scholarly journals Watching the tide roll away – contested interpretations of the nature of the Lower Lakes of the Murray Darling Basin

2020 ◽  
Vol 26 (2) ◽  
pp. 130 ◽  
Author(s):  
Peter A. Gell
Keyword(s):  
Sea Water ◽  
South Australia ◽  
Ramsar Convention ◽  
Independent Evidence ◽  
Murray Darling Basin ◽  
Entire History ◽  
Variable Condition ◽  
Consumptive Water ◽  
New Evidence ◽  
Management Challenge

The Murray Darling Basin Plan (Murray Darling Basin Authority 2012) represents the largest investment by government in an Australian environmental management challenge and remains highly conflicted owing to the contested allocation of diminishing water resources. Central to the decision to reallocate consumptive water to environmental purposes in this Plan was the case made to maintain the freshwater character of two lakes at the terminus of the Murray Darling Basin, in South Australia. This freshwater state was identified as the natural condition on the basis of selected anecdotal evidence and was enshrined in the site’s listing under the Ramsar Convention. The commitment to the freshwater state was challenged under drought when sea water was seen as a means of averting acidification when low river flows risked the exposure of sulfidic sediments. Independent evidence from water quality indicators (diatoms) preserved in lake sediment records, however, attested to an estuarine, albeit variable, condition before the commissioning of near-mouth barrages in 1940. This interpretation for a naturally estuarine history, published after peer review, was overlooked in a report to the South Australian government, which argued, without the provision of new evidence from the lakes, that they were fresh for their entire history. This revised interpretation is widely cited in the scientific literature, government reports and online discussion and underpins a watering strategy aimed at a freshwater future for the Lower Lakes. The allocation of large volumes of fresh water to achieve this condition presents significant difficulties owing to the highly contested nature of water use across the Basin.

scholarly journals Corrigendum to: Watching the tide roll away – contested interpretations of the nature of the Lower Lakes of the Murray Darling Basin

2020 ◽  
Vol 26 (2) ◽  
pp. 211
Author(s):  
Peter A. Gell
Keyword(s):  
Sea Water ◽  
South Australia ◽  
Ramsar Convention ◽  
Independent Evidence ◽  
Murray Darling Basin ◽  
Entire History ◽  
Variable Condition ◽  
Consumptive Water ◽  
New Evidence ◽  
Management Challenge

The Murray Darling Basin Plan (Murray Darling Basin Authority 2012) represents the largest investment by government in an Australian environmental management challenge and remains highly conflicted owing to the contested allocation of diminishing water resources. Central to the decision to reallocate consumptive water to environmental purposes in this Plan was the case made to maintain the freshwater character of two lakes at the terminus of the Murray Darling Basin, in South Australia. This freshwater state was identified as the natural condition on the basis of selected anecdotal evidence and was enshrined in the site's listing under the Ramsar Convention. The commitment to the freshwater state was challenged under drought when sea water was seen as a means of averting acidification when low river flows risked the exposure of sulfidic sediments. Independent evidence from water quality indicators (diatoms) preserved in lake sediment records, however, attested to an estuarine, albeit variable, condition before the commissioning of near-mouth barrages in 1940. This interpretation for a naturally estuarine history, published after peer review, was overlooked in a report to the South Australian government, which argued, without the provision of new evidence from the lakes, that they were fresh for their entire history. This revised interpretation is widely cited in the scientific literature, government reports and online discussion and underpins a watering strategy aimed at a freshwater future for the Lower Lakes. The allocation of large volumes of fresh water to achieve this condition presents significant difficulties owing to the highly contested nature of water use across the Basin.

Watching the Tide Roll Away – reply to Tibby et al. (2020)

2020 ◽  
Vol 26 (4) ◽  
pp. 338
Author(s):  
Peter A. Gell
Keyword(s):  
State Government ◽  
Climatic Variability ◽  
Anecdotal Evidence ◽  
Valuable Contribution ◽  
Ramsar Convention ◽  
Murray Darling Basin ◽  
New Evidence ◽  
Future Management

The published findings on the diatom-inferred condition of a terminal lake in the Murray–Darling Basin were overlooked in favour of a revised unpublished interpretation, without the provision of new evidence or argument, posted on the website of the managing state government. Coauthors of the posted report have responded (Tibby et al. 2020) to the publication (Gell 2020) that outlined the changes made to this interpretation. This reply reaffirms that subtle changes were made to published interpretations and that these were critical in the development of a watering plan for the system. It also illustrates that anecdotal evidence was used selectively but would be a valuable contribution if aligned to known climatic variability. Further, this response corrects the widespread misunderstanding that signatory nations to the Ramsar Convention are obliged to retain listed wetlands in the condition observed at the time of listing. Finally, this response contests the favouring of certain evidence and seeks an approach that reconciles all available evidence, incorporates variability into planning and prepares for future management challenges.

The Relation Between the Food of the Australian Barracouta, Thyrsites atun (Euphrasen), and Recent Fluctuations in the Fisheries

1957 ◽  
Vol 8 (1) ◽  
pp. 29 ◽  
Author(s):  
M Blackburn
Keyword(s):  
Population Distribution ◽  
New South ◽  
New South Wales ◽  
South Australia ◽  
Downward Trend ◽  
Small Fish ◽  
Fish Diet ◽  
Upward Trend ◽  
Independent Evidence ◽  
South Wales

The diet of surface-swimming Australian barracouta was studied from over 10,000 stomachs. The principal prey organisms in Bass Strait are the euphausiid Nyctiphanes australis Sars, the anchovy Engraulis australis (White), and young barracouta, in that order; and in eastern Tasmania Nyctiphanes, Engraulis, and the sprat Clupea bassensis McCulloch, in that order. The pilchard Sardinops neopilchardus (Steindachner) is not an important item of the diet in these regions although it is so in New South Wales, South Australia, and Western Australia. The jack mackerel Trachurus declivis Jenyns is a significant item in eastern Tasmania and New South Wales but not in Bass Strait. These and other features of the fish diet of the barracouta reflect actual availability of the various small fish species in the waters. Barracouta eat Nyctiphanes by herding them into dense masses (or finding them already concentrated) and swallowing them. The movements of the anchovy make it unavailable to Bass Strait and eastern Tasmanian barracouta for much of the summer and autumn period, when the barracouta are thus dependent upon Nyctiphanes for the bulk of their food. A close positive relationship between the availability of barracouta and Nyctiphanes might therefore be expected at those seasons. There is evidence of such a relationship between mean availability (catch per boat-month) of barracouta and mean percentage of barracouta stomachs containing Nyctiphanes, at those seasons, from year to year. For southern Victorian coastal waters both show a downward trend from 1948-49 to 1950-51 and then an upward trend to 1953-54; for eastern Tasmania both show a downward trend (for autumn only) from 1949-50 through 1952-53. The records of catch per boat-month furnish independent evidence that the main variations in this index were effects of availability (population distribution or behaviour) rather than abundance (population size), at least for southern Victoria. It is therefore considered that when scarcity of barracouta occurs in summer and autumn in the coastal fishing areas it may be due to scarcity of Nyctiphanes, forcing the fish to go offshore for this food which is known to be available there. This would take the fish out of range of the fishermen.

scholarly journals A conceptual model of flow to the Waikoropupu Springs, NW Nelson, New Zealand, based on hydrometric and tracer (<sup>18</sup>O, Cl,<sup>3</sup>H and CFC) evidence

2008 ◽  
Vol 12 (1) ◽  
pp. 1-19 ◽  
Author(s):  
M. K. Stewart ◽  
J. T. Thomas
Keyword(s):  
New Zealand ◽  
Flow Model ◽  
Sea Water ◽  
Quantitative Description ◽  
Water Volume ◽  
Deep Aquifer ◽  
Submarine Springs ◽  
Recharge Sources ◽  
Flow Systems ◽  
New Evidence

Abstract. The Waikoropupu Springs, a large karst resurgence 4 km from the coast, are supplied by the Arthur Marble Aquifer (AMA) underlying the Takaka Valley, South Island, New Zealand. New evidence on the recharge sources in the catchment, combined with previous results, is used to establish a new recharge model for the AMA. Combined with the oxygen-18 mass balance, this yields a quantitative description of the inputs and outputs to the aquifer. It shows that the Main Spring is sourced mainly from the karst uplands (74%), with smaller contributions from the Upper Takaka River (18%) and valley rainfall (8%), while Fish Creek Spring contains mostly Upper Takaka River water (50%). In addition, much of the Upper Takaka River contribution to the aquifer (58%) bypasses the springs and is discharged offshore via submarine springs. The chemical concentrations of the Main Spring show input of 0.5% of sea water on average, which varies with flow and derives from the deep aquifer. Tritium measurements spanning 40 yr, and CFC-11 measurements, give a mean residence time of 8 yr for the Main Spring water using the preferred two-component model. Our conceptual flow model, based on the flow, chloride, oxygen-18 and age measurements, invokes two different flow systems with different recharge sources to explain the flow within the AMA. One system contains deeply penetrating old water with mean age 10.2 yr and water volume 3 km3, recharged from the karst uplands. The other, at shallow levels below the valley floor, has much younger water with mean age 1.2 yr and water volume 0.4 km3, recharged by Upper Takaka River and valley rainfall. The flow systems contribute in different proportions to the Main Spring, Fish Creek Springs and offshore springs. Their very different behaviours, despite being in the same aquifer, are attributed to the presence of a diorite intrusion below the surface of the lower valley, which diverts the deep flow towards the Waikoropupu Springs and allows much of the shallow flow to pass over the intrusive and escape via submarine springs.

Study of the spectral variation of absorption and scattering in some Australian coastal waters.

1984 ◽  
Vol 35 (6) ◽  
pp. 635 ◽  
Author(s):  
DM Phillips ◽  
JTO Kirk
Keyword(s):  
Attenuation Coefficient ◽  
Sea Water ◽  
Empirical Relationship ◽  
South Australia ◽  
Spectral Variation ◽  
Scattering Coefficients ◽  
Relative Contribution ◽  
Beam Attenuation ◽  
Dissolved Matter ◽  
Beam Attenuation Coefficient

The spectral variation of absorption and scattering of sea water in Jervis Bay on the east coast of Australia has been studied over the wavelength range from 400 to 700 nm. The absorption and scattering coefficients were derived from measurements of the beam attenuation coefficient and the vertical attenuation coefficient for downward irradiance using an empirical relationship based on Monte Carlo calculations. The results indicate that scattering is essentially independent of wavelength whereas absorption due to suspended and dissolved matter increases rapidly at short wavelengths. The relative contribution of absorption to total attenuation is smaller for Jervis Bay waters than for the waters of Gulf St Vincent, South Australia.

Sea water reverse osmosis - energy efficiency & recovery

2015 ◽  
Vol 10 (1) ◽  
pp. 187-195 ◽  
Author(s):  
A. R. Evenden
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Specific Energy ◽  
Sea Water ◽  
Specific Energy Consumption ◽  
South Australia ◽  
Public Utility ◽  
Actual Performance ◽  
Australian Water ◽  
Desalination Plant

The Adelaide desalination plant, located in South Australia, was designed and built by the AdelaideAqua construction consortium for the South Australian Water Corporation (SA Water), a wholly owned public utility. Construction commenced in 2009 at a green field site (Port Stanvac) south of Adelaide, with drinking water production from October 2011 and full production capability and handover to the plant operator on 12 December 2012. The facility uses 100% renewable energy and provides the people of South Australia with one of the most energy efficient sea water desalination plants in the World. This paper examines the performance of the Adelaide desalination plant in terms of energy efficiency. Specific energy saving technologies and innovations are described, including assessment of design and actual performance. The Adelaide desalination plant has achieved 8% lower energy consumption compared to the project's initial design requirements and the specific energy consumption of 3.48 kWh/m3 compares well with industry benchmark efficiencies.

scholarly journals The predominantly fresh history of Lake Alexandrina, South Australia, and its implications for the Murray–Darling Basin Plan: a comment on Gell (2020)

2020 ◽  
Vol 26 (2) ◽  
pp. 142 ◽  
Author(s):  
John Tibby ◽  
Deborah Haynes ◽  
Kerri Muller
Keyword(s):  
Sediment Cores ◽  
South Australia ◽  
Minor Component ◽  
Environmental Water ◽  
Freshwater Ecosystem ◽  
European Settlement ◽  
Murray Darling Basin ◽  
History Of ◽  
The Subject ◽  
A Minor

The pre-European settlement state of Lake Alexandrina, a lake system at the mouth of the River Murray has been the subject of some debate. Fluin et al. (2007) concluded on the basis of diatom evidence from sediment cores that ‘Marine water indicators were never dominant in Lake Alexandrina’. In a report to the South Australian Government, Fluin et al. (2009) stated, consistent with the earlier research, that ‘There is no evidence in the 7000 year record of substantial marine incursions into Lake Alexandrina’. Gell (2020) has argued both that Fluin et al. (2009) is in error and claims that it, and Sim and Muller’s (2004) book that describes early European settler accounts of the lake being fresh, underpin water provisions for Lake Alexandrina under the Murray–Darling Basin Plan. This response demonstrates that all these claims are untrue. Of the three diatom species suggested by Gell (2020) to be indicators of marine waters, Thalassiosira lacustris grows in the freshwater River Murray today, Cyclotella striata was never more than a minor component of the diatom flora and Paralia sulcata has not been detected in the lake in over 3000 years. Water provisions for Lake Alexandrina under The Basin Plan are founded on contemporary environmental water requirements and achievement of agreed socio-ecological-economic objectives, rather than the history of the lake. Nevertheless, the aim to maintain the lake as a freshwater ecosystem under The Murray–Darling Basin Plan is consistent with its history.

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