High-resolution, multiproxy palaeoenvironmental changes recorded from Two Mile Lake, southern Western Australia: implications for Ramsar-listed playa sites

2016 ◽  
Vol 67 (6) ◽  
pp. 748 ◽  
Author(s):  
C. Gouramanis ◽  
P. De Deckker ◽  
D. Wilkins ◽  
J. Dodson
Keyword(s):  
Western Australia ◽  
Environmental Variability ◽  
Health Management ◽  
Diverse Range ◽  
Playa Lakes ◽  
Optical Luminescence ◽  
Biogenic Carbonates ◽  
Catchment Responses ◽  
Palaeoenvironmental Changes ◽  
Lake Record

Numerous saline playa lakes exist across the arid, semiarid and temperate regions of Australia. These playa lakes exhibit a diverse range of hydrological conditions to which the Australian aquatic invertebrate biota have become adapted and which the biota can utilise as refugia in times of hydrological deterioration. Saline playas also yield palaeoenvironmental records that can be used to infer lacustrine and catchment responses to environmental variability. We present a palaeoenvironmental record recovered from Two Mile Lake, a saline playa from southern Western Australia. Dating, based on quartz optical luminescence and 14C accelerator mass spectrometry of biogenic carbonates and organic fibres, suggests that most of the sediment was rapidly deposited at 4.36 ± 0.25 thousand years ago. Ostracods and non-marine foraminifera preserved in the sediment show periods of faunal colonisation of the lake with oscillations between hypersaline and oligosaline conditions. The geochemistry of ostracod valves and foraminifera tests suggests higher-frequency variability within the lake, and palynological changes indicate landscape changes, possibly in response to fire. The Two Mile Lake record highlights the utility of saline playas as archives of environmental change that can be used to guide wetland health management, particularly under the impacts of a changing climate.

Development of Playa Lakes in South Western Australia

Nature ◽  
1974 ◽  
Vol 247 (5441) ◽  
pp. 454-455 ◽  
Author(s):  
L. P. KILLIGREW ◽  
R. J. GILKES
Keyword(s):  
Western Australia ◽  
Playa Lakes

scholarly journals Annual plankton community metabolism in estuarine and coastal waters in Perth (Western Australia)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5081 ◽  
Author(s):  
Susana Agusti ◽  
Lorena Vigoya ◽  
Carlos Manuel Duarte
Keyword(s):  
Organic Matter ◽  
Western Australia ◽  
Environmental Variability ◽  
Gross Primary Production ◽  
Marine Ecosystem ◽  
Community Respiration ◽  
Metabolic Rates ◽  
Metabolic Balance ◽  
Net Community Production ◽  
R Ratio

The planktonic metabolic balance that is the balance between gross primary production (GPP) and community respiration (CR) was determined in Matilda Bay (estuarine) and Woodman Point (coastal) in Perth, Western Australia. The rates of net community production (NCP = GPP – CR) and the ratio between GPP and CR (P/R) were assessed to evaluate whether the metabolic balance in the two coastal locations tends to be net autotrophic (production exceeding community respiration) or net heterotrophic (respiration exceeding production). We also analyzed environmental variability by measuring temperature, salinity, and nutrients and chlorophyll a concentration. Samples were collected biweekly from March 2014 to March 2015. During the study period the metabolic rates were three times higher in Matilda Bay than in Woodman Point. The predominant metabolism was net autotrophic at both sites with P/R ratios >1 in the majority of the sampling dates. In Matilda Bay, the metabolic rates were negatively correlated with salinity denoting river dynamics influence, and positively with chlorophyll a. In Woodman Point only the GPP was positively correlated with chlorophyll a. The positive correlation between P/R ratio and GPP in Matilda Bay and the positive correlations between the metabolic rates and chlorophyll a suggest that factors controlling autotrophic processes are modulating the planktonic metabolic balance in the coastal marine ecosystem in Perth. Significant correlations were found between CR and GPP-standardized to chlorophyll a and water temperature. The net autotrophic metabolic balance indicates that in both ecosystems planktonic communities are acting as a sink of CO2 and as a source of organic matter and oxygen to the system and are able to export organic matter to other ecosystems.

The distribution and roost habitat of the orange leaf-nosed bat, Rhinonicteris aurantius, in the Pilbara region of Western Australia

2001 ◽  
Vol 28 (1) ◽  
pp. 95 ◽  
Author(s):  
K. N. Armstrong
Keyword(s):  
Western Australia ◽  
Nature Reserve ◽  
Iron Formation ◽  
Banded Iron Formation ◽  
Diverse Range ◽  
Breeding Range ◽  
New Localities ◽  
Orange Leaf ◽  
First Time ◽  
Landform Units

The endemic orange leaf-nosed bat, Rhinonicteris aurantius, is a relict both in a phylogenetic and a geographic sense. Prior to this study, two colonies in disused mines and seven other records of single animals were known from the disjunct Pilbara population of Western Australia. Cave roosts were located in the region for the first time, five new roosts were found in disused mines and the species was recorded in five new localities. Cave roosts were discovered in sandstone bedding. Free-flying R. aurantius were located in a diverse range of landscapes composed of banded iron formation, Cleaverville Formation geology and granite. Mines utilised as roosts were structurally complex and in some cases breached the watertable. This study revealed that while the species is widespread throughout the region, it is restricted to certain landform units, the number of suitable roosts within landform units is limited and the population appears to be subdivided within the region. Dispersal and connectivity within the population may be dependent on the availability of roosts in intervening areas, which may be a function of the availability of groundwater to subterranean formations for the control of roost microclimate. Currently, the known breeding range is one gorge at Barlee Range Nature Reserve and one mine at Bamboo Creek.

scholarly journals <i>δ</i><sup>11</sup>B as monitor of calcification site pH in divergent marine calcifying organisms

2018 ◽  
Vol 15 (5) ◽  
pp. 1447-1467 ◽  
Author(s):  
Jill N. Sutton ◽  
Yi-Wei Liu ◽  
Justin B. Ries ◽  
Maxence Guillermic ◽  
Emmanuel Ponzevera ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Exchange Reactions ◽  
Diverse Range ◽  
Biogenic Carbonate ◽  
Inductively Coupled ◽  
Seawater Ph ◽  
Wide Range ◽  
Oculina Arbuscula ◽  
Biogenic Carbonates ◽  
Species Specific

Abstract. The boron isotope composition (δ11B) of marine biogenic carbonates has been predominantly studied as a proxy for monitoring past changes in seawater pH and carbonate chemistry. However, a number of assumptions regarding chemical kinetics and thermodynamic isotope exchange reactions are required to derive seawater pH from δ11B biogenic carbonates. It is also probable that δ11B of biogenic carbonate reflects seawater pH at the organism's site of calcification, which may or may not reflect seawater pH. Here, we report the development of methodology for measuring the δ11B of biogenic carbonate samples at the multi-collector inductively coupled mass spectrometry facility at Ifremer (Plouzané, France) and the evaluation of δ11BCaCO3 in a diverse range of marine calcifying organisms reared for 60 days in isothermal seawater (25 °C) equilibrated with an atmospheric pCO2 of ca. 409 µatm. Average δ11BCaCO3 composition for all species evaluated in this study range from 16.27 to 35.09 ‰, including, in decreasing order, coralline red alga Neogoniolithion sp. (35.89 ± 3.71 ‰), temperate coral Oculina arbuscula (24.12 ± 0.19 ‰), serpulid worm Hydroides crucigera (19.26 ± 0.16 ‰), tropical urchin Eucidaris tribuloides (18.71 ± 0.26 ‰), temperate urchin Arbacia punctulata (16.28 ± 0.86 ‰), and temperate oyster Crassostrea virginica (16.03 ‰). These results are discussed in the context of each species' proposed mechanism of biocalcification and other factors that could influence skeletal and shell δ11B, including calcifying site pH, the proposed direct incorporation of isotopically enriched boric acid (instead of borate) into biogenic calcium carbonate, and differences in shell/skeleton polymorph mineralogy. We conclude that the large inter-species variability in δ11BCaCO3 (ca. 20 ‰) and significant discrepancies between measured δ11BCaCO3 and δ11BCaCO3 expected from established relationships between abiogenic δ11BCaCO3 and seawater pH arise primarily from fundamental differences in calcifying site pH amongst the different species. These results highlight the potential utility of δ11B as a proxy of calcifying site pH for a wide range of calcifying taxa and underscore the importance of using species-specific seawater-pH–δ11BCaCO3 calibrations when reconstructing seawater pH from δ11B of biogenic carbonates.

scholarly journals δ<sup>11</sup>B as monitor of calcification site pH in marine calcifying organisms

2017 ◽  
Author(s):  
Jill N. Sutton ◽  
Yi-Wei Liu ◽  
Justin B. Ries ◽  
Maxence Guillermic ◽  
Emmanuel Ponzevera ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Dominant Role ◽  
Boron Isotope ◽  
Exchange Reactions ◽  
Saturation State ◽  
Diverse Range ◽  
Inductively Coupled ◽  
Seawater Ph ◽  
Oculina Arbuscula ◽  
Biogenic Carbonates

Abstract. The isotope composition of boron (B) in marine biogenic carbonates has been predominantly studied as a proxy for monitoring past changes in seawater pH and carbonate chemistry. In order to derive seawater pH from boron isotope ratio data, a number of assumptions related to chemical kinetics and themodynamic isotope exchange reactions are necessary. Furthermore, the boron isotope composition (δ11B) of biogenic carbonates (δ11BCaCO3) is assumed to reflect the δ11B of dissolved borate (B(OH)4−) in seawater. Here we report the development of methodology for measuring the δ11B in biogenic carbonate samples at the multi-collector inductively coupled mass spectrometry facility at Ifremer (Plouzané, France) and the evaluation of δ11BCaCO3 in a diverse range of marine calcifying organisms. We evaluated the δ11BCaCO3 of 6 species of marine calcifiers (a temperate coral, Oculina arbuscula; a coralline red alga, Neogoniolithion sp.; a tropical urchin, Eucidaris tribuloides; a temperate urchin, Arbacia punctulata; a serpulid worm, Hydroides crucigera; and an American oyster, Crassostrea virginica) that were reared for 60 days in isothermal seawater (25 °C) equilibrated with an atmospheric pCO2 of ca. 409 μatm. We observe large inter-species variability in δ11BCaCO3 (ca. 20 ‰) and significant discrepancies between measured δ11BCaCO3 and δ11BCaCO3 expected from established relationships between δ11BCaCO3 and seawater pH. We discuss these results in the context of various proposed mechanisms of biocalcification, including the potential dominant role that internal calcifying site pH plays in regulating CaCO3 saturation state and borate δ11B at the site of calcification and, thus, the δ11B composition of calcifers’ shells and skeletons.

scholarly journals High-Resolution Metatranscriptomics Reveals the Ecological Dynamics of Mosquito-Associated RNA Viruses in Western Australia

2017 ◽  
Vol 91 (17) ◽  
Author(s):  
Mang Shi ◽  
Peter Neville ◽  
Jay Nicholson ◽  
John-Sebastian Eden ◽  
Allison Imrie ◽  
...  
Keyword(s):  
Western Australia ◽  
Rna Viruses ◽  
Rna Virus ◽  
Geographic Location ◽  
Striking Difference ◽  
Sampling Location ◽  
Virus Species ◽  
Diverse Range ◽  
Content Type ◽  
Virus Diversity

ABSTRACT Mosquitoes harbor a high diversity of RNA viruses, including many that impact human health. Despite a growing effort to describe the extent and nature of the mosquito virome, little is known about how these viruses persist, spread, and interact with both their hosts and other microbes. To address this issue we performed a metatranscriptomics analysis of 12 Western Australian mosquito populations structured by species and geographic location. Our results identified the complete genomes of 24 species of RNA viruses from a diverse range of viral families and orders, among which 19 are newly described. Comparisons of viromes revealed a striking difference between the two mosquito genera, with viromes of mosquitoes of the Aedes genus exhibiting substantially less diversity and lower abundances than those of mosquitoes of the Culex genus, within which the viral abundance reached 16.87% of the total non-rRNA. In addition, there was little overlap in viral diversity between the two genera, although the viromes were very similar among the three Culex species studied, suggesting that the host taxon plays a major role in structuring virus diversity. In contrast, we found no evidence that geographic location played a major role in shaping RNA virus diversity, and several viruses discovered here exhibited high similarity (95 to 98% nucleotide identity) to those from Indonesia and China. Finally, using abundance-level and phylogenetic relationships, we were able to distinguish potential mosquito viruses from those present in coinfecting bacteria, fungi, and protists. In sum, our metatranscriptomics approach provides important insights into the ecology of mosquito RNA viruses. IMPORTANCE Studies of virus ecology have generally focused on individual viral species. However, recent advances in bulk RNA sequencing make it possible to utilize metatranscriptomic approaches to reveal both complete virus diversity and the relative abundance of these viruses. We used such a metatranscriptomic approach to determine key aspects of the ecology of mosquito viruses in Western Australia. Our results show that RNA viruses are some of the most important components of the mosquito transcriptome, and we identified 19 new virus species from a diverse set of virus families. A key result was that host genetic background plays a more important role in shaping virus diversity than sampling location, with Culex species harboring more viruses at higher abundance than those from Aedes mosquitoes.

scholarly journals Wood structure explained by complex spatial source-sink interactions

2020 ◽  
Author(s):  
Andrew D. Friend
Keyword(s):  
Environmental Variability ◽  
High Sensitivity ◽  
Wood Formation ◽  
Current Theory ◽  
Strength Properties ◽  
Wall Thickening ◽  
Diverse Range ◽  
Latewood Density ◽  
Increasing Temperature ◽  
Source Sink

AbstractWood is a remarkable material. It is responsible for the sequestration of significant anthropogenic CO21, aids understanding of past climates2, has unique acoustic, thermal, and strength properties, and is an endlessly renewable source of energy3. However, we lack a general integrated understanding of how its structure is created. A theoretical framework of wood formation is presented here that explains a diverse range of poorly understood observations, including: (i) the anatomy of growth rings, with a transition from low-density earlywood to high-density latewood; (ii) the high sensitivity of latewood density to temperature; (iii) cell-size regulation; and (iv) relationships between growth and temperature. These features arise from interactions in time and space between the production of cells, the dynamics of developmental zones, and the supply of carbohydrates. Carbohydrate distribution is critical for the final density profile, challenging current theory which emphasises compensation between the rates and durations of cell enlargement and wall thickening. These findings have implications for our understanding of how growth responds to environmental variability and the interpretation of tree rings as proxies of past climates. In addition, they provide a framework for the incorporation of explicit growth processes into models, such as those used to predict the role of vegetation in the future global carbon cycle. Finally, divergent responses in volume and mass with increasing temperature suggest caution in interpreting observations based on volume alone.

Fungi consumed by translocated Gilbert's potoroos (Potorous gilbertii) at two sites with contrasting vegetation, south coastal Western Australia

2009 ◽  
Vol 31 (2) ◽  
pp. 97 ◽  
Author(s):  
N. L. Bougher ◽  
J. A. Friend
Keyword(s):  
Western Australia ◽  
Nature Reserve ◽  
Sampling Period ◽  
Vegetation Types ◽  
Sustainable Food ◽  
Diverse Range ◽  
South West ◽  
Breeding Populations ◽  
Over Time ◽  
Selection Of

Gilbert’s potoroo (Potorous gilbertii) was previously widespread in south-west Australia but is now restricted to one location – a granitic area of shrubby heath at Two Peoples Bay Nature Reserve on the south coast of Western Australia. To alleviate the threat of extinction a program is under way to establish potoroos in other locations. At Two Peoples Bay Gilbert’s potoroos feed almost exclusively on truffle fungi. However, it was not known whether potoroos translocated to any new areas would be able to rapidly access and consume fungi after translocation, or whether truffles could be a sustainable food supporting breeding populations of potoroos in translocation sites. Furthermore, it was not known whether translocation of potoroos would be successful only in areas with vegetation similar to their refuge at Two Peoples Bay. The current study addressed these questions by analysing the diet of potoroos translocated into two contrasting areas – one on Bald Island with similar topography and vegetation to that of Two Peoples Bay, and the other a 14-ha enclosure on the mainland dominated by Eucalyptus–Allocasuarina woodland. The diet of potoroos was characterised by microscopic examination of scats from individuals trapped after their translocation to these areas. At Bald Island a diverse range of fungi was consumed immediately after translocation. Four potoroos released onto the island only 4–8 days previously consumed 23 species of fungi. Consumption was sustained over time. Three potoroos released onto Bald Island 1–2 years previously and one island-born individual consumed 27 species of fungi during a two-day sampling period. Nine of the 27 fungi species were the same as those that had been consumed by the potoroos within days after their release onto the island. This indicates that production of fungi and their consumption by potoroos on the island was sustained at least 1–2 years after translocation. Potoroos bred on Bald Island during this period. During the same period, two potoroos that were moved from captivity to the mainland site (Ryedene) were consuming six species of truffles within 29 days after release, and 14 species within three months. Such data indicate that a wider selection of vegetation types and areas than just those similar to where potoroos occur at Two Peoples Bay may be able to sustain potoroos and should be investigated for future translocations.

Early and late colonizers in mine site rehabilitated waste dumps in the Goldfields of Western Australia

2007 ◽  
Vol 13 (4) ◽  
pp. 235 ◽  
Author(s):  
Graham G. Thomson ◽  
Scott A. Thompson
Keyword(s):  
Western Australia ◽  
Mammal Species ◽  
Open Spaces ◽  
Diverse Range ◽  
Waste Dumps ◽  
Reptile Species ◽  
Successional Stages ◽  
Generalist Diet ◽  
Species Richness And Abundance ◽  
Early And Late Colonizers

We examined the abundance of reptile and mammal species on five rehabilitated waste dumps in the early successional stages in the mined area around Ora Banda in Western Australia and compared these data with species richness and abundance in adjacent undisturbed areas. Mammal species common in the undisturbed areas were also found in relatively high abundance on waste dumps, with the exception of Pseudomys hermannsburgensis. In contrast, not all reptile species in the adjacent undisturbed areas had colonized waste dumps. However, a high proportion of those reptile species that were caught on rehabilitated waste dumps were at lower numbers than in the adjacent undisturbed areas, indicating that they were slow colonizers. Reptiles Underwoodisaurus milii, Heteronotia binoei and Pogona minor and mammals Mus musculus and Sminthopsis crassicauda are among the early colonizing species that flourish in the developing ecosystem on waste dumps. Species able to exploit a diverse range of niches, tolerate open spaces, have a generalist diet and good dispersal capabilities are the early colonizers. In contrast, species with a specialist diet or micro-habitat requirements are slow to colonize rehabilitated waste dumps and will initially be represented in low numbers. We encourage mining companies and regulators to change the size and shape of waste dumps, and to seed with species found in the adjacent undisturbed areas to hasten the colonization of vertebrate species on to waste dumps and the creation of functional ecosystems.

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