to grow, in the water. The Great Barrier Reef is predicted to lose aragonite at
10465-688: The Great Barrier Reef is used for farming including intensive cropping of sugar cane, and major beef cattle grazing. Farming practices damage the reef due to overgrazing , increased run-off of agricultural sediments, nutrients and chemicals including fertilisers , herbicides and pesticides representing a major health risk for the coral and biodiversity of the reefs. According to a 2016 report, while higher regulation contributes to less overall pollution from "other land uses, such as industrial, mining, port development, dredging and urban development", these can still be locally significant. Sediments containing high levels of copper and other heavy metals sourced from
10626-406: The Great Barrier Reef was James Cook in 1770, who sailed and mapped the east coast of Australia. On 11 June 1770 Cook's ship, HMS Endeavour , ran aground on a shoal south of the present-day location of Cooktown , requiring seven weeks to repair. It was Matthew Flinders who named the Great Barrier Reef, after his more detailed mapping of it in 1802. Flinders used various terms to describe
10787-458: The Great Barrier Reef, including the dwarf minke whale , Indo-Pacific humpback dolphin , and the humpback whale . Large populations of dugongs live there. More than 1,500 fish species live on the reef, including the clownfish , red bass , red-throat emperor, and several species of snapper and coral trout . Forty-nine species mass spawn , while eighty-four other species spawn elsewhere in their range. Seventeen species of sea snake live on
10948-402: The Great Barrier Reef. A March 2016 report stated that coral bleaching was more widespread than previously thought, seriously affecting the northern parts of the reef as a result of warming ocean temperatures . In October 2016, Outside published an obituary for the reef; the article was criticised for being premature and hindering efforts to bolster the resilience of the reef. In March 2017,
11109-443: The Great Barrier Reef. In Queensland, sharks found alive on the baited hooks are shot. Queensland's "shark control" program killed about 50,000 sharks from 1962 to 2018. Also, Queensland's "shark control" program has also killed many other animals (such as dolphins and turtles ) – the program killed 84,000 marine animals from 1962 to 2015, including in the Great Barrier Reef. In 2018, Humane Society International filed
11270-621: The Herald led to considerable navigational improvements, as they outlined the contrasting advantages and perils of the Inner Route (between Australia's east coast and the western edge of the reefs) and the Outer Route, in the open sea. The Great Barrier Reef supports an extraordinary diversity of life, including many vulnerable or endangered species , some of which may be endemic to the reef system. Thirty species of cetaceans have been recorded in
11431-864: The Holocene ( c. 4,200 years ago). The researchers had two theories for this: either some Indians had contact with people in Indonesia who eventually transferred those Indian genes to Aboriginal Australians, or a group of Indians migrated from India to Australia and intermingled with the locals directly. However, a 2016 study in Current Biology by Anders Bergström et al. excluded the Y chromosome as providing evidence for recent gene flow from India into Australia. The study authors sequenced 13 Aboriginal Australian Y chromosomes using recent advances in gene sequencing technology. They investigated their divergence times from Y chromosomes in other continents, including comparing
11592-714: The Indian Ocean, for example, in the Maldives , the Chagos Islands , the Seychelles and around Cocos Island . The entire Maldives consist of 26 atolls. Coral reef ecosystems contain distinct zones that host different kinds of habitats. Usually, three major zones are recognized: the fore reef, reef crest, and the back reef (frequently referred to as the reef lagoon). The three zones are physically and ecologically interconnected. Reef life and oceanic processes create opportunities for
11753-849: The Northern, Southern and Central cultural areas. The Northern and Southern areas, having richer natural marine and woodland resources, were more densely populated than the Central area. There are various other names from Australian Aboriginal languages commonly used to identify groups based on geography , known as demonyms , including: Other group names are based on the language group or specific dialect spoken . These also coincide with geographical regions of varying sizes. A few examples are: However, these lists are neither exhaustive nor definitive, and there are overlaps. Different approaches have been taken by non-Aboriginal scholars in trying to understand and define Aboriginal culture and societies, some focusing on
11914-759: The Philippines known as Mamanwa . This study confirms Aboriginal Australians as one of the oldest living populations in the world. They are possibly the oldest outside Africa, and they may have the oldest continuous culture on the planet. A 2016 study at the University of Cambridge suggests that it was about 50,000 years ago that these peoples reached Sahul (the supercontinent consisting of present-day Australia and its islands and New Guinea ). The sea levels rose and isolated Australia about 10,000 years ago, but Aboriginal Australians and Papuans diverged from each other genetically earlier, about 37,000 years BP, possibly because
12075-559: The Reef Research Centre (RRC). Outbreaks are believed to occur in natural cycles, worsened by poor water quality and overfishing of the starfish's predators. The unsustainable overfishing of keystone species , such as the giant Triton , can disrupt food chains vital to reef life. Fishing also impacts the reef through increased water pollution from boats, by-catch of unwanted species (such as dolphins and turtles) and habitat destruction from trawling , anchors and nets. As of
12236-422: The Reef's health, pressures, and future every five years. The last report was published in 2019. In March 2022, another mass bleaching event has been confirmed, which raised further concerns about the future of this reef system, especially when considering the possible effects of El Niño weather phenomenon. The Australian Institute of Marine Science conducts annual surveys of the Great Barrier Reef's status, and
12397-596: The UV radiation and allowing them to better adapt to warmer water temperatures. In the event of UV or thermal damage, if and when repair occurs, it will increase the likelihood of survival of the host and symbiont. This leads to the idea that, evolutionarily, clade A is more UV resistant and thermally resistant than the other clades. Clades B and C are found more frequently in deeper water, which may explain their higher vulnerability to increased temperatures. Terrestrial plants that receive less sunlight because they are found in
12558-414: The affected areas, altering the species composition . A study by Katharina Fabricius and Glen Death of Australian Institute of Marine Science found that hard corals numbers were almost double on reefs that were far from agricultural areas. Fertilizers also increase the amount of phytoplankton available for the crown-of-thorns starfish larvae to consume. A study showed that a doubling of the chlorophyll in
12719-444: The ancient people expanded and differentiated into distinct groups, each with its own language and culture. More than 400 distinct Australian Aboriginal peoples have been identified, distinguished by names designating their ancestral languages, dialects, or distinctive speech patterns. According to noted anthropologist , archaeologist and sociologist Harry Lourandos , historically, these groups lived in three main cultural areas,
12880-548: The animal phylum Cnidaria , which includes sea anemones and jellyfish . Unlike sea anemones, corals secrete hard carbonate exoskeletons that support and protect the coral. Most reefs grow best in warm, shallow, clear, sunny and agitated water. Coral reefs first appeared 485 million years ago, at the dawn of the Early Ordovician , displacing the microbial and sponge reefs of the Cambrian . Sometimes called rainforests of
13041-460: The base, was found in the northern area in 2020. There are no atolls in the system, and reefs attached to the mainland are rare. Fringing reefs are distributed widely, but are most common towards the southern part of the Great Barrier Reef, attached to high islands, for example, the Whitsunday Islands . Lagoonal reefs are found in the southern Great Barrier Reef, and further north, off the coast of Princess Charlotte Bay . Crescentic reefs are
13202-475: The beginning of the growth of the current reef at the time of the Last Glacial Maximum . At around that time, sea level was 120 metres (390 ft) lower than it is today. From 20,000 years ago until 6,000 years ago, sea level rose steadily around the world. As it rose, the corals could then grow higher on the newly submerged maritime margins of the hills of the coastal plain. By around 13,000 years ago
13363-538: The coast near the reef. Nesting has not been reported, and the salt water crocodile population in the GBRWHA is wide-ranging but low density. Around 125 species of shark , stingray , skates or chimaera live on the reef. Close to 5,000 species of mollusc have been recorded on the reef, including the giant clam and various nudibranchs and cone snails . Forty-nine species of pipefish and nine species of seahorse have been recorded. At least seven species of frog inhabit
13524-497: The coast. The fringing reefs of the Red Sea are "some of the best developed in the world" and occur along all its shores except off sandy bays. Barrier reefs are separated from a mainland or island shore by a deep channel or lagoon . They resemble the later stages of a fringing reef with its lagoon but differ from the latter mainly in size and origin. Their lagoons can be several kilometres wide and 30 to 70 metres deep. Above all,
13685-416: The coastal plains had become continental islands . As sea level rise continued, water topped most of the continental islands. The corals could then overgrow the hills, forming cays and reefs. Sea level on the Great Barrier Reef has not changed significantly in the last 6,000 years. The age of living reef structure is estimated to be between 6,000 and 8,000 years. Although the Great Barrier Reef formed along
13846-451: The coral animals. Coral that loses a large fraction of its zooxanthellae becomes white (or sometimes pastel shades in corals that are pigmented with their own proteins) and is said to be bleached , a condition which, unless corrected, can kill the coral. There are eight clades of Symbiodinium phylotypes . Most research has been conducted on clades A–D. Each clade contributes their own benefits as well as less compatible attributes to
14007-415: The corals shelter the zooxanthellae, averaging one million for every cubic centimetre of coral, and provide a constant supply of the carbon dioxide they need for photosynthesis. The varying pigments in different species of zooxanthellae give them an overall brown or golden-brown appearance and give brown corals their colors. Other pigments such as reds, blues, greens, etc. come from colored proteins made by
14168-416: The cover in the southern part had decreased and bleaching events occurred more frequently. The Great Barrier Reef Marine Park Authority considers the greatest threat to the Great Barrier Reef to be climate change, causing ocean warming which increases coral bleaching . Mass coral bleaching events due to marine heatwaves occurred in the summers of 1998, 2002, 2006, 2016, 2017 and 2020, and coral bleaching
14329-525: The deep sea away from continental shelves , around oceanic islands and atolls . The majority of these islands are volcanic in origin. Others have tectonic origins where plate movements lifted the deep ocean floor. In The Structure and Distribution of Coral Reefs , Charles Darwin set out his theory of the formation of atoll reefs, an idea he conceived during the voyage of the Beagle . He theorized that uplift and subsidence of Earth's crust under
14490-511: The deep split between Leang Panninge and Aboriginal/Papuans. Mallick et al. 2016 and Mark Lipson et al. 2017 study found the bifurcation of Eastern Eurasians and Western Eurasians dates to least 45,000 years ago, with indigenous Australians nested inside the Eastern Eurasian clade. Two genetic studies by Larena et al. 2021 found that Philippines Negrito people split from the common ancestor of Aboriginal Australians and Papuans before
14651-497: The desert-dwelling Pitjantjatjara people compared with a group of European people showed that the cooling adaptation of the Aboriginal group differed from that of the white people, and that they were able to sleep more soundly through a cold desert night. A 2014 Cambridge University study found that a beneficial mutation in two genes which regulate thyroxine , a hormone involved in regulating body metabolism , helps to regulate body temperature in response to fever. The effect of this
14812-399: The early stage of a "huge natural selection event unfolding". Many of the mature breeding adults died in the bleaching events of 2016–17, leading to low coral birth rates. The types of corals that reproduced also changed, leading to a "long-term reorganisation of the reef ecosystem if the trend continues." The Great Barrier Reef Marine Park Act 1975 (section 54) stipulates an Outlook Report on
14973-627: The eastern tip of India ( Chennai ) to the Bangladesh and Myanmar borders —as well as along the coasts of northeastern South America and Bangladesh, due to the freshwater release from the Amazon and Ganges Rivers respectively. Significant coral reefs include: When alive, corals are colonies of small animals embedded in calcium carbonate shells. Coral heads consist of accumulations of individual animals called polyps , arranged in diverse shapes. Polyps are usually tiny, but they can range in size from
15134-471: The exchange of seawater , sediments , nutrients and marine life. Most coral reefs exist in waters less than 50 m deep. Some inhabit tropical continental shelves where cool, nutrient-rich upwelling does not occur, such as the Great Barrier Reef . Others are found in the deep ocean surrounding islands or as atolls, such as in the Maldives . The reefs surrounding islands form when islands subside into
15295-401: The floor often supports seagrass meadows which are important foraging areas for reef fish. The reef drop-off is, for its first 50 m, habitat for reef fish who find shelter on the cliff face and plankton in the water nearby. The drop-off zone applies mainly to the reefs surrounding oceanic islands and atolls. The reef face is the zone above the reef floor or the reef drop-off. This zone
15456-403: The fringing reef, barrier reef, atoll and table reef based on Stoddart, D.R. (1969). Spalding et al. list four main reef types that can be clearly illustrated – the fringing reef, barrier reef, atoll, and "bank or platform reef"—and notes that many other structures exist which do not conform easily to strict definitions, including the "patch reef". A fringing reef, also called a shore reef,
15617-463: The fringing reefs keep pace by growing upwards on a base of older, dead coral, forming a barrier reef enclosing a lagoon between the reef and the land. A barrier reef can encircle an island, and once the island sinks below sea level a roughly circular atoll of growing coral continues to keep up with the sea level, forming a central lagoon. Barrier reefs and atolls do not usually form complete circles but are broken in places by storms. Like sea level rise ,
15778-419: The growth of the coral. This technique is often used by climate scientists to infer a region's paleoclimate . Since Darwin's identification of the three classical reef formations – the fringing reef around a volcanic island becoming a barrier reef and then an atoll – scientists have identified further reef types. While some sources find only three, Thomas lists "Four major forms of large-scale coral reefs" –
15939-694: The haplogroup C chromosomes. They found a divergence time of about 54,100 years between the Sahul C chromosome and its closest relative C5, as well as about 54,300 years between haplogroups K*/M and their closest haplogroups R and Q. The deep divergence time of 50,000-plus years with the South Asian chromosome and "the fact that the Aboriginal Australian Cs share a more recent common ancestor with Papuan Cs" excludes any recent genetic contact. The 2016 study's authors concluded that, although this does not disprove
16100-489: The history of the change in sea level relative to that substrate. The approximately 20,000-year-old Great Barrier Reef offers an example of how coral reefs formed on continental shelves. Sea level was then 120 m (390 ft) lower than in the 21st century. As sea level rose, the water and the corals encroached on what had been hills of the Australian coastal plain. By 13,000 years ago, sea level had risen to 60 m (200 ft) lower than at present, and many hills of
16261-401: The idea of ancient Aboriginal isolation. Genetic data extracted in 2011 by Morten Rasmussen et al., who took a DNA sample from an early-20th-century lock of an Aboriginal person's hair, found that the Aboriginal ancestors probably migrated through South Asia and Maritime Southeast Asia , into Australia, where they stayed. As a result, outside of Africa, the Aboriginal peoples have occupied
16422-653: The increased suicide rate, many researchers have suggested that the inclusion of more cultural aspects into suicide prevention programs would help to combat mental health issues within the community. Past studies have found that many indigenous leaders and community members, do in fact, want more culturally-aware health care programs. Similarly, culturally-relative programs targeting indigenous youth have actively challenged suicide ideation among younger indigenous populations, with many social and emotional wellbeing programs using cultural information to provide coping mechanisms and improving mental health. The outstation movement of
16583-506: The indigenous populations of Borneo and Malaysia , sharing drift with them than compared to the groups from Papua New Guinea and Indonesia. This indicates that populations in Australia were isolated for a long time from the rest of Southeast Asia. They remained untouched by migrations and population expansions into that area, which can be explained by the Wallace line . In a 2001 study, blood samples were collected from some Warlpiri people in
16744-637: The island erodes away and sinks below sea level. Atolls may also be formed by the sinking of the seabed or rising of the sea level. A ring of reefs results, which enclose a lagoon. Atolls are numerous in the South Pacific, where they usually occur in mid-ocean, for example, in the Caroline Islands , the Cook Islands , French Polynesia , the Marshall Islands and Micronesia . Atolls are found in
16905-566: The islands of Tasmania , K'gari (previously Fraser Island) , Hinchinbrook Island , the Tiwi Islands , Kangaroo Island and Groote Eylandt . Indigenous people of the Torres Strait Islands, however, are not Aboriginal. In the 2021 census , people who self-identified on the census form as being of Aboriginal and/or Torres Strait Islander origin totalled 812,728 out of a total of 25,422,788 Australians, equating to 3.2% of Australia's population and an increase of 163,557 people, or 25.2%, since
17066-552: The islands. 215 species of birds (including 22 species of seabirds and 32 species of shorebirds) visit the reef or nest or roost on the islands, including the white-bellied sea eagle and roseate tern . Most nesting sites are on islands in the northern and southern regions of the Great Barrier Reef, with 1.4 to 1.7 million birds using the sites to breed. The islands of the Great Barrier Reef also support 2,195 known plant species; three of these are endemic. The northern islands have 300–350 plant species which tend to be woody, whereas
17227-408: The journal Nature published a paper showing that huge sections of an 800-kilometre (500 mi) stretch in the northern part of the reef had died in the course of 2016 of high water temperatures, an event that the authors put down to the effects of global climate change. The percentage of baby corals being born on the Great Barrier Reef dropped drastically in 2018 and scientists are describing it as
17388-527: The land was inundated at the start of the Holocene inter-glacial period , about 11,700 years ago. Despite this, Aboriginal people maintained extensive networks within the continent and certain groups maintained relationships with Torres Strait Islanders and the Makassar people of modern-day Indonesia. Aboriginal Australians have a wide variety of cultural practices and beliefs that some scientists believe make up
17549-400: The land was inundated at the start of the Holocene , the inter-glacial period that started about 11,700 years ago. Scholars of this ancient history believe that it would have been difficult for Aboriginal people to have originated purely from mainland Asia. Not enough people would have migrated to Australia and surrounding islands to fulfill the beginning of the size of the population seen in
17710-406: The last 10,000 years it may have occurred—newer analytical techniques have the potential to address such questions. Bergstrom's 2018 doctoral thesis looking at the population of Sahul suggests that other than relatively recent admixture, the populations of the region appear to have been genetically independent from the rest of the world since their divergence about 50,000 years ago. He writes "There
17871-428: The last 6,000 years. The CRC Reef Research Centre estimates the age of the present, living reef structure at 6,000 to 8,000 years old. The shallow water reefs that can be seen in air-photographs and satellite images cover an area of 20,679 km, most (about 80%) of which has grown on top of limestone platforms that are relics of past (Pleistocene) phases of reef growth. The remains of an ancient barrier reef similar to
18032-518: The latter two diverged from each other, but after their common ancestor diverged from the ancestor of East Asian peoples . The dingo reached Australia about 4,000 years ago. Near that time, there were changes in language (with the Pama-Nyungan language family spreading over most of the mainland), and in stone tool technology. Smaller tools were used. Human contact has thus been inferred, and genetic data of two kinds have been proposed to support
18193-496: The life span and value of this global heritage. The plan contains all the elements for measurement and improvements, including; long-term sustainability plan, water quality improvement plan and the investment plan for the protection and preservation of The Reef until 2050. However, whereas the 2050 plan aims to incorporate protective measures such as improving water quality, reef restoration, killing of predatory starfish, it does not incorporate additional measures to address what may be
18354-496: The likely migration routes of the peoples as they moved across the Australian continent to its southern reaches and what is now Tasmania , then part of the mainland. The modelling is based on data from archaeologists , anthropologists , ecologists , geneticists , climatologists , geomorphologists , and hydrologists . It is intended to compare this data with the oral histories of Aboriginal peoples, including Dreaming stories, Australian rock art , and linguistic features of
18515-418: The main reef, containing chunks of coral. This zone may border a lagoon and serve as a protective area, or it may lie between the reef and the shore, and in this case is a flat, rocky area. Fish tend to prefer it when it is present. The reef lagoon is an entirely enclosed region, which creates an area less affected by wave action and often contains small reef patches. However, the topography of coral reefs
18676-484: The mainland. Unlike fringing and barrier reefs which extend only seaward, platform reefs grow in all directions. They are variable in size, ranging from a few hundred metres to many kilometres across. Their usual shape is oval to elongated. Parts of these reefs can reach the surface and form sandbanks and small islands around which may form fringing reefs. A lagoon may form In the middle of a platform reef. Platform reefs are typically situated within atolls, where they adopt
18837-423: The many Aboriginal languages which reveal how the peoples developed separately. The routes, dubbed "superhighways" by the authors, are similar to current highways and stock routes in Australia. Lynette Russell of Monash University believes that the new model is a starting point for collaboration with Aboriginal people to help reveal their history. The new models suggest that the first people may have landed in
18998-457: The material to the environment and to develop a management plan to eliminate this potential hazard; however, GBRMPA does not have legislative control over how the Yabulu tailings dam is managed". The crown-of-thorns starfish preys on coral polyps. Large outbreaks of these starfish can devastate reefs. In 2000, an outbreak contributed to a loss of 66% of live coral cover on sampled reefs in a study by
19159-403: The micro-level (tribe, clan, etc.), and others on shared languages and cultural practices spread over large regions defined by ecological factors. Anthropologists have encountered many difficulties in trying to define what constitutes an Aboriginal people/community/group/tribe, let alone naming them. Knowledge of pre-colonial Aboriginal cultures and societal groupings is still largely dependent on
19320-403: The middle of 2004, approximately one-third of the Great Barrier Reef Marine Park is protected from species removal of any kind, including fishing, without written permission. Shipping accidents are a pressing concern, as several commercial shipping routes pass through the Great Barrier Reef. Although the route through the Great Barrier Reef is not easy, reef pilots consider it safer than outside
19481-603: The most common shape of reef in the middle of the system, for example the reefs surrounding Lizard Island . Crescentic reefs are also found in the far north of the Great Barrier Reef Marine Park, and in the Swain Reefs ( 20 – 22 degrees south ). Planar reefs are found in the northern and southern parts, near Cape York Peninsula , Princess Charlotte Bay, and Cairns. Most of the islands on the reef are found on planar reefs. Wonky holes can have localised impact on
19642-400: The name "patch reefs" and often span a diameter of just a few dozen meters. In instances where platform reefs develop along elongated structures, such as old and weathered barrier reefs, they tend to arrange themselves in a linear formation. This is the case, for example, on the east coast of the Red Sea near Jeddah . In old platform reefs, the inner part can be so heavily eroded that it forms
19803-528: The name implies, coral reefs are made up of coral skeletons from mostly intact coral colonies. As other chemical elements present in corals become incorporated into the calcium carbonate deposits, aragonite is formed. However, shell fragments and the remains of coralline algae such as the green-segmented genus Halimeda can add to the reef's ability to withstand damage from storms and other threats. Such mixtures are visible in structures such as Eniwetok Atoll . The times of maximum reef development were in
19964-411: The observers' interpretations, which were filtered through colonial ways of viewing societies. Some Aboriginal peoples identify as one of several saltwater, freshwater, rainforest or desert peoples . The term Aboriginal Australians includes many distinct peoples who have developed across Australia for over 50,000 years. These peoples have a broadly shared, though complex, genetic history, but it
20125-415: The ocean, and atolls form when an island subsides below the surface of the sea. Alternatively, Moyle and Cech distinguish six zones, though most reefs possess only some of the zones. The reef surface is the shallowest part of the reef. It is subject to surge and tides . When waves pass over shallow areas, they shoal , as shown in the adjacent diagram. This means the water is often agitated. These are
20286-528: The oceans formed the atolls. Darwin set out a sequence of three stages in atoll formation. A fringing reef forms around an extinct volcanic island as the island and ocean floor subside. As the subsidence continues, the fringing reef becomes a barrier reef and ultimately an atoll reef. Darwin predicted that underneath each lagoon would be a bedrock base, the remains of the original volcano. Subsequent research supported this hypothesis. Darwin's theory followed from his understanding that coral polyps thrive in
20447-525: The oceans' surface area. The Indo-Pacific region (including the Red Sea , Indian Ocean , Southeast Asia and the Pacific ) account for 91.9% of this total. Southeast Asia accounts for 32.3% of that figure, while the Pacific including Australia accounts for 40.8%. Atlantic and Caribbean coral reefs account for 7.6%. Although corals exist both in temperate and tropical waters, shallow-water reefs form only in
20608-478: The offshore outer reef edge formed in open water rather than next to a shoreline. Like an atoll, it is thought that these reefs are formed either as the seabed lowered or sea level rose. Formation takes considerably longer than for a fringing reef, thus barrier reefs are much rarer. The best known and largest example of a barrier reef is the Australian Great Barrier Reef . Other major examples are
20769-418: The oldest continuous cultures in the world, although this is disputed. At the time of European colonisation of Australia, the Aboriginal people consisted of complex cultural societies with more than 250 languages and varying degrees of technology and settlements. Languages (or dialects) and language-associated groups of people are connected with stretches of territory known as "Country", with which they have
20930-633: The oldest living populations in the world, certainly the oldest outside of Africa." Their ancestors left the African continent 75,000 years ago. They may have the oldest continuous culture on earth. In Arnhem Land in the Northern Territory , oral histories comprising complex narratives have been passed down by Yolngu people through hundreds of generations. The Aboriginal rock art , dated by modern techniques, shows that their culture has continued from ancient times. The ancestors of present-day Aboriginal Australian people migrated from Southeast Asia by sea during
21091-447: The open ocean, in fact anywhere where the seabed rises close enough to the surface of the ocean to enable the growth of zooxanthemic, reef-forming corals. Platform reefs are found in the southern Great Barrier Reef, the Swain and Capricorn Group on the continental shelf, about 100–200 km from the coast. Some platform reefs of the northern Mascarenes are several thousand kilometres from
21252-421: The original 250–400 Aboriginal languages (more than 250 languages and about 800 dialectal varieties on the continent) are endangered or extinct, although some efforts are being made at language revival for some. As of 2016, only 13 traditional Indigenous languages were still being acquired by children, and about another 100 spoken by older generations only. Dispersing across the Australian continent over time,
21413-420: The other studies had utilised complete Y chromosome sequencing, which has the highest precision. For example, use of a ten Y STRs method has been shown to massively underestimate divergence times. Gene flow across the island-dotted 150-kilometre-wide (93 mi) Torres Strait, is both geographically plausible and demonstrated by the data, although at this point it could not be determined from this study when within
21574-429: The polyps' tissues and provide organic nutrients that nourish the polyp in the form of glucose , glycerol and amino acids . Because of this relationship, coral reefs grow much faster in clear water, which admits more sunlight. Without their symbionts, coral growth would be too slow to form significant reef structures. Corals get up to 90% of their nutrients from their symbionts. In return, as an example of mutualism ,
21735-420: The precise condition under which corals flourish. The light is sufficient for photosynthesis by the symbiotic zooxanthellae, and agitated water brings plankton to feed the coral. The off-reef floor is the shallow sea floor surrounding a reef. This zone occurs next to reefs on continental shelves. Reefs around tropical islands and atolls drop abruptly to great depths and do not have such a floor. Usually sandy,
21896-440: The presence of any Holocene gene flow or non-genetic influences from South Asia at that time, and the appearance of the dingo does provide strong evidence for external contacts, the evidence overall is consistent with a complete lack of gene flow, and points to indigenous origins for the technological and linguistic changes. They attributed the disparity between their results and previous findings to improvements in technology; none of
22057-414: The previous census in 2016. Reasons for the increase were broadly as follows: Most Aboriginal people speak English, with Aboriginal phrases and words being added to create Australian Aboriginal English (which also has a tangible influence of Aboriginal languages in the phonology and grammatical structure ). Some Aboriginal people, especially those living in remote areas, are multi-lingual. Many of
22218-400: The reef in the event of mechanical failure, since a ship can sit safely while being repaired. There have been over 1,600 known shipwrecks in the Great Barrier Reef region. On 3 April 2010, the bulk coal carrier Shen Neng 1 ran aground on Douglas Shoals, spilling up to four tonnes of oil into the water and causing extensive damage to the reef. The government of Queensland has
22379-453: The reef, including thirteen species of genus Halimeda , which deposit calcareous mounds up to 100 metres (110 yd) wide, creating mini-ecosystems on their surface which have been compared to rainforest cover. Climate change , pollution, crown-of-thorns starfish and fishing are the primary threats to the health of this reef system. Other threats include shipping accidents, oil spills , and tropical cyclones. Skeletal Eroding Band ,
22540-578: The reef, providing upwellings of fresh water, sometimes rich in nutrients contributing to eutrophication . Navigation through and around the reefs is a major challenge. More than 20 ships were recorded lost in the region between 1791 and 1850, Surveys between 1815 and 1860 by Phillip Parker King in the Mermaid, Francis Price Blackwood in HMS Fly , Owen Stanley in the Rattlesnake, and Henry Mangles Denham in
22701-492: The reef. The majority of these spawn gametes , breeding in mass spawning events that are triggered by the rising sea temperatures of spring and summer, the lunar cycle, and the diurnal cycle. Reefs in the inner Great Barrier Reef spawn during the week after the full moon in October, while the outer reefs spawn in November and December. Its common soft corals belong to 36 genera. Five hundred species of marine algae or seaweed live on
22862-519: The reefs comprising what we now call the Great Barrier Reef including "great reef", for one such reef, "barrier reef", for any reef preventing a sailing vessel in, or waves from, the open sea, from reaching the coast, and "Barrier Reefs", for the collection of such reefs. The Great Barrier Reef is a distinct feature of the East Australian Cordillera division. It reaches from Torres Strait (between Bramble Cay , its northernmost island, and
23023-487: The remaining land bridge was impassable. This isolation makes the Aboriginal people the world's oldest culture. The study also found evidence of an unknown hominin group, distantly related to Denisovans, with whom the Aboriginal and Papuan ancestors must have interbred, leaving a trace of about 4% in most Aboriginal Australians' genome. There is, however, increased genetic diversity among Aboriginal Australians based on geographical distribution. Carlhoff et al. 2021 analysed
23184-401: The root cause the problem – climate change, which is caused by greenhouse gas emissions. As such, experts doubted whether it would be enough to save the fragile environment. Another issue is that the time left to the 1.5 °C warming threshold (the temperature limit that coral reefs can still cope with) is very limited. As part of the Reef 2050 plan, an AUD$ 443 million grant was given to
23345-406: The same territory continuously longer than any other human populations. These findings suggest that modern Aboriginal Australians are the direct descendants of the eastern wave, who left Africa up to 75,000 years ago. This finding is compatible with earlier archaeological finds of human remains near Lake Mungo that date to approximately 40,000 years ago. The idea of the "oldest continuous culture"
23506-1330: The sea , shallow coral reefs form some of Earth's most diverse ecosystems. They occupy less than 0.1% of the world's ocean area, about half the area of France, yet they provide a home for at least 25% of all marine species , including fish , mollusks , worms , crustaceans , echinoderms , sponges , tunicates and other cnidarians . Coral reefs flourish in ocean waters that provide few nutrients. They are most commonly found at shallow depths in tropical waters, but deep water and cold water coral reefs exist on smaller scales in other areas. Shallow tropical coral reefs have declined by 50% since 1950, partly because they are sensitive to water conditions. They are under threat from excess nutrients (nitrogen and phosphorus), rising ocean heat content and acidification , overfishing (e.g., from blast fishing , cyanide fishing , spearfishing on scuba ), sunscreen use, and harmful land-use practices, including runoff and seeps (e.g., from injection wells and cesspools). Coral reefs deliver ecosystem services for tourism, fisheries and shoreline protection . The annual global economic value of coral reefs has been estimated at anywhere from US$ 30–375 billion (1997 and 2003 estimates) to US$ 2.7 trillion (a 2020 estimate) to US$ 9.9 trillion (a 2014 estimate). Though
23667-412: The sea bed begins to drop steeply. The surface of the fringe reef generally remains at the same height: just below the waterline. In older fringing reefs, whose outer regions pushed far out into the sea, the inner part is deepened by erosion and eventually forms a lagoon . Fringing reef lagoons can become over 100 metres wide and several metres deep. Like the fringing reef itself, they run parallel to
23828-400: The sea level was only 60 metres (200 ft) lower than the present day, and corals began to surround the hills of the coastal plain, which were, by then, continental islands . As the sea level rose further still, most of the continental islands were submerged. The corals could then overgrow the submerged hills, to form the present cays and reefs. Sea level here has not risen significantly in
23989-585: The sea turtle's population and available habitat. Bleaching events in benthic coral communities (deeper than 20 metres or 66 feet) in the Great Barrier reef are not as well documented as those at shallower depths, but recent research has shown that benthic communities are just as negatively impacted in the face of rising ocean temperatures. Five Great Barrier Reef species of large benthic corals were found bleached under elevated temperatures, affirming that benthic corals are vulnerable to thermal stress. A threat for
24150-560: The sediment until its edge was too far away for suspended sediments to inhibit coral growth. In addition, approximately 400,000 years ago there was a particularly warm Interglacial period with higher sea levels and a 4 °C (7 °F) water temperature change. The land that formed the substrate of the current Great Barrier Reef was a coastal plain formed from the eroded sediments of the Great Dividing Range with some larger hills (most of which were themselves remnants of older reefs or, in rare cases, volcanoes). The Reef Research Centre,
24311-600: The shallow water tropical coral reefs are best known, there are also deeper water reef-forming corals, which live in colder water and in temperate seas. Most coral reefs were formed after the Last Glacial Period when melting ice caused sea level to rise and flood continental shelves . Most coral reefs are less than 10,000 years old. As communities established themselves, the reefs grew upwards, pacing rising sea levels . Reefs that rose too slowly could become drowned, without sufficient light. Coral reefs are also found in
24472-447: The south coast of Papua New Guinea ) in the north to the unnamed passage between Lady Elliot Island (its southernmost island) and Fraser Island in the south. Lady Elliot Island is located 1,915 km (1,190 mi) southeast of Bramble Cay as the crow flies . It includes the smaller Murray Islands . The plate tectonic theory indicates Australia has moved northwards at a rate of 7 cm (2.8 in) per year, starting during
24633-468: The southern islands have 200 which tend to be herbaceous; the Whitsunday region is the most diverse, supporting 1,141 species. The plants are propagated by birds. There are at least 330 species of ascidians on the reef system with the diameter of 1–10 cm (0.4–4 in). Between 300 and 500 species of bryozoans live on the reef. Four hundred coral species, both hard corals and soft corals inhabit
24794-572: The story of creation known as The Dreamtime . Additionally, traditional healers were also custodians of important Dreaming stories as well as their medical roles (for example the Ngangkari in the Western desert ). Some core structures and themes are shared across the continent with details and additional elements varying between language and cultural groups. For example, in The Dreamtime of most regions,
24955-424: The survival of their coral hosts. Each photosynthetic organism has a specific level of sensitivity to photodamage to compounds needed for survival, such as proteins. Rates of regeneration and replication determine the organism's ability to survive. Phylotype A is found more in the shallow waters. It is able to produce mycosporine-like amino acids that are UV resistant , using a derivative of glycerin to absorb
25116-409: The term Aboriginal has changed over time and place, with the importance of family lineage, self-identification and community acceptance all being of varying importance. The term Indigenous Australians refers to Aboriginal Australians and Torres Strait Islander peoples, and the term is conventionally only used when both groups are included in the topic being addressed, or by self-identification by
25277-425: The undergrowth are analogous to clades B, C, and D. Since clades B through D are found at deeper depths, they require an elevated light absorption rate to be able to synthesize as much energy. With elevated absorption rates at UV wavelengths, these phylotypes are more prone to coral bleaching versus the shallow clade A. Australian Aborigines Aboriginal Australians are the various Indigenous peoples of
25438-415: The water leads to a tenfold increase in the crown-of-thorns starfish larvae's survival rate. Sediment runoff from farming carries chemicals into the reef environment also reduces the amount of light available to the corals decreasing their ability to extract energy from their environment. Pesticides used in farming are made up of heavy metals such as lead, mercury, arsenic and other toxins are released into
25599-517: The wider Australian community. Due to the aforementioned disadvantage, Aboriginal Australian communities experience a higher rate of suicide, as compared to non-indigenous communities. These issues stem from a variety of different causes unique to indigenous communities, such as historical trauma, socioeconomic disadvantage, and decreased access to education and health care. Also, this problem largely affects indigenous youth, as many indigenous youth may feel disconnected from their culture. To combat
25760-455: The wider environment due to erosion of farm soil, which has a detrimental effect on the coral. Mining company Queensland Nickel discharged nitrate-laden water into the Great Barrier Reef in 2009 and 2011 – on the later occasion releasing 516 tonnes (508 long tons; 569 short tons) of waste water. The Great Barrier Reef Marine Park Authority (GBRMPA) stated "We have strongly encouraged the company to investigate options that do not entail releasing
25921-481: Was still in temperate waters south of the tropics – too cool to support coral growth. The Great Barrier Reef's development history is complex; after Queensland drifted into tropical waters, it was largely influenced by reef growth and decline as sea level changed. Reefs can increase in diameter by 1 to 3 centimetres (0.39 to 1.18 in) per year, and grow vertically anywhere from 1 to 25 cm (0.39 to 9.84 in) per year; however, they grow only above
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