Status Of Water Bodies Research Articles

In vitro bioassays to screen for endocrine active pharmaceuticals in surface and waste waters

In the context of the European Water Framework Directive (WFD) it is fully recognized that pharmaceuticals can represent a relevant issue for the achievement of the good chemical and ecological status of European surface water bodies. The recent European Directive on the review of priority substances in surface water bodies has included three pharmaceuticals of widespread use (diclofenac, 17α-ethinylestradiol (EE2), 17β-estradiol (E2)) in the European monitoring list, the so-called watch list. Endocrine active pharmaceuticals such as EE2 and E2 (also occurring as natural hormone) can cause adverse effects on aquatic ecosystems at very low levels. However, monitoring of these pharmaceuticals within the watch list mechanism of the WFD and national monitoring programs can be difficult because of detection problems of most routine analytical methods. With proposed annual average Environmental Quality Standards (AA-EQS) of 0.035ng/L and 0.4ng/L, respectively, the estrogenic pharmaceutical EE2 and the natural hormone E2 are among those substances. Sensitive in vitro bioassays could reduce the current detection problems by measuring the estrogenic activity of environmental samples. In a short review article the application of this approach to screen and assess the risks of endocrine active pharmaceuticals with a focus on estrogenic pharmaceuticals in environmental waters is discussed.

Integrated assessment of ecological status and misclassification of lakes: The role of uncertainty and index combination rules

The European Water Framework Directive (WFD) requires that the ecological status of waterbodies is assessed using multiple biological quality elements (BQEs) that are combined into a single status class. The recommended combination rule (the “one-out, all-out” rule; OOAO) has been criticised for being unreasonably conservative and for being sensitive to uncertainty. In this study, the objective was to compare the sensitivity to uncertainty of four different combination rules: (1) OOAO, (2) OOAO with exclusion of one element, (3) average and (4) weighted average. Index values for 5 BQEs (phytoplankton, phytobenthos, macrophytes, macroinvertebrates and fish) sampled from 10 lakes in the Wel River catchment in Poland were used to classify the lakes according to the OOAO and the three alternative combination rules. Based on the mean and (where possible) standard deviation of these index values, we modelled the risk of misclassification by simulating 10,000 resamples for each BQEs in each lake, classifying each resample and calculating the proportion of misclassified resamples under each combination rule. For individual BQEs, the risk of misclassification increased both with higher uncertainty (standard deviation) and with the proximity of the index value to a class boundary. Under the OOAO rule, the risk of misclassification was more biased towards worse status (“underclassification”) than towards better status. Furthermore, risk of underclassification was more affected by uncertainty under the OOAO rule compared with the alternative combination rules. This analysis has demonstrated the weaknesses associated with the OOAO rule for integration of BQEs for lake classification. However, the alternative combination rules are associated with other shortcomings, such as the need for subjective judgement, and involve a higher risk of not protecting the most sensitive BQE and thus the whole ecosystem. We recommend that future versions of instructions for WFD implementation consider alternatives to the OOAO combination rule, and provide guidelines for weighting of individual BQEs.

Emergy evaluation of an integrated livestock wastewater treatment system

Wastewater treatment practices should pay more attention to their environmental performances due to their resources consumption and emissions’ impact. While reclaimed water reuse seems to have become a promising practice, is it always feasible in any condition? To address this issue, this study carried out an extended emergy evaluation of a holistic wastewater treatment system. On one hand, this method was extended to include the emissions’ impact. On the other hand, this study integrated a wastewater treatment plant, its excess sludge disposal system and treated water disposal system into an integrated wastewater treatment system (IWTS), so as to evaluate its performances more completely. And then several indicators, including cost per unit pollutant eliminated (CUPE), ratio of positive output (RPO), environmental load ratio (ELR), and sustainability index (SI), were proposed for evaluating the performances of an IWTS. Two scenarios (scenario A: wastewater treatment+sludge landfilling+treated water discharges; scenario B: wastewater treatment+sludge landfilling+reclaimed water reuse) for a livestock wastewater treatment plant in Sichuan Agricultural University located in Ya’an City in Southwest China, as cases, were researched. The results show that scenario B has lower positive output efficiency and greater environmental load than scenario A. Meanwhile, the reclaimed water reuse raises cost per unit pollutant eliminated compared with the treated water being discharged directly; emissions’ impact enhances the environmental load of the two scenarios to different degree; emissions’ impact has decisive effect on the sustainability of the two scenarios. These results mean that the reclaimed water reuse should not be advocated in this case. This study provides some policy implications: (1) wastewater treatment process should be comprehensively evaluated from its resources consumption and impact of emissions; (2) reclaimed water reuse should be carefully evaluated from its pros and cons simultaneously; (3) the local conditions should be considered when implementing reclaimed water reuse, such as local water body conditions, market demands, the related laws and regulations, corporations’ economic conditions, etc.

Can we predict biological condition of stream ecosystems? A multi-stressors approach linking three biological indices to physico-chemistry, hydromorphology and land use

We built a corpus of models capable of explaining the variability of the biological indices used in the French surveillance monitoring network and also predict the ecological status of non-monitored water bodies. Benthic macroinvertebrates, diatoms and fish indices have been used to determine the ecological status of 1100 sites of the monitoring network distributed homogeneously over national territory.The pressures taken into account to explain and predict ecological status cover three spatial scales: catchment, reach, site. The set of predictive data cover three types of pressure: land use pressure, hydromorphological pressure and physico-chemical pressure measured at catchment, reach and site scale, respectively.We showed that the parameters characterising the load of nutrients and organic matter had a predominant effect on the three biological compartments, and that land use variables played an integrating role of the different pressures acting on rivers and explained a major part of their degradation. On the contrary, we also showed that it was more difficult to characterise the role of the hydromorphological descriptors measured at the intermediate scale of the reach due to the difficulty of characterising the links between scales.The three predictive models developed demonstrated good performances to evaluate biological condition and are of great interest for managers as it permits using a set of pressure data to successively predict the status of water bodies for which biological monitoring data are unavailable.

UV-vis in situ spectrometry data mining through linear and non linear analysis methods

UV-visible spectrometers are instruments that register the absorbance of emitted light by particles suspended in water for several wavelengths and deliver continuous measurements that can be interpreted as concentrations of parameters commonly used to evaluate physico-chemical status of water bodies. Classical parameters that indicate presence of pollutants are total suspended solids (TSS) and chemical demand of oxygen (CDO). Flexible and efficient methods to relate the instruments’s multivariate registers and classical measurements are needed in order to extract useful information for management and monitoring. Analysis methods such as Partial Least Squares (PLS) are used in order to calibrate an instrument for a water matrix taking into account cross-sensitivity. Several authors have shown that it is necessary to undertake specific instrument calibrations for the studied hydro-system and explore linear and non-linear statistical methods for the UV-visible data analysis and its relationship with chemical and physical parameters. In this work we apply classical linear multivariate data analysis and nonlinear kernel methods in order to mine UV-vis high dimensional data, which turn out to be useful for detecting relationships between UV-vis data and classical parameters and outliers, as well as revealing non-linear data structures.

Using Zooplankton Indicators to Assess the Ecological Condition of a Lake

Nowadays zooplankton is widely used as an indicator of ecological conditions of waterbodies. This article shows the result of the research in zooplankton community of Kamenik Lake. Diversity of zooplankton community, species composition, indicating species, quantitative characteristics, trophic status and saprobity are being evaluated. Hydrochemical data is provided and a development forecast is made.

Coping with Urban & Agriculture Water Demand Uncertainty in Water Management Plan Design: the Interest of Participatory Scenario Analysis

Managing water scarcity is a major challenge for regions all over the world. In the European Union, robust methodologies are needed to establish effective programmes of measures aimed at achieving the “good status” of water bodies according to the Water Framework Directive (WFD). These programmes often target the current gap between the actual status of water bodies and the “good” status without accounting for uncertainty in water demand. We develop a new methodological framework that enable to account for uncertainty in future water demand and design programmes in order to increase their likelihood of attaining the good quantitative status. The foresight approach enables to construct and quantify future water demand scenarios hand-in-hand with stakeholders during workshops. They consist in identifying drivers, debating pre-constructed scenarios, reconstructing scenarios and estimating water demand. The impact of the co-constructed scenarios is simulated with a resource-demand balance model for all water resources and a cost-effectiveness analysis makes it possible to construct programmes that target the estimated future water deficits at least cost. The methodology is illustrated with an application to Reunion Island (Indian Ocean, France) considering agriculture (Ag) and urban water (Uw) demand. Three combinations of sector scenarios (Uw, Ag) were produced and coherence was eventually ensured by fitting the land use parameter. This solution can accommodate case studies faced with a binding land constraint for housing and agriculture. As each scenario implies significantly different programmes of measure in terms of intensity and spatial distribution, results demonstrate the importance of taking uncertainty on water demand into account.

THE MIRAGE TOOLBOX: AN INTEGRATED ASSESSMENT TOOL FOR TEMPORARY STREAMS

ABSTRACTThe assessment of the ecological status of water bodies, as requires by the European Water Framework Directive, can raise a number of problems when applied to temporary streams. These problems are because of the particular physical, chemical and biological conditions resulting from the recurrent cessation of flow or even the complete drying of the stream beds. In such non‐permanent water bodies, the reference quality standards developed for permanent streams may only be applicable under certain circumstances or may not be applicable at all. Work conducted within the collaborative EU‐funded project Mediterranean Intermittent River ManAGEment (MIRAGE) has addressed most of these difficulties and has used diverse approaches to solve them. These approaches have been brought together in the so‐called MIRAGE Toolbox. This toolbox consists of a series of methodologies that are designed to be used in a sequential manner to allow the establishment of the ecological and chemical status of temporary streams and to relate these findings to the hydrological status of the streams. The toolbox is intended to serve the following purposes: (i) the determination of the hydrological regime of the stream; (ii) the design of adequate schedules for biological and chemical sampling according to the aquatic state of the stream; (iii) the fulfillment of criteria for designing reference condition stations; (iv) the analysis of hydrological modifications of the stream regime (with the definition of the hydrological status); and (v) the development of new methods to measure the ecological status (including structural and functional methods) and chemical status when the stream's hydrological conditions are far from those in permanent streams. Copyright © 2014 John Wiley & Sons, Ltd.

The relevance of ecological status to ecosystem functions and services in a large boreal lake

Summary Environmental conventions aim to protect ecosystem structures and functions to provide goods and services for mankind. The degree of aquatic ecosystem naturalness, or ecological status as it is defined in the Water Framework Directive (WFD) of the European Union, is notionally linked to supplies of ecosystem services. In practice, these links have rarely been documented or even investigated, and to justify conservation and management objectives based on the status indicators, it is essential to demonstrate their relationships to ecosystem functions and services. The WFD requires member states to classify their surface waters aiming to achieve good ecological status of water bodies. However, an implicit assumption of the WFD, that the ecosystem functions and services targeted to be protected and maintained are related to the measured status, remains uncertain. Using a time‐series data set covering almost 50 years, we examined the development of ecological status of eight sub‐basins of a large boreal lake in response to improved wastewater management and decreasing pollution. We particularly evaluated whether the observed descriptors of biodiversity, ecosystem functions and services were associated with the judgements of ecological status, and hence whether the ecological status is a relevant proxy for ecosystem values to be protected. The ecological status of the polluted sub‐basins responded consistently to the decreased nutrient and organic loading. Temporal trends in the biological quality elements and water quality were mostly parallel and showed good status roughly simultaneously. Combined ecological status also appeared to predict some features of taxon diversity (profundal macroinvertebrate and phytoplankton richness), ecosystem functions (primary and bacterial production) and ecosystem services (fish catch and reproductive potential of coregonids). Synthesis and applications. We observed that some ecosystem service supplies and taxon diversity increased with increasing ecological status of the lake. Therefore, our results suggest that ecological status estimates based on simple structural characters are relevant to the ultimate management goals of maintaining biodiversity, ecosystem functions and services and hence might suffice for extensive assessment and monitoring of lake ecosystems.

Uncertainty associated with river health assessment in a varying environment: The case of a predictive fish-based index in France

Sensitive biological measures of river ecosystem quality are needed to assess, maintain or restore ecological conditions of water bodies. Since our understanding of these complex systems is imperfect, decision-making requires recognizing uncertainty. In this study, a new predictive multi-metric index based on fish functional traits was developed to assess French rivers. Information on fish assemblage structure, local environment and human-induced disturbances of 1654 French river sites was compiled. A Bayesian framework was used to predict theoretical metric values in absence of human pressure and to estimate the uncertainty associated with these predictions. The uncertainty associated with the index score gives the confidence associated with the evaluation of site ecological conditions.Among the 228 potential metrics tested, only 11 were retained for the index computation. The final index is independent from natural variability and sensitive to human-induced disturbances. In particular, it is affected by the accumulation of different degradations and specific degradations including hydrological perturbations. Predictive uncertainty is globally lower for IPR+ than for underlying metrics.This new methodology seems appropriate to develop bio-indication tools accounting for uncertainty related to reference condition definition and could be extended to other biological groups and areas. Our results support the use of multi-metric indexes to assess rivers and strengthen the idea that examination of uncertainty could contribute greatly to the improvement of the assessment power of bio-indicators.

The influence of cadmium chloride and hyperthermia on the fatty acid composition of high aquatic plants from Angara River

Water is the basic component of all living organisms and the biosphere. The intensification of using water in the industrial, agricultural and domestic consumption leads to an increased anthropogenic impact on water ecosystems. High aquatic plants are the most important component of aquatic ecosystems. They take part in the process of exchange of nutrients in self-purification of water, can accumulate and transform organic and inorganic pollutants. Aquatic plants are considered and used as sites for monitoring ecological status of water bodies. In this study we investigated the fatty acid composition of higher aquatic plants from Angara River under the influence of hyperthermia 30 °C, and cadmium chlo­ride 100 mg/l. Macrophytes Elodea canadensis Michx. and Myrio­phyllum spicatum L. were gathered at a high flow of Angara River. After cultivation in the laboratory conditions the plants from experimental group were replaced in a solution of cadmium chloride (100 mg/l) during 24 and 48 h. In another experiment the plants were replaced in distilled water, 30 °C heated, and incubated during 24 or 48 h. Lipids were extracted with mixture of chloroform: methanol (2:1). Analysis of fatty acids composition was carried out in form of methyl ethers by the method of chromato-mass-spectrometry. The changes of the fatty acid composition in response to hyperthermia and cadmium chloride were found. The differences in the fatty acid composition changes of the studied species were shown after 24 and 48 h of exposure. Differences in the metabolism of fatty acids should be considered for the development of methods of biomonitoring and bioassay.

Environmental controls and composition of anoxygenic photoheterotrophs in ultraoligotrophic high‐altitude lakes (Central Pyrenees)

The phylogenetic composition of freshwater anoxygenic photoheterotrophs (APs) has been poorly investigated as compared with their marine counterparts. In this study, we explored a set of ultraoligotrophic cold high mountain lakes (Central Pyrenees, Spain) by both pufM gene denaturing gradient gel electrophoresis fingerprinting, and cloning and sequencing of selected lakes samples. Different ranges of limnological and physico-chemical values were explored as environmental drivers of APs richness and composition. We did not observe significant relationships between richness/diversity of pufM and any of the limnological characteristics measured or trophic status, but a negative correlation with ammonia concentration. Conductivity, pH and nitrate concentration were significantly related to changes in APs community composition, whereas lake area, altitude, temperature and trophic status did not. Most of the sequences (> 85%) had the pufM sequences of Limnohabitans (Betaproteobacteria) as the closest relative in databases, whereas less abundant clones were more closely related to Rhodobacter, Sulfitobacter and Brevundimonas (Alphaproteobacteria), in agreement with 16S rRNA gene sequences previously found in the area. Congregibacter-like Gammaproteobacteria were not detected. Comparison with available studies in inland waters showed taxonomic partitioning along salinity gradients, and Congregibacter-like sequences restricted to high saline conditions in continental water bodies.

Ecological status assessment of Skalenski Lakes (Bulgaria)

Over the past decade new ecological indices based on phytoplankton and macrophytes were developed as part of the tools for assessment of the ecological status of water bodies. This study demonstrates the applicability of two of them (Assemblage index /Q/ and Algae Group Index /AGI/) for evaluation of water bodies from a lake type L4 as well as their comparability. Assessment of the ecological status of two lake ecosystems was performed in order to ensure successful protection, enhancement and management of lowland and semi-mountain lakes in Bulgaria. Data on the aquatic flora from Golyamo Skalensko Lake and Malko Skalensko Lake over a period of two years were used to assess their ecological status. In addition, the toxic potential of the established dominant cyanoprokaryotic species was also evaluated. Phytoplankton- and macrophyte-based metrics resulted in complementary evaluation of temporary and long-term environmental conditions. Despite the hydraulic connection and proximity between the two lakes, Golyamo Skalensko Lake and Malko Skalensko Lake appear as completely different ecosystems, according to the phytoplankton structure (species composition, number of species, abundance, seasonal succession), macrophytes and ecological status.

Testing and development of different metrics and indexes describing submerged aquatic vegetation for the assessment of the ecological status of semi-enclosed coastal water bodies in the NE Baltic Sea

A national assessment system for the classification of the ecological status of coastal waters according to the requirements of the EU Water Framework Directive was established in Estonia in the year 2007. The Estonian Phytobenthos Index was used to assess the ecological status of coastal waters based on submerged aquatic vegetation. After the testing period it appeared that the selected method did not respond to anthropogenic pressure in two national water types: the Vainameri and Parnu Bay. During this study new indexes were developed and validated against pressure for these areas. The PCF index was combined from the proportion of perennial species, charophytes, and Fucus spp. This index is suitable for the assessment of the ecological status in the Vainameri area. In Parnu Bay the depth distribution of higher plants and the proportion of opportunistic species showed the strongest correlation with eutrophication variables. These metrics were combined into the HPO index. The class boundaries for assessing the ecological status of water quality were determined for both indexes. The paper describes the calculation of the indexes.

Assessment of small water bodies in Ireland

:ABSTRACTFirst and second order streams comprise 77% of the 74,000km of river channel in Ireland but monitoring stations are typically on third or higher order rivers. Ireland has over 12,200 lakes: 745 of these have been defined as water bodies for the Water Framework Directive and 222 lakes are included in the monitoring programme. The ecological status of unmonitored water bodies is extrapolated from the monitored network. Some 30% of the main-stem monitored river channel length fails to achieve good ecological status. Of this, half is impacted by diffuse pollution and half by point source pollution. Pollution from diffuse sources such as agriculture or scattered rural dwellings is more difficult to pinpoint than that from point sources such as wastewater treatment plants. A simple ‘pathways’ hypothesis suggests that the risk of diffuse pollution is proportional to the length of river bank and thus, small stream channels comprising 77% of the total river network pose a challenge. The Small Stream Risk Score (SSRS), designed to pinpoint sources of diffuse pollution, is a simplified macroinvertebrate risk score for non-specialists. By comparing SSRS values for small streams immediately upstream of a polluted main-stem monitoring station the source can be narrowed down and pinpointed more accurately.

European small water bodies

Small inland water bodies (streams and ponds) are abundant in most European countries. Eighty per cent of the millions of kilometers of river network in Europe consist of small rivers, commonly known as headwaters, creeks, streams, brooks or wadeable rivers, and there are many hundred thousands of small lakes and ponds. Small water bodies are ecologically very important. They support specific and important hydrological, chemical and biological processes. Unfortunately, due to human activities, the ecological condition of small water bodies is poor in many places in Europe. There is now an urgent need to raise awareness about their ongoing destruction and their many beneficial functions to society. This will increase political recognition of their importance for maintaining a healthy and diverse aquatic environment. Coordinated activities with the protected habitats under the nature directives and EU Water Framework Directive activities should help to ensure the protection of these valuable small water bodies.

European small water bodies

Small inland water bodies (streams and ponds) are abundant in most European countries. Eighty per cent of the millions of kilometers of river network in Europe consist of small rivers, commonly known as headwaters, creeks, streams, brooks or wadeable rivers, and there are many hundred thousands of small lakes and ponds. Small water bodies are ecologically very important. They support specific and important hydrological, chemical and biological processes. Unfortunately, due to human activities, the ecological condition of small water bodies is poor in many places in Europe. There is now an urgent need to raise awareness about their ongoing destruction and their many beneficial functions to society. This will increase political recognition of their importance for maintaining a healthy and diverse aquatic environment. Coordinated activities with the protected habitats under the nature directives and EU Water Framework Directive activities should help to ensure the protection of these valuable small water bodies.

Amino Acid Content of Benthic Macroscopic Growths of Algae and Sediments in Hypersaline Water Bodies

The amino acid content of benthic growths of algaeand sediments (peloids) in hypersaline water bodies has been investigated and analised for Berdiansk Spit and Arabatskaya Spit (northwestern coast of the Asow Sea, Ukraine). The content of amino acid of benthic macroskopic growths of algae correlates with amino acids of corresponding peloids within 93-98 %. Accumulation of amino acids in peloids depends on the reduclive-oxidative conditions in hypersaline water bodies, including the amount of biomass and species of benthic macroskopic growths of algae.

Assessment of the hydromorphological quality of streams in the Venta River Basin District, Latvia

INTRODUCTION According to the EU Water Framework Directive (WFD), surface waters in Europe must achieve good ecological quality by 2015 (European Commission, 2000). The WFD requires ecological quality assessment of running waters based on various biotic (phytoplankton, macrophytes, phytobenthos, benthic invertebrates, and fish fauna), chemical, and hydromorphological elements (European Commission, 2000). When evaluating the quality status of water bodies, the predominant role used to be given to the assessment of biotic elements (Logan and Furse, 2002), with the support of hydromorphology and physico-chemical assessment (European Commission, 2000). Previous monitoring focused on chemical parameters and assessment of benthic invertebrates in running waters (O'Hare et al., 2006), but the new legislation of the WFD states that it is necessary to include hydromorphology in the assessment of ecological status. Assessment of river hydromorphology is needed not only for the implementation of the WFD but also for nature conservation purposes, such as the monitoring of the condition of Special Areas of Conservation under the EC Habitats Directive and helping the management and restoration of rivers (Boon et al., 2010). Rivers have important functions in ecosystems, such as natural flood control, ecological refuge development, production, and species conservation. However, aquatic ecosystems are among the most severely affected habitats (Sala et al., 2000). Streams and their floodplains have been modified as a result of land drainage, floodplain urbanization, and flood defence (Sparks, 1995; Kronvang et al., 2007). More recently, physical disturbances such as damming, channelization, separation of channel and floodplain, and destruction of riparian vegetation have become more relevant in Europe and have therefore been included into the assessment methods (Feld, 2004; Lorenz et al., 2004; Timm et al., 2011). The morphology, longitudinal and lateral connectivity, as well as the discharge regime of running waters are severely disturbed in Central Europe. Only 10% of the river reaches in the alpine region can be classified as near natural (Muhar et al., 2000). In Latvia there are still streams with sites corresponding to 'conditions that are representative of a group of minimally disturbed sites, i.e. reference site, described by selected physical, chemical and biological characteristics' (Springe et al., 2010). There is a long history of biological assessments in Europe but systems for the assessment of hydromorphological quality are far less developed (Erba et al., 2006). Various methods and indices (Muhar et al., 2000; Friberg et al., 2005; Kamp et al., 2007) are used in different countries to characterize hydromorphological quality. Characterization of the physical structure and assessment of the habitat quality of rivers are gaining importance in the context of environmental planning, appraisal, and impact assessment. Hydromorphological quality assessment plays a crucial role in the WFD because it is used to determine 'undisturbed' and 'heavily modified' conditions of rivers (Raven et al., 2002). In order to fulfil the demands of the WFD, stream and river assessment must be changed fundamentally from a single index system to a more holistic approach (Feld, 2004). Numerous researchers emphasize that the stream quality assessment requires knowledge about the hydrological regime, geological formation, and geomorphological processes of the stream, as well as about impacts of natural and anthropogenic origin both in the past and present (Riis and Biggs, 2003; Tremp, 2007). Several European countries have developed methodologies to identify the morphological character of rivers (Muhar and Jungwirth, 1998; Raven et al., 2000; Buffagni and Kemp, 2002; Rinaldi et al., 2013). The reason for the wide application of these methods is that they rely on well-established monitoring activities and simple classification criteria (Bizzi and Lerner, 2012). …

Evaluation of empirical models coupled with EUTROMOD for water quality prediction in Kansas reservoirs

Agricultural land use contributes high nutrient and sediment loads to nearby streams, lakes, and reservoirs, which can lead to excessive algal growth and increased siltation. Future intensification of agricultural production could further aggravate water quality concerns. To objectively evaluate the effects of agricultural intensification on future water quality, modeling tools must be able to quantitatively predict the degree to which land use change will affect the trophic state of water bodies. This study evaluated the water quality model EUTROMOD as well as several national and regional in-lake empirical water quality models as predictive tools for analyzing and estimating water quality in 28 Kansas reservoirs of varying size and watershed land use. Model-predicted nutrient loading was used with several in-lake empirical models to predict values for total nitrogen (TN), total phosphorus (TP), and chlorophyll a concentrations. Predicted values were then compared to long-term water quality measurements obtained from the Kansas lake and reservoir monitoring program. All models over-predicted concentrations of TN and TP in Kansas reservoirs; however, predictions from the Bachmann TN and Canfield-Bachmann TP in-lake empirical models were most closely coupled to observed trends and had the least error. Two possible sources of model bias were identified: the sedimentation coefficient in the in-lake empirical models and the nutrient loading estimates from the watershed model. Areas of further research are suggested for determining the dominant source of model bias and improving quantitative predictions of water quality in the Midwest, USA.