The Sustainable Restoration of Lakes Towards the Challenges of the Water Framework Directive777

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Ecohydrology & Hydrobiology 14 (2014) 68–74

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he sustainable restoration of lakes—towards the challengesf the Water Framework Directive

szard Gołdyn a,*, Stanisław Podsiadłowski b, Renata Dondajewska a,nna Kozak a

epartment of Water Protection, Faculty of Biology, Adam Mickiewicz University in Poznan, Umultowska 89, 61-614 Poznan, Poland

stitute of Biosystems Engineering, Poznan University of Life Sciences, Wojska Polskiego 50, 60-627 Poznan, Poland

Introduction

According to the Water Framework Directive (WFD)uropean Community, 2000) all water bodies shouldhieve good ecological and chemical status before 2015.

Poland there are 1036 lakes above 50 ha that are ofterest under the WFD and only about half of them meetese requirements (Ciecierska and Dynowska, in press).

achieve improvements in such a large number of lakes

in a short time, appropriate tools and effective methods areindispensable. It is possible to use many methods toprotect lake ecosystems. The most important are: (i)diversion of municipal and industrial sewage (both rawand treated), (ii) thorough treatment of storm watersbefore discharge to the receiving water, (iii) limitation ofinput of diffuse water pollution from agriculture, bycreation of buffer zones, use of sustainable or ecologicalagriculture, reduction of water and wind erosion of soils,(iv) reduction of the nutrient load reaching the lake bybuilding preliminary reservoirs on inflow rivers to inter-cept nutrients. In some cases, protection measures aloneare sufficiently effective in improving the status of

R T I C L E I N F O

icle history:

ceived 15 October 2013

ceived in revised form 26 December 2013

cepted 30 December 2013

ailable online 13 January 2014

ywords:

n treatment

manipulation

ind aerator

polimnion supply

A B S T R A C T

Most in-lake restoration projects use deeply intrusive methods. They include the removal

of bottom sediments and the use of high doses of precipitants. They are very radical,

causing extinction of many organisms, and are very expensive. Alternative methods

described in this paper are inexpensive, easy to use, effective, and sustainable (energy-

efficient, not destructive for most of the biota). They have been applied to three lakes

located in Poznan and the surrounding area (Western Poland) and their effectiveness has

been documented. They include: (i) use of biomanipulation to increase trophic influence of

zooplankton on phytoplankton, and small doses of iron sulphate to reduce phosphorus

content in the water column, used in Maltanski Reservoir, (ii) delivering water rich in

nitrates from small tributaries to the deepest part of the lake, thus increasing redox

potential and limiting the release of phosphorus from bottom sediments, used in

Uzarzewskie Lake, (iii) oxygenation of hypolimnetic waters using wind aerators, iron

treatment with small doses of coagulant and biomanipulation, used in Durowskie Lake.

Use of limited doses of an innovative solid phosphorus precipitant called Sinobent1 is also

possible. These methods, in accordance with the intermediate disturbance hypothesis,

increased the diversity of flora and fauna in the lakes and contributed to improvements in

water quality. Simultaneous application of several methods, which prevented feedback

mechanisms, increased the efficiency of lake restoration.

� 2014 European Regional Centre for Ecohydrology of Polish Academy of

Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Corresponding author. Tel.: +48 692107516; fax: +48 618295636.

E-mail address: [email protected] (R. Gołdyn).

Contents lists available at ScienceDirect

Ecohydrology & Hydrobiology

jo ur n al ho mep ag e: www .e lsev ier . c om / loc ate /ec o hyd

2-3593/$ – see front matter � 2014 European Regional Centre for Ecohydrology of Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

p://dx.doi.org/10.1016/j.ecohyd.2013.12.001

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R. Gołdyn et al. / Ecohydrology & Hydrobiology 14 (2014) 68–74 69

egraded lakes. The example of Lake Washington is wellnown. About ten years after diversion of sewage effluentreviously discharged to the lake from Seattle and otherwns, the lake improved in terms of water quality (Kajak,

998). However, Lake Washington is a large and deep lake8 km2 and 65 m max. depth) and had ancillary mechan-ms involving changes in the food webs that contributed

improvements of water quality. Smaller and shallowerkes may or may not spontaneously return to good

cological status after the application of protectiveeasures only. The example of Lake Sławskie, with a

urface area of 8.28 km2 and 12.3 m maximum depth,hich has been studied for several years, confirms that it is

ossible. The lake was polluted for many years by sewageom the city of Sława, which resulted in cyanobacterialater blooms and the closing of the bathing areas. The

onstruction of a new sewage treatment plant in 2008, andansfer of treated wastewater to filtration ponds severalilometres distant from the lake, led to a gradual

provement of its water quality (Kozak et al., 2012).In many cases, however, protection measures are not

ufficient and lakes need additional in-lake restorationeatment. These methods, in order to meet the require-ents of the WFD, should be inexpensive, easy to use,

ffective, and sustainable (energy-efficient, not destructiver most of the biota). Many technical and biologicalethods of lake restoration are known, but only a few ofem fulfil the requirements stated above. Some of suchnovative methods have been tested and improved in

everal lakes situated near Poznan (Wielkopolska Region,est Poland) by our team and a brief account of them is

iven in this paper.

. The Maltanski Reservoir case study

This reservoir is a shallow and polymictic water bodyith an area of 64 ha, 5.5 m max. depth and mean depth of

.1 m, situated near the centre of Poznan. It is used forecreation and water sports, but since its filling with water

1990, it has been hypertrophic with cyanobacterialater blooms, owing to a high load of nutrients from theain tributary, the River Cybina. Creation in the river

ourse of four small preliminary reservoirs did not result inny apparent reduction of the nutrient concentrations;ecause they were shallow and warm water bodies, theirresence even caused an increase of phosphorus concen-ation in the river water in summer (Gołdyn, 1994, 2000).xpected improvement of water quality in the Maltanskieservoir did not follow after biomanipulation measuresarried out in the years 1992–1996 and 2000–2004 either

ołdyn and Mastynski, 1998; Kozak et al., 2009). Theeservoir was stocked with predatory species like pike,ikeperch, eel and catfish, with from 236 to 1140sh ha�1 yr�1 initially. In the second period, 1120 hatchl-gs and 400 summer fry of pikeperch, plus 25 kg of

utumn fry and spawning pikeperch, and autumn fry, andpawning pike, plus some stocking of eel and 1+ catfishere made per ha for each of the four years.

Owing to many feedback effects, like entry into theeservoir of large quantities of roach and perch from the

the emergence of predatory heteropterans of the genusSigara, large crustacean filter-feeders could not survive,and the biomanipulation measures were undermined. As aresult, permanent water blooms appeared in the growthseasons. The most important reason for cyanobacterialwater blooms was probably a high annual averageconcentration of phosphorus (0.17–0.73 mg L�1), owingto high input from tributary waters and internal loadingfrom the shallow bottom sediments (Dondajewska et al.,2010a).

Since 2005 it was decided to use iron treatment as anadditional method of restoration for reducing the con-centration of phosphorus in the water column. Laboratorytests have shown that coagulation of suspended matterand decrease in concentration of phosphorus by 60% couldbe achieved by using 20 ml m�3 of liquid iron sulphate, themain component of the proprietary PIX-112 (Sobczynskiand Joniak, 2008). To treat the whole lake would take 40tonnes of chemicals, which was not acceptable for thereservoir users. It was decided to use only 4–15 kg ha�1

(300 kg for the whole lake on average), just for precipita-tion of phosphorus. As large amounts of phosphorus werestill entering the reservoir, iron treatment had to berepeated 5–6 times each year, using special equipment(Fig. 1).

Such small doses of PIX did not have direct influence onthe biota, including the phytoplankton diversity. However,decreasing the concentration of phosphates in the watercolumn led to limitation of phytoplankton growth. As canbe seen in Fig. 2, in the first year of iron treatmentcyanobacterial water blooms still appeared at the end ofthe summer. In subsequent years, the phytoplanktonabundance was significantly lower and not dominated bycyanobacteria, with the exception of 2007 and 2011. In2007 the reservoir was not stocked with fingerlings ofpredatory fish but hatchlings of pike, which proved to becompletely ineffective. In the autumn of 2010 water wasdrained from two of the preliminary reservoirs situatedupstream and the total fish stock moved through theCybina River to the Maltanski Reservoir. It was dominatedby small roach, perch and bream, but also recently stockedcarp fry (Wisniewski, pers. com.). All these fish caused

ig. 1. Iron dosing on Maltanski Reservoir from a specially equipped boat.

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R. Gołdyn et al. / Ecohydrology & Hydrobiology 14 (2014) 68–7470

tensification of the eutrophication symptoms. A largead of silt from the bottom of the preliminary reservoirsas also flushed out and flowed into Maltanski Reservoir.is silt was mineralized in the summer of 2011, causing adden increase in phosphorus internal supply. Theseents caused a very strong cyanobacterial water bloomring summer and autumn of 2011, which it was notssible to stop by means of recently used restorationeasures. The following year, however, everything wasck to the previous order.Inactivation of phosphorus in bottom sediments using

eparations such as Phoslock1, based on compounds ofe rare earth lanthanum, would be very helpful.boratory tests have shown that it is very effective atst at a dose of 80 g m�2, i.e. 800 kg ha�1. For the

activation of whole reservoir sediments, 51 tonnes of thisoduct would be needed, which would be a very largead of chemicals for the ecosystem, and would be verypensive. Our team, together with the Mining-Metallicmpany Zebiec has developed a new product that would

more effective and less expensive, based on mineralsund in Poland. It is based on bentonite, iron, magnesium,lcium and nitrate, has been named Sinobent1 andtented in 2013, no. 214384 (Wiadomosci, 2013).cording to laboratory tests it is effective even at a dose

20 g m�2 and thus 4-fold lower than Phoslock. Besides, itmuch cheaper. Three-month tests carried out on Lakewskie in special enclosures with an area of 0.8 m2 each,

aced at the depth of 1.5 m, confirmed the effectiveness ofactivation of phosphorus using Sinobent (Dondajewska al., 2010b).

The Lake Uzarzewskie case study

Lake Uzarzewskie is a small lake, with an area of 10.4 had a maximum depth of 7.2 m, but is thermally stratified.is hypertrophic owing to a high external load of nutrientsm its agricultural catchment area, treated sewage from

e village of Uzarzewo, and outflow from a fish farm. It

internal loading was temporarily decreased, but waterquality has improved only slightly. This was due to adeoxygenated meta- and hypolimnion with presence ofhydrogen sulfide, indicating a very low redox potential. Toincrease this potential, a new sustainable method ofrestoration was used. It relied on delivering water fromsmall tributaries flowing from sources (subsurface ground-water derived from intensively fertilized fields) at thebottom of the slope at the edge of the lake to the deepest

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Fig. 2. Phytoplankton response to the restoration measures of the Maltanski Reservoir during last 8 years.

Fig. 3. Water from a spring enters a special pit from which it flows through

lastic pipe to the deepest part of the hypolimnion.

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R. Gołdyn et al. / Ecohydrology & Hydrobiology 14 (2014) 68–74 71

art of the lake (Fig. 3). This water was fully oxygenatednd contained a very high concentration of nitratesable 1).

As a result, hydrogen sulfide disappeared from the lakeaters, redox potential in the hypolimnion increased andternal loading of phosphorus from bottom sediments

ecreased (Fig. 4). Concentration of phosphorus in theypolimnion also decreased (Fig. 5), especially in summer,ut the surface transparency increased only slightly. Theain reason for the water blooms is excessive external

utrient loading on this lake (Dondajewska et al., 2013). It planned to divert sewage effluent from the treatmentlant to another receiver in a near future.

4. The Lake Durowskie case study

Lake Durowskie is a post-glacial lake, thermallystratified, with an area of 143.7 ha and a maximum depthof 14.6 m. In one part it is surrounded by a forest, butotherwise it is adjacent to a city. It is important forrecreation for the local population, especially for swim-ming and fishing. By 2008, the lake had large cyanobacter-ial water blooms, lack of oxygen and presence of hydrogensulphide in the hypolimnion, and high external andinternal loading of phosphorus. Restoration of the lakebegan in 2009 using three methods: (i) oxygenation ofhypolimnetic waters, using wind aerators, (ii) iron treat-ment, using small doses of coagulant (PIX 112), (iii)biomanipulation – stocking of the lake with the fry of pikeand pikeperch. Two aerators were installed in the lake, onein the deepest part adjacent to the city, the second one at12 m water depth in the part surrounded by forest (Fig. 6).

The operation of the aerator used water movement withthe help of a paddle wheel, which moved water from onetank to another, resulting in its oxygenation (Fig. 7). Thetwo tanks are linked by hoses to the hypolimnion. The lossof water in the first tank, as a result of its movement to thesecond tank, causes pressure-induced flow of water fromthe water just above the bottom layer. Rising water level inthe second tank, causes its gravitational sinking down tothe hypolimnion.

able 1

haracteristic of water from two sources, delivered to the lake bottom

ean values � standard deviation).

Variable Units N Source 1 Source 2

Temperature 8C 27 9.8 � 3.4 9.8 � 3.2

Oxygen mg l�1 25 11.2 � 2.0 11.3 � 1.9

Oxygen saturation % 25 99.3 � 15.4 100.0 � 14.4

Nitrate-N mg l�1 N 29 37.2 � 6.14 39.9 � 8.46

Nitrite-N mg l�1 N 30 0.003 � 0.003 0.003 � 0.003

Ammonium-N mg l�1 N 30 0.357 � 0.188 0.354 � 0.183

SRP mg l�1 P 30 0.062 � 0.058 0.066 � 0.092

Total P mg l�1 P 30 0.087 � 0.121 0.078 � 0.149

Conductivity mS cm�1 29 1115 � 141 1389 � 188

ig. 4. The amounts of released (positive values) or accumulated (negative values) phosphorus in sediments of Uzarzewskie Lake in three seasons of 2005

nd 2013.

Fig. 5. Changes of total phosphorus concentration in vertical profile of Uzarzewskie Lake in three selected months of 2005 and 2013.

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R. Gołdyn et al. / Ecohydrology & Hydrobiology 14 (2014) 68–7472

As a result of restoration treatments, water quality isadually improving. Water transparency increased from

in 2009 to ca. 2 m in 2011, oxygen content in theetalimnion increased from zero to ca. 1 mg O2 l�1, andlorophyll-a in the surface water layer decreased fromove 50 mg l�1 to 14 mg l�1. The phytoplankton speciesmposition changed from the dominant cyanobacteria toatoms, dinoflagellates and chrysophytes. Submergedacrophytes increased their bottom coverage from5 m2 in 2009 to 2550 m2 in 2011 and nymphaeidsubled their area. Number of benthic macroinvertebrate

xa increased from 15 to 26 and their total densitycreased from 691 to 2482 specimens m�2 in the littoralne near the forest. Benthic biomass was dominated byge mussels Anodonta anatina (L.), A. cygnea (L.), Unio

ctorum (L.) and Unio tumidus Phil. (Gołdyn et al., 2013).

5. Discussion

The use of minimally invasive measures for lakerestoration enables a gradual reconstruction of thecomposition of communities, from phytoplankton andzooplankton to benthic macroinvertebrates and macro-phytes. The most important change is the reduction ofcyanobacteria, which allows use of the water by peopleeven if other groups of phytoplanktonic organisms are stillrelatively frequent. Disappearance of harmful toxic meta-bolites released by many species of cyanobacteria (Man-kiewicz-Boczek et al., 2009; Zagajewski et al., 2009) is thekey change. These toxins have an impact not only on therecreational use of lakes for swimming, but also on fishing,as the toxins accumulate in the muscles of fish, leading todiseases in their consumers (Pawlik-Skowronska et al.,2012). The elimination of cyanobacteria is mainly attri-butable to a significant reduction in the concentration ofphosphorus in the water column, resulting from irontreatment. A large water bloom caused by cyanobacteriaoccurred in the Maltanski Reservoir in 2011, whenreducing phosphorus level was not possible owing tostrong internal loading from fresh organic sedimentsbrought in with the Cybina River. In this case also, a largepopulation of common carp which drifted with the riverwaters had an important role in enhancing the level ofphosphorus, as the carp were resuspending bottomsediments, thus contributing to a greater release ofphosphorus (Kajak, 1980).

Large doses of treatment chemicals may cause a sharpdecline in biodiversity in a lake because of coagulating orlethal effects. This results in disturbance to the ecosystemand a random succession of new aquatic organisms. In thecase of small doses which were used in the studied lakes,biodiversity increased, reflecting the positive response ofthe ecosystem to the treatments applied. This is consistentwith the intermediate disturbance hypothesis (Padisaket al., 1993). In this case, restoration brings intermediatedisturbances. It is not degrading the ecosystem, but byincreasing biodiversity allows organisms that are betteradapted to reduced trophy to outcompete more aggressivespecies. At the same time, such restoration enablesintensive growth of organisms that can improve waterquality, e.g. zooplankton crustaceans in the pelagial ormolluscs in the littoral zone. Methods of sustainablerestoration take advantage of a lake ecosystem’s naturalresponse to the changes made, so that they are much lessexpensive than methods strongly affecting the ecosystem.This approach to the restoration of lakes is a good exampleof the concept of ecohydrology, which gives a holisticperspective to ecological processes that determine thespecies structure and functioning of ecosystems (Zalewski,2013).

Sinobent1, a new product invented by our team fits theidea of sustainable use of chemicals. An experimentallydetermined dose of 200 kg ha�1 is much less harmful forthe ecosystem than the 800 kg ha�1 estimated to beneeded for Phoslock1 (Gołdyn et al., 2010). In other lakeseven higher doses of Phoslock1 have been applied, e.g. 24 tfor 9 ha in the man-made Clatto Reservoir in UK (Meiset al., 2012). It is important also to realize that high

. 6. Wind aerator on Durowskie Lake (arrow indicates the paddle

eel, which aerates the hypolimnetic water during its movement from

e part of a container to the other). See Fig. 7.

. 7. Functional diagram of the aerator (1 – water level in the lake, 2 –

ered water level in the first tank, as a result of its movement to the

ond tank through action of the wind-driven paddle wheel, as a result of

ich water flows down hose 6 to the hypolimnion, 3 – raised water level

the second tank, 4 – paddle-wheel moving water from the first tank to

second tank, 5 hose through which water is drawn by the movement

the paddle wheel from the hypolimnion, 7 – epilimnion, 8 –

oxygenated hypolimnion, 9 – bottom sediments) (modified from

dsiadłowski, 2002).

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R. Gołdyn et al. / Ecohydrology & Hydrobiology 14 (2014) 68–74 73

oncentrations of lanthanum are alien to Polish lakes.eanwhile iron, the main ingredient of Sinobent, is a

ormal element in the lakes, and is supplied from theatchment.

Supply of nitrates to the hypolimnion from smallributaries is similar to a method called Limnox, which

volves recurrent dosing of calcium nitrate to theypolimnion (Klapper, 2003) to increase the redoxotential. Comparison of these two methods indicateshat the new method of supplying hypolimnion initrates from tributaries is more effective, because itorks continuously. High variability of nitrate concen-

ration at the bottom of the lake in the Limnox methodesults in a variable decomposition of organic matter byhe bacteria responsible for denitrification, which leadso a variable redox potential. The new method isustainable, because the bacteria responsible for deni-rification of nitrates keep the redox potential at aonstant positive level without any additional costs.uch redox potential prevents the reduction of iron andnhances the binding of phosphorus in the sedimentSøndergaard et al., 2002).

Very important in restoration is also to increase theurface area of the lake occupied by submergedacrophytes. The role of macrophytes is very complex.

egetation is an important limiting factor for the growthf phytoplankton, resulting in a shift to a clear-watertate (Strand and Weisner, 2001; Celewicz-Gołdyn,010). This is due to both resource competition andllelopathy (Gross et al., 2007). Macrophytes also serves substrates for periphyton, storage of nutrients,efuges for zooplankters and other macroinvertebrates.hey consolidate sediments, reducing resuspensionf bottom sediments and are a place of spawningnd survival of juvenile stages of fish (Meijer et al.,999).

. Conclusions

It is possible to use sustainable lake restorationethods which are cheap, easy to use, effective,

nergy-efficient and not destructive for most of theiota. These include the use of wind aerators, biom-nipulation, iron treatment with small doses of ironulphate or chloride, and supplying the hypolimneticater with water from tributaries that are rich in

itrates. Simultaneous application of several methods,hich prevents feedback mechanisms, increases the

fficiency of restoration.

inancial disclosure

This research was partly supported by the Ministry ofcience and Higher Education (Poland), grant nos. N 3050831/3632 and NN305 372838.

onflict of Interest

Acknowledgments

The authors are very grateful to Professor Brian Moss forhis kindly review of the manuscript, which led to asubstantial improvement of the final version of this paper.

References

Celewicz-Gołdyn, S., 2010. Influence of Ceratophyllum demersum L. onphytoplankton structure in a shallow eutrophic lake. Oceanologicaland Hydrobiological Studies 39 (3) 121–128.

Ciecierska, H., Dynowska, M., in press. Klasyfikacje jakosci wodpowierzchniowych. (Classifications of surface water quality). In:Ciecierska, H., Dynowska, M. (Eds.), Biologiczne Metody Oceny StanuSrodowiska – Tom II. Ekosystemy Wodne. (Biological Methods ofEnvironment State Assessment – vol. II. Water Ecosystems). MantisPress, Olsztyn (in Polish)

Dondajewska, R., Gołdyn, R., Joniak, T., Kowalczewska-Madura, K., Kozak,A., 2010a. Zmiany jakosci wod Zbiornika Maltanskiego w latach1993–2008.(Changes of water quality of Maltanski Reservoir in years1993–2008). In: Zietkowiak, Z. (Ed.), Zanieczyszczenie i Ochrona WodPowierzchniowych. Woda – Srodowisko – Zmiany. Seria: Studia iPrace z Geografii i Geologii nr 13. (Pollution and Protection of SurfaceWater. Water – Environment – Changes. Series: Studies and Works ofGeography and Geology).Bogucki Scientific Publishing, Poznan, (inPolish), pp. 17–29.

Dondajewska, R., Gołdyn, R., Kozak, A., Podsiadłowski, S., Gruza, A., 2010b.Ograniczenie wydzielania fosforu z osadow dennych oraz zmiany wskładzie fitoplanktonu pod wpływem nowych preparatow chemicz-nych w warunkach in-situ.(A reduction of phosphorus loading frombottom sediments and changes in phytoplankton composition underthe influence of new chemicals in in situ conditions). In: Wisniewski,R. (Ed.), Ochrona i Rekultywacja Jezior. (Protection and Restoration ofLakes).PZITS, Torun, (in Polish), pp. 31–43.

Dondajewska, R., Gołdyn, R., Podsiadłowski, S., Kozak, A., Kowalczewska-Madura, K., Kozlik, K., 2013. Zmiany jakosci wody Jeziora Uzarzews-kiego na skutek zabiegow rekultywacyjnych.(Changes in water qual-ity of Uzarzewskie Lake as a result of restoration treatment). In:Wisniewski, R. (Ed.), Ochrona i Rekultywacja Jezior. (Protectionand Restoration of Lakes).PZITS, Torun, (in Polish), pp. 47–54.

European Community, 2000. Directive 2000/60/EC of the European Par-liament and of the Council of 23 October 2000 establishing a frame-work for Community action in the field of water policy. OfficialJournal of the European Union L327 (22) 1–73.

Gołdyn, R., 1994. The role of preliminary reservoirs in the protection of theMaltanski Reservoir. Archiv fur Hydrobiologie–Beiheft Ergebnisse derLimnologie 40, 253–262.

Gołdyn, R., 2000. Zmiany Biologicznych i Fizyczno-Chemicznych CechJakosci Wody Rzecznej Pod Wpływem Jej Pietrzenia We Wstepnych,Nizinnych Zbiornikach Zaporowych, (Changes in Biological and Phy-sico-chemical Parameters of River Water Quality as a Result of itsDamming in Preliminary Lowland Reservoirs. Series: Biologia).65.Adam Mickiewicz University Press, Poznan (in Polish).

Gołdyn, R., Dondajewska, R., Kowalczewska-Madura, K., 2010. Wpływnowych preparatow chemicznych na ograniczanie wydzielania fos-foru z osadow dennych.(The influence of new chemicals on thereduction of phosphorus release from bottom sediments)). In: Malina,G. (Ed.), Rekultywacja i Rewitalizacja Terenow Zdegradowanych.(Reclamation and Revitalization of Demoted Areas).PZITS, Poznan,(in Polish), pp. 53–64.

Gołdyn, R., Mastynski, J., 1998. Biomanipulation in the Maltanski Reser-voir. International Review of Hydrobiology 83, 393–400.

Gołdyn, R., Messyasz, B., Domek, P., Windhorst, W., Hugenschmidt, C.,Nicoara, M., Plavan, G., 2013. The response of Lake Durowskie eco-system to restoration measures. Carpathian Journal of Earth andEnvironmental Sciences 8 (3) 43–48.

Gross, E.M., Hilt, S., Lombardo, P., Mulderij, G., 2007. Searching forallelopathic effects of submerged macrophytes on phytoplankton –state of the art and open questions. Hydrobiologia 584, 77–88.

Kajak, Z., 1980. Influence of phosphorus loads and of some limnologicalprocesses on the purity of lake water. Hydrobiologia 72 (1–2) 43–50.

Kajak, Z., 1998. Hydrobiologia-Limnologia. Ekosystemy Wod Srodlado-wych. (Hydrobiology – Limnology. Ecosystems of InlandWaters). PWN, Warszawa.

Klapper, H., 2003. Technologies for lake restoration. Journal of Limnology

Ko

Ko

Ma

Me

Me

Pa

Pa

R. Gołdyn et al. / Ecohydrology & Hydrobiology 14 (2014) 68–7474

zak, R., Gołdyn, R., Dondajewska, R., Kowalczewska-Madura, K., Pod-siadłowski, S., 2009. Rekultywacja Zbiornika Maltanskiego w Pozna-niu w latach 2005–2008.(Restoration of Maltanski Reservoir inPoznan in years 2005–2008). In: Malina, G. (Ed.), Rekultywacja iRewitalizacja Terenow Zdegradowanych. PZiTS, Poznan, pp. 329–344.

zak, A., Gołdyn, R., Kowalczewska-Madura, K., Zimmer, M., 2012. Waterquality and phytoplankton of the recreationally used Lake Sławskie.Polish Journal of Natural Sciences 27 (4) 419–431.

nkiewicz-Boczek, J., Gagała, I., Kokocinski, M., Jurczak, T., Stefaniak, K.,2009. Perennial toxigenic Planktothrix agardhii bloom in selectedlakes of western Poland. Environmental Toxicology 26 (1) 10–20.

ijer, M.-L., de Boois, L., Scheffer, M., Portielje, R., Hosper, H., 1999.Biomanipulation in shallow lakes in The Netherlands: an evaluationof 18 case studies. Hydrobiologia 408–409, 13–30.

is, S., Spears, B.M., Maberly, S.C., O’Malley, M.B., Perkins, R.G., 2012.Sediment amendment with Phoslock1 in Clatto Reservoir (Dundee,UK): investigating changes in sediment elemental composition andphosphorus fractionation. Journal of Environmental Management 93(1) 185–193.

disak, J., Reynolds, C.S., Sommer, U. (Eds.), 1993. Development inHydrobiology, vol. 81. Kluwer Academic Publishers, Dordrecht/Bos-ton/London (reprinted from Hydrobiologia 249).

wlik-Skowronska, B., Toporowska, M., Rechulicz, J., 2012. Simultaneousaccumulation of anatoxin-a and microcystins in three fish speciesindigenous to lakes affected by cyanobacterial blooms. Oceanologicaland Hydrobiological Studies 41 (4) 53–65.

Podsiadłowski, S., 2002. Wykorzystanie energii wietrznej w rekultywacjijezior. (Use of wind energy in lakes restoration). Czysta Energia 4,14–15.

Sobczynski, T., Joniak, T., 2008. Srodowiskowe uwarunkowania inakty-wacji fosforu w wodach Jeziora Witobelskiego.(Environmental deter-minants of inactivation of phosphorus in the waters of LakeWitobelskie). In: Garbacz, J. (Ed.), Diagnozowanie Stanu Srodowiska.Metody Badawcze – Prognozy. Pr. Kom. Ekol. i Ochr. Srod., vol. II. BTN,Bydgoszcz, pp. 95–102.

Søndergaard, M., Wolter, K.-D., Ripl, W., 2002. Chemical treatment ofwater and sediments with special reference to lakes. In: Perow, M.R.,Davy, A.J. (Eds.), Handbook of Ecological Restoration. CambridgeUniversity Press, Cambridge, pp. 184–205.

Strand, J.A., Weisner, S.E.B., 2001. Dynamics of submerged macrophytepopulations in response to biomanipulation. Freshwater Biology 46(10) 1397–1408.

Wiadomosci, U.P., 2013. Srodek do rekultywacji powierzchniowych wodsrodladowych. Nr patentu 214384 (Agent for the restoration of inlandsurface waters. Patent number 214384), Wiadomosci Urzedu Paten-towego 2013, 7, 1682.

Zagajewski, P., Gołdyn, R., Fabis, M., 2009. Cyanobacterial volume andmicrocystin concentration in recreational lakes (Poznan – WesternPoland). Oceanological and Hydrobiological Studies 38 (Suppl. 2)113–120.

Zalewski, M., 2013. Ecohydrology: process-oriented thinking towardssustainable river basins. Ecohydrology and Hydrobiology 13,97–103.