Location
The spectacular 22,000 km 2 Shark Bay World Heritage Property, on Australia’s most westerly point 850 km north of Western Australia’s capital Perth, is one of the world’s most outstanding marine and semi-arid terrestrial areas.
Shark Bay was inscribed on the World Heritage List in December 1991 and was just one of 11 places (now 21) in the world to satisfy all four natural criteria. Shark Bay is a complex marine and terrestrial ecosystem containing many important features, including; outstanding examples of the Earth’s evolutionary history, significant ongoing geological and biological processes; superlative natural phenomena like the world’s largest seagrass meadows and the abundance of marine mega fauna; and secure habitats for threatened species, with populations of five of Australia’s 26 endangered mammal species, 15 species of rare plants and 12 threatened reptile species. Almost 70% of the property is marine environment, fringed with 1,500 km of coastline and containing 120 islands.
Marine Ecology
Shark Bay is Australia’s largest enclosed marine embayment with its unusual geomorphology producing a diverse range of marine communities including coral, seagrass meadows, mangroves and hypersaline areas. It is also transitional between tropical and temperate environmental zones so the area contains a range of terrestrial and marine ecological communities that support a wide variety of native fauna and flora. The conservation of these ecological communities is essential in maintaining biological diversity and the World Heritage values.
Shark Bay’s marine environment is an intricate and interlinked system which incorporates several of the World Heritage criteria. It contains the stromatolites and the hypersaline environment of Hamelin Pool. The Wooramel seagrass bank and Faure Sill are examples of the unique natural marine formations. Seagrass covers over 4, 000 km2 of Shark Bay, with the 1,030 km2 Wooramel Bank being the largest known structure of its type in the world. The 12 species of seagrass in Shark Bay make it one of the most diverse seagrass assemblages in the world.
Seagrass has significantly contributed to the evolution of Shark Bay and modified the physical, chemical and biological environment, as well as the geology and also led to the development of major marine features like the Faure Sill. Barrier banks associated with seagrass have, with low rainfall, high evaporation and low tidal flushing, produced the hypersaline
environments that have led to the growth of cyanobacteria and the formation of the stromatolites.
Shark Bay is also renowned for its marine megafauna and with an estimated 10,000 dugong has one of the largest and most stable populations in the world. It is also a staging post for migrating Humpback whales, inhabited by both Green and Loggerhead marine turtles with Dirk Hartog Island being one of the most important Loggerhead nesting sites within Australia. As it is near the northern limit between temperate and tropical zones, Shark Bay is home to 323 fish species and 218 species of bivalves and supports significant populations of sharks, rays, manta rays and sea snakes.
Steep environmental gradients have produced genetic variability among populations of marine species, resulting in Shark Bay being a focal point for genetic divergence. The waters of the Bay are characterised by three quite distinctive marine ecosystems according to salinity – oceanic, metahaline and hypersaline.
Living Fossils
Microbial communities flourish as algal mats in the inter-tidal and sub-tidal zones of the most saline embayments of the Shark Bay marine reserves, particularly Hamelin Pool, L’haridon Bight and Petit Point. These microbial mats are actually communities dominated by microbes which can flourish only in environments where biotic diversity is limited, thus allowing slow-growing structures to gain a foothold. The warm, shallow, super salty waters of Hamelin Pool favour the growth of micro-organisms whilst inhibiting other major competitors and predators which cannot survive in the conditions.
The hypersaline conditions have led to the development of the stromatolites which are ‘living fossils’ built mainly by cyanobacteria – the same kind which appeared on the planet some 3.5 billion years ago and were the first living organisms to evolve on Earth. They are of great scientific importance and rarity and offer an extensive living analogue for the study of the nature and evolution of Earth’s biosphere up until the early Cambrian.
Colonies of cyanobacteria bond together and secrete a sticky gel that traps drifting shells, sand and other sediments. The outer layer of a stromatolite is a thin strip of living, active cyanobacteria which releases oxygen into the atmosphere and has therefore played a paramount part in the evolutionary history on Earth.
Shark Bay is one of only two places in the world where these living marine stromatolites still exist. At Exuma Cays in the Bahamas, the stromatolites are in an open marine environment and are not as preserved or extensive.
The Faure Sill maintains the distinctive hypersaline conditions in areas which also contain restricted marine species tolerant of hypersalinity. Any alteration to the morphology of the Sill could jeopardise conservation values of the marine reserves and Hamelin Pool.
Conservation Protection/Park Administration
The World Heritage Convention was adopted by the United Nations Educational, Scientific and Cultural Organisation (UNESCO) in 1972, coming into force in 1975. Australia became a signatory to the Convention in 1974 and remains a strong supporter of its aims, recognising a duty to ensure the protection, conservation, presentation, and where appropriate, rehabilitation of World Heritage values for their transmission of this cultural and natural heritage to future generations. The Australian Government’s Environment Protection and Biodiversity Conservation Act (EPBC) regulations ensures that World Heritage conservation, protection and rehabilitation principals and goals are adhered to across all World Heritage properties within the country, whilst individual State-Commonwealth agreements establish administrative, monitoring, planning and reporting arrangements for the protection and management of these areas.
The Department of Biodiversity, Conservation and Attractions (DBCA) – Parks and Wildlife Service is the lead State Government agency responsible for the on-ground management, operational support and administrative structures of © the property
Ecotourism
Shark Bay has an intriguing heritage of maritime exploration, scientific discovery and natural resource usage through pearling, guano mining, sandalwood cutting, fishing and pastoralism. It is also the site of the first recorded landing of a European on the Australian coast by the Dutch sea captain Dirk Hartog in 1616. Remoteness has protected Shark Bay from many of the pressures of human use. Changes in visitor numbers bring potential threats to the pristine quality of the area’s marine ecosystems and wildlife populations. The arid environment is fragile and vulnerable to impact by uncontrolled access.
Shark Bay’s natural environment and ecological integrity are the essence of its attraction for visitors and protection of these values is fundamental to developing and maintaining sustainable tourism experiences, thus high yield, rather than high volume, visitation is the goal. Although the wild Monkey Mia bottlenose dolphins are not a specific World Heritage value, they are world famous, with daily feeding of the inshore dolphins occurring each morning. This dolphin experience began in the 1960’s when a local Aboriginal fisherman began feeding fish to a dolphin which followed his boat to shore. Today there are around 90 000 visitors to Monkey Mia annually either as day visitors or resort guests.
Not only can visitors interact directly with the wild dolphins that visit the beach each day, they are also able to experience a variety of marine and terrestrial pursuits such as sea-kayaking and snorkelling provided by local commercial tourism operators and cultural tours with an indigenous Malgana guide. Boat cruises to spot more local marine life, including dugong, rays and turtles are also available at Monkey Mia.
Other Shark Bay attractions include; a diversity of on-water activities; the Ocean Park aquarium housing several species of shark and a wide variety of other marine life on display; and 4WD touring into Francois Peron National Park to explore the rich red sand dune landscape and the stunning turquoise waters surrounding Peron Peninsula. The artesian hot water tub and station life walk are attractions at the old pastoral station homestead.
Management Issues
To qualify as having an ‘outstanding universal value’ a World Heritage area must have adequate systems in place to protect and manage the listed values into the future and the Shark Bay World Heritage property has legal and legislative protection via three tiers of government – Commonwealth, State and Local, whereby any action that is likely to have a significant impact on World Heritage values must undergo an environmental assessment and approval process. The DBCA, as the lead agency has responsibility to protect and conserve the State’s natural environment when managing national parks, marine parks and reserves. It is also responsible for fire preparedness and pest and animal control on unallocated Crown Land and unmanaged reserves.
A World Heritage advisory committee also provides advice to governments on conservation and protection of the area’s values, research priorities and the scientific basis of management principles and practices. These combined processes provide comprehensive protection and management of the Shark Bay property.
Key threats to the site’s values include:
introduced plants, animals and marine pests; human impacts including coastal recreational use and access; climate change long-term effects, fire threats (particularly to species highly restricted in distribution) and fisheries and
aquatic activities.
