The Peel-Harvey Estuarine System ( nys, Djilba) is a natural

estuarine 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 environment ...

system that lies roughly parallel to the coast of

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

and south of the town of

Mandurah Mandurah () is a coastal city in the Australian state of Western Australia, situated approximately south of the state capital, Perth. It is the state's second most populous city, with a population of 107,641 as of the 2021 Australian census, 2 ...

. The strip of land between the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

and the estuarine system carries the Old Coast Road and to the east is the

Forrest Highway Forrest Highway is a highway in Western Australia's Peel and South West regions, extending Perth's Kwinana Freeway from east of Mandurah down to Bunbury. Old Coast Road was the original Mandurah–Bunbury route, dating back to the 1840s. ...

which is the main thoroughfare between

Perth Perth is the capital and largest city of the Australian state of Western Australia. It is the fourth most populous city in Australia and Oceania, with a population of 2.1 million (80% of the state) living in Greater Perth in 2020. Perth is ...

and the coastal towns of the south west corner of the state including Bunbury and

Busselton Busselton is a city in the South West region of the state of Western Australia approximately south-west of Perth. Busselton has a long history as a popular holiday destination for Western Australians; however, the closure of the Busselton ...

Description

The estuarine system, which the

Bindjareb The Bindjareb, Binjareb, Pindjarup or Pinjareb are an Indigenous Noongar people that occupy part of the South West of Western Australia. Name It is not clear if ''Pindjarup'' is the historically correct ethnonym for the tribe. After their di ...

Noongar people call , covers an area of approximately in total, with an average water depth of about . The

Harvey River The Harvey River is a river in Western Australia and is the southernmost of the three major waterways which drain into the Peel-Harvey Estuary, with its delta in the southern extreme of the Harvey Estuary. It is about 90 km in length, risi ...

discharges into the extreme southern end of the elongated Harvey Estuary, which has an area of about . This in turn feeds into the south-western corner of the more northerly Peel Inlet which is roughly circular and occupies an area of about . The Serpentine River and

Murray River The Murray River (in South Australia: River Murray) (Ngarrindjeri: ''Millewa'', Yorta Yorta: ''Tongala'') is a river in Southeastern Australia. It is Australia's longest river at extent. Its tributaries include five of the next six longest r ...

s discharge into the eastern edges of Peel Inlet. A long channel, the Mandurah Estuary (also called Mandurah Entrance Channel or just Mandurah Channel) which passes through the town of Mandurah, then runs into the ocean. After several decades of severe

algal bloom An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term ''algae'' encompas ...

s in the estuaries caused by discharge of nutrients from agricultural land and piggeries along the rivers, an artificial

channel Channel, channels, channeling, etc., may refer to: Geography * Channel (geography), in physical geography, a landform consisting of the outline (banks) of the path of a narrow body of water. Australia * Channel Country, region of outback Austral ...

was constructed and opened in 1994 as the

Dawesville Channel Dawesville Channel (also known as Dawesville Cut) is an artificial channel between the Peel-Harvey Estuary and the Indian Ocean at Dawesville, about south of Perth in Western Australia. It is south of the regional city of Mandurah and north o ...

. The channel had the effect of allowing saline sea-water to regularly ''flush'' the estuary using tidal flows. Whilst the ecology of the estuary has changed markedly due to the flushing process, water quality generally has improved. The catchment area to the east is largely flat coastal plain with about 75% cleared of native vegetation and used for dryland, dairy and beef grazing. Clearing was done in the early days of settlement to allow

agricultural expansion Agricultural expansion describes the growth of agricultural land (arable land, pastures, etc.) especially in the 20th and 21st centuries. The agricultural expansion is often explained as a direct consequence of the global increase in food and ene ...

. Drainage systems into the three main rivers have been constructed in much of the catchment to remove excess water quickly. Lake Preston, Lake Clifton and the

Leschenault Estuary Leschenault Estuary is an estuarine lagoon that lies to the north of Bunbury, Western Australia. It had in the past met the Indian Ocean at the Leschenault Inlet, but that has been altered by harbour works for Bunbury, and the creation of The Cu ...

are farther south.

Flora and fauna

The estuary is home to abundant marine wildlife including crustaceans such as the

blue swimmer crab Blue is one of the three primary colours in the RYB color model, RYB colour model (traditional colour theory), as well as in the RGB color model, RGB (additive) colour model. It lies between Violet (color), violet and cyan on the optical sp ...

(''Portunus pelagicus'') and the western king prawn (''Melicertus latisulcatus'') and fish species such as

black bream Black bream may refer to one of several fish species: * Black drummer, ''Girella elevata'' * Black seabream, ''Spondyliosoma cantharus'', a silvery fish found in northern Europe and the Mediterranean * Galjoen, ''Dichistius capensis'', the nationa ...

mulloway ''Argyrosomus japonicus'' is a silvery to bronze-green colored fish, a member of the family Sciaenidae, which may grow up to in length. It is known as Japanese meagre (FAO), mulloway or jewfish on the east coast of Australia, butterfish in South ...

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 ...

and

cobbler Cobbler(s) may refer to: *A person who repairs, and sometimes makes, shoes Places * The Cobbler, a mountain located near the head of Loch Long in Scotland * Mount Cobbler, Australia Art, entertainment and media * ''The Cobbler'' (1923 film) ...

. It is occasionally visited by

dolphin A dolphin is an aquatic mammal within the infraorder Cetacea. Dolphin species belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae (the ...

s. The estuary has been identified by

BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding ...

as an

Important Bird Area An Important Bird and Biodiversity Area (IBA) is an area identified using an internationally agreed set of criteria as being globally important for the conservation of bird populations. IBA was developed and sites are identified by BirdLife Int ...

(IBA) because it supports a significant population of

fairy tern The fairy tern (''Sternula nereis'') is a small tern which is native to the southwestern Pacific. It is listed as " Vulnerable" by the IUCN and the New Zealand subspecies is " Critically Endangered". There are three subspecies: * Australian f ...

s, is a

drought refuge A drought refuge is a site that provides permanent fresh water or moist conditions for plants and animals, acting as a refuge habitat when surrounding areas are affected by drought and allowing ecosystems and core species populations to survive unt ...

for

blue-billed duck The blue-billed duck (''Oxyura australis'') is a small Australian stiff-tailed duck, with both the male and female growing to a length of 40 cm (16 in). The male has a slate-blue bill which changes to bright-blue during the breeding sea ...

s, and sometimes holds over 1% of the world populations of

red-necked stint The red-necked stint (''Calidris ruficollis'') is a small migratory wader. The genus name is from Ancient Greek ''kalidris'' or ''skalidris'', a term used by Aristotle for some grey-coloured waterside birds. The specific ''ruficollis'' is from La ...

sharp-tailed sandpiper The sharp-tailed sandpiper (''Calidris acuminata'') (but see below) is a small wader. Taxonomy A review of data has indicated that this bird should perhaps better be placed into the genus ''Philomachus'' – as ''P. acuminatus'' – which now ...

banded stilt The banded stilt (''Cladorhynchus leucocephalus'') is a nomadic wader of the stilt and avocet family, Recurvirostridae, native to Australia. It belongs to the monotypic genus ''Cladorhynchus''. It gets its name from the red-brown breast band fo ...

red-necked avocet The red-necked avocet (''Recurvirostra novaehollandiae'') also known as the Australian avocet, cobbler, cobbler's awl, and painted lady, is a wader of the family Recurvirostridae that is endemic to Australia and is fairly common and widespread th ...

s and

red-capped plover The red-capped plover (''Charadrius ruficapillus''), also known as the red-capped dotterel, is a small species of plover. It breeds in Australia. This species is closely related to (and sometimes considered conspecific with) the Kentish plover, ...

Recreational use

The estuary is used heavily for recreational boating and fishing with numerous boat ramps and picnic spots along the extensive foreshore with shaded sandy beaches.

Houseboats A houseboat is a boat that has been designed or modified to be used primarily as a home. Most houseboats are not motorized as they are usually moored or kept stationary at a fixed point, and often tethered to land to provide utilities. How ...

can be hired at Mandurah to explore the estuary and the Murray River. Urban developments along the shores as well as canal developments in Mandurah and at

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography. Etymology T ...

and

South South is one of the cardinal directions or Points of the compass, compass points. The direction is the opposite of north and is perpendicular to both east and west. Etymology The word ''south'' comes from Old English ''sūþ'', from earlier Pro ...

Yunderup pose significant challenges for its successful future management.

References

Sources

*
Potter, Ian: The influence of the Dawesville Channel on recruitment, distribution and emigration of crustaceans and fish in the Peel-Harvey estuary
*C.C. Wilson & J. Latchford (1995). ''Water Quality of the Peel-Harvey, July 1994 to April 1995'' C.C. Wilson & J. Latchford (1995) *Lane, J., Clarke, A. and Pearson, G. (2002). ''Waterbirds of Peel-Harvey estuary in 1998-99''. Department of Conservation and Land Management, 40 p.

External links

Wikimapia map of the Dawesville Channel
{{coord, 32, 37, S, 115, 39, E, display=title, region:AU_type:waterbody_source:GNS-enwiki Estuaries of Western Australia Ramsar sites in Australia Swan Coastal Plain Important Bird Areas of Western Australia Peel (Western Australia)