Barker Inlet

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This page is about the inlet in South Australia. For other uses, see Barker (disambiguation).

Barker Inlet
Barker Inlet location.png
The inlet in relation to Adelaide's Central business district
Location South Australia
Coordinates Lua error in package.lua at line 80: module 'strict' not found.
River sources Dry Creek
Basin countries  Australia
Settlements Adelaide

The Barker Inlet is a tidal inlet of the Gulf St Vincent in Adelaide, South Australia, named after Captain Collet Barker who first sighted it in 1831. It contains one of the southernmost mangrove forests in the world, a dolphin sanctuary, seagrass meadows and is an important fish and shellfish breeding ground. The inlet separates Torrens Island and Garden Island from the mainland to the East and is characterized by a network of tidal creeks, artificially deepened channels, and wide mudflats. The extensive belt of mangroves are bordered by samphire saltmarsh flats and low-lying sand dunes, there are two boardwalks (at Garden Island and St Kilda), and ships graveyards in Broad Creek, Angas Inlet and the North Arm.

The inlet has been adversely impacted since the settlement of South Australia with stormwater and raw sewage discharge, fishing, landfill rubbish dumping, power generation and other activities adversely affecting its flora and fauna. Much of this has changed with the landfill dump on adjacent Garden Island closed in 2000 and remediation work begun.[1] Some stormwater is now being filtered through wetlands before discharge and the inlet has been declared a reserve for the preservation of dolphins, fish, crabs and aquatic plants. The mangroves and waterways are still affected by the adjacent salt crystallization pans, hot wastewater discharge from Torrens Island power station, heavy metal contamination from stormwater and treated sewage, and disturbances from boat traffic.

Physical structure

Barker Inlet is a shallow tidal inlet which, with the adjacent Port River Estuary, formed during the Holocene by the progressive extension of the Lefevre Peninsula by northward littoral drift of sand carried by wave action along the eastern shore of Gulf St Vincent.[2]

It has a narrow central channel used for boating. Spring tides are over 2½ metres and at low tide much of the inlet is mudflats that are above water level. Most of the creeks through the mangroves drain surrounding land and are not navigable except at high tide by very small boats. There is an artificial channel, running along the side of a breakwater, from a boat ramp at St Kilda near the inlet's north end. The coast side of the mangroves are bounded by extensive salt evaporation ponds leased for industrial usage by the South Australian Government.

Most of the creeks on the eastern side are tidal although Swan Alley creek is the outlet for the Dry Creek and the Little Para River, and the North Arm Creek for the Barker Inlet Wetlands. The wetlands were created in 1994 as part of a stormwater treatment system with both tidal and freshwater sections. There is 1.72 km2 of constructed wetlands holding 1.2 Gigalitres of stormwater before discharging via the creek.[3]

Flora and fauna

Flora

The grey mangroves are uniformly of the type Avicennia marina var. resinifera and cover most of the pre-settlement area, but the surrounding samphire salt flats have been greatly reduced in size by changes in the landform with Tecticornia flabelliformis now listed as threatened in the area.[4] The inlet's deeper sections are dominated by strap or tape weed (Posidonia spp.). Eelgrass (Zostera muelleri) and garweed (Heterozostera tasmanica) dominate the shallows, often being exposed on mudflats at low tide.[5]

Fauna

Over 70 species of fish have been recorded, along with over 110 of crustaceans and almost 50 of molluscs including species such as western king prawns, King George and yellowfin whiting and blue swimmer crabs.[5] Many bird species use the inlet including cormorants, terns, ducks, swans, pelicans, egrets and herons, as well as silver gulls and white-bellied sea eagles. Including migratory birds, over 250 species have been recorded in the inlet, surrounding wetlands and lagoons.[6]

Pelicans on mudflats, Barker Inlet

Former uses

From 1906 until 1972, the inlet's Broad Creek was used as a landing point for explosives that were then transported by a 2.4 km (1.5 mi) tramway to the Dry Creek explosives depot. There are abandoned ships in Broad Creek, Angas Inlet and the North Arm of the Port River. The remains of over 30 iron and wooden ships abandoned up until 1945 are now bird roosts and a canoeing attraction.[7]

Protected areas

Reserves declared by the South Australian government

Barker Inlet Aquatic Reserve

The Barker Inlet Aquatic Reserve was declared in 1973 for the purpose of ‘conservation of mangrove seagrass communities and for the protection of nursery areas for several important commercial and recreational species, including the western king prawn, King George whiting, yellowfin whiting and blue swimmer crabs for fisheries management.’ The following activities are permitted - boating, the removal of fish by rod and line or handline and the collecting of blood worms for bait by use of a hand net. The reserve which covers the extent of Barker Inlet south of a line the runs from Point Grey in the west alongside the boat channel to St. Kilda in the east and bounded at the south by the causeway serving both Torrens and Garden Islands. It has an area of Lua error in Module:Convert at line 272: attempt to index local 'cat' (a nil value)..[8][9]

St Kilda – Chapman Creek Aquatic Reserve

The St Kilda – Chapman Creek Aquatic Reserve was declared in 1980 for the purpose of ‘the conservation of mangrove seagrass communities and the protection of nursery areas for major commercial and recreational fish species’ and to provide ‘buffer area between commercial fishing activity and the Barker Inlet Aquatic Reserve.’ Permitted Activities include the use of boats, swimming and fishing activity which consists of both blue swimmer crab captured by hand, crab rake or hoop net, and land-based line fishing from the breakwater. It extends northwards from the north boundary of the Barker Inlet Aquatic Reserve in Barker Inlet to Chapman Creek. It has an area of Lua error in Module:Convert at line 272: attempt to index local 'cat' (a nil value)..[8][10]

Adelaide Dolphin Sanctuary

The Adelaide Dolphin Sanctuary, a Dolphin sanctuary of an area of Lua error in Module:Convert at line 272: attempt to index local 'cat' (a nil value). which was enacted in 2005 includes all of the Barker Inlet as part of its extent. Bottlenose dolphins are often seen in the inlet, examine and follow small boats and have become a well known tourist attraction.[11]

Terrestrial reserves

The Torrens Island Conservation Park immediately adjoins Barker Inlet's western side.[9]

Non-statutory arrangements

The Baker Inlet is located at the southern extent of an Important Bird Area (IBA) known as the Gulf St Vincent Important Bird Area.[12]

See also

References

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  2. Bowman, G. & Harvey, N. (1986): Geomorphic Evolution of a Holocene Beach-Ridge Complex, LeFevre Peninsula, South Australia. Journal of Coastal Research 2(3):345-362
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  6. BirdLife International. (2011). Important Bird Areas factsheet: Gulf St Vincent. Downloaded from http://www.birdlife.org on 03/07/2011
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External links