Lake Muir is a freshwater lake, with a larger surrounding wetlands area, that is located in the South West region of Western Australia. The lake lies near Muirs Highway, north of Walpole and southeast of Manjimup.

Lake Muir
A flat expanse of very short vegetation with some low shrubs in the foreground and a horizontal line of pale sand in the far distance under a cloudless sky
Lake Muir in October 2010
A map of Western Australia with a mark indicating the location of Lake Muir
A map of Western Australia with a mark indicating the location of Lake Muir
Lake Muir
Location in Western Australia
LocationSouth West, Western Australia
Coordinates34°26′49″S 116°44′54″E / 34.44694°S 116.74833°E / -34.44694; 116.74833
Primary outflowsDeep River
Catchment area384 km2 (148 sq mi)
Basin countriesAustralia
DesignationMuir-Byenup System Ramsar Site
Max. length11 km (6.8 mi)
Max. width5 km (3.1 mi)
Surface area46 km2 (18 sq mi)
Surface elevation170 m (560 ft)
References[1][2]

Description edit

The lake has a surface area of 46 square kilometres (18 sq mi). Lake Muir and its surrounding wetland lies within the Lake Muir-Byenup System, a 694 km2 (268 sq mi) area of internal drainage containing a complex of wetland systems. Lake Muir may, in flood, overflow southwest into the Deep River catchment (and possibly also southeast into the Frankland River via Poorginup Gully).[3]

Lake Muir is usually brackish (1000–3000 mg/L TDS) at the end of winter, saline by summer and dry throughout autumn.[3]

Lake Muir is protected within Lake Muir Nature Reserve, which was designated in 2001.[4]

Flora and fauna edit

A 14-square-kilometre (5.4 sq mi) section of wetland around Lake Muir has been identified by BirdLife International as an Important Bird Area (IBA) because it provides habitat for 10 or more pairs of endangered Australasian bitterns. The wetlands within the IBA are shallow with extensive beds of dense sedgeland and fringing stands of shrubland and woodland. Lake Muir has been excluded from the IBA as it is unsuitable for bitterns but it has supported large numbers of Australian Shelduck and may prove to be globally significant for that species.[5]

History edit

Lake Muir was named after brothers Thomas and John Muir, the first European settlers in the Warren district, who settled at Deeside, 25 kilometres (16 mi) west of the lake, in 1852 and built a rush hut there in 1856.[6]

Historically the area was a Game Reserve, with a duck shooting season. The Department of Environment and Conservation (CALM) started monitoring the wetlands system in 1980 in order to manage the duck shooting.

On 5 January 2001, a 106-square-kilometre (41 sq mi) area was designated, under the Ramsar Convention as Ramsar site 1050, a wetland of international importance, acknowledging its rich ecological diversity. Lake Muir Nature Reserve was designated in the same year by the Government of Western Australia.[4]

A magnitude 5.7 earthquake was centred at the lake on 16 September 2018[7] and was followed by a magnitude 4.7 quake on 13 October[8] and a 5.4 quake on 9 November.[9]

See also edit

References edit

  1. ^ "Bonzle Digital Atlas – Map of Lake Muir". 2009. Retrieved 2 March 2009.
  2. ^ "Information Sheet on Ramsar Wetlands - Muir – Byenup System, Western Australia". 2003. Archived from the original on 31 July 2008. Retrieved 2 March 2009.
  3. ^ a b Smith, Robin (April 2003). Hydrogeology of the Muir–Unicup catchments (PDF). East Perth, WA: Water and Rivers Commission. pp. 3–5. ISBN 1-920849-12-2. Retrieved 21 January 2017.
  4. ^ a b UNEP-WCMC (2022). Protected Area Profile for Lake Muir from the World Database of Protected Areas. Accessed 3 May 2022. [1]
  5. ^ "Muir-Unicup Wetlands". BirdLife International. Retrieved 21 January 2017.
  6. ^ Shire of Manjimup (1 January 2017). "Deeside Homestead Group". inHerit. Perth, WA: Heritage Council of Western Australia. Retrieved 22 January 2017.
  7. ^ "Magnitude-5.7 earthquake rocks southern WA". Australian Broadcasting Corporation. 17 September 2018. Retrieved 9 November 2018.
  8. ^ "Magnitude-4.7 earthquake rocks area surrounding Lake Muir in WA's Great Southern". Australian Broadcasting Corporation. 13 October 2018. Retrieved 9 November 2018.
  9. ^ Ben Anserson (9 November 2018). "Earthquake at Lake Muir shakes Perth and WA's South West". News Corporation. Retrieved 9 November 2018.

External links edit