66,080 research outputs found

    Fish and freshwater crayfish communities of the Brunswick and Preston Rivers

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    The Leschenault Inlet, located on the Swan Coastal Plain near Bunbury, is the estuary of the Brunswick, Collie, Preston and Ferguson Rivers. There is a considerable amount of information detailing the fish fauna of the Leschenault Inlet with Potter et al. (1997, 2000) recording 42 species of fish from 26 families. The estuary is dominated by gobies, atherinids and clupeids which comprised almost 90% of the fishes. Potter et al. (2000) also reported 13 species from gill net captures in the lower (tidal) Collie River. Neither of these studies reported on the fishes found within the freshwaters of the Leschenault Inlet catchment and although Pen & Potter (1990, 1991a, b, c, d, 1992) conducted biological studies on a number of native and introduced freshwater fishes in the upper Collie River by, there is no published information regarding the prevailing fishes (or freshwater crayfishes) of the Brunswick or Preston Rivers. Hale et al. (2000) reported on the fish fauna of one site in the upper Brunswick River, near the confluence with the Augustus River, one site in the Augustus River and two sites in the Ernest River. While they recorded only two species of freshwater fish from the Ernest River (i.e. Western Pygmy Perch (Edelia vittata) and Nightfish (Bostockia porosa)), they captured a further two endemic freshwater fishes from the Augustus and upper Brunswick Rivers (i.e. Western Minnow (Galaxias occidentalis) and Freshwater Cobbler (Tandanus bostocki)) as well as larval (ammocoetes) Pouched Lampreys (Geotria australis) and three introduced fishes (i.e. Rainbow Trout (Oncorhynchus mykiss), Brown Trout (Salmo trutta) and Eastern Mosquitofish (Gambusia holbrooki)). The presence of the larger introduced fishes, the lamprey and the Freshwater Cobbler in the Augustus River compared to the Ernest River was attributed to the provision of environmental water releases from Freshwater Lake. These species are more often associated with permanent waters over ephemeral systems. The distributions of fishes inhabiting the inland waters of the south-western corner of Western Australia were documented in Morgan et al. (1998) and include the systems from Capel to Two People’s Bay east of Albany and thus does not encompass the more northerly Leschenault catchments, but does include some sites on the Collie River South Branch. The aims of the present study were to ameliorate the paucity of knowledge of the fishes and freshwater crayfishes inhabiting two of the major systems flowing into the Leschenault Inlet and thereby provide the Leschenault Catchment Council with an overview of the fishes of the Brunswick and Preston Rivers

    Re-establishment of native freshwater fishes in Bull Creek

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    Bull Creek is a perennial, urban stream located in the City of Melville and is a tributary to the Canning River. The catchment has been largely altered for urban development (i.e. housing) and receives a considerable amount of storm-water runoff. Substantial effort has been made recently to re-habilitate the riparian zone of Bull Creek through weed eradication (particularly blackberry control) and native re-vegetation programs. The Melville City Council recognised the need to extend this rehabilitation effort to include the instream aquatic fauna and thus a fish re-establishment program was implemented; the details of which are described in this report

    UAH/NASA Workshop on Space Science Platform

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    The scientific user requirements for a space science platform were defined. The potential user benefits, technological implications and cost of space platforms were examined. Cost effectiveness of the platforms' capabilities were also examined

    Freshwater fish and crayfish communities of the tributaries of the Margaret River

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    Tributaries and headwaters of major rivers are known to be important spawning and nursery habitats of freshwater endemic fishes in south-western Australia (see for example the Collie River in Pen & Potter 1990, and the Blackwood River in Beatty et al. 2006, 2008). Fishes of the Margaret River have previously been examined by Morgan et al. (1998) and Morgan & Beatty (2003) with the monitoring of the functioning of the two fishways on the river documented in Morgan & Beatty (2004, 2007) and Beatty & Morgan (2008). The river is known to be of conservation importance due to it housing five of the eight endemic freshwater fishes of the south-west region, as well as housing the majority (five of the six species) of the Cherax species of freshwater crayfishes found in the south-west; including the Margaret River endemic Critically Endangered Hairy Marron. Despite this known value and considerable volume of research on the fishes in the main channel of the Margaret River, little is known on the fishes and freshwater crayfishes of the river 19s major tributaries. The aim of this study is to document the freshwater fish distribution in the major tributaries of the Margaret River (i.e. Bramley, Darch, and Yalgardup Brooks) during or close to the breeding period for the majority of the species and to provide a broad assessment and comparison of population demographics of the different species in the different tributaries. This information is required for the formulation of River Action Plans for these systems by the Cape to Cape Catchments Group

    Coupling Rydberg atoms to microwave fields in a superconducting coplanar waveguide resonator

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    Rydberg helium atoms traveling in pulsed supersonic beams have been coupled to microwave fields in a superconducting coplanar waveguide (CPW) resonator. The atoms were initially prepared in the 1s55s 3^3S1_1 Rydberg level by two-color two-photon laser excitation from the metastable 1s2s 3^3S1_1 level. Two-photon microwave transitions between the 1s55s 3^3S1_1 and 1s56s 3^3S1_1 levels were then driven by the 19.556 GHz third-harmonic microwave field in a quarter-wave CPW resonator. This superconducting microwave resonator was fabricated from niobium nitride on a silicon substrate and operated at temperatures between 3.65 and 4.30 K. The populations of the Rydberg levels in the experiments were determined by state-selective pulsed electric field ionization. The coherence of the atom-resonator coupling was studied by time-domain measurements of Rabi oscillations.Comment: 6 pages, 5 figure
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