Water Journal May - June 1998

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waterVolume 25 No 3 May/ June 1998 Journal Australia n Water & Wastewater Associat ionEditorial Board F R Bishop, C hairman B N Anderson , G Cawston, M R Chapman…
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waterVolume 25 No 3 May/ June 1998 Journal Australia n Water & Wastewater Associat ionEditorial Board F R Bishop, C hairman B N Anderson , G Cawston, M R Chapman P Draayers, W J Dulfer, GA Holder M Muntisov, P Nadebaum, J D Parker AJ Priestley,] RissmanGeneral EditorCONTENTS From the Federal President .............................................. ................. ............ 2 From the Executive Director ............... .... ....................................................... 4 MY POINT OF VIEWMargaret Metz AWWA Federal Office (see address below)The Next Millennium-Are We Ready For It? .................... ... .. ....................... 3Features EditorT FlapperE A (Bob) Swinton 4 Pleasant View Cres, Wheelers Hill Vic 3150 T el/ Fax (03) 9560 4752Branch Correspondents ACT - Ian Bergman Tel (06) 248 3133 Fax (06) 248 3806 New South W ales - Mitchell Laginestta Tel (02) 9412 9974 Fax (02) 9412 9676 Northern Territory - Bill Bean Tel (08) 8924 7201 Fax (08) 8941 0703 Queensland - Tom Belgrove Tel (07) 3810 7967 Fax (07) 3810 7964 South Austcalia - Angela Colliver Tel (08) 8227 1111 Fax (08) 8227 1100 Tasmania - Ed Kleywegt Tel (036) 238 2841 Fax (036) 234 7109 Victoria - Mike Muntisov Tel (03) 9600 1100 Fax (03) 9600 1300 Western Australia - Jane O liver Tel (09) 420 2462 Fax (09) 420 3178Advertising & Administration AWWA Federal O ffice Advertising: Angela Makris Graphic Design: Eliz.abeth Wan PO Box 388 Artam1on NSW 1570 Level 2, 44 Hampden Road, Artam1on Tel (02) 9413 1288 Fax (02) 9413 1047 Email: info@awwa.asn.auWater (ISSN 0310 • 0367) is published six times per year:January, March, May,July, September, November byAustralian Water & Wastewater Inc ARBN 054 253 066Federal President Greg CawstonCRCWater is sent to all members of A WWA as one of the privileges of membership. Non- members can obtain Water on subscription at an annual subscription rate ofS39 (surface mail).ECOLOGYP C ullen Should We Care About Mlcrofauna? ............................. ........ ..... ... ....... ... .... 11RShiel The Campaspe River Project ...................................... ... ... ... ... .... ...... ........... 13J Growns Blue-green Algae and Artiflcal Destratlficatlon ............... .. ........... ............ 15·J W hittington, B S Sherman, RL O liverInvasion of an Exotic Freshwater Snail ......... ...... .................... ... .......... ... .. 17S Schreiber Cyanobacterial Blooms In the Darling River .......................... ... ...... .......... 18R L O liver, C M Rees, MR Grace, B T Hart, G Caitcheon, J OlleySalinity: A Threat to Our Streams and Wetlands ....... ........................... ..... 20P Bailey, N Warwick Flooding: The Lifeblood of Our Billa bongs .................... ..... ............... ....... .. 22D Nielsen New Risk-based Water Quality Guidelines ............................................... . 24B T H art, W Maher, I Lawrence Guidelines for Designing Pollution Control Ponds .... ............ ................... 25I Lawrence, P Breen Assessing Water Quality in Kosciuszko National Park Using AusRivAS 28R H Norris, J Simpson, K Beggs NSW Rivers Need Urgent Restoration ............................. .. ........... .............. 31J H arris, PGehrke, S H artleyWhere Do Carp Prosper? .......................................... ... ... ........ ..... ..... ... ..... ... . 33P D river WATER ·, A Moblle Water Treatment Plant for Small Town Water Supplies .. ..... 34N H ealey Radon-222 Concentrations In Potable Groundwater in Australia ........... 37A L H erczeg, J C DightonExecutive DirectorSubscriptionsFRESHWATERIntroduction to CRC for Freshwater Ecology Special Feature .. .. . ... ... ... . .. . 9 Transferring Knowledge-The CRC Approach .. ...................................... .... 10WASTEWATERChris D avis Australian Water & Wastewater Association assumes no responsibility for opinions or statements of facts expressed by contributors or advertisers and editorials do not necessarily represent the official policy of the organisation. Display and classifi ed advertisements are included as an infom1ation service to readers and are reviewed by the Editor before publication to ensure their relevance to the water environment and to the objectives of the Association. All material in Water is copyright and should not be reproduced wholly or in pare without the written permission of the Editor.FOR•·, On-line Process Monitoring of Nutrients In BNR Plants ....................... 38I D McKelvie , G J C ross, TE H arris, B T H art ENVIRONMENT Reducing Phosphorus In Aquatic Systems Using Modified Clays .......... . 42G B D ouglas, D N Coad, J A Adeney BUSINESS ·, Privatisation-Who Decides? ............................. ....... ... ... ..... .... ..... .... ...... 44R Loo, C Porter Who WIii Train Our Future Water Engineers? ....... ... ... ... ............................ 46L Reeder DEPARTMENTS International Afflllates ............................ .............. ... ... ........... .. .. ... ............ .. .. 5 From the Bottom of the Well ... .... ......................................... ........... ... ........... 2 Meetings ... ....................................... .. ... ... .... ........................................ .......... 48 New Products ................ .......... ... .. .... ........ ... .... ...................... ........ ........ ..... ... 47 OUR COVER: Read about th e fresh water New Zealand snail Potamopyrgusantipodarum invading o ur waters (page 17). Photo co1trtesy of Sabine Schreiber, Cooperative R esearch C entre for Freshwater Ecology .FRESHWATERECOLOGYSignificant declines in abundance, Multiplicity of Species range o r distribution of birds, fish, In terms of biodiversity, it is not amphibians and macroinvertebrates in possible to provide a comprehensive list Australian and Murray-Darling aquatic of the microfauna of any inland ecosystems have been reported. How- Australian waters. Whilst protists ever, the complex co mmunities of largely remain unknown, rotifers are microinvertebrates which provide the better studied, albeit for a very small food web links between bacteria/algae number of habitats, primarily billabongs and higher order consumers have been or reservoirs of the middle reaches of virtually ignored (see Figure 1). the Rive r Murray. More than 100 After bacteria and phytoplankton, species of rotifer have been recorded microfauna- protists, rotifers and from single net tows in billabongs, microcrustaceans-are commonly the w here densities may exceed 75,000 most abundant organisms in inland individuals per litre, making them a Australian waters. Their rapid genera- significant and dynamic component of tion times and high population densities both biomass and biodiversity. produce dynamic grazing/p redation Billabong microcrustacean commuimpacts on their preferred food items, nities commonly are less diverseproviding in turn a rich food source for 20-40 species may occur together on a those organisms that eat plankton. given sampling date. High species T here is some evidence that higher diversity is possible because the various orde r co nsumers were cued, pre- components have evolved to partition regulation at least, to use the rich plank- the available resources. Some taxa are so ton 'soup' of sheltered billabongs as specialised that they feed on only a nursery and feeding refuges. single species of alga-others are generRecent studies by NSW Fisheries alists, grazing anything they can catch of suggest a strong correlation between the an appropriate size (see Figures 2, 3). diversity of microfauna and that of Transposing such species numbers native fish. Microfauna are more sensi- into the compartments in Figure 1 illustive to changes in water quality than trates the complexity of microfaunal higher organisms such as macroinverte- food webs-in the ancient, highly brates or fish. Protists are, after all, compartmented, niche-rich billabong single-celled, and rotifers generally only ecosystem, many hundreds and potenca . 1000 cells. Rapid response times tially thousands of species may occur, make them ideal environmental indica- particularly in spring and autumn. tors of the 'health ' of aquatic ecoReservoirs, with their general lack of systems-a value not presently used in submerged and emergent vegetation Australia. and rapid fluctuations in level, do notsupport a microfaunal assemblage of the complexity of that found in billabongs. Rive rs provide a more extrem e environment again for aquatic microfauna, with a consequent reduction in biomass and diversity. Those microfauna persisting from upstream impoundments or flushed in from backwaters or the floodplain in times of high flow generally are only a small fraction of the reservoir or billabong plankton or littoral assemblage. Australian inland rivers are unusual in the global sense because thei r slow flows and frequent impediment by locks and weirs provide a sequence of lakelike or billabong-like habitats in which a diverse microfaunal community may be partly represented.The Seedbank In inland river systems the floodplain is critical to the maintenance of microfa unal assemblages-it is the seedbank or genetic repository. As is seen in island populations, adj acent billabongs commonly have different dominants, reflecting a mosaic of environmental cu es, and w hi ch species em erges from the seedbank at any given time depends on the required (or supplied) stimuli. Successional events may be very rapid, particularly at break of season, when inflows of water into billabongs provide cues to emergence from resting stages. Figure 4 shows differing responses of rotifer species to such aWATER MAY/JUNE 199811FRESHWATERECOLOGYFigure 2 A live-in special ised herbivore, Ascomorphe/la volvocicola eats Volvox, a colonial f lagellate, from t he inside outj,, ! ¡ 1~12WATER MAY/JUNE 19983IL.;Figure 1 Simplified microfaunal food web from Murray-Darling waters. Except for fish , each compartment may contain scores to hundreds of species on any sampling occasion (from Shiel & Green (1992) Viet. Nat. 109)flood event. The dynamics of these events are hours and days. The preliminary results of flooding experiments in Barmah-Millewa Forest and artificial billabongs near AlburyW odonga suggest that timing of inundation is not critical-'something' will be cued whatever time of year flooding occurs and regardless of duration. What is critical to the seedbank is that flooding does occur-not necessarily annual floods, or even regular floods, but occasional inundation. T he persistence of cysts, resting eggs, winter eggs or other diapausing stages is unknown and may be remarkable-up to tens or scores of years-but they are finite. As has been demonstrated for macroinvertebrate emergence from floodplain sediments, the longer a particular section of floodplain remains dry, the less likely its full complement of microfaunal resting stages is to break dormancy on subsequent re-wetting. The commitment of some of the river flow to environmental needs is the first positive step in conservmg seedbank diversity, but the urgent need to conserve the floodplain is also critical. Loss offloodplain habitats, or loss of access to them, is a primary causal factor in the existing decline in range or abundance of floodplain biota. Some of the more heavily used floodplains of the Murray- Darling Basin have lost more than half of their billabongs and wetlands to agriculture, horticulture and other activities or to general degradation. Given that some of the groups of43 22Figure 3 The centropagid calano id copepod, Boecke/la triarticu/ata, a more generalist grazer, from the 1991 Darling River Anabaena circinalis bloom. The filaments are the cyanobacteria, which the copepod ca n grazemicrofauna mentioned have a high degree of endemism-more than 80% for some of the microcrustacea- the implication must be that we have already lost a proportion of our indigenous microfauna. If we continue to degrade floodplains and diminish the remaining seedbank it is certain that more will be lost. The declines we now see at the top of food chains (e.g. our fish) are surely a reflection of what is happening, unseen and unremarked, at the bottom of food chains.We Must Care! It should be evident that the answer to the question posed in the title of this p aper is an unequivocal 'yes!' The unseen microbiota of our inland waters are a necessary component of all10 20 March 1990Taxa are (l¡R from top) Brachionus /yratus, Fillnia pej/eri, Lecane bu/fa, Brachionus falcatus, Filinia opoliensis, Proa/ides tentacu/atus (From Shiel (1996) GeoJournal 40)Figure 4 Population density of selected rotifer species demonstrating specifically different responses t o summer intrusion of river water (indi cated by vertical broken line) into Ryan's #1 Billabong near Alburyaquatic ecosystems. Any of 2ur activities which act directly or indirectly to reduce their diversity may have farreaching ramifications that include removing their grazing influence on bacte rial or algal populations and removing them as food items for macroinvertebrates and higher order consumers. Microfauna may be low on the systematic scale, but they are no less important to the Australian aquatic enviro nment than the 'warm and cuddlies' are to our terrestrial ecosystems.Author Dr Russ Shiel is at the MurrayDarling Freshwater Research Centre in Albury.FRESHWATERTHEECOLOGYCAMPASPE RIVERPROJECTJ GrownsT he allocation of wate r for is p iped fro m Lak e Eppalock to Ben digo but m ost of the diversion is environm ental flows in Australian regulated rivers is the subj ec t of for irrigation during summer and many debates. The complexi ty of autumn. river ecosystems, lack of clear obj ecFrom October to January water is released and diverted to irrigation tives and short history of scientific studies of environmental flows mean ch annels at the Campaspe W eir. that there is no single, clearly defined From February to April extra water is pro cess by w hich environme ntal released from Lake Eppalock and flows can be determined. Whilst a allowed to pass ove r the Campaspe quick solution to the problem is W eir and is diverted to the W aranga unlikely, it is clear that large-scale The Campaspe River Is being studied to Western Main C hannel at the experimen tal manipulations of flow balance human, Irrigation and ecologlcal Campaspe Siphon. w ill be necessary to test wh ether needs for water Under the presen t release regime specific release regimes produ ce the only a small environmental allocathe collec tion of baseline data and tion of 10-1 5 ML/day is released from desired results. T he Campaspe River Project is the imple men tatio n of changes in the Lake Eppalo ck after the irrigatio n first such large- scale experimental mani- release regime, and three years fo r more season fi nishes in April until winter pulation to be performed in Australia. It data collection after the flow change rains have filled the lake. In late winter is a collab orative project between the begins in May 1998. in about 50% of years, heavy rain can CRC for Freshw ater Ecology, includcause the dam to overflow, leadi ng to ing Monash University and the The Campaspe River increased flows which pass all the way T he Campaspe River is in n orthern down the river (see Figure 1). Murray-Darling Freshwater R esearch Centre, and Gou lburn- Murray W ater, central Victoria. It flows north to meet There are currently three hydrologithe Marine and Freshwater R esources the Murray River at Echuca and drains cally distinct sections of the Campasp e Institute, Snobs Creek and the C RC fo r an area of about 3400 km2 . The chann el River below Lake Eppalock. Be tween Catchment H ydrology. T he project, is deeply in cised and does not have Lake Eppalock and Campaspe W eir w hich is funded by Land and W ater significant wetland or billabong systems. there are relatively constan t moderate Before regulation there w ould have flows in summer/autumn and constant R esources R esearch and D evelopmen t Corp oration, Environme n t Australia been generally low flows in summer and very low flow for mu ch o f w inter and the CRC for Freshwater Ecology, the river may often have dried to a series until Lake Eppalock spills. Between should provide a model for similar of pools. However, occasional rain Campaspe W eir to Campaspe Siphon wo uld have flu shed the river in there are constant low flows in summer future experime nts. summer. In w inter there would have with increased bu t still relatively Negotiating and Developing been higher and variable flows for much constant flows in March and April and of the period from M ay to Novemb er constant low flow for much of w inter the Project until Lake Eppalock spills. Below the When developing the experimental (see Figure 1). The main storage o n the system , C ampaspe Siphon there are constant design, a compromise had to be reached between scientific issues and the n eeds Lake Eppalock, was completed in 1962 low flows fo r most of th e yc!ar until and has a capacity of 312,000 ML. Lake Eppalock spills in late winter. of water users. About 114,000 ML is diverted annually From May to O ctob er 1998, 25% of Goulburn-M urray W ater (G-MW) is from th e Campaspe' s mean annual daily inflow to Lake Eppalock will be the Victo rian Governme n t water au tho rity that manages Lake Eppalo ck. discharge of 314,000 ML. Some water released downstream so long as Lake Eppalock is at least 64% full. Th e W hile little could be done abo ut releases w ill pass down th e full the high summer flows destin ed length of the river and will be in for the irrigators, ch anges to 1~00 excess of any abstraction from the winte r flows were able to b e nver. n egotiated through detailed modelling analyses and extensive The Studies discussions w ith G-MW. i : ; ~·=···= · ~·1=···~--·~ ·J" ---~··1~-----·-- --·-~·-··· ···T · · ... · ...·~ / -·--+-·~ ~ \ -~..~ ... ...r,. .. The support of the irrigators River regulation has been A s 0 N D J F M A M was obtained through ex ten sive Month show n to severely affec t the consultation, during w hich th e ecology of riverine ecosystems - - shows pre-regulation flows ·· ··· ·· shows regulated conditions concerns of sec uri ty of su pply all over the world, particularly were addressed. downstream of deep reservoirs Figure 1 The project was then formalwhich release very cold an d Median mean monthly flows in t he Campaspe River ised to run for five years-two for below Rochester sometimes chemically unfavour-li:m~~~ -rn~}·· . : ~--?~-.~:~:§~-:- · . ~::~; !', ....-~1- ~~-- ~--~----~·,;.;~ ,.,.:.;.:c:"0--.. .,. .r . ~, ~ - ..... . • --lz;..-:; ~•---. - ":.~. -r~ . ., ~ -<,.---. . ~ - - • ~-=:: ... : ~ ~,.,.., ;~ - ~ ~ - . - ~ ........- ~~~'........ 7-..r:y• . "(...- 1 ' 1 t : ' . " ~....-- .. ,-.z. liS' ..~ ~; ~~... ,,,. .----\ . , ~ -· - -.... - -,. ~ ~ ~,;.,. ;,--,-,c,. , ..~...I.••. :. -.....,::::-,-... ........ -~,..' ... .....:-r".t;;':.·"/~--, .,~- ·,WATER MAY/ JUNE 1998·'13FRESHWATER able water and also below hydroelectric dams which cause wild fluctuations in flow rates over short periods. The effects include changes in benthic algal communities, zooplankton and fish but most work has been done on macroinvertebrates including shrimp, larval and ad ult insects, worms, molluscs and mites. The general pattern detected is that species ric hness is greatly reduced for varying distances below dams and the species composition is changed.Fish Before regulation the Campaspe River supported a dive rse community of native fish species, although it is not certain that they completed their life cycle in th e river. Over the last two years regular sampling has shown that very few species of native fi sh now occur in the Campaspe and none in large n umbers. However, introduced carp and mosquito fish are plentiful. Continue
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