Bailey-Watts, A. E.

Kirika, A.

English

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Principal Investigators:Project Manager: A E Bailey-WattsA E Bailey-Watts, BSc, PhD, MIWEMA Kirika31 March 1996Contract Completion Date:TFS Proj ect No.:Institute of Freshwater EcologyEdinburgh Laboratory, Bush Estate, PenicuikMidlothian EH26 OQB, ScotlandTelephone 031 445 4343; Fax 031 445 3943Report on progress to Scottish Natural Heritage and the ForthRiver Purification Board (March 1995)A RE-ASSESSMENT OF THE PHOSPHORUS LOADING TO LOCH LEVEN, KINROSS(TAYSIDE), 1994The Institute of Freshwater Ecology is part of the NaturalEnvironment Research Council's Centre for Ecology and Hydrology.This is an unpublished report and should not be cited withoutpermission, which should be sought through the Director of theInstitute of Freshwater Ecology in the first instance: WindermereLaboratory, Far Sawrey, Ambleside, Cumbria LA22 OLP, UK. Tel.:05394 4246B; Fax. 05394 46914.IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIA RE-ASSESSMENT OF THE PHOSPHORUS LOADING TO LOCH LEVEN,KINROSS (TAYSIDE), 1995BackgroundIn 1985-1986 the Freshwater Research Group of The Institute of Terrestrial Ecology (now, TheInstitute of Freshwater Ecology, Edinburgh Laboratory), led a multi-departmental project toassess the overall loading of phosphorus (P) to Loch Leven (Bailey-Watts, A.E., Sargent, R.,Kirika, A. and Smith, M. 1987. Loch Leven phosphorus loading. Final Report to the DAFS,NCC, SDD and TRC).The targeting of P in that very extensive and intensive survey (withmeasurements at 27 sampling sites over 14 months at 8-day intervals) reflected the fact that thiswas the primary nutrient limiting phytoplankton productivity. Of particular concern then, andnow, is the development - in approximately 50% of years - of very large populations ('blooms')of blue-green algae at Loch Leven. Under certain weather conditions, these organisms can formunsightly surface scums which may accumulate on a downwind shore. Moreover, toxins areproduced by some species.The study quantified the contributions of diffuse runoff of P from agricultural land, point sourcesof effluent from industrial concerns and sewage treatment works (STWs), the input in rain fallingdirectly onto the surface of the loch, and that in wildfowl faeces. The study concluded thatapproximately 21 t P entered the loch during 1985 - with ca. 8 t coming in diffuse runoff, 6.3 tfrom an industrial source (woollen mill), and a further 5.3 t from STWs.The report recommended that in order to stem the production of planktonic algae, priorityattention should be given to reducing P inputs, and that the material emanating from the millshould be targeted as soon as possible. These recommendations were followed up, and it appears -on the basis of continued surveillance results from the South Queich which received mill effluent -that virtually no P has entered the loch from the mill, since the end of 1987, and possibly evenearlier than this. Improvements have also been made as regards the P removal performance of themain STWs in the catchment. As a result, the total P load is now less than that estimated from the1985 study. In addition, the relative contribution from land runoff is likely to be greater than itwas some 10 years ago, and as a consequence, the inputs from point sources is smaller thanhitherto. The latter change is of special significance. Relative to most runoff sources, STWeffluent is considerably richer in soluble reactive P (SRP) - which is almost certainly the form ofP that is most readily taken up by phytoplankton - and woollen mill effluent was relatively richin soluble P compounds that were rapidly hydrolysed to SRP.In spite of the reductions in P loading, the loch has continued to produce as dense, and as durable,blooms of phytoplankton as before. Indeed, only in years (such as 1985 itself) in which thesummer was very wet, has the loch appeared less characteristically eutrophic. This resulted inrapid flushing which would have mediated against the accumulation of algal cells produced;releases of P from the sediments, and accumulation of the nutrient in the column also are lessmarked under such conditions.The relative lack of a response, so far, by the loch to reduced P loading is by no means uncommonin world terms. Nevertheless, it is thought that the current situation as regards the total P loadingto the loch and the main sources of this nutrient should be re-assessed. After all, a decade haselapsed since the first study was completed.IIIIIIIIIIII IIIIIIIIIIObjectivesThe main objectives of the study are as follows:- to assess the total phosphorus loading and the inputs of the particulate and solublefractions, to the loch for the calendar year 1995.- to distiguish between the various contributions to the total loading, by means of chemicalsampling at 19 sites, on some 12 of which flow data will also be gathered.- to prepare a short summary of the analytical results by 31 March 1995.- to prepare a draft final report of the findings, including comparisons with the P loadingstudy of 1985/86, by 28 Feb 1996, and the final version by 31 March 1996.- to prepare outlines of manuscripts for publication in internationally-refereed journals,by 31 March 1996.MethodsChemical sampling commenced on 26 January. This followed (i) a re-inspection of the 1985sampling sites, (ii) modification of the programme following e.g diversion of all Kinross sewageto the North works, and (iii) instalment of new staff guages. The new programme includes a sub-catchment in the upper South Queich drainage area which was not assessed as a separate entityin 1985/86. The new programme also being executed in parallel with a project led by the ForthRiver Purification Board which focuses on P inputs in storm events. Such phenomena are often'missed' in schedules of regularly spaced sampling such as the 8-daily one adopted here. TheBoard is also responsible for the sampling programme aimed at assessing P loadings derived fromthe STWs.Table 1 indicates the overall sampling coverage and the points at which water discharge is alsogauged. Eight of the sites are worthy of comment, as they have been added to the list envisagedwhen the project was first mooted:- Sa on the South Queich facilitates assessment of any differences in nutrient content fromthat measured upstream ofthe mill (at Sc) due to discharge or overflow from the mill or the oldKinross South STWs.- Nb and Ne: Nb is on the North Queich, at the furthest point downstream before theconfluence with the Hatton Burn; any differences in chemical concentrations between this pointand Ne at Lathro, could identify discharge from the old Milnathort works.- Na, which lies below the confluence with the Hatton, is included because the eventualoutfall from the new Milnathort STWs will be too close to the Hatton for sampling at Nb tocontinue.- Ca, which is situated on the Camel Burn below the outflow pipes from the fishponds,and Cp - the pipes themselves: the fIrst accounts for all of the water in the Camel Burn, whilst thesecond accounts for the water passing through the ponds.- Kc lies on the Kinnesswood Burn in the village above the STWs; comparisons betweenthe samples taken there with those collected at Kb - the Grahamstone field drain pump site - willallow some estimation of the STW contribution.- Gu is an easily accessible point on a tributary (the Bog Bum) draining mostly agriculturalland on the Gairney.IIIIIIIIIIIIIIIIIIIIITable 1. Chemical sampling points (including those monitored by FRPB in the parallelproject, and the discharge gauging sites.II source Chemical sampline site Flow l;!aul;!ing or recordinl!'STW(FRPB KINROSS NORTH ?MILNATHORT ?CATCHMENT S.OUEICH RECORDERSTORM N.OUEICH RECORDEREVENTS (FRPB) GAIRNEY WATER RECORDERPOW BURN RECORDERS.QUEICH THE HECKS - Sa ***********OUEICH BRIDGE - So RECORDERCARNBO- Se STAFF GAUGEN.QUEICH BELOW BURGHER BRIDGE - Na ***********ABOVE BURGHERBRIDGE - Nb OLDSTAFF GAUGELATHRO~Ne RECORDERPOCHYBURN MILNATHORT - Nf STAFF GAUGEHATTON BURN NEAR OLD RAILWAY BRIDGE - Nh STAFF GAUGEURYBURN BEHIND WILLIE WILSONS HOUSE - Ua STAFF GAUGEGAIRNEYWATER GAIRNEY BRIDGE - Gb STAFF GAUGECARSEGOUR BRIDGE - Gc STAFF GAUGEBOG BURN AT MAIN ROAD -Gu ***********CAMEL BURN BELOW FISH PONDS - Ca ***********LOTHRIES BRIDGE - Co STAFF GAUGEFISH PONDS OUlFALL - Co *******>1""**POW BURN POWMILL- Pb RECORDERKINNESSWOOD BURN GRAHAMSTONE FIELD DRAIN PUMP SITE - Kb STAFF GAUGEIN KINNESSWOOD - Ko BUCKETLOCH LEVEN AT SLUICES - L RECORDERWe are also taking note of the water level at the staff gauge in the harbour at Kinross - althoughthat gauge has not yet been levelled.A single detennination of the following is being made on each of two samples collected at eachfield site: total phosphorus (TP), total soluble P (TSP, which approximates to 'dissolved organic'P), SRP, dissolved silica (Si02 or soluble reactive silica - SRS), and nitrate-nitrogen (N03-N).Data will be logged, analysed and interpreted as in the earlier study, but they will be presentedin keeping with much-improved typescript and computer graphic facilities.ResultsThere is relatively little to report at this early stage. There have been only 6 sampling 'tours'.However, as noted in the earlier study, water levels in all of the bums and streams appear to riseIIIIIIII IIIIIIIIIIIIIIIIIIIand fall in unison, although the actual and possibly the relative, week-to-week fluctuations varybetween the water courses. So far, the majority of the total P concentrations measured at thepoints corresponding to the lowermost sampling stations on each of 7 inflows (the two Queichs,the Gairney Water, and the Pow, Dry, Camel and Kinnesswood Bums) have come in the range10 to 120 fig 1-'. Some considerably higher values have been recorded, however. These are asfollows:- in the Kinnesswood Burn, approximately 300, 400 and 450 fig 1-1 in late January, lateFebruary and early March, respectively- 200 flg ]"1 in early February and between 300 and 350 J.Ig 1- 1 in mid-February in both theDry and the Pow Burns.Each of these peaks in total P concentrations are attributable primarily to rises in the levels ofSRP.Stream and burn SRS concentrations are generally high although there is a two-fold range i.e.from ca 6 to 12 mg Si02 1-1• This is in keeping with the high levels of some 9 mg ]"1 recorded inthe loch at the turn of the year - although diatom growth has reduced the in-loch levels to some5 mg ]"J at the time of writing.A E Bailey-Watts and A Kirika11 March 1995

A re-assessment of the phosphorus loading to Loch Leven, Kinross (Tayside), 1994 [Progress Report]

http://nora.nerc.ac.uk/8963/1/N008963CR.pdf

A re-assessment of the phosphorus loading to Loch Leven, Kinross (Tayside), 1994 [Progress Report]

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