Donnelly River (Western Australia)

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Donnelly River
Donnellyriver1.jpg
Limestone cliff near the mouth of the river
Origin between Bridgetown and Manjimup
Mouth Southern Ocean
Basin countries Australia
Length 151 kilometres (94 mi)[1]
Mouth elevation sea level
Avg. discharge 331 GL/yr [2]
Basin area 1,725 square kilometres (666 sq mi)[3]

The Donnelly River is a river in the South West of Western Australia.

The main tributaries of the Donnelly River are Barlee Brook and Carey Brook.

The first European to sight the river was Lieutenant William Preston in 1831. The river was named by James Stirling, the Governor of Western Australia, in the 1830s after a friend of his family, Admiral Sir Ross Donnelly.[4] The river runs primarily through State Forest reserves, although 43 land-holdings do have river frontage. The clearing of the catchment area is estimated at 15–20% with the land mostly being used for perennial horticulture, dairy and grazing.

Fauna[edit]

The Donnelly is one of the few catchments left in the state that contains all of the regions endemic freshwater fishes. The native freshwater species that are found include salamanderfish (Lepidogalaxias salamandroides), freshwater cobbler (Tandanus bostocki), Western Minnow, western mud minnow (Galaxiella munda), black-stripe minnow, western pygmy perch (Nannoperca vittata), Balston's Pygmy Perch and nightfish.

The ancient pouched lamprey is also known to inhabit the river.

Many estuarine fish are found close to the mouth of the river, these include black bream (Acanthopagrus butcheri), sea mullet (Mugil cephalus), yellow-eye mullet, silverfish, Hardyhead, South West Goby (favonigobius tamerensis), Tarwhine, flathead, Australian herring (Arripis georgianus), and cobbler.[5]

Several species have been introduced into the river, these include Eastern mosquitofish (Gambusia holbrooki), redfin perch (Perca fluviatilis), and rainbow trout (Oncorhynchus mykiss). The latter is the most common, being specifically introduced for angling purposes, with over 500,000 being stocked into the system between 1999 and 2004.[6]

Flora[edit]

Donnelly River, approximately 6km from mouth of river

The river originates in the an area of open Jarrah Marri forest between Bridgetown and Manjimup, The area contains an understorey composed of such species as Banksia grandis, Allocasuarina fraseriana, Agonis flexuosa, Persoonia longifolia, Acacia pulchella, Macrozamia reidlei, Xanthorrhoea preissii and Xanthorrhoea gracilis.

The river then flows through a large area of tall Karri forests these forests have an understory containing many species such as Allocasuarina decussata, Agonis flexuosa, Bossiaea laidlawiana, Trymalium floribundum, Thomasia quercifolia and Pimelia clavata.

Toward the coast the floral composition changes as the soils change to swampy flats and consolidated dunes. Species such as Stout Paperbark, Swamp Paperbark, Yate, Warren River Cedar, Wonnich and various Banksia species start to dominate.

References[edit]

  1. ^ "Donnelly River Action Plan". 2006. Retrieved 10 November 2008. 
  2. ^ "Context Report on Southwest Water Resources". 2008. Retrieved 10 November 2008. 
  3. ^ "South West Water Resources - Regional Overview". 2007. Retrieved 10 November 2008. 
  4. ^ Western Australian Land Information Authority. "History of river names". Retrieved 3 September 2011. 
  5. ^ "Fish Fauna of the Donnelly River, Western Australia". 2006. Retrieved 10 November 2008. 
  6. ^ "Donnelly River Action Plan". 2006. Retrieved 10 November 2008. 

Coordinates: 34°29′S 115°40′E / 34.483°S 115.667°E / -34.483; 115.667