Shark Bay (Malgana: Gathaagudu, meaning "two waters") is a World Heritage Site in the Gascoyne region of Western Australia. The area covers 23,000 square kilometers (about 8,900 square miles) and is located approximately 800 kilometers (500 miles) north of Perth, at the westernmost point of the Australian continent.

UNESCO describes Shark Bay as a World Heritage Site by stating:

The bay is home to some of Australia's most diverse marine ecosystems. It is a well-known location for fishing.

History

The Australian Aboriginal people lived in Shark Bay for about 22,000 years before the present time. At that time, most of the area was dry land. Later, rising sea levels caused Shark Bay to become flooded between 8,000 and 6,000 years ago. Many Aboriginal midden sites have been found, especially on Peron Peninsula and Dirk Hartog Island. These sites show what foods were collected from the nearby waters and land.

In 1616, an expedition led by Dirk Hartog reached Shark Bay. This was the second known group of Europeans to visit Australia, after a group from the ship Duyfken arrived at Cape York in 1606. The English explorer William Dampier named the area Shark Bay on August 7, 1699. Later, other Europeans, including Louis Aleno de St Aloüarn in 1772, Nicolas Baudin from 1801 to 1803, and Louis de Freycinet in 1818, also visited Shark Bay. Europeans, mainly farmers, began settling in Shark Bay during the 1860s and 1870s. Pearling became a major industry starting in 1870.

In the early 1900s, Norwegian-owned ships hunted whales in Shark Bay. These ships used factory ships and smaller boats to catch whales. By the late 1930s, up to 1,000 humpback whales were hunted each season.

As of the 2011 census, the heritage-listed Shark Bay area had fewer than 1,000 people living there. These people live in six small communities that cover less than 1% of the total area.

Climate

The Shark Bay Heritage Area has a hot desert climate, as classified by the Köppen system. This area experiences very hot and dry summers, and winters that are not too cold with some rainfall.

Shark Bay World Heritage Site

The World Heritage status of the region was created and negotiated in 1991, making it the first such site in Western Australia. The site was officially listed on the Australian National Heritage List on May 21, 2007, under a law passed in 2003 called the Environment and Heritage Legislation Amendment Act (No. 1).

Declared a World Heritage Site in 1991, the area covers 23,000 square kilometers (8,900 square miles), with about 70% of it being marine waters. It includes many protected areas and conservation reserves, such as Shark Bay Marine Park, Francois Peron National Park, Hamelin Pool Marine Nature Reserve, Zuytdorp Nature Reserve, and several protected islands. Denham and Useless Loop are within the site’s boundary but are not included in the protected area.

The bay itself covers 1,300,000 hectares (3,200,000 acres) and has an average depth of 9 meters (30 feet). It is divided by shallow banks and has many peninsulas and islands. The coastline is over 1,500 kilometers (930 miles) long. There are about 300 kilometers (190 miles) of limestone cliffs overlooking the bay. One famous part of the cliffs is called the Zuytdorp Cliffs. The bay lies in the area where three major climate zones and two major plant regions meet.

The Peron Peninsula divides the bay and is home to the largest settlements in the area, as well as a National Park at its northern end.

Dirk Hartog Island is historically important because early explorers landed there. In 1616, Dirk Hartog arrived at Inscription Point on the island’s northern end and placed a pewter plate with his name and the date on a post. This plate was later replaced by Willem de Vlamingh and sent back to the Netherlands. It is now displayed in the Rijksmuseum. A copy of the plate is shown at the Shark Bay Discovery Centre in Denham.

Bernier and Dorre Islands, in the northwest corner of the heritage area, are home to two types of Australian mammals called hare-wallabies, which are at risk of extinction. These islands, along with many others in the marine park, are used to release animals bred at Project Eden in Francois Peron National Park. These islands are free of non-native animals that could harm the threatened species, making them safe places for their recovery.

In 1999, the Australian Wildlife Conservancy took over a 5,816-hectare (14,370-acre) pastoral lease on Faure Island, near Monkey Mia. Sea turtles nest there seasonally, and studies about them are conducted with the Department of Biodiversity, Conservation and Attractions.

Shark Bay is an important area for wildlife. It is home to about 10,000 dugongs (sea cows), which make up around 12.5% of the world’s population. There are also many Indo-Pacific bottlenose dolphins, especially near Monkey Mia. These dolphins have been friendly to humans since the 1960s. The area supports over 26 threatened mammal species, more than 230 bird species, and nearly 150 reptile species. It is a key place for fish, crustaceans, and jellyfish to breed and grow. There are over 323 fish species, including many sharks and rays.

Some bottlenose dolphins in Shark Bay use sponges to protect their noses while searching for food on the seafloor, a rare behavior among marine mammals. Humpback and southern right whales use the bay as a stop during their migration, while Bryde’s whales visit less often to feed or rest. Threatened green and loggerhead sea turtles lay their eggs on the bay’s sandy beaches. Whale sharks, the largest fish in the world, gather in the bay during the April and May full moons.

Shark Bay has the largest known seagrass area, with seagrass meadows covering over 4,000 square kilometers (1,500 square miles). It includes the Wooramel Seagrass Bank, the world’s largest seagrass bank, and a 200-square-kilometer (77-square-mile) Posidonia australis meadow formed by a single plant, the largest of its kind.

Shark Bay also has the highest number of seagrass species recorded in one place, with 12 species found there. These seagrasses are essential to the bay’s ecosystem. Over thousands of years, sediment and shells have built up in the seagrass, raising the sea floor and making the bay shallower. Seagrasses support the food chain, providing shelter for marine life and attracting dugongs.

In Shark Bay’s hot, dry climate, water evaporates much faster than it rains, making the seawater in shallow bays extremely salty, or hypersaline. Seagrasses also limit the flow of ocean tides into the bay, keeping the water saltier than surrounding ocean areas. The bay’s water is 1.5 to 2 times saltier than the surrounding ocean.

About 1,000 years ago, cyanobacteria (blue-green algae) began forming stromatolites in Hamelin Pool, part of the Hamelin Station Reserve in the bay’s southern area. These microbial structures are modern examples of some of Earth’s earliest life forms. Fossilized stromatolites from 3.5 billion years ago have been found near Marble Bar in Western Australia. Shark Bay’s living stromatolites were first discovered in 1956 at Hamelin Pool and are the most diverse and numerous in the world. Other stromatolites are found at Lake Clifton near Mandurah and Lake Thetis near Cervantes. Scientists believe some stromatolites may contain a new type of chlorophyll called chlorophyll f.

Facilities near the World Heritage area, managed by the Shire of Shark Bay and the Department of Biodiversity, Conservation and Attractions, include the Shark Bay World Heritage Discovery Centre in Denham, which offers interactive displays and information about the region.

Access to Shark Bay is by air through Shark Bay Airport or by the World Heritage Drive, a 150-kilometer (93-mile) road connecting Denham to the Overlander Roadhouse on the North West Coastal Highway.

Specific reserved areas

The Shark Bay area includes three bioregions within the Interim Biogeographic Regionalisation for Australia (IBRA) system: Carnarvon, Geraldton Sandplains, and Yalgoo. Each bioregion is divided into smaller areas called sub-bioregions.