Annex 2 - Ecological, Socio-Economic, and Scientific Attributes of the PSSA Extension Area: South-West Coral Sea
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Statutory Documents - IMO Publications and Documents - Resolutions - Marine Environment Protection Committee - Resolution MEPC.268(68) - Designation of the South-West Coral Sea as an Extension of the Great Barrier Reef and Torres Strait Particularly Sensitive Sea Area – (Adopted on 15 May 2015) - Annex 2 - Ecological, Socio-Economic, and Scientific Attributes of the PSSA Extension Area: South-West Coral Sea

Annex 2 - Ecological, Socio-Economic, and Scientific Attributes of the PSSA Extension Area: South-West Coral Sea

(Note: More detailed descriptions of the ecological, socio-economic and cultural, scientific and educational criteria are contained in paragraphs 17 to 80 of document MEPC 68/10/1.)

1 Ecological criteria

Uniqueness or rarity

1.1 The Coral Sea is considered one of the most distinctive and undisturbed natural systems in the world and is internationally recognized for its rich biodiversity, unique species and important heritage values.

1.2 In the area of the Coral Sea to be covered by the PSSA, three large-scale unique ecological features that support distinct or important ecological communities at a regional scale are present. The Queensland and Marion Plateaux, together support over 20 coral reefs and cays, which provide complex habitats with diverse and abundant invertebrate and fish communities. Similarly, the northernmost parts of the Tasmantid Seamount Chain contain a diverse range of habitats, including deep-water sponge gardens and near-pristine tropical coral reef systems. Collectively these are known to be biological hot-spots, with significant species diversity.

1.3 Over millennia, the geological and oceanographic history of the region and its warm and cool current patterns have prevented the migration of species, prompting the development of flora and fauna that evolved, adapted and spread in isolation. Localized currents can act as a barrier to dispersal; as a result the area has high levels of species endemism.

1.4 The area contains some of the world's most unique and globally significant marine species, such as the leatherback turtle (Dermochelys coriacea), humphead Maori wrasse (Cheilinus undulatus) and nautilus (Nautilus pompilius).

1.5 The Coral Sea provides migratory corridors for cetaceans, sharks, fish, turtles and seabirds, many of which are of conservation concern. Successive research efforts have highlighted the significance of the Coral Sea in patterns of dispersal, whereby the reefs provide a series of dispersal stepping-stones from the western Pacific towards the GBR.

1.6 Deep, cold water troughs and abyssal basins are habitat for an array of benthic species, many of which are a protected matter under Australia’s Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) or international agreement or are unique to the area, including 18 endemic species of deep-water sharks, rays and chimaera fish.

1.7 The remoteness and challenging environment of the area means much of its biodiversity remains undescribed and new species found nowhere else are routinely discovered. Surveys in the deeper reef habitats at Osprey Reef have revealed prehistoric six-gilled sharks, giant oil fish and many crustaceans and unidentified fish at depths of 1400 metres. A unique, dwarf speciation of Nautilus pompilius was also identified on Osprey Reef. This species evolved isolated from nautilus in the nearby Coral Sea and GBR, and is a reflection of the endemic nature of ecosystems within the area.

1.8 The north-western Coral Sea hosts the only confirmed spawning aggregation of black marlin (Makaira indica) in the world. This species migrates throughout the Pacific Ocean, but only uses the Coral Sea to spawn.

1.9 The few detailed surveys undertaken have shown that as many as 40% of the invertebrates inhabiting seamounts in the area are new to science while up to 34% of the species may be endemic. Scientists expect that research into the lesser known, deeper areas of the region will uncover many new species.

Critical habitat

1.10 The area contains outstanding examples of reef communities and a diverse array of isolated sandy cays, islands, deep-sea plains, seamounts and canyons. Collectively, these areas provide foraging, breeding and nesting grounds for a rich array of marine species, including 341 species that are recognized for their conservation significance under the EPBC Act and under international agreements. This includes 26 species of cetaceans, 219 species of corals, 21 species of fish, 46 species of sharks and rays, five species of marine turtles and 24 species of birds. Many of these species are listed as threatened or migratory species, or both, and, whilst over half of these species show declining population trends worldwide, many are still found at healthy levels in the Coral Sea.

Dependency

1.11 The reefs of Coral Sea provide stepping-stones for the dispersal of species between the GBR and the greater Pacific Ocean region. Maintaining the overall integrity and resilience of these reefs is therefore necessary to ensure that they can function effectively as stepping-stone habitats.

1.12 The Coral Sea also provides migratory corridors for cetaceans, sharks, fish, turtles and seabirds, many of which are of conservation concern. There are likely to be further important areas for feeding, breeding, migrating and resting that have yet to be clearly identified, and which may act as critical habitat for many species.

1.13 Thousands of species rely on the ecosystem processes within the Coral Sea region to provide opportunities for foraging, breeding and migration. These processes are largely driven by the availability of energy within the system, which in turn is dependent upon the unique interactions between the region's oceanographic and topographic features.

1.14 Localized turbulence in the lee of reefs, islands and seamounts influences biological communities by creating patches of high to intermediate productivity in the nutrient-poor open-water environment. These sites of enhanced productivity are important aggregators for a range of pelagic species including small fish, mid-trophic predatory fish and large predators. They are also known to attract a range of species of conservation concern including marine turtles, marine mammals and seabirds.

1.15 Cays in the area offer important habitat for seabirds to roost and nest, and turtles to lay eggs above the high tide mark. Seabirds provide the main source of energy on these cays, through their nutrient-rich guano, eggs and carrion, which support food webs of terrestrial and intertidal invertebrates and over time facilitate the development of soil and organic matter, which in turn provides habitat for more complex plant communities.

1.16 The species assemblage and trophic structure of the region relies on the highly interlinked web of local oceanographic patterns, topography and energy inputs. An impact on any one of these can disrupt this web, destabilizing ecosystem processes and the species that rely on them.

Representativeness

1.17 The reefs, cays and herbivorous fish of the Queensland and Marion Plateaux and the northern extent of the Tasmantid Seamount Chain highlight the biological significance and ecological value of the region.

1.18 The Queensland and Marion Plateaux are considered important for aggregations of marine life and the high levels of biodiversity they support. The reefs and islands of these plateaux are approximately 200–400 kilometres from the coast and provide for diverse and abundant invertebrate (e.g. sea cucumber) and fish communities.

1.19 These reefs of the Queensland and Marion Plateaux are known for their particularly high densities of shark species, and Osprey Reef in particular is also recognized for its populations of the iconic humphead Maori wrasse and nautilus. The lagoons of these reefs are important nursery sites for sharks and predatory fish, while the island areas support critical nesting sites for the green turtle and a range of seabird species. The plateaux also abut two significant deep-water regions: the Queensland Trough, which separates the Queensland Plateau from the GBR, and the Townsville Trough, which separates the two plateaux from each other. These troughs contain canyons and gullies that are likely to support unique deep-water ecosystems.

Diversity

1.20 The reef systems in the Coral Sea are dominated by spectacular sponge gardens, and support high biodiversity. Approximately 745 species of molluscs (shellfish, squid and octopus) have been found, including several that are considered rare. Six hundred and twenty eight species of fish are known to occur in the Coral Sea. The small islets and cays of the Coral Sea are important nesting places for many species of seabirds.

1.21 Reefs in the area provide a habitat mosaic for diverse and abundant invertebrate and fish communities. A diversity of hard and soft corals, sponge gardens, crustaceans and molluscs are found in the area, as well as a distinct Coral Sea reef fish community that includes many unique species.

1.22 Significant variation in water depth and sea floor features are contributing factors to the high levels of species diversity in the area. Sections of the continental shelf have a mosaic of rocky reefs and soft sediments and support species from a diverse range of taxonomic groups. The extensive seamount systems of the Coral Sea contain a large variety of sponges, corals, gorgonians, sea squirts and crinoids, the latter of which can grow unusually large and are frequently very long-lived, often exceeding several hundred years.

1.23 Abyssal regions are yet to be fully explored, but there is evidence of biologically important systems likely to contain a vast reservoir of undiscovered species.

Productivity

1.24 The pelagic environment of the area is akin to a vast desert with small oases of biodiversity and productivity. These areas of primary productivity influence the spread of algae, one of the area's most abundant and diverse life forms, covering a greater region than corals and forming an important part of the food chain. Areas with a high biomass of algae increase planktonic activity and create high levels of prey abundance, attracting aggregations of higher order herbivorous and apex predator species. These localized productivity hot spots in an otherwise nutrient-poor environment provide habitat, migration and dispersal corridors for many iconic and endangered species.

1.25 Marine species and seabirds can journey hundreds or even thousands of kilometres to breed in the Coral Sea, or to travel through en route to breeding areas beyond the region. Areas of high productivity such as the seamounts are therefore critical "stepping stones" within the barren open ocean and are important aggregators for a range of species including lantern fish, albacore tuna, billfish and sharks. These species rely on foraging opportunities supplied by productivity hot spots in the Coral Sea to sustain them on their journey. Large marine mammals journey many kilometres to breed in the Reserve, or to travel through en route to breeding areas.

1.26 It is also thought that the organic particulates contained in nutrient-rich intrusions in the area are responsible for the settlement and sustained growth of coral reef ecosystems, which have the highest gross primary productivity of all ocean ecosystems. These waters carry organic matter into the region where they contribute significantly to the overall productivity of the system.

Spawning and breeding grounds

1.27 The area contains critical habitat features used by numerous species to spawn and breed and which are therefore essential for their survival.
  • .1 The waters over the Queensland and Townsville Troughs appear important for attracting aggregations of large pelagic species, either to feed or spawn.

  • .2 Extensive seabird rookeries within the small islets and cays of the area are of global and national importance.

  • .3 The area is a major feeding and breeding location for six of the world's seven species of sea turtles, all of which are listed on the IUCN Red List of Threatened Species.

  • .4 Particularly sheltered regions, such as lagoons, are thought to be important nursery sites for sharks and predatory fish, while other species, such as the dwarf minke whale, the hawksbill and leatherback turtles and the endangered Herald petrel, forage in these calmer areas.

  • .5 The northern extension of the Tasmantid Seamount Chain, where the seamounts extend to the surface and are capped by islands and reefs, provide feeding and breeding grounds for open ocean species including billfish, marine turtles and marine mammals.

  • .6 Each year from September to December, black marlin aggregate in the area to spawn. This is the only known spawning location for black marlin in the world.

Naturalness

1.28 The Coral Sea is considered one of the most distinctive and undisturbed natural systems in the world.

1.29 The area is not directly threatened by land-based sources of pollution and has relatively low levels of fishing. It is one of the world's last tropical oceanic regions containing high biodiversity coral reefs that are virtually pristine, and where large populations of pelagic predators have not been severely depleted. The topography of the area has also contributed to its pristine nature, with recent surveys identifying deep-sea ecosystems which have remained largely unchanged for millions of years.

1.30 The Coringa Cays and Lihou Islets contain important bird and turtle nesting sites that are almost totally free from anthropogenic disturbances such as lighting, beach use, pollution, feral animals, and boat traffic compared to nesting sites throughout the GBR. These areas, therefore, are reference sites to determine the impacts of such disturbances on breeding success within the populations.

Integrity

1.31 The extension area covers a large area, and encompasses parts of six provincial bioregions identified in the Integrated Marine and Coastal Regionalisation of Australia Version 4.0 (IMCRA v.4.0). These bioregions contain a wide variety of interconnected habitats, and also provide important "stepping-stone" links between the GBR and the wider Pacific Ocean.

1.32 The integrity of the area is in part due to its remote nature, with the nearest point to a mainland coast over 60 kilometres away, and the furthest point 1100 kilometres.

1.33 The area therefore demonstrates the characteristics of an isolated, effectively self-sustaining ecological unit, as evidenced by the high proportion of endemism both within the region, and between individual reef communities.

Fragility

1.34 Although the Coral Sea contains a number of critical shallow reef and terrestrial habitats, these represent less than 1% of the total area. Their small size, isolation from each other and high exposure to cyclones and storms make them more vulnerable to catastrophic impacts of natural disturbances than the contiguous reef systems of the GBR. These precarious conditions increase the area's ecological fragility and the risk of local extinctions. A high proportion of pelagic and deep-water species are particularly vulnerable to anthropogenic impacts.

1.35 While the isolation of the area's ecosystems has ensured a great deal of diversity and endemicity between communities and populations, it also means these systems can be particularly fragile and susceptible to external factors with potentially catastrophic, long-term cascade effects.

1.36 The area's deep-sea organisms are generally slow growing, long-lived, late-reproducing species with few offspring, and as a result can take a significant amount of time to rebuild populations. The cold coral reef systems take thousands of years to develop even in areas with stable conditions. They are fragile and extremely susceptible to damage as recovery rates are immensely slow.

Bio-geographic importance

1.37 A number of biologically important areas are located within, or intersect with the area:
  • .1 Seasonal migration routes and feeding sites for cetaceans including the humpback whale occur throughout the region. The humpback whale is also known to breed and calve in the area.

  • .2 Migration routes and foraging and feeding sites for 13 species of seabird listed under the EPBC Act as threatened, endangered and/or migratory are located in the area.

  • .3 The green turtle breeds in the area, with the Coringa-Herald-Lihou area particularly important for nesting and inter-nesting activities.

  • .4 In spring and summer, whale sharks aggregate to feed around Bougainville Reef and white sharks use the south west Coral Sea, adjacent to the Swain Reefs, as they move between nursery areas and for opportunistic feeding.

  • .5 The minimal impacts on the area and its relative lack of disturbance mean that its various ecosystems provide a representation of what the geographic distribution of organisms would naturally resemble in comparable, but more highly impacted marine ecosystems around the world.

2 Social, cultural and economic criteria

Social or economic dependency

2.1 Commercial fisheries have a relatively small presence in the south west Coral Sea compared to other marine regions around Australia. Commonwealth and Queensland state managed fisheries occur in the area, including line, hand collection, trawl, purse seine, trap and net fisheries.

2.2 Almost all tourism activities that occur in the south west Coral Sea are nature-based and reliant on an intact Coral Sea ecosystem. They include charter fishing, snorkelling, scuba diving, whale watching and cruising.

2.3 Known scuba diving and snorkelling hotspots in the Coral Sea region include the Osprey and Shark Reefs, for their significant populations of shark. These activities also occur in the Coringa Islets, Herald Cays and at Lihou Reef, although the extreme isolation of these locations means that they are not often visited. They also take place off other islands and shallow water seafloor features in the Coral Sea region, albeit on a limited basis.

2.4 Scuba diving and snorkelling are predominantly eco-tourism or heritage-based tourism activities with participants preferring locations that offer near-pristine marine environments or dive wrecks of interest. Some commercial and educational organizations offer science-based tourism opportunities where divers and snorkelers participate in experiments or surveys. Cruise ships also frequent the region, some regularly visiting Willis Island.

Cultural heritage

2.5 Like the GBR and Torres Strait, the Coral Sea is also of indigenous cultural and social significance to island and coastal communities. Many Aboriginal and Torres Strait island people undertake traditional use of marine resource activities to provide traditional food, practice their living maritime culture and to educate younger generations about traditional and cultural rules and protocols.

2.6 The area contains a large number of historic shipwrecks, including the wrecks of the Cato and HMS Porpoise, which are located in protected zones established under Australia's Historic Shipwrecks Act 1976. The region was significant in the Battle of the Coral Sea during World War II.

3 Scientific and educational criteria

Research

3.1 Given the scale and location of the proposed extension area to the PSSA, large-scale oceanographic features are well known and documented. However, there is a lack of knowledge of finer-scale hydrodynamics linking habitats within the Coral Sea. Further, the potential impacts of climate change on the Coral Sea are yet to be understood.

3.2 In spite of the relatively few detailed studies on the area, it remains one of high scientific interest. The remote location of the area, and its reputation as one of the most distinctive and undisturbed natural systems in the world, offers researchers a rare opportunity to study a biota over an area of significant scale that has not been markedly impacted by fishing and which is likely to remain undisturbed.

3.3 Domestic and international research institutions are actively undertaking research in the area. In addition to research institutions, tourist operators and volunteer organisations maintain active monitoring programs.

3.4 The occupied meteorological facility on Willis Island has been providing data to Bureau of Meteorology scientists and others since 1921. Automatic weather stations are located on Bougainville Reef, Cato Island, Flinders Reef (Flinders Coral Cay), Frederick Reef, Holmes Reef, Lihou Reef (Turtle Islet), Marion Reef and Moore Reef. Observations from Willis Island and the automatic weather stations are important for climate analysis and numerical weather prediction models, for fine-tuning forecasts and warnings, and are particularly important for early warning of tropical cyclones.

Baseline for monitoring studies

3.5 The extension area to the PSSA is remote and considered a relatively undisturbed natural system. Although its location has meant that detailed studies of the area are limited, the Coral Sea is a known habitat for many protected species, and spawning aggregations and nesting locations have been identified. The area also provides migratory corridors for a variety of important species, and as such provides suitable baseline conditions for future monitoring studies.


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