Upper Parramatta River Catchment Education Resource Kit, 2002

Information Sheet (catchment)

C1 - Biodiversity Overview

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1. General Description

Isolated pockets of natural vegetaion surrounded by urban development are typical in the catchment

Biodiversity refers to the variety of living things in an environment. Natural and balanced ecosystems show considerable to high levels of biodiversity. Urban catchments such as the Upper Parramatta River Catchment include residential, industrial and commercial activity. Impacts on biodiversity result from the interactions between these activities such as urban flooding, water and air pollution and loss of natural habitat for flora and fauna. Urban catchments also include areas for refuge and recreation such as the “green corridors” or “green belts”. Green belts in the Upper Parramatta Catchment provide natural habitat for native species, respite for people from the urban environment and areas of recreation such as swimming, bushwalking and boating. These bushland areas are small outposts of the natural environment surrounded by dominating urbanisation.

A major reason for the disappearance of biodiversity in Sydney is the gradual reduction in the size of habitat areas and vegetation communities. Often, all that remain are a number of isolated pockets of native vegetation surrounded by agricultural, residential and industrial landscapes. Isolated, small patches of habitat may be insufficient to sustain viable populations of some native species of fauna. In such instances, wildlife corridors, which are lines of native vegetation connecting separate habitat areas, are essential for maintaining biodiversity. Wildlife corridors enable fauna to access larger habitats by encouraging mobility between areas. Corridors may also assist native plant species to spread and colonise new areas over time. (NPWS, 1998)

2. Map

Refer to Map 1: Rare and Endangered Species Map

3. Description of Types

The largest green belt in the Upper Parramatta River Catchment is in the sub-catchments of Hunts Creek, which flows into Lake Parramatta, and the Darling Mills Creek corridor. These sub-catchments includes the Blue Gum High Forests, Sydney Sandstone Heath and Sydney Sandstone Ridgetop complexes which are found in the Cumberland State Forest, Darling Mills Forest and Excelsior Park. (see Vegetation Communities Overview)

Animals likely to be present in the remnant bushland include:

Birds These are by far the most significant fauna by number in this region. More than 100 species of birds have been recorded in the Cumberland State Forest while over 50 different species have been identified in Excelsior Park alone. Common examples include the White-napped Honeyeater, Yellow-tufted Honeyeater and the Tawny Frogmouth Owl.

Water dwelling birds such as native ducks eg Wood Ducks and the Mallard, are common in Lake Parramatta. Domestic white ducks, which have been released in Lake Parramatta Park, are creating a severe impact on the less aggressive and slower breeding native species.

Small Mammals Brush-tailed and Ring Tail Possums, Sugar Gliders, bats and bandicoots are common. Feral predators such as foxes and cats have a major impact on the small mammal population and rabbits cause habitat destruction in the more open woodlands.

Reptiles. The most common lizards found include the Eastern Water Dragon, Blue-tongue Lizard and numerous varieties of skinks. The Red-bellied Black Snake and the Eastern Brown Snake are the most frequently encountered snakes in the catchment.

Amphibians. Amphibians are a major part of the biodiversity of western Sydney. Because some species have managed to survive even in populated or highly developed areas, many people encounter frogs in their neighbourhoods. There are 31 native species of frogs that occur in the area of western Sydney. Of these, five are listed as threatened or vulnerable on the Threatened Species Conservation Act — the Green and Golden Bell Frog, Red-crowned Toadlet, Giant Burrowing Frog, Green-thighed Frog and Stuttering Frog.

Aquatic Habitats. The original diversity of aquatic fauna has been reduced significantly as a result of urbanisation in the catchment. Poor water quality and engineering of many sections of creek bed have led to this decrease. Typical fauna existing in the freshwater section of the Parramatta River and its tributaries are:

eels
carp
eastern long-necked turtle (pictured)
Aquatic macro invertebrates including insects (beetles, moths, dragonflies), aquatic earthworms, freshwater mussels, snails and limpets, and prawns and crayfish. Freshwater invertebrates have been identified in the catchment and are listed in Lee Lau and Associates (1997).

Macroinvertebrate studies indicate that there is significant variation of diversity and abundance of organisms across the catchment. The results also expose a significant difference in health between the two major sub-catchments in the Upper Parramatta River catchment, Toongabbie Creek and Darling Mills/Hunts Creek. The ecology of the Darling Mills sub-catchment is more productive and its ecology less affected by pollution than the Toongabbie Creek sub-catchment. The ‘healthiest’ creeks in the catchment, according to Lee Lau & Associates (1997), are located in the Darling Mills Creek system:

· Upper Rifle Range Creek at North Rocks,

· Bellbird Creek at North Rocks,

· Darling Mills Creek at North Rocks and Baulkham Hills.

The Toongabbie Creek sub-catchment does not support a rich diversity of macroinvertebrates, and it is evident that ecosystem health is poor (Lee Lau and Associates, 1997). Examples of such poor health are:

· Upper Toongabbie Creek at Crestwood Reserve,

· Lower Toongabbie Creek at Westmead,

· Blacktown Creek at Blacktown

This contrast in the sub-catchments can be explained by the land use of each. Toongabbie Creek sub-catchment contains large areas of residential, industrial and commercial development with only small remnants of bushland. The creeks in many areas have been converted to concrete channels. Conversely, Darling Mills Creek sub-catchment contains relatively extensive tracts of bushland with mainly residential land use, and the majority of the sub-catchment has natural creeks.

Freshwater Fish Based upon surveys of freshwater fish species in NSW, (eg ‘The NSW Rivers Survey’ (Harris and Gehrke, 1997) native fish that occur or are expected to occur in the catchment are:

· Recreational fish and other large species - Australian Bass (Macquaria novemaculeata), Freshwater Mullet (Myxus petardi), Long-finned Eel (Anguilla reinhardtii), and Striped Mullet (Mugil cephalis).

· Small species - Common Jollytails (Galaxias maculatus), Striped Gudgeon (Gobiomorphus australis), Empire Gudgeon (Hypseleotris compressa), Australian Smelt (Retropinna semoni), Flathead Gudgeon (Philypnodon grandiceps), and Cox’s Gudgeon (Gobiomorphus coxii).

· Alien species which are known to occur in the catchment are European Carp (Cyprinus carpio), Goldfish (Carassius auratus) and Mosquitofish (Gambusia holbrooki).

The weirs located adjacent to Charles Street and Marsden Street, Parramatta impede the movement and migration of fish. It is unknown to what extent migratory fish are restricted by these structures.

4. Reasons for Distribution

The combination of soils, geology and climate within the Upper Parramatta River Catchment creates a highly diverse range of natural ecosystems. The catchment lies at the junction of two major soil and geological types (see Geology Overview) and there is a significant change in rainfall pattern from the north-eastern boundary of the catchment to the south-west (see Rainfall Overview). Remnant bushland on public land is the main refuge of native flora and fauna but the lack of links between remnants isolates populations making them vulnerable to urban pressures. However a number of species and communities within the catchment are of conservation significance and well worthy of restoration, eg Cumberland Plains Woodland

5. Other Resources and Links

· Upper Parramatta River Catchment Trust www.uprct.nsw.gov.au

· Parramatta City Council www.parracity.nsw.gov.au

· Baulkham Hills Shire Council http://www.baulkhamhills.nsw.gov.au/

· Holroyd City Council http://www.blacktown.nsw.gov.au

· Blacktown City Council www.holroyd.nsw.gov.au

· Natural Resource Directory www.nrims.nsw.gov.au

· State Forest NSW www.forest.nsw.gov.au

· Department of Land & Water Conservation www.dlwc.nsw.gov.au

· National Parks & Wildlife Service www.npws.nsw.gov.au

· www.dmoz.org