Wilson Inlet is a shallow, seasonally open

estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime enviro ...

located on the coast of the Great Southern region of

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

Description

The inlet receives water from the two main rivers: the Denmark River and the Hay River and some smaller rivers and streams such as the Sleeman River, Little River and Cuppup Creek. It is located south east of the town of

Denmark Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...

. The inlet is a

wave In physics, mathematics, engineering, and related fields, a wave is a propagating dynamic disturbance (change from List of types of equilibrium, equilibrium) of one or more quantities. ''Periodic waves'' oscillate repeatedly about an equilibrium ...

dominated estuary with an opening mouth that has a width of with a bar blocking it from late January to August. The inlet is separated into two basins, the eastern and western basin. The estuary is situated on a narrow coastal plain between

granite Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly coo ...

hills to the north and the west and the coastal dunes to the south. The area of the inlet is and it has an average depth of ; its deepest point is . The inlet is long from east to west and has a width of The inlet has a total catchment area of covering parts of the Shire of Plantagenet, the Shire of Denmark and the City of Albany. The inlet discharges through Nullaki Point at the eastern end of Ocean Beach into the

Southern Ocean The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the world ocean, generally taken to be south of 60th parallel south, 60° S latitude and encircling Antarctica. With a size of , it is the seco ...

at Ratcliffe Bay when the sandbar is open. The Wilson Inlet bar is sometimes breached by the Water Corporation at Ocean Beach near Denmark. The low lying land adjacent to the inlet consists of

swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

s with lakes to the east. The

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension (chemistry), suspension with water. Silt usually ...

beds in the area indicate that it was of recent estuarine origin. The majority of the catchment is contained within the Albany-Fraser geological province with the original granite overlaid with sands and

laterite Laterite is a soil type rich in iron and aluminium and is commonly considered to have formed in hot and wet tropical areas. Nearly all laterites are of rusty-red coloration, because of high iron oxide content. They develop by intensive and prolo ...

deposited in the

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

period.

History

The inlet was formed 6000–8000 years ago when rising sea levels led to an ancient

river valley A valley is an elongated low area often running between hills or mountains and typically containing a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over a ...

being flooded. The original human inhabitants of the inlet and surrounds were

Aboriginal Australian Aboriginal Australians are the various indigenous peoples of the Australian mainland and many of its islands, excluding the ethnically distinct people of the Torres Strait Islands. Humans first migrated to Australia 50,000 to 65,000 year ...

people, the

Noongar The Noongar (, also spelt Noongah, Nyungar , Nyoongar, Nyoongah, Nyungah, Nyugah, and Yunga ) are Aboriginal Australian people who live in the South West, Western Australia, south-west corner of Western Australia, from Geraldton, Western Aus ...

. Many Aboriginal artefacts have been found in the area, including fish traps, corroboree sites,

ochre Ochre ( ; , ), iron ochre, or ocher in American English, is a natural clay earth pigment, a mixture of ferric oxide and varying amounts of clay and sand. It ranges in colour from yellow to deep orange or brown. It is also the name of the colou ...

excavation site and campsites. The

name for the inlet is ''Koorabup'', which means ''Place of the Black Swan''. The area was visited by Dr Thomas Wilson in his 1829 expedition from King George Sound. The inlet was named after Wilson by Governor Stirling. The first Europeans to settle in the catchment area were the Randall and Young families in the 1890s. Timber mills were constructed in 1895, land clearing began in the 1920s, and by 1982 46% of the catchment was privately owned. In total 44% of the catchment has been cleared and 38% remains as

forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...

and

national park A national park is a nature park designated for conservation (ethic), conservation purposes because of unparalleled national natural, historic, or cultural significance. It is an area of natural, semi-natural, or developed land that is protecte ...

s. In 1911 a local farmer William Leonard Smeed and six members of his family (four adults and three children), were drowned when their small yacht ''Little Wonder'' was knocked down in a squall while sailing on the inlet near Pelican Island. The inlet is breached at Ocean Beach near Denmark at times to reduce the chances of flooding around the local river systems. The bar was breached in 2014, 2017, 2018 and again in 2020.

Flora

The mouth of the inlet is dominated by stands of rushes (

Juncaceae Juncaceae is a family of flowering plants, commonly known as the rush family. It consists of 8 genera and about 464 known species of slow-growing, rhizomatous, herbaceous monocotyledonous plants that may superficially resemble grasses and ...

) of a single species, the South African '' Juncus kraussi''. '' Melaleuca cuticularis'', a salt tolerant paperbark, also fringes the inlet and follows the channels, and is present in the tidal parts of the rivers. The salt marsh is predominantly made up of '' Juncus kraussi'', '' Sarcocornia quinqueflora'', and '' Samolus repens''.

Fauna

Recreational fishing is popular within the inlet, which many species of fish inhabit, including cobbler, King George whiting,

tailor A tailor is a person who makes or alters clothing, particularly in men's clothing. The Oxford English Dictionary dates the term to the thirteenth century. History Although clothing construction goes back to prehistory, there is evidence of ...

, mullet, salmon trout and flathead. Other fish found in the estuary include sandy sprat, yellow eye mullet, sea mullet and

blue mackerel The blue mackerel (''Scomber australasicus''), also called Japanese mackerel, Pacific mackerel, slimy mackerel, or spotted chub mackerel, is a fish of the family (biology), family Scombridae. Description The blue mackerel typically reaches i ...

. Wilson Inlet is a key nursery for many juvenile fish species especially pink snapper that migrate from the inlet to mature in the greater oceanic breeding stock. Because of this the size of pink snapper that could be removed from the inlet was raised from to in July 2007. Many waterbird species inhabit the inlet and its surrounds, including the silver gull, Australian pelican,

black swan The black swan (''Cygnus atratus'') is a large Anatidae, waterbird, a species of swan which breeds mainly in the southeast and southwest regions of Australia. Within Australia, the black swan is nomadic, with erratic migration patterns dependent ...

, little black cormorant, red-necked stint,

little pied cormorant The little pied cormorant, little shag or kawaupaka (''Microcarbo melanoleucos'') is a common species of Australasian waterbird, found around the coasts, islands, Estuary, estuaries, and inland waters of Australia, New Guinea, New Zealand, Timor- ...

, grey teal, red-necked avocet, blue-billed duck and the Australasian shoveller. 22 species of migratory shorebird have been recorded. The inlet is home to a mussel and oyster farm that was established in 2002. The farm operates on a lease on the south side of the inlet and completed its first harvest in 2005–2006. Blue mussels are produced using a longline cultivation technique. Belon oysters are cultivated using a similar technique. An earlier operation had attempted to commercially produce blue mussels in the 1970s, but the small scale raft culture was destroyed by Cyclone Alby just prior to harvest.

External links

Wilson Inlet Tourism
*

References

{{reflist, 2 Shire of Denmark Inlets of Western Australia South coast of Western Australia