Ecohydrological system solutions to enhance ecosystem services: the Pilica River Demonstration Project

DOI: 10.2478/V10104-009-0042-8 Vol. 9 No 1, 13-39 2009 UNESCO-IHP Demonstration Projects in Ecohydrology

Ecohydrological system solutions to enhance ecosystem services: the Pilica River Demonstration Project

Iwona Wagner1,2, Katarzyna Izydorczyk1, Edyta Kiedrzyńska1, Joanna Mankiewicz-Boczek1, Tomasz Jurczak2, Agnieszka Bednarek2, Adrianna Wojtal-Frankiewicz2, Piotr Frankiewicz1,2, Sebastian Ratajski2, Zbigniew Kaczkowski2, Maciej Zalewski1,2 1International

Institute of Polish Academy of Sciences, European Regional Centre for Ecohydrology under the auspices of UNESCO, 3 Tylna Str., 90-364 Łódź, Poland 2Department of Applied Ecology, University of Lodz, 12/16 Banacha Str., 90-237 Łódź, Poland. e-mails: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; kaczko@ biol.uni.lodz.pl; [email protected];

Abstract The application of ecohydrology principles as part of Integrated Water Resources Management (IWRM) has the potential to enhance the resilience of a catchment to anthropogenic impacts. Linking this approach with an understanding of water users and social and economic conditions in a given region, provides a foundation for the development of system solutions. Improving the quality of the environment, and the ecosystem services provided, can be a driver of new employment opportunities that contribute to both the overall economy of a region and sustainability. With these goals in mind, the paper presents a four-step approach for implementation of ecohydrology principles in IWRM, including a) monitoring of threats, b) analysis of the cause-effect relationships, c) development of methods, and d) system solutions. This approach was formulated and tested within a UNESCO-IHP and UNEP-IETC Demonstration Project on the Pilica River in Poland. This project aims to support fulfilment of Poland’s obligations resulting from the EU Water Framework Directive and other European directives, and her constitutional obligations for sustainable development. Attempts to transfer lessons learned to other catchments and socioecological systems (such as urban catchments) are highlighted. Key words: Ecohydrology; Integrated Water Resources Management; system solution; reservoir; catchment; eutrophication.

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1. Introduction There is an increasing number of evidences in the scientific literature that hydrology and biological processes are strongly interconnected: it is not possible to explain the behaviour of one without taking into account the other. This interdependence has been quantified and validated at various scales including the landscape (e.g., Kędziora et al. 1989; Baird, Willby 1999; Kędziora, Olejnik 2002; Ryszkowski 2002), floodplains and wetlands (e.g., Junk et al. 1989; Agostinho et al. 2004; Mitsch et al. 2005, 2008), rivers (e.g., Zalewski, Naiman 1985), lakes and reservoirs (e.g., Ploskey 1985; Zalewski et al. 1990a, b; Straskraba, Tundisi 1999) and coastal zones (e.g., Chicharo et al. 2001; Wolanski et al. 2004, 2006). These interconnections resulting from the properties of the ecosystems stood behind formulation of the ecohydrology concept (Zalewski et al. 1997), within the UNESCO International Hydrological Programme (IHP). The underlying key assumption of ecohydrology was formulated in early 80’s as the concept of Abiotic-Biotic Regulatory Continuum (Zalewski et al. 1985; Zalewski Naiman 1985). Shortly, a first step towards understanding and appreciating the potential of ecosystem properties as a management tool was made within the UNESCO Man and Biosphere (MAB) Programme “The role of land –inland water ecotones in landscape management and restoration” (Naiman et al. 1989; Schiemer et al. 1995). A major driver in using these experiences for formulating more integrated problem-solving ecohydrology science was the need to address the challenges of longterm, large-scale degradation of natural processes in catchments as a result of intensive human interventions. Destabilisation of the water and matter cycles in catchments reduces their capacity to absorb and buffer against escalating impacts. This loss of catchment resilience threatens the ecological security of the dependent societies. The applied dimension of ecohydrology utilises the “dual regulation” between biological and hydrological processes in individual ecosystems that aim to manage the above impacts. Enhancement of a catchment resilience, leading to improvements in water resources (quality and quantity) and ecosystem status (biodiversity and environmental health) while meeting the needs of water users, is a fundamental goal of ecohydrological management. This relies on synergistic effects of individual measures applied at different scales often based on operating hydraulic infrastructure in ways that improve the perceived performance of ecological systems (Zalewski 2006). Implementation of the ecohydrology approach for IWRM encompasses activities related to the atmospheric/terrestrial and aquatic phas-

es of the hydrological water cycle (Zalewski 2009). In the terrestrial phase, diverse biota play a role in moderating water quantity and quality (e.g., Eagelson 1982, 2002; Baird, Wilby 1999; Rodriguez-Iturbe 2000; Ryszkowski 2002). Here, land-use and management, especially control of vegetation cover, play an important role in shaping the water cycle (e.g., Ryszkowski 2002). In the aquatic phase, biotic processes are strongly controlled by hydrology, which is a key factor in aquatic vegetation performance and related water quality outcomes e.g. eutrophication leading to toxic cyanobacterial blooms (e.g., Zalewski 1999; Traczyńska et al. 2002). The important steps were also made through studying constructed wetlands (Mitsh, Gosselink 2007). One of the key concepts which strengthen the application of ecohydrology is phytotechnology, described as application of science and engineering to examine problems and provide solutions involving plants (UNEP-DTIEIETC, 2003). Phytotechnology contributes not only to the water cycle regulation, but also to water quality improvement (phytoremediation), bioenergy production and others. The new paradigm proposed by ecohydrology expands the scope and perspectives of environmental management from protection and conservation towards active regulation of ecological processes especially in “novel ecosystems” (sensu Hobbs et al. 2006) and “engineering harmony“ between society and ecosystems (Zalewski 2005). Its intensive development within recent years and the links made with other sciences such as toxicology and health (Mankiewicz et al. 2001, 2002, 2003; Codd et al. 2005), economy (e.g., Ohl et al. 2007; Krauze, Wagner 2008), and sociology (e.g., Hiwasaki, Arico 2007; Mirtl, Krauze 2007), have taken ecohydrology into trans-disciplinary science (Castri, Hadley 1986). This evolution has also been inspired by growing demands for alternative science-based, cost-efficient responses to sustainability and water issues, called a demand-driven research (Gyawali et al. 2006). System solutions that link, ecohydrology-based management methods, and social and economic challenges and opportunities in water use can contribute not only to better environmental quality, but also to the overall wellbeing of a region and its sustainability.

2. System Solutions: methodology for implementation of ecohydrology principles in IWRM Following the recommendation of International Council for Science (ICSU) on the applicability of science in XXI century (ASCEND 21 Conference held in Vienna in 1991) ecohydrology has become trans-disciplinary, problem-solving science. A methodology for ecohydrology implementation for Integrated Water Resources Management includes

Ecohydrological system solutions to enhance ecosystem services (Pilica River)

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Table I. Objectives and characteristics of the four steps in the methodology for implementation of the ecohydrology principles into IWRM and development of system solutions. Step / objective 1. Monitoring of threats - identification and quantification of a threat, its seasonal and/or spatial dynamics and effect on the societal systems (I EH principle)

Characteristics - demand driven research: the threat recognised by stakeholders as the priorities– existing and potential issues; - involves both qualitative and quantitative assessment methods; - monitors both the threat and its drivers and causes;

2. Assessment of cause-effect relationships - quantification of the cause-effect relationships determining the threat and its causes (I EH principle); - identification of the hierarchy of factors influencing the dynamics of the threat (I EH principle); - quantification of the resilience (or resistance) of the catchment and/or their individual elements (II EH principle);

- based on the analysis of the results of the monitoring of threats; - involves additional experimental research both in the large scale (in the field) and meso-and microscale (laboratory) and /or validation of the achieved results; - involves modelling methods for anticipating of the system behaviour and short-/long-term predictions;

- carrying-capacity evaluation as a key factor shaping delivery of ecological services for the society (II EH principle); 3. Elaboration of methods - elaboration of tools and methods based on the ecohydrological methodology (III EH principle) for enhancement of assimilation capacity against impacts and/or protection of individual elements of the system (II EH principle);

- methods are elaborated for: i) control of the drivers and causes of the threat, and/or ii) control of the threat appearance; - the methods make use of cause-effect relationships identified in the previous step and are based on their dual regulation; - if possible, the methods reflect the hierarchy of factors identified in the previous step; - each method is focused on an individual element of the system; - the potential existing infrastructure is consider as a tool for hydrological regulation (harmonisation);

4. Development of system solutions - elaboration of a system solution based on the synergistic use of the EH methods and their integration with social system;

- linking the methods elaborated in the previous step in a synergistic way; - identification and economical evaluation of ecosystem services related to the system; - identification and evaluation of other social benefits; - testing of the system solution according to the AAM concept;

the following four steps: a) monitoring of threats, b) assessment of cause-effect relationships, c) development of ecohydrological methods, and d) development of system solutions (Zalewski 2002). Table I defines the goals and characteristics of these steps. Identification of threats is usually driven by stakeholder concerns and the existing and potential environmental problems they perceive. Quantification of threats requires monitoring of

its the appearance, intensity, seasonal and/or spatial dynamics, as well as the risk or costs to society (and stakeholders). Monitoring programmes provide a basis for the identification and quantification of the causeeffect relationships that determine the dynamics of the threat, as well as its drivers. This step requires a close look at hydrology-biota relationships, and recognition of the impact of other abiotic and biotic

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drivers. Understanding cause-effect relationships can help to recognise the hierarchy of factors controlling the threat, and thresholds for the switch between the abiotic and biotic regulation, following the assumption that the abiotic ones are the primary force of ecosystem dynamics while biotic regulation may become dominant at optimal abiotic conditions (first principle of ecohydrology). Based on these results, the thresholds for the resilience (or resistance) of individual ecosystems can be determined, which is necessary for enhancing their absorbing capacity (second principle). The hierarchy of factors controlling the dynamics of a threat can be used to identify the key processes that can be regulated using ecohydrological tools and methods in the individual elements of the catchment (e.g., for wetlands, prereservoirs, ecotones, floodplains, constructed systems) to improve or rehabilitate water resources. The methods use intrinsic properties of these ecosystems such as the pulsing character of water, energy and matter flows through floodplains, high productivity of ecotone zones, enhanced sedimentation and siltation in the upper reaches of reservoirs, hydrodynamic effects on phytoplankton composition, and others. Existing hydrological infrastructure, such as dams, levees, and irrigation systems, can actually provide an advantage in lowering the costs of potential adjustments of hydrological parameters (e.g. water level, water retention time, and hydroperiod). Dual regulation may be also employed by using new soft-constructions such as vegetated embankments for hydrodynamic alteration, and the reconstruction of floodplain banks for hydroperiod control and others. These individual methods can be synergistically linked as part of the described earlier system solutions contributing to the enhancement of the overall resilience of a catchment (third principle of ecohydrology), enhancing a catchments ability to provide ecosystem services (Krauze, Wagner 2008) and improving ecological security of societies and sustainability. At this stage, the system solution should also be tested and modified accordingly, following the concept of Adaptive Assessment Management (AAM; Holling 1978).

3. System Solutions for the Pilica River Characteristics of the Demonstration Project

Pilica

River

The Pilica River Demonstration Project was the first effort towards implementation of ecohydrology and phytotechnology in solving existing problems under the auspices of the UNESCO IHP (International Hydrological Programme of the United Nations Educational, Scientific, and Cultural Organization), UNESCO-ROSTE

(Regional Bureau for Science in Europe) and UNEP-DTIE-IETC (United Nations Environment Programme – Division of Technology, Industry and Economics - International Environmental Technology Centre (Wagner-Lotkowska et al. 2004). The key management issue addressed has been the ecological and health hazards resulting from eutrophication of the river-reservoir system and toxic cyanobacterial blooms which also impact on recreational uses of the area. The natural landscape of a large part of the upper reservoir’s catchment, including several parks and protected forests, as well as cultural and historical attractions are major regional assets. The reservoir itself provides a recreational area for over 60 000 visitors during the summer. However, the poor water quality reduces the recreational potential and restricts further development in the surrounding areas. Understanding factors underlying the degradation of the catchment was a necessity to develop plans for its reversal. The management strategy that was developed has been constantly updated, following the Adaptive Assessment Management approach, and included several local stakeholders, such as Regional Board for Water Resources Management, Polish Association of Anglers (NGO), the Marshal’s Office in Łódź, Municipal and Commune Office in Sulejów and Przedbórz, Pilica Counties Association, and Regional and Province Found for Environmental Protection and Water Management in Łódź, among others. The demonstration project on the Pilica River address four spatial levels: the river, its catchment, the floodplains, and a lowland reservoir (Fig. 1). The Pilica River (total length 342 km, catchment area of 9258 km2) is a tributary of the largest Polish river, Vistula. The Pilica river has a natural, meandering character along almost the whole river. However, almost 64% of the catchment area is agricultural, contributing to high nutrient loads in surface and groundwaters. The floodplains and banks are generally covered by shrubs and trees, but the character of the floodplain vegetation depends on the groundwater level and hydroperiod (Kiedrzyńska et al. 2008a). Nevertheless, large areas of floodplain are cultivated which inversely impacts on water quality. In the middle section of the river above the reservoir, an experimental floodplain (with a surface area of 26.6 ha) was selected for testing ecohydrology principles in flooded areas (Kiedrzyńska et al. 2008b). The Sulejów Reservoir was established in 1973 for multiple uses, with drinking water supply to the city of Łódź (agglomeration of about 1 million people), flood protection and recreation being the most important. At full capacity the reservoir has an area of 22 km2, mean depth of 3.3 m, volume of 75 x 106 m 3 and average water retention time (WRT) of 30 days. The presence of toxic cyanobacteria and high concentrations of

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Ecohydrological system solutions to enhance ecosystem services (Pilica River)

The Sulejów Reservoir mean depth:: 3.3 . m mean retention tim e: ~ 30 days. maximum capacity:: 75 * 106 m3 AREA: 22 km2

POLAND

km

Piotrków Trybunalski Town

The Pilica River catchment

Demonstration floodplain

ER

A RIV

PILIC

ŻA IĄ C LU

Sulejów Town

R VE RI

Pilica & Luciąża Rivers

Przedbórz Town CATCHMENT USE agriculture forests others

PILICA LUCIĄŻA catchment area A [km2] 3921 766 river length L [km] 160 49 A/L ratio 25 16 mean discharge [m 3 s-1] 21.2 2.89 (all data for the rivers and catchment above the reservoir)

Fig. 1. Location of the Pilica River Demonstration Project on Ecohydrology with the four spatial level of activities: reservoir, rivers, floodplain and catchment.

humic substances flushed from the catchment after rainfall events have led to problems with purification of drinking water from the reservoir, lowering the quality of the final product and increasing the complexity and cost of treatment. In 2004, after almost 30 years of abstraction, the water company operating the drinking water facility (“Sulejów-Łódź” - Water Supply Systems Waterworks and Sewage Company) stopped the water abstraction from the reservoir intake and switched to wells. Because of its high economic value resulting from the recreational potential for the region, potential reserves of water for Łódź, and the serious health risks linked to the appearance of toxic cyanobacterial blooms, the reservoir was a central part for the demonstration project.

Methodology Monitoring of threats Monitoring of threats was designed around the problem of cyanobacterial blooms in the reservoir, their causes, toxicity and the consequent

health risks (e.g., Tarczyńska et al. 2001a,b; Mankiewicz et al. 2001, 2002; Jurczak et al 2004). Conventional monitoring of cyanobaterial blooms started in 1994, and included weekly analysis during growing seasons of phytoplankton biomass and composition, and measurement of chlorophyll a. In 2000 and 2001, a flow-through fluorometer was used to map horizontal differences in the phytoplankton community across the reservoir based on the chlorophyll a and phycocyanin distribution (Tarczyńska et al. 2001c; Izydorczyk 2002). Between 1996 and 2005, weekly monitoring also included determination of alkaline phosphatase activity (ATP) in water (Trojanowska 2004) and sediments (Trojanowska, Izydorczyk 2010) for study of enzymatic processes and their role in phosphorus recycling. To assess the abiotic background, the chemical and physical parameters of water were monitored, along with data collection on river and reservoir hydrology and weather. Complimentary long-term data from national monitoring networks, including International Meteorology and

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Wa t e r M a n a g e m e n t I n s t i t u t e , P r o v i n c e Inspectorate for Environmental Protection, Regional Board for Water Management were also collected. Among other reasons, there were used to develop the scenarios of the effect of global climate change on the river and reservoir, and forecasting future dynamics of the processes influencing the risk of cyanobacterial blooms (Wagner, Zalewski 1997; Wagner 2008). In 2002, weekly monitoring also included determination of the concentrations of microcystins (cyanobacterial hepatotoxins) using two methods: enzyme-linked immunosorbent assay (screening ELISA test) and high-performance liquid chromatography (chemical analysis HPLC) with diode-array detection (Meriluoto, Codd 2005; Jurczak et al. 2004, 2005, 2006a; MankiewiczBoczek et al. 2006a). The toxicity of microcystins was also measured by the PPIA (protein phosphatase inhibition assay) colorimetric method (Mankiewicz-Boczek et al. 2006a,b,c). The bacterial SOS Chromotest with Escherichia coli PQ37 and comet assay with human lymphocytes was used to determine the genotoxicity of microcystin-containing cyanobacteria during summer monitoring (Mankiewicz et al. 2002; Bonislawska et al. 2003; Palus et al. 2007). Moreover, the cytotoxic potential of cyanobacterial extracts with microcystins on rat hepatocytes was researched using fluorescence and differential interference contrast microscopy with DNA-specific day (Mankiewicz et al. 2001). The genotoxic activity and cytotoxic activity including apoptotic changes of cyanobacerial extracts with microcystins from Sulejów Reservoir were observed for bacteria E. coli PQ73, rat hepatocyts and human lymphocytes (Mankiewicz et al. 2001, 2002; Bonislawska et al. 2003; Palus et al. 2007). To develop an early warning method for cyanobacteria and help in improvement of the water purification system, molecular analysis of the microcystin synthetase (mcy) genes has been undertaken since 2003 to identify toxigenic cyanobacterial strains in reservoir (Mankiewicz-Boczek et al. 2006a,c). Detection of mcyE and mcyA genes at the beginning of July was used to assess the potential toxicity of cyanobacteria and the possibility of microcystins production in the next period of summer (Mankiewicz-Boczek et al. 2006a,b,c). Monitoring of the major tributaries of the reservoir (Pilica and Luciąża rivers) – was undertaken since 1996 to quantify their contributions to reservoir eutrophication (Wagner, Zalewski 2000; Wagner-Lotkowska 2002; Kiedrzyńska 2006; Bednarek 2007). Water sampling was carried out three to six times per month and daily during floods, with analysis according to the methodologies of Goltermann et al. (1978) and Greenberg et al. (1992) for all forms of phosphorus and

ammonia nitrogen concentration, total nitrogen (TN) using Hach test N’Tube (no.10071), nitrate nitrogen (N-NO 3) using Hach test NitraVer 5, total and mineral and suspended matter content. Progressive development of a GIS based database for the Pilica River Basin since 2007 has provided a tool for the analysis of land use in the Pilica sub-catchments and its effect on the rivers’ chemical characteristics (Wagner, unpublished data, project in progress). The assessment of the point pollution sources impact in the upper Pilica catchment is also on-going (Kiedrzyńska, unpublished data, project in progress). Cause-effect and feedback analysis The appearance of cyanobacteria is a typical consequence of eutrophication, especially in shallow reservoirs. However their intensity and effect varies depending on the nutrient supply pattern, weather conditions, the reservoir hydrology, limnology and morphology, and the dynamics of the biotic component. Data were therefore statistically analysed to determine cause-effect relationships for both abiotic and biotic factors influencing the appearance of cynobacteria and its toxicity. The changes of water chemistry of the major tributaries (Wagner 2000, Zalewski et al. 2000) and small tributaries of the direct catchment (Bednarek 2007) was studied on the background of their hydrological dynamics. This allowed for quantification of the reservoir nutrient balance, and the identification of episodes of high nutrient loading. The role of denitrification in the nitrogen balance of the reservoir was studied between 1998-2001 (Bednarek 2007; Bednarek, Zalewski 2007a,b) with quantification of the process in sediments and identification of the main influencing environmental factors as the goal of the study. Denitrification rates were studied in the littoral zone of reservoir using an in situ chamber for direct measurements of gaseous reaction products (Tomaszek 1991; Bednarek et al. 2002; Hodgman et al. 1960). The gas samples were analysed using a Philips gas chromatograph and the in situ denitrification rate was calculated from the total N2 flux out of the sediment (Tomaszek, Czerwiniec 2000; Czerwieniec 1998; Bednarek 2007). Work on the direct factors influencing the appearance of cyanobacteria in the reservoir focused on the response of the reservoir biotic structure (phytoplankton, zooplankton, fish) to its hydrochemical characteristics (Izydorczyk et al. 2008a,b), water retention time (Tarczyńska et al. 2001a), flood peaks (Wagner-Lotkowska et al, 2002; Wagner-Lotkowska 2002; Wojtal et al. 2008), and the effect of the hydrological regime on the microbial loop (Trojanowska 2004). The ecosystem trophic structure dynamics and biotic interactions have been amongst the most important aspects of the research carried out

Ecohydrological system solutions to enhance ecosystem services (Pilica River)

on the reservoir (Zalewski et al 1990a,b; Frankewicz et al. 2001). Much attention has been given to Daphnia sp., which is the most significant filter-feeding zooplankter in lakes influencing the phytoplankton community structure and biomass (e.g. Sterner 1989). Quantification of interactions between phytoplankton, Daphnia, invertebrate predator Leptodora kindtii, and juvenile Percids in the pelagic zone of the Sulejów Reservoir were studied weekly from the end of May to the end of September since 1994 (Wojtal et al. 1999). The zooplankton were preserved in 4% Lugol’s solution, then identified and counted under a microscope according to the methods described by Wojtal (2000). Biomass for each zooplankton genus was estimated based on species-specific length/weight regressions (Karabin 1974; Bottrell et al. 1976; Wojtal et al. 1999). Contribution of L. kindtii and juvenile percids to the decline of Daphnia sp. biomass in different biotic (food) and abiotic (hydrology) conditions was then assessed (Wojtal et al. 2008). Research on the role of fish predation in the dynamics of filtering zooplankton has been carried out in the Sulejów Reservoir since 1983 (Zalewski et al 1990a,b). This has focused on determination of the young-of-the-year (YOY) fish abundance, community structure, spatial and temporal distribution and the top-down effect on the reservoir ecosystem biotic structure. In the littoral zone, YOY fish have been collected using a beech seine net - every three hours in a 24-hour cycle - in the first half of July, since 1983. In the pelagic zone, a bongo net (0.5 m diameter, 1.0 mm mesh size) was pushed in the front of a motor boat at different depths with sampling done weekly in June and July between 1993-1997 (Frankiewicz et al. 1997). A horizontally looking split beam echosounder (Simrad EY-500) was also used to monitor fish distribution and migrations. Additionally, both YOY and older fish have been sampled using low selective gill nets, monthly from May to November, since 1994 (Frankiewicz, Swierzowski 2004; Godlewska et al. 2004). Fish catch by anglers was estimated according to the yearly assessments prepared by Polish Anglers Association Regional Fisheries Board in Piotrków Trybunalski (PAA), responsible for fishery management in Pilica river and Sulejów Reservoir. In summary, the monitoring allowed identification of the key factors determining the appearance of toxic cyanobacteria in the reservoir. Development of Ecohydrological methods The methods of management of toxic cyanobacteria blooms focused on two aspects: firstly, reducing nutrient availability through reduction in pollutant loads into the reservoir, and secondly, control of cyanobacteria within the reservoir.

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Recognition of the pattern of nutrient transport and dynamics created a basis for design of a method to reduce reservoir external loading (e.g., Wagner, Zalewski 2000). The method was based on diverting the highest pollutant loads transported by the reservoir’s tributaries into floodplain areas upstream the reservoir. Subsequent research within the demonstration floodplain examined possible ways to enhance the nutrient retention process through both sedimentation and assimilation within the vegetation biomass. Optimisation of the sedimentation process was based on analysis using a Digital Terrain Model and hydraulic model (Kiedrzyńska et al. 2008b). Efficiency of nutrients assimilation and biomass production by autochthonous vegetation communities, with special emphasis on the willow patches, was examined against hydroperiod (Kiedrzyńska et al. 2008a). Research on the effect of hydrology on fish reproductive success (Zalewski et al. 1990a,b) was a basis for development of hydrobiomanipulation method (Zalewski et. al. 2009). This aims to regulate water level to reduce juvenile fish density, diminishing their predatory pressure on filtering zooplankton and therefore preventing cyanobacterial blooms. Testing of the efficiency of water level regulation on fish reproductive success started in 2006 with cooperation of the Regional Water Management Board in Warsaw, responsible for managing the reservoir. This approach was adapted based on the analysis of the first year results and successively tested in 2007 and 2008. Denitrification is, quantitatively the most important mechanism of removing nitrates from freshwater ecosystems. Optimisation of the denitrification process through regulating the water retention time aimed to enhance nitrate removal from the available nutrient pool. The method has to be harmonised with hydrobiomanipulation to consider the effect of water level regulation on zooplanktivorous fish recruitment, and to avoid adverse effects on water quality due to ”topdown” effect on the reservoir trophic cascade (Bednarek, Zalewski 2007a,b). Design of system solutions Following the third principle of ecohydrology, these methods were integrated to obtain an overall synergistic effect on the reservoir. Potential benefits for the local economy and social systems were also identified at this stage for the proposed solutions. A complementary activity for improving the reservoir as a potable water source was the development of an improved water treatment system to remove microcystins. A method was developed and tested in 2002 and 2003 in the summer time when toxicity levels were high. Sampling was undertaken weekly at every treatment step (raw water, after oxidation by ClO2, coagulation, fil-

Cause-effect relationships

Monitoring of threats

Effects of flood events on phytoplankton dynamics (Wagner-Lotkowska 2002)

Impact of Global Climate Change on eutrophication and its effects (Wagner, Zalewski 1997; Wagner 2008)

Hierarchy of factors determining appearance of cyanobacterial blooms (Izydorczyk et al. 2008a,b)

Microbial loop and phosphatase vs reservoir hydrological dynamics (Trojanowska 2004)

Internal load from botom sediments (Trojanowska, Izydorczyk 2010)

Effect of filtering zooplankton and Dreissena on phytoplankton (Wojtal et al, 2004, 2008)

Biotic factors effecting fish community structure and dynamic (Frankiewicz 1998; Frankiewicz et al. 1996, 1997, 1999; Lapińska et al. 2001)

Effect of water level dynamics on fry communities and ecosystem structure (Frankiewicz et al. 2001; Zalewski et al. 1990a,b, 1995)

Elaboration of early warning system for cyanobacteria cells and toxicity (Tarczyńska et al. 2001b,c; Izydorczyk et al.2005, 2009; Mankiewicz-Boczek et al. 2006c)

Quality of water for potable use Tarczyńska et al. 2001b,c; Jurczak et al. 2005)

Quality of water for recreational use (Mankiewicz-Boczek et al. 2006b)

Cyanobacterial blooms, toxicity and health constraints (Tarczyńska et al. 2001a,b; Mankiewicz et al. 2001, 2002; Bonislawska et al. 2003; Jurczak et al. 2004; Mankiewicz-Boczek et al. 2006a; Palus et al. 2007)

reservoir

relationship between hydrological pattern of tributaries and timing of nutrient loads supplying the reservoir (Wagner, Zalewski 2000; Zalewski et al. 2000; WagnerLotkowska 2002; Kiedrzyńska, Jozwik 2006)

Water quality in the Pilica tributaries (Wagner, unpubl.)

Nutrient balance of small rivers in direct reservoir’s catchment (Bednarek 2007)

Nutrient balance of main tributaries of the reservoir (Wagner, Zalewski 2000; Wagner-Lotkowska 2002)

rivers

effect of inundation period on distribution and condition of ectomycorrhizal fungi in plants communities (Sumorok, Kiedrzyńska 2007; Sumorok et al. 2008)

effect of hydroperiod on distribution of vegetation and efficiency of nutrient assimilation (Kiedrzyńska et al. 2008a)

effect of floodplain hydraulics on nutrient sedimentation (Kiedrzyńska et al. 2004; Magnuszewski et al. 2005; Kiedrzyńska 2006; Altinakar et al. 2006; Magnuszewski et al. 2007)

floodplain

Table II. Steps in development of ecohydrological system solution for the Pilica River Demonstration Project.

catchment landcover effect on water quality in subcatchments (Wagner, unpubl.)

Quantification of pointpollution sources in the Pilica catchment (Kiedrzyńska, unpubl.)

Landuse differenciation of Pilica sub-catchments (Wagner, unpubl.)

catchment

20 I. Wagner et al.

4. Results and discussion Research undertaken at the Pilica Demonstration Project, according to the ecohydrological methodology for development system solution is presented in Table II.

Threats: Eutrophication and the toxic cyanobacterial blooms

Pilica Case study spin-off to other areas (LTSER Network, HELP Network, Floodplain Declaration 2008)

Up-scaling ecohydrology concept and application into other systems – urban ecohydrology (Zalewski, Wagner 2005; Wagner et al. 2008; Wagner, Zalewski 2009)

Identification of socio-economic benefits and ecohydrological ecosystem services (Wagner et al. 2004; Krauze, Wagner 2008)

Building integrated databases for ecohydrological and social processes (project in progress)

Elaboration of system solutions (Zalewski 2002; Zalewski et al. 2004): UNESCO UNEP Guidelines and Manual on Ecohydrology and Phytotechnology;

Formulation of the ecohydrology concept and its principles (e.g., Zalewski et al. 1997; Zalewski 2000; Zalewski 2006)

Elaboration of system solutions

Enhancing denitrification rates in sediments by hydrological regime (Bednarek 2007; Bednarek, Zalewski 2007 a, b)

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tration, ozonation and chlorination) for identification of intra- and extracellular microcystins by HPLC method (Jurczak et al. 2004).

Enhancement of ecotones filtering role along the rivers in catchment (project in progress) Hydro-biomanipulation (Zalewski et al.2009)

Ecosystem biotechnologies for reservoir management (Zalewski 1994, 1995; Zalewski, Wisniewski 1997) Elaboration of methods

Table II. Continuation

Retention of nutrients transported by high flows in pre-reservoirs and floodplains (Wagner, Zalewski 2000; Wagner-Lotkowska 2002; Kiedrzyńska 2006; Kiedrzyńska et al. 2008b)

Denitrification walls for reducing nitrogen loads (Bednarek, unpubl.)

Ecohydrological system solutions to enhance ecosystem services (Pilica River)

Cyanobacterial blooms and their toxicity The mean total phosphorus concentration in the reservoir during the period 1997-2006 was about 137μg dm-3 (ranging from 13 μg dm-3 to 1053 μg dm-3). High phytoplankton biomass development occurs during summers, and at mean water temperatures exceeding 18˚C is dominated by cyanobacteria. The phytoplankton community in the reservoir has a typical composition for Central Europe characterised by the dominance of the microcystin-producing genus of Microcystis (Tarczyńska et al. 2001a; Jurczak et al. 2004; Mankiewicz-Boczek et al. 2006a,b,c; Palus et al. 2007; Izydorczyk et al. 2008a,b). Regular long-term monitoring showed that the average annual cyanobacterial biomass varied between 1.8 mg dm-3 and 13.4 mg dm-3, with a maximum peak value of 180 mg dm-3 in 1999 in the reservoir pelagial (unpublished data for period 1996-2006).Toxigenic cyanobacterial blooms dominated by Microcystis aeruginosa and biosynthesing microcystins occurred in summers between June and October (Mankiewicz-Boczek et al. 2006a,b,c). The concentration of microcystins reached an average if 5.83 μg dm -3 in September 2004 (Izydorczyk et al. 2008a), and in the areas of the bloom concentration were found at up to 22-30 μg dm -3 (Jurczak 2006a; Izydorczyk et al. 2008b). In general, the average total microcystin toxicity and concentration in the summers between 2003 and 2005 were at the First Alert Level for recreational usage according the World Health Organisation guidelines (microcystin at 2-10 μg dm-3) (WHO 2003). Several studies conducted within the demonstration project revealed serious threats from toxins produced by Microcystis aeruginosa - the dominant species of the bloom-forming cyanobacteria in the Sulejów Reservoir (Mankiewicz et al. 2001, 2002; Bonislawska et al. 2003; Jurczak et al. 2005; Mankiewicz-Boczek et al. 2006b; Palus et al. 2007). Microcystis aeruginosa produces different variants of microcystin with identification of microcystin-LR, -YR, -RR and -WR (Mankiewicz et al. 2001; Jurczak et al. 2004;

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Jurczak 2006a; Palus et al. 2007). Contact with microcystin-producing cyanobacteria in bathing water can cause skin irritations, allergic reactions and gastrointestinal symptoms (Falconer 1999; Mankiewicz et al. 2003). Moreover, chronic exposure to low microcystin concentrations in drinking water can lead to cancer promotion (Carmichael 2001). Development of an early warning method to identify toxigenic cyanobacteria The toxigenic and nontoxigenic strains of Cyanobacteria can be distinguished only by molecular analysis (Kurmayer et al. 2002; Hisbergues et al. 2003; Dittman, Börner 2005). Therefore, microcystin biosynthesis (mcy) genes were used to establish molecular techniques to detect toxigenic cyanobacteria in laboratory and environmental studies. Detection of mcyE and mcyA genes at the beginning of summer indicated the potential toxicity of cyanobacteria and the possibility of microcystin production in the next period of monitoring (Mankiewicz-Boczek et al. 2006a,b,c). This is an effective alert to possible health risk. Molecular monitoring based on amplification of mcy genes showed that the potential to produce microcystins by cyanobacteria persisted throughout the summer from July till October. Moreover, molecular analysis indicated that the mcyE gene which encodes the glutamate-activating adenylation domain is the best molecular marker for the determination of potential toxicity of cyanobacteria in different environmental samples, including Sulejów Reservoir, even if their biomass is very low (