Konstantinos Stefanidis

Konstantinos Stefanidis
Hellenic Centre for Marine Research | hcmr · Institute of Marine Biological Resources and Inland Waters

PhD

About

67
Publications
26,649
Reads
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1,403
Citations
Citations since 2017
37 Research Items
1242 Citations
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20172018201920202021202220230100200300
20172018201920202021202220230100200300
20172018201920202021202220230100200300
Additional affiliations
March 2018 - present
Hellenic Centre for Marine Research
Position
  • Research Associate
April 2014 - March 2018
National Technical University of Athens
Position
  • PostDoc Position
October 2005 - December 2013
University of Patras
Position
  • Research Associate
Education
October 2005 - March 2012
University of Patras
Field of study
  • Limnology
October 2003 - October 2005
University of Patras
Field of study
  • Ecology, Conservation and Management of Natural Environment"
September 1999 - October 2003
University of Patras
Field of study
  • Biology

Publications

Publications (67)
Article
Water turbidity is one of the more important water quality parameters that is strictly linked with the productivity of the lake and is commonly used as an indicator of the trophic state. However, limited field data availability across wide geographic gradients may hinder the conduction of large scale longitudinal studies. In this study, time series...
Article
Full-text available
Aquatic macrophytes are one of the four biological quality elements (BQE) used for assessing the ecological status of inland waters according to the EU Water Framework Directive (WFD 2000/60). With this article, we present the methodological approach for the implementation of a WFD compliant macrophyte index to the riverine systems of Greece. In ad...
Research Proposal
Full-text available
Dear Colleagues, Regional/local (e.g., land cover transformation, pollution, hydromorphological alterations and invasive species) and global (e.g., climate change) environmental changes are responsible for the loss of many aquatic biota and ecosystem functions. In addition, freshwater resources, especially rivers and lakes, are under severe pressu...
Article
Lakes are particularly vulnerable ecosystems to global warming. Surface temperature of most lakes in the world has significantly increased. Here, we analysed time-series of water temperature, mixing-depth, and ice depth of 51 European lakes over the last four decades. We used data of surface temperature, total layer water temperature, mix-layer tem...
Article
Full-text available
The ecological assessment of all surface water bodies in Europe according to the Water Framework Directive involves the monitoring of biological, physicochemical and hydromorphological quality elements. For the hydromorphological assessment in particular, there are numerous methods that have been developed and adopted by EU member countries. With t...
Article
Full-text available
Precipitation is one of the most variable climatic parameters, as it is determined by many physical processes. The spatiotemporal characteristics of precipitation have been significantly affected by climate change during the past decades. Analysis of precipitation trends is challenging, especially in regions such as Greece, which is characterized b...
Article
Full-text available
Regardless of the efforts of the European Union, freshwaters are in a state of environmental crisis. The Water Framework Directive has established a basis for the protection and restoration of European inland and coastal waters. In parallel, the Birds and Habitats Directives protect, maintain or restore, at favourable conservation status, selected...
Article
Full-text available
Climate change is known to affect world’s lakes in many ways. Lake warming is perhaps the most prominent impact of climate change but there is evidence that changes of precipitation and wind speed over the surface of the lakes may also have a significant effect on key limnological processes. With this study we explored the interannual trends of sur...
Article
Aquatic and riparian plants play a crucial role in the functioning of riverine ecosystems. Hence, analyzing multiple facets of plant diversity could be extremely useful for assessing the ecological integrity of lotic ecosystems. The main objective of this study was to investigate the response of multiple facets of aquatic plant diversity, such as s...
Technical Report
Full-text available
Greece's Schinias Marathon National Park has serious fish kill problems. This report documents a research collaboration among the Fisheries Department of the Region of Attika, the Schinias-Marathon National Park, Ymittos and Southeast Attica Management Body and the Inland Waters Section of HCMR. Τhe main aims of the 26 month research work was to ad...
Article
Full-text available
Artificial Neural Networks (ANNs) have wide applications in aquatic ecology and specifically in modelling water quality and biotic responses to environmental predictors. However, data scarcity is a common problem that raises the need to optimize modelling approaches to overcome data limitations. With this paper, we investigate the optimal k-fold cr...
Article
Interactions between stressors in freshwater ecosystems, including those associated with climate change and nutrient enrichment, are currently difficult to detect and manage. Our understanding of the forms and frequency of occurrence of such interactions is limited; assessments using field data have been constrained as a result of varying data form...
Article
Full-text available
Riparian zones play an important role in the ecological stability of rivers. In particular, the quality of the riparian vegetation is a significant component of the hydromorphological status. In Europe, the QBR index (Qualitat del Bosc de Ribera) and the River Habitat Survey (RHS) are commonly used for the qualitative assessment of the riparian veg...
Article
Understanding the climatic drivers of eutrophication is critical for lake management under the prism of the global change. Yet the complex interplay between climatic variables and lake processes makes prediction of phytoplankton biomass a rather difficult task. Quantifying the relative influence of climate-related variables on the regulation of phy...
Article
Full-text available
The biota of European rivers are affected by a wide range of stressors impairing water quality and hydro‐morphology. Only about 40% of Europe’s rivers reach ‘good ecological status’, a target set by the European Water Framework Directive (WFD) and indicated by the biota. It is yet unknown how the different stressors in concert impact ecological sta...
Conference Paper
Full-text available
The riparian zone plays an important role in the ecological stability of rivers. In particular the quality of the riparian vegetation is a significant component of the hydromorphological status. In Europe, the QBR index (Qualitat del Bosc de Ribera) and the River Habitat Survey (RHS) are commonly used for the qualitative assessment of the riparian...
Article
Full-text available
Submerged macrophytes are of key importance for the structure and functioning of shallow lakes and can be decisive for maintaining them in a clear water state. The ongoing climate change affects the macrophytes through changes in temperature and precipitation, causing variations in nutrient load, water level and light availability. To investigate h...
Article
Full-text available
Climate and land-use change drive a suite of stressors that shape ecosystems and interact to yield complex ecological responses, i.e. additive, antagonistic and synergistic effects. Currently we know little about the spatial scale relevant for the outcome of such interactions and about effect sizes. This knowledge gap needs to be filled to underpin...
Article
Full-text available
Disentangling the main drivers of species richness and community composition is a central theme in ecology. Freshwater biodiversity patterns have been poorly explored; yet, it has been shown that different freshwater biota have different, often contrasting responses to environmental gradients. In this study, we investigated the relative contributio...
Article
Full-text available
Reduction of nutrient loadings is often prioritized among other management measures for improving the water quality of freshwaters within the catchment. However, urban point sources and agriculture still thrive as the main drivers of nitrogen and phosphorus pollution in European rivers. With this article we present a nationwide assessment of nitrog...
Article
Full-text available
The Water Framework Directive (WFD) requires from member states to monitor hydromorphological features of rivers in order to assess their ecological quality. Thus, numerous hydromorphological assessment methods have been developed with most of them focusing on the dynamics of hydrology, geomorphology and riparian zone extent. Within the scope of th...
Article
Full-text available
Urbanization of stream ecosystems with the purpose of managing flash-flood events is considered nowadays responsible for habitat loss and alteration of the natural flow regime with severe implications for the ecosystem functioning. Not surprisingly river scientists have started seeking alternative options inspired from nature for mitigating flood-r...
Conference Paper
Full-text available
The Water Framework Directive (WFD) requires from member states to monitor hydromorphological features of rivers in order to assess their ecological quality. Thus, numerous hydromorphological assessment methods have been developed with most of them focusing on the dynamics of hydrology, geomorphology and riparian zone extent. Within the scope of th...
Article
Full-text available
European rivers are under ecological threat by a variety of stressors. Nutrient pollution, soil erosion, and alteration in hydrology are considered the most common problems that riverine ecosystems are facing today. Not surprisingly, river monitoring activities in Europe have been intensified during the last few years to fulfil the Water Framework...
Article
Full-text available
Freshwater ecologists have shown increased interest in assessing biotic responses to environmental change using functional community characteristics. With this article, we investigate the potential of using functional traits of the aquatic plants to assess eutrophication in freshwater lakes. To this end we collected macrophyte and physicochemical d...
Article
Full-text available
The hydrologic regime of a river is one of the factors determining its ecological status. This paper tries to indicate the present hydrologic stress occurring across European rivers on the basis of model integration. This results in a pan-European assessment at the resolution of the functional elementary catchment (FEC), based on simulated daily ti...
Article
• Aquatic macrophytes play a key role in lake dynamics, but human activities and eutrophication have resulted in macrophyte loss in many lakes throughout Europe. In this study, the relationships between aquatic macrophytes and gradients of environmental factors were explored using an extensive set of data collected from 13 lakes of the Greek mainla...
Article
Full-text available
The metabolic balance between gross primary production (GPP) and ecosystem respiration (R) is known to display large spatial and temporal variations within shallow lakes. Thus, although estimation of aquatic metabolism using free-water measurements of dissolved oxygen concentration has become increasingly common, the explanation of the variance in...
Article
Important drivers of gross primary production (GPP) and ecosystem respiration (ER) in lakes are temperature, nutrients, and light availability, which are predicted to be affected by climate change. Little is known about how these three factors jointly influence shallow lakes metabolism and metabolic status as net heterotrophic or autotrophic. We co...
Article
Full-text available
During the last decades, Mediterranean freshwater ecosystems, especially lakes, have been under severe pressure due to increasing eutrophication and water quality deterioration. In this article, we compared the effectiveness of different data analysis methods by assessing the contribution of environmental parameters to eutrophication processes. For...
Article
Streams and rivers are among the most threatened ecosystems in Europe due to the combined effects of multiple pressures related to anthropogenic activities. Particularly in the Mediterranean region, changes in hydromorphology along with increased nutrient loadings are known to affect the ecological functions and ecosystem services of streams and ri...
Article
Full-text available
The Ali Efenti catchment is a rural upstream subcatchment of the Pinios river basin in central Greece. The average annual precipitation in this subcatchment is relatively higher and groundwater recharge is relatively faster than in the rest of the river basin. Yet, seasonal water shortages occur due to the rapid increase of water abstractions in th...
Article
Full-text available
Lentic ecosystems act as sentinels of climate change, and evidence exists that their sensitivity to warming varies along a latitudinal gradient. We assessed the effects of nutrient and water level variability on zooplankton community composition, taxonomic diversity and size structure in different climate zones by running a standardised controlled...
Article
Eutrophication is a serious problem that affects water quality and it may cause Harmful Algal Bloom (HAB) events with many unpleasant consequences. For that purpose, an Artificial Neural Network (ANN) was developed able to forecast one month ahead the Chlorophyll-a (Chl-a) levels and by that way to act as a warning tool when a HAB event might follo...
Technical Report
Full-text available
Summary D5.1-1 Part 1: Multi-stressors on surface water and effects on ecological statusHumans have increased the discharge of pollution, altered water flow regime and modified the morphology of rivers. All these actions have resulted in multiple pressures on freshwater ecosystems, undermining their biodiversity and ecological functioning. The Euro...
Article
Full-text available
Lakes in the Mediterranean climate zone experience high variation in rainfall and are vulnerable to changes in climate, land cover and anthropogenically induced effects on water level and salinity. This paper presents the results from the analyses of spatiotemporal changes of land cover/uses at catchment scale of two connected lakes in Greece that...
Technical Report
Full-text available
Deliverable D4.1 is a synthesis report of the 16 regional case studies being undertaken in WP4 (Multi-stressors at the river basin scale. The report is composed of 3 parts. Part 1: Task 4.2 - Southern Basins region Part 1 reports the background to, and results and conclusions from Task 4.2 on four case studies from the Southern Basins region. The...
Article
Full-text available
Losses of phosphorus (P) and nitrogen (N) have important influences on in-lake concentrations and nutrient loading to downstream ecosystems. We performed a series of mesocosm experiments along a latitudinal gradient from Sweden to Greece to investigate the factors influencing N and P loss under different climatic conditions. In six countries, a sta...
Article
Full-text available
Lake Pamvotis (Greece) is a shallow hypereutrophic lake with a natural tendency to eutrophication. Several restoration measures were applied, but with no long-term success. To examine the causes for this an Artificial Neural Network (ANN) was created in order to simulate the chlorophyll-a (Chl-a) levels and to investigate the role of the associated...
Technical Report
Part 1: This deliverable consists two manuscripts (MS) of lake time-series analysis in north-temperate region of Europe. 1st MS ‘Is fish able to regulate filamentous blue-green dominated phytoplankton?’ submitted to ‘Hydrobiologia’, analyzes >40-year data on biota, fish catches, hydrochemistry, hydrology, and meteorological parameters in Lake Võrts...
Article
Periphyton communities play an important role in shallow lakes and are controlled by direct forces such as temperature, light, nutrients, and invertebrate grazing, but also indirectly by planktivorous fish predation. We performed a pan-European lake mesocosm experiment on periphyton colonization covering five countries along a north/south geographi...
Article
Full-text available
Rivers in semi-arid climates are extremely sensitive to hydrological and anthropogenic pressures. However, they have been poorly studied, especially in east Mediterranean countries. In Cyprus, the freshwater flora of fluvial corridors has not been extensively investigated. In this paper, an updated inventory of aquatic and riparian flora from perma...
Article
The likelihood of an ecological system to undergo undesired regime shifts is expected to increase as climate change effects unfold. To understand how regional climate settings can affect resilience; i.e., the ability of an ecosystem to tolerate disturbances without changing its original structure and processes, we used a synchronized mesocosm exper...
Article
According to the Intergovernmental Panel on Climate Change report released in September 2014, unprecedented changes in temperature and precipitation patterns have been recorded globally in recent decades and further change is predicted to occur in the near future, mainly as the result of human activity. In particular, projections show that the Medi...
Article
Full-text available
Riparian corridors are among the most sensitive ecosystems in the Mediterranean as they are significantly altered by human interventions. In this study, we explored the composition patterns of the aquatic vegetation in 17 rivers of Cyprus. Hierarchical clustering and Detrended Correspondence Analysis were conducted in order to distinguish plant com...
Article
Climate change is expected to profoundly affect both temperature and net precipitation, with implications for lake water level. We describe the design of a harmonized, simultaneous, cross-European mesocosm experiment to elucidate the effects of climate change on community structure, functioning, and metabolism in shallow lakes at low and high nutri...
Article
Full-text available
Climate change is expected to profoundly affect both temperature and net precipitation, with implications for lake water level. We describe the design of a harmonized, simultaneous, cross-European mesocosm experiment to elucidate the effects of climate change on community structure, functioning, and metabolism in shallow lakes at low and high nutri...
Data
Full-text available
Key-words: fish, macrophytes, water level fluctuation, water quality, zooplankton Water level fluctuations play a significant role in the lake nutrient dynam-ics, and consequently may have a strong influence on the biological com-munities and productivity. In this article we investigated the effects of a long term water level reduction on key chemi...
Article
Full-text available
Key-words: fish, macrophytes, water level fluctuation, water quality, zooplankton Water level fluctuations play a significant role in the lake nutrient dynam-ics, and consequently may have a strong influence on the biological com-munities and productivity. In this article we investigated the effects of a long term water level reduction on key chemi...
Article
Full-text available
In the current study, the relationships between lake morphological characteristics, water chemistry parameters and aquatic macrophyte data of nineteen lakes of Greece were investigated. Statistical and ordination analysis was performed in order to distinguish possible correlations between lake morphology features, key water quality parameters and h...
Article
Full-text available
Submerged hydrophyte vegetation consists of a highly important biotic component of maintaining lake ecosystems towards a ‘‘clear water’’ ecological status. Aquatic macrophytes are well known to play a significant multidimensional role in lakes by competing with phytoplankton growth, stabilising sediment and offering refuge to fishes, macro-inverteb...
Article
Full-text available
Lake Pamvotis, NWGreece is a shallowMediterranean eutrophic lake that has changed drastically over the past 50 years. Strong effects, resulted mainly from anthropogenic causes, in the hydrological regime are shown for this area using long term hydrological data and a GIS system for extracting land cover/use changes. A set of aerial imagery acquired...
Article
Full-text available
Lake Pamvotis is a shallow urban Mediterranean lake located in northwestern Greece (region of Epirus). During the last three decades, the trophic status of the lake has changed as a result of anthropogenic activity and especially domestic sewage discharge, resulting in severe deterioration. During the 1980s, the lake has been stocked with several n...

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