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Hans Hahn

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Kansas State University

Victor Camacho-Ibar

Universidad Autonoma de Baja California

Armando Marques-Guedes

UNL - New University of Lisbon

Universidade Federal de Santa Catarina - UFSC (Federal University of Santa Catarina)

Institute for Advanced Studies in Basic Sciences

Shabib H . Syed

University of the Punjab, Lahore, Pakistan

Dhundi Raj Pathak

Tribhuvan University

Mugla University

Helena de Godoy Bergallo

UERJ - Universidade do Estado do Rio de Janeiro / Rio de Janeiro State University

The University Of Jordan

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Papers by Hans Hahn

Groundwater fauna in an urban area: natural or affected?

In Germany 70 % of the drinking water demand is met by groundwater, whose quality is the product ... more In Germany 70 % of the drinking water demand is met by groundwater, whose quality is the product of manifold physical-chemical and biological cleaning processes. As healthy groundwater ecosystems help to provide clean drinking water, it is necessary to assess the ecological conditions of these ecosystems. This is particularly true for densely populated, urban areas, where faunistic groundwater investigations are still scare. The aim of this study is therefore to provide a first-tier assessment of the groundwater fauna in an urban area. Thus, we assess the ecological condition of an anthropogenically influenced aquifer by analysing the groundwater fauna in 39 groundwater monitoring wells in Karlsruhe (Germany) and a nearby forest land. For classification we apply the scheme from the Federal Environmental Agency (UBA), in which a threshold of more than 70 % of Crustaceans and of less than 20 % of Oligochaetes serves as an indication for good ecological conditions. In our study 35 % of the wells in the urban area fulfil these criteria, and even in the pristine forest land only 50 % of the wells indicate fine ecological conditions. While the assessment reveals that ecological conditions in the studied urban area are predominantly not in a good ecological state, there is no clear spatial pattern with respect to land use and anthropogenic impacts. However, there are noticeable differences in the spatial distribution of species and abiotic groundwater characteristics between wells in forest land and the urban area, which indicates that more comprehensive assessment methods are required to fully capture the different effects on groundwater fauna.

A Global Agenda for Advancing Freshwater Biodiversity Research

Freshwater biodiversity is declining dramatically, and the current biodiversity crisis requires d... more Freshwater biodiversity is declining dramatically, and the current biodiversity crisis requires defining bold goals and mobilizing substantial resources to meet the challenges. While the reasons are varied, both research and conservation of freshwater biodiversity lag far behind efforts in the terrestrial and marine realms. We identify fifteen pressing global needs to support informed global freshwater biodiversity stewardship. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated action towards its sustainable management and conservation.

Stygoregions – a promising approach to a bioregional classification of groundwater systems

Scientific Reports, Sep 19, 2012

Linked to diverse biological processes, groundwater ecosystems deliver essential services to mank... more Linked to diverse biological processes, groundwater ecosystems deliver essential services to mankind, the most important of which is the provision of drinking water. In contrast to surface waters, ecological aspects of groundwater systems are ignored by the current European Union and national legislation. Groundwater management and protection measures refer exclusively to its good physicochemical and quantitative status. Current initiatives in developing ecologically sound integrative assessment schemes by taking groundwater fauna into account depend on the initial classification of subsurface bioregions. In a large scale survey, the regional and biogeographical distribution patterns of groundwater dwelling invertebrates were examined for many parts of Germany. Following an exploratory approach, our results underline that the distribution patterns of invertebrates in groundwater are not in accordance with any existing bioregional classification system established for surface habitats. In consequence, we propose to develope a new classification scheme for groundwater ecosystems based on stygoregions. G roundwater systems are diversely populated habitats. The world wide number of described obligate groundwater invertebrates, the so-called stygofauna, sums up to 7000 species 1. The true species richness though, is believed to exceed that number by far taking into account that groundwater systems have not been studied to a great extent and a multitude of species await detection and description 2-5. The groundwater fauna is mainly composed of small crustaceans, oligochaetes, nematodes, acari, and molluscs, less than 1 mm to several centimeters in body size 4 (Fig. 1 ad). The goods and services provided by groundwater ecosystems (i.e ecosystem services) which include the purification of water by the breakdown of organic matter, nutrients and contaminants, are fundamental to both the integrity of the ecosystems and the sustaining of human life 6-10. Intimately connected to microbiological remineralization processes, invertebrates are believed to play an important role in the purification of subterranean water and thus, the maintainance of good water quality 11,12. Feeding, burrowing and bioturbating activities of the fauna in highly active transition zones (e.g. hyporheic zone) contribute to maintain the hydraulic connectivity between surface systems and aquifers 11 , a service groundwater dependant ecosystems (e.g. soils, wetlands, rivers) strongly rely on 11. Ecosystem services such as those mentioned above are only provided sustainably by groundwater communities with a structural and functional integrity 13,14. Recently, the need for an ecologically sound management of groundwater resources has become increasingly recognised by national and international political authorities 15-19. The European Union Groundwater Directive 20 (EU-GWD), released in 2006, emphasize the importance of protective measures for groundwater ecosystems proposing the conductance of more ecological research in order to provide better criteria for ensuring groundwater ecosystem quality in the future 13. This triggered new scientific research on identifying and evaluating biological criteria related to groundwater ecosystem health and water quality, and vice versa 13,14,19,21. Organisms integrate impacts over space (their habitat) and time, clearly extending the information obtained from abiotic monitoring 21. Indeed groundwater invertebrates have been shown to be sensitive sentinels indicating the influence from surface water infiltration, changes of hydrological conditions, the impact of organic contaminants and nutrients, and were shown valuable biomonitors of heavy metal pollution as well as heat discharge 14 and citations therein. Only recently, first integrative approaches for the assessment of groundwater ecosystem health, which define criteria, reference conditions and thresholds for individual physicochemical, microbiological and faunistic

1.3.5 Groundwater Ecology as a Necessary Link to the EU Water Framework Directive

GroundCare - Invertebrates as indicators for untreated water and intrusion of surface water in water supply systems

ARPHA Conference Abstracts, 2018

Functioning, healthy groundwater ecosystems are essential for high quality drinking water, and th... more Functioning, healthy groundwater ecosystems are essential for high quality drinking water, and they minimize costs of processing groundwater for drinking purposes. GroundCare is a multidisciplinary project, which is led by the Helmholz Institute in Munich, Germany and funded by the BMBF (German federal Ministry of education and Research). The aim is to parametrize and to quantify groundwater ecosystem services as a basis for sustainable water management and water pollution control by biomonitoring. In other words: the development of biological assessment techniques. Multiple parameters are evaluated (physico-chemical parameters, microbial and fauna community composition, ecotoxicological effects). Invertebrate fauna is investigated at five sites all across Germany. During the project, molecular identification through DNA Barcoding and Metabarcoding of groundwater invertebrates is being implemented and compared to traditional morphological bio-assessment. The subterranean fauna can b...

Hydro(geo)chemische und ökologische Bestandsaufnahme von Quellregionen als isolierte Grundwasser-Ökosysteme

Grundwasser

ZusammenfassungZwei Untersuchungsgebiete im zentralen Münsterland (Baumberge, NRW, Deutschland) s... more ZusammenfassungZwei Untersuchungsgebiete im zentralen Münsterland (Baumberge, NRW, Deutschland) sind aufgrund der geologischen Reliefumkehr-Situation isolierte Grundwasser-Ökosysteme, welche nur von infiltrierendem Niederschlagswasser beeinflusst werden. Als sogenannte „Natur-Lysimeter“ eignen sie sich mit ihren insgesamt bis zu 200 natürlichen Quellaustritten als multidisziplinäre Bezugssysteme für wasserdurchlässige Kluftgrundwasserleitersysteme (aus Kalkmergelsteinen). Die Betrachtung der langjährigen Veränderungen des Stoffaustrags an den Quellen deuten auf zunehmende Verkarstung und raumzeitlich wechselnde Einflüsse durch die land- und forstwirtschaftlich genutzte Geländeoberfläche hin. Stabile Sulfatisotope zeigen, dass die Mehrheit der Quellen durch den Eintrag von Gülle in deren Quell-Einzugsgebiet beeinflusst wird und dass die Pyritoxidation ein wichtiger Prozess im tieferen Grundwasserkörper ist. Die Nitratkonzentrationen sind im Allgemeinen hoch (über 50 mg/l) und stammen...

Groundwater fauna in an urban area: natural or affected?

In Germany, 70 % of the drinking water demand is met by groundwater, for which the quality is the... more In Germany, 70 % of the drinking water demand is met by groundwater, for which the quality is the product of multiple physical-chemical and biological processes. As healthy groundwater ecosystems help to provide clean drinking water, it is necessary to assess their ecological conditions. This is particularly true for densely populated urban areas, where faunistic groundwater investigations are still scarce. The aim of this study is, therefore, to provide a first assessment of the groundwater fauna in an urban area. Thus, we examine the ecological status of an anthropogenically influenced aquifer by analysing fauna in 39 groundwater monitoring wells in the city of Karlsruhe (Germany). For classification, we apply the groundwater ecosystem status index (GESI), in which a threshold of more than 70 % of crustaceans and less than 20 % of oligochaetes serves as an indication for very good and good ecological conditions. Our study reveals that only 35 % of the wells in the residential, commercial and industrial areas and 50 % of wells in the forested area fulfil these criteria. However, the study did not find clear spatial patterns with respect to land use and other anthropogenic impacts, in particular with respect to groundwater temperature. Nevertheless, there are noticeable differences in the spatial distribution of species in combination with abiotic groundwater characteristics in groundwater of the different areas of the city, which indicate that a more comprehensive assessment is required to evaluate the groundwater ecological status in more detail. In particular, more indicators, such as groundwater temperature, indicator species, delineation of site-specific characteristics and natural reference conditions should be considered.

Dienstleistungen der Grundwasserökosysteme

Services Provided By Groundwater Ecosystems Our daily lives depend on the provision of services b... more Services Provided By Groundwater Ecosystems Our daily lives depend on the provision of services by different ecosystems. An important contribution is made by our ground- water ecosystems. They make sure that groundwater is purified until it reaches drinking water quality; they ensure an active storage of clean water of constant quality, the biological degra- dation of pollutants, the removal of pathogenic microorganisms, the integrity of water supply, and many other things. These serv- ices are provided, last but not least, by a great variety of bio- cenoses in groundwater aquifers. To ensure the provision of these services in the long run requires a good ecological status of our groundwater habitats.

Sampling Fauna in Stream Sediments as well as Groundwater Using One Net Sampler

Acta hydrochimica et hydrobiologica, 2004

... Fauna in Stream Sediments as well Hans J. Hahna, Gerald D. Watsonb, as Groundwater Using One ... more

Does groundwater influence the sediment fauna beneath a small, sandy stream?

Limnologica, 2007

Gradients in the sediment fauna comprising groundwater (GW) and hyporheic taxa were investigated ... more Gradients in the sediment fauna comprising groundwater (GW) and hyporheic taxa were investigated in the sand/ silt-bottomed Marbling Brook in Western Australia. The structure of sediment invertebrate assemblages from Marbling Brook sediments and the adjacent GW were studied at five sites over 1 year and hydrological interactions were characterized using a suite of abiotic factors. Although all five stream sites were upwelling, the sites differed in the degree of hydrological interactions between GW and surface water. Sediment fauna taxa abundances were not correlated with any of the abiotic factors investigated and did not change gradually with depth. Faunal assemblages in the stream sediments were distinct from faunal assemblages in alluvial GW. While water exchanged between alluvial GW and sediment water, as shown by abiotic factors, the distinct differences in faunal assemblages indicated an unpredicted complexity in the catchment with fundamentally different hydrogeological situations on the decimetre scale. Sampling in sandy sediments needs to take this small-scale variability into account.

Testing unbaited stygofauna traps for sampling performance

Limnologica, 2008

Unbaited phreatic traps are a promising new method for sampling subterranean limnofauna. The aim ... more Unbaited phreatic traps are a promising new method for sampling subterranean limnofauna. The aim of this study is to evaluate whether such trap systems are suitable to gather representative samples of the physico-chemical parameters and the invertebrate fauna of the aquifer. Fifteen traps, installed in five groundwater bores, and four traps located in the hyporheic zone, were sampled twice monthly over a 1 year period (June 2003-June 2004). Water samples were removed in three separated fractions (hose, trap and aquifer water), analysed for physico-chemical and faunal characteristics and compared with one another. The study was carried out in the Nakdong River floodplain, Korea. Physico-chemical characteristics of trap and aquifer were similar, but differed greatly from the hose samples. Abundances of fauna inside the traps were higher than in the aquifer, whereas there were no differences in taxonomic composition of the trap and aquifer samples. Biases of abundances suspected due to the use of traps were negligible in the groundwater, though it is recommended that comparisons between groundwater and hyporheic abundances ascertained by traps be handled cautiously.

Do faunal assemblages reflect the exchange intensity in groundwater zones?

Hydrobiologia, 2007

The exchange of water with groundwater is a key determinant of water quality and faunal assemblag... more The exchange of water with groundwater is a key determinant of water quality and faunal assemblage. Water exchange not only occurs with running waters, but also through percolation, interception (soil, porous alluvium), and evaporation. The aim of this study was to identify how different types of exchange were related to the groundwater faunal assemblage of an alluvial aquifer. Hydrological exchange is largely governed by pore space and thus ultimately by geological formation. In the Marbling Brook catchment of Western Australia the different geological formations did not eventuate in hydrochemically distinct groundwater zones. The cluster analysis of faunal assemblages revealed five groups within the faunal samples which did not reflect spatial patterns such as geological, chemical or topographic features. Discriminant analysis showed that these five groups were best characterized by a range of abiotic features including dissolved oxygen, land-use, and temperature. These variables signal different types and intensities of exchange with the surface.

Ecological assessment of groundwater ecosystems – Vision or illusion?

Ecological Engineering, 2010

Environmental policy and in particular the European water legislation, in the framework of the EU... more Environmental policy and in particular the European water legislation, in the framework of the EU Groundwater Directive, has started to consider groundwater not only as a resource but as a living ecosystem. A precondition for comprehensive groundwater protection is thus the assessment of the biological and ecological state. The assessment of ecosystems requires consideration of ecological criteria, which so far

What is groundwater and what does this mean to fauna? – An opinion

Limnologica, 2012

ABSTRACT Many subsurface waters are considered groundwater but are influenced in shallow depths b... more ABSTRACT Many subsurface waters are considered groundwater but are influenced in shallow depths by hyporheic, parafluvial and/or soil interception water to such a degree that groundwater fauna (stygofauna) communities may be significantly altered. Recharge, even if spatially and temporally distinct, delivers input of dissolved oxygen, organic matter (OM), and nutrients that caters sustainably for ubiquists such as stygophiles and hyporheic fauna, but renders the life of uncompetitive stygobites difficult or impossible. The impact of recharge at shallow groundwater thus needs to be taken into account when determining groundwater fauna reference communities and when evaluating monitoring studies.One of the main characteristics of groundwater is low OM concentration. In contrast, high OM concentrations are typical of hyporheic or parafluvial waters, which are enriched by OM from the river, the riparian soils and from interflow, and which contribute significantly to river OM balance. Consequently, for ecological studies on subsurface waters, both the origin of the water and OM, and the intensity of surface water interactions should be considered. Here, we discuss how groundwater spatial and temporal heterogeneity translates into faunal distribution patterns. In terms of the origin of water and OM, and from an ecological point of view, we need to distinguish between (i) shallow groundwater characterized by infiltrating precipitation and soil recharge, (ii) shallow groundwater interacting with surface water bodies such as continuously flowing and ephemeral streams and rivers, and (iii) “old” groundwater which has no recent connections to the surface and is thus largely secluded from input of nutrients and carbon. Water in the first two groups is characterized by high amounts of OM of varying quality, while water in the third group is characterized by low amounts of low quality OM. Consequently, stygophiles dominate in groups 1 and 2, with hyporheic fauna taking up a considerable proportion in group 2, while stygobites only dominate in group 3. Thus, for studies aiming to assess impacts on groundwater, only sampling sites of the third group should be used for reference sites as these are the most likely sites to have little surface impact and a stygofauna representative of the deeper aquifer.

Efficiency of sampling invertebrates in groundwater habitats

Limnologica - Ecology and Management of Inland Waters, 2013

ABSTRACT Sampling efficiency is directly linked to (faunistic) stability issues of any sampled si... more ABSTRACT Sampling efficiency is directly linked to (faunistic) stability issues of any sampled site. It is more probable to sample a high proportion of the species occurring at a certain site, if communities remain constant in species composition with time. For this study 64 groundwater monitoring wells in Southwestern Germany were sampled six times to determine sampling efficiency. False-Negative (FN) rates and SIMPER values, two independent models expressing Faunistic values of the sampled bores, were calculated and three groups of faunistic stability could be identified based on calculated SIMPER-values. FN-rates as well as SIMPER values proved to be a valuable approach for the estimation of faunistic stability/instability, as these methods showed a highly negative correlation with each other. To collect 95% of species a number of 1.7–16.4 samples was calculated to be necessary depending on faunistic stability of the sampled habitat. On the six sampling occasions the sites harbouring a stable groundwater meiofauna resulted in 98.2% of occurring species, whereas the percentage decreased over intermediate sites (94.9%) and stressed sites (79.5%). A consequence of the data presented may be to view surveys using only two samples as campaign with orienting character, with further studies of stability issues of groundwater communities which would provide efficient and effective sampling for various kinds of sites.

A proposal for a groundwater habitat classification at local scale

Subterranean Biology, 2014

Distribution of groundwater invertebrate communities in porous aquifers (and their habitats) vari... more Distribution of groundwater invertebrate communities in porous aquifers (and their habitats) varies on spatial scales and many attempts have been made to classify these on various scales. The new data-based approach, presented here, classifies the complex distribution of groundwater habitats on a local scale (i.e. along transects of < 100 m) and merges the latest classification approaches at this scale. Data from a regional (i.e. approximately 100 km 2) biogeographic groundwater survey was analysed in terms of stability of: community structure, different intensities of surface water influence, and occurrence, together with the distribution of stygobites within those groundwater ecosystems. On the investigated local scale, the faunistic communities' composition is mainly depending on surface water influence, coupled with immision of dissolved oxygen and organic matter. Derived from this finding, five types of faunistic habitats are proposed: (I) Stressed groundwater habitats, (II) Stable groundwater habitats, (III) Rain fed groundwater habitats , (IV) Surface water fed groundwater habitats, and (V) Hyporheic habitats.

Periodic alterations of the hydrological exchange in hyporheic sediments: colmation, hyporheic fauna and abiotic parameters in a second order stream during one year

Grundwasserökosysteme im Recht?

Grundwasser

ZusammenfassungDas Grundwasser ist der größte und älteste kontinentale Lebensraum. Trotzdem wird ... more ZusammenfassungDas Grundwasser ist der größte und älteste kontinentale Lebensraum. Trotzdem wird in der europäischen und deutschen Rechtspraxis Grundwasser bisher als Ressource und nicht als Lebensraum behandelt. Allerdings kann der Lebensraumbezug über die Definition des Grundwassers als Gewässer im deutschen Wasserhaushaltsgesetz bzw. als „aquatisches Ökoysystem“ in der Europäischen Grundwasserrichtlinie (EG-GWRL) hergestellt werden. Die Umsetzung des Grundwasserschutzes sollte sich am ökosystemaren Ansatz für Oberflächengewässer in der Europäischen Wasserrahmenrichtlinie (EG-WRRL) und den Zielen der nationalen Biodiversitätsstrategie orientieren. Für das Grundwasser wird die Einführung der Begriffe „guter ökologischer Zustand“ und „Grundwasserökosysteme“ in das Umweltrecht vorgeschlagen. Grundwasserlebensräume und -arten sollten durch die Eingriffsregelung berücksichtigt und in die FFH-Richtlinie, in das Bundesnaturschutzgesetz und die Bundesartenschutzverordnung aufgenommen werden. Fachlich und rechtlich ist die Diskriminierung der Grundwasserökosysteme gegenüber Oberflächengewässern nicht zu begründen. Die Autoren argumentieren für die „Gleichberechtigung“ von Oberflächen- und Grundwasser und machen Vorschläge für die Anpassung des bestehenden Rechts im Sinne eines ökologisch begründeten Grundwasserschutzes.AbstractGroundwater is the largest and oldest continental biome. However, in the German and EU legislation, groundwater is still considered an abiotic resource rather than an ecosystem. On the other hand, the German Water Act (WHG, Wasserhaushaltsgesetz) mentions groundwaters along with other water bodies that carry the status of ecosystems. Its ecosystem status is also referred to in the preamble of the European Groundwater Directive (EC-GWD). The implementation of groundwater protection measures should be geared to the ecosystemic approach for surface waters contained in the European Water Framework Directive (EC-WFD) and to the German National Biodiversity Strategy (BMU 2007). Addition of the terms “good ecological status” and “groundwater ecosystems” into the German and EU environmental water laws is recommended. Groundwater habitats and species should be subject to impact assessment and included into the FFH directive and German nature conservation laws. There is no technical or legal argument for the discrimination of groundwater ecosystems and species in environmental legislation. The authors argue for the legal equality of ground and surface water, and propose the adaption of the existing legislation according to ecological requirements.

Uso da fauna de metazoários de subsuperfície como indicador das interacções águas subterrâneas–águas superficiais na planície aluvial do Rio Nakdong, Coreia do Sul

Hydrogeol J, 2008

Bewertung von Altlasten im Grundwasser anhand der Meiofaunagemeinschaften?erste Ergebnisse

Grundwasser, 2005

Groundwater fauna in an urban area: natural or affected?

In Germany 70 % of the drinking water demand is met by groundwater, whose quality is the product ... more In Germany 70 % of the drinking water demand is met by groundwater, whose quality is the product of manifold physical-chemical and biological cleaning processes. As healthy groundwater ecosystems help to provide clean drinking water, it is necessary to assess the ecological conditions of these ecosystems. This is particularly true for densely populated, urban areas, where faunistic groundwater investigations are still scare. The aim of this study is therefore to provide a first-tier assessment of the groundwater fauna in an urban area. Thus, we assess the ecological condition of an anthropogenically influenced aquifer by analysing the groundwater fauna in 39 groundwater monitoring wells in Karlsruhe (Germany) and a nearby forest land. For classification we apply the scheme from the Federal Environmental Agency (UBA), in which a threshold of more than 70 % of Crustaceans and of less than 20 % of Oligochaetes serves as an indication for good ecological conditions. In our study 35 % of the wells in the urban area fulfil these criteria, and even in the pristine forest land only 50 % of the wells indicate fine ecological conditions. While the assessment reveals that ecological conditions in the studied urban area are predominantly not in a good ecological state, there is no clear spatial pattern with respect to land use and anthropogenic impacts. However, there are noticeable differences in the spatial distribution of species and abiotic groundwater characteristics between wells in forest land and the urban area, which indicates that more comprehensive assessment methods are required to fully capture the different effects on groundwater fauna.

A Global Agenda for Advancing Freshwater Biodiversity Research

Freshwater biodiversity is declining dramatically, and the current biodiversity crisis requires d... more Freshwater biodiversity is declining dramatically, and the current biodiversity crisis requires defining bold goals and mobilizing substantial resources to meet the challenges. While the reasons are varied, both research and conservation of freshwater biodiversity lag far behind efforts in the terrestrial and marine realms. We identify fifteen pressing global needs to support informed global freshwater biodiversity stewardship. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated action towards its sustainable management and conservation.

Stygoregions – a promising approach to a bioregional classification of groundwater systems

Scientific Reports, Sep 19, 2012

Linked to diverse biological processes, groundwater ecosystems deliver essential services to mank... more Linked to diverse biological processes, groundwater ecosystems deliver essential services to mankind, the most important of which is the provision of drinking water. In contrast to surface waters, ecological aspects of groundwater systems are ignored by the current European Union and national legislation. Groundwater management and protection measures refer exclusively to its good physicochemical and quantitative status. Current initiatives in developing ecologically sound integrative assessment schemes by taking groundwater fauna into account depend on the initial classification of subsurface bioregions. In a large scale survey, the regional and biogeographical distribution patterns of groundwater dwelling invertebrates were examined for many parts of Germany. Following an exploratory approach, our results underline that the distribution patterns of invertebrates in groundwater are not in accordance with any existing bioregional classification system established for surface habitats. In consequence, we propose to develope a new classification scheme for groundwater ecosystems based on stygoregions. G roundwater systems are diversely populated habitats. The world wide number of described obligate groundwater invertebrates, the so-called stygofauna, sums up to 7000 species 1. The true species richness though, is believed to exceed that number by far taking into account that groundwater systems have not been studied to a great extent and a multitude of species await detection and description 2-5. The groundwater fauna is mainly composed of small crustaceans, oligochaetes, nematodes, acari, and molluscs, less than 1 mm to several centimeters in body size 4 (Fig. 1 ad). The goods and services provided by groundwater ecosystems (i.e ecosystem services) which include the purification of water by the breakdown of organic matter, nutrients and contaminants, are fundamental to both the integrity of the ecosystems and the sustaining of human life 6-10. Intimately connected to microbiological remineralization processes, invertebrates are believed to play an important role in the purification of subterranean water and thus, the maintainance of good water quality 11,12. Feeding, burrowing and bioturbating activities of the fauna in highly active transition zones (e.g. hyporheic zone) contribute to maintain the hydraulic connectivity between surface systems and aquifers 11 , a service groundwater dependant ecosystems (e.g. soils, wetlands, rivers) strongly rely on 11. Ecosystem services such as those mentioned above are only provided sustainably by groundwater communities with a structural and functional integrity 13,14. Recently, the need for an ecologically sound management of groundwater resources has become increasingly recognised by national and international political authorities 15-19. The European Union Groundwater Directive 20 (EU-GWD), released in 2006, emphasize the importance of protective measures for groundwater ecosystems proposing the conductance of more ecological research in order to provide better criteria for ensuring groundwater ecosystem quality in the future 13. This triggered new scientific research on identifying and evaluating biological criteria related to groundwater ecosystem health and water quality, and vice versa 13,14,19,21. Organisms integrate impacts over space (their habitat) and time, clearly extending the information obtained from abiotic monitoring 21. Indeed groundwater invertebrates have been shown to be sensitive sentinels indicating the influence from surface water infiltration, changes of hydrological conditions, the impact of organic contaminants and nutrients, and were shown valuable biomonitors of heavy metal pollution as well as heat discharge 14 and citations therein. Only recently, first integrative approaches for the assessment of groundwater ecosystem health, which define criteria, reference conditions and thresholds for individual physicochemical, microbiological and faunistic

1.3.5 Groundwater Ecology as a Necessary Link to the EU Water Framework Directive

GroundCare - Invertebrates as indicators for untreated water and intrusion of surface water in water supply systems

ARPHA Conference Abstracts, 2018

Functioning, healthy groundwater ecosystems are essential for high quality drinking water, and th... more Functioning, healthy groundwater ecosystems are essential for high quality drinking water, and they minimize costs of processing groundwater for drinking purposes. GroundCare is a multidisciplinary project, which is led by the Helmholz Institute in Munich, Germany and funded by the BMBF (German federal Ministry of education and Research). The aim is to parametrize and to quantify groundwater ecosystem services as a basis for sustainable water management and water pollution control by biomonitoring. In other words: the development of biological assessment techniques. Multiple parameters are evaluated (physico-chemical parameters, microbial and fauna community composition, ecotoxicological effects). Invertebrate fauna is investigated at five sites all across Germany. During the project, molecular identification through DNA Barcoding and Metabarcoding of groundwater invertebrates is being implemented and compared to traditional morphological bio-assessment. The subterranean fauna can b...

Hydro(geo)chemische und ökologische Bestandsaufnahme von Quellregionen als isolierte Grundwasser-Ökosysteme

Grundwasser

ZusammenfassungZwei Untersuchungsgebiete im zentralen Münsterland (Baumberge, NRW, Deutschland) s... more ZusammenfassungZwei Untersuchungsgebiete im zentralen Münsterland (Baumberge, NRW, Deutschland) sind aufgrund der geologischen Reliefumkehr-Situation isolierte Grundwasser-Ökosysteme, welche nur von infiltrierendem Niederschlagswasser beeinflusst werden. Als sogenannte „Natur-Lysimeter“ eignen sie sich mit ihren insgesamt bis zu 200 natürlichen Quellaustritten als multidisziplinäre Bezugssysteme für wasserdurchlässige Kluftgrundwasserleitersysteme (aus Kalkmergelsteinen). Die Betrachtung der langjährigen Veränderungen des Stoffaustrags an den Quellen deuten auf zunehmende Verkarstung und raumzeitlich wechselnde Einflüsse durch die land- und forstwirtschaftlich genutzte Geländeoberfläche hin. Stabile Sulfatisotope zeigen, dass die Mehrheit der Quellen durch den Eintrag von Gülle in deren Quell-Einzugsgebiet beeinflusst wird und dass die Pyritoxidation ein wichtiger Prozess im tieferen Grundwasserkörper ist. Die Nitratkonzentrationen sind im Allgemeinen hoch (über 50 mg/l) und stammen...

Groundwater fauna in an urban area: natural or affected?

In Germany, 70 % of the drinking water demand is met by groundwater, for which the quality is the... more In Germany, 70 % of the drinking water demand is met by groundwater, for which the quality is the product of multiple physical-chemical and biological processes. As healthy groundwater ecosystems help to provide clean drinking water, it is necessary to assess their ecological conditions. This is particularly true for densely populated urban areas, where faunistic groundwater investigations are still scarce. The aim of this study is, therefore, to provide a first assessment of the groundwater fauna in an urban area. Thus, we examine the ecological status of an anthropogenically influenced aquifer by analysing fauna in 39 groundwater monitoring wells in the city of Karlsruhe (Germany). For classification, we apply the groundwater ecosystem status index (GESI), in which a threshold of more than 70 % of crustaceans and less than 20 % of oligochaetes serves as an indication for very good and good ecological conditions. Our study reveals that only 35 % of the wells in the residential, commercial and industrial areas and 50 % of wells in the forested area fulfil these criteria. However, the study did not find clear spatial patterns with respect to land use and other anthropogenic impacts, in particular with respect to groundwater temperature. Nevertheless, there are noticeable differences in the spatial distribution of species in combination with abiotic groundwater characteristics in groundwater of the different areas of the city, which indicate that a more comprehensive assessment is required to evaluate the groundwater ecological status in more detail. In particular, more indicators, such as groundwater temperature, indicator species, delineation of site-specific characteristics and natural reference conditions should be considered.

Dienstleistungen der Grundwasserökosysteme

Services Provided By Groundwater Ecosystems Our daily lives depend on the provision of services b... more Services Provided By Groundwater Ecosystems Our daily lives depend on the provision of services by different ecosystems. An important contribution is made by our ground- water ecosystems. They make sure that groundwater is purified until it reaches drinking water quality; they ensure an active storage of clean water of constant quality, the biological degra- dation of pollutants, the removal of pathogenic microorganisms, the integrity of water supply, and many other things. These serv- ices are provided, last but not least, by a great variety of bio- cenoses in groundwater aquifers. To ensure the provision of these services in the long run requires a good ecological status of our groundwater habitats.

Sampling Fauna in Stream Sediments as well as Groundwater Using One Net Sampler

Acta hydrochimica et hydrobiologica, 2004

... Fauna in Stream Sediments as well Hans J. Hahna, Gerald D. Watsonb, as Groundwater Using One ... more

Does groundwater influence the sediment fauna beneath a small, sandy stream?

Limnologica, 2007

Gradients in the sediment fauna comprising groundwater (GW) and hyporheic taxa were investigated ... more Gradients in the sediment fauna comprising groundwater (GW) and hyporheic taxa were investigated in the sand/ silt-bottomed Marbling Brook in Western Australia. The structure of sediment invertebrate assemblages from Marbling Brook sediments and the adjacent GW were studied at five sites over 1 year and hydrological interactions were characterized using a suite of abiotic factors. Although all five stream sites were upwelling, the sites differed in the degree of hydrological interactions between GW and surface water. Sediment fauna taxa abundances were not correlated with any of the abiotic factors investigated and did not change gradually with depth. Faunal assemblages in the stream sediments were distinct from faunal assemblages in alluvial GW. While water exchanged between alluvial GW and sediment water, as shown by abiotic factors, the distinct differences in faunal assemblages indicated an unpredicted complexity in the catchment with fundamentally different hydrogeological situations on the decimetre scale. Sampling in sandy sediments needs to take this small-scale variability into account.

Testing unbaited stygofauna traps for sampling performance

Limnologica, 2008

Unbaited phreatic traps are a promising new method for sampling subterranean limnofauna. The aim ... more Unbaited phreatic traps are a promising new method for sampling subterranean limnofauna. The aim of this study is to evaluate whether such trap systems are suitable to gather representative samples of the physico-chemical parameters and the invertebrate fauna of the aquifer. Fifteen traps, installed in five groundwater bores, and four traps located in the hyporheic zone, were sampled twice monthly over a 1 year period (June 2003-June 2004). Water samples were removed in three separated fractions (hose, trap and aquifer water), analysed for physico-chemical and faunal characteristics and compared with one another. The study was carried out in the Nakdong River floodplain, Korea. Physico-chemical characteristics of trap and aquifer were similar, but differed greatly from the hose samples. Abundances of fauna inside the traps were higher than in the aquifer, whereas there were no differences in taxonomic composition of the trap and aquifer samples. Biases of abundances suspected due to the use of traps were negligible in the groundwater, though it is recommended that comparisons between groundwater and hyporheic abundances ascertained by traps be handled cautiously.

Do faunal assemblages reflect the exchange intensity in groundwater zones?

Hydrobiologia, 2007

The exchange of water with groundwater is a key determinant of water quality and faunal assemblag... more The exchange of water with groundwater is a key determinant of water quality and faunal assemblage. Water exchange not only occurs with running waters, but also through percolation, interception (soil, porous alluvium), and evaporation. The aim of this study was to identify how different types of exchange were related to the groundwater faunal assemblage of an alluvial aquifer. Hydrological exchange is largely governed by pore space and thus ultimately by geological formation. In the Marbling Brook catchment of Western Australia the different geological formations did not eventuate in hydrochemically distinct groundwater zones. The cluster analysis of faunal assemblages revealed five groups within the faunal samples which did not reflect spatial patterns such as geological, chemical or topographic features. Discriminant analysis showed that these five groups were best characterized by a range of abiotic features including dissolved oxygen, land-use, and temperature. These variables signal different types and intensities of exchange with the surface.

Ecological assessment of groundwater ecosystems – Vision or illusion?

Ecological Engineering, 2010

Environmental policy and in particular the European water legislation, in the framework of the EU... more Environmental policy and in particular the European water legislation, in the framework of the EU Groundwater Directive, has started to consider groundwater not only as a resource but as a living ecosystem. A precondition for comprehensive groundwater protection is thus the assessment of the biological and ecological state. The assessment of ecosystems requires consideration of ecological criteria, which so far

What is groundwater and what does this mean to fauna? – An opinion

Limnologica, 2012

ABSTRACT Many subsurface waters are considered groundwater but are influenced in shallow depths b... more ABSTRACT Many subsurface waters are considered groundwater but are influenced in shallow depths by hyporheic, parafluvial and/or soil interception water to such a degree that groundwater fauna (stygofauna) communities may be significantly altered. Recharge, even if spatially and temporally distinct, delivers input of dissolved oxygen, organic matter (OM), and nutrients that caters sustainably for ubiquists such as stygophiles and hyporheic fauna, but renders the life of uncompetitive stygobites difficult or impossible. The impact of recharge at shallow groundwater thus needs to be taken into account when determining groundwater fauna reference communities and when evaluating monitoring studies.One of the main characteristics of groundwater is low OM concentration. In contrast, high OM concentrations are typical of hyporheic or parafluvial waters, which are enriched by OM from the river, the riparian soils and from interflow, and which contribute significantly to river OM balance. Consequently, for ecological studies on subsurface waters, both the origin of the water and OM, and the intensity of surface water interactions should be considered. Here, we discuss how groundwater spatial and temporal heterogeneity translates into faunal distribution patterns. In terms of the origin of water and OM, and from an ecological point of view, we need to distinguish between (i) shallow groundwater characterized by infiltrating precipitation and soil recharge, (ii) shallow groundwater interacting with surface water bodies such as continuously flowing and ephemeral streams and rivers, and (iii) “old” groundwater which has no recent connections to the surface and is thus largely secluded from input of nutrients and carbon. Water in the first two groups is characterized by high amounts of OM of varying quality, while water in the third group is characterized by low amounts of low quality OM. Consequently, stygophiles dominate in groups 1 and 2, with hyporheic fauna taking up a considerable proportion in group 2, while stygobites only dominate in group 3. Thus, for studies aiming to assess impacts on groundwater, only sampling sites of the third group should be used for reference sites as these are the most likely sites to have little surface impact and a stygofauna representative of the deeper aquifer.

Efficiency of sampling invertebrates in groundwater habitats

Limnologica - Ecology and Management of Inland Waters, 2013

ABSTRACT Sampling efficiency is directly linked to (faunistic) stability issues of any sampled si... more ABSTRACT Sampling efficiency is directly linked to (faunistic) stability issues of any sampled site. It is more probable to sample a high proportion of the species occurring at a certain site, if communities remain constant in species composition with time. For this study 64 groundwater monitoring wells in Southwestern Germany were sampled six times to determine sampling efficiency. False-Negative (FN) rates and SIMPER values, two independent models expressing Faunistic values of the sampled bores, were calculated and three groups of faunistic stability could be identified based on calculated SIMPER-values. FN-rates as well as SIMPER values proved to be a valuable approach for the estimation of faunistic stability/instability, as these methods showed a highly negative correlation with each other. To collect 95% of species a number of 1.7–16.4 samples was calculated to be necessary depending on faunistic stability of the sampled habitat. On the six sampling occasions the sites harbouring a stable groundwater meiofauna resulted in 98.2% of occurring species, whereas the percentage decreased over intermediate sites (94.9%) and stressed sites (79.5%). A consequence of the data presented may be to view surveys using only two samples as campaign with orienting character, with further studies of stability issues of groundwater communities which would provide efficient and effective sampling for various kinds of sites.

A proposal for a groundwater habitat classification at local scale

Subterranean Biology, 2014

Distribution of groundwater invertebrate communities in porous aquifers (and their habitats) vari... more Distribution of groundwater invertebrate communities in porous aquifers (and their habitats) varies on spatial scales and many attempts have been made to classify these on various scales. The new data-based approach, presented here, classifies the complex distribution of groundwater habitats on a local scale (i.e. along transects of < 100 m) and merges the latest classification approaches at this scale. Data from a regional (i.e. approximately 100 km 2) biogeographic groundwater survey was analysed in terms of stability of: community structure, different intensities of surface water influence, and occurrence, together with the distribution of stygobites within those groundwater ecosystems. On the investigated local scale, the faunistic communities' composition is mainly depending on surface water influence, coupled with immision of dissolved oxygen and organic matter. Derived from this finding, five types of faunistic habitats are proposed: (I) Stressed groundwater habitats, (II) Stable groundwater habitats, (III) Rain fed groundwater habitats , (IV) Surface water fed groundwater habitats, and (V) Hyporheic habitats.

Periodic alterations of the hydrological exchange in hyporheic sediments: colmation, hyporheic fauna and abiotic parameters in a second order stream during one year

Grundwasserökosysteme im Recht?

Grundwasser

ZusammenfassungDas Grundwasser ist der größte und älteste kontinentale Lebensraum. Trotzdem wird ... more ZusammenfassungDas Grundwasser ist der größte und älteste kontinentale Lebensraum. Trotzdem wird in der europäischen und deutschen Rechtspraxis Grundwasser bisher als Ressource und nicht als Lebensraum behandelt. Allerdings kann der Lebensraumbezug über die Definition des Grundwassers als Gewässer im deutschen Wasserhaushaltsgesetz bzw. als „aquatisches Ökoysystem“ in der Europäischen Grundwasserrichtlinie (EG-GWRL) hergestellt werden. Die Umsetzung des Grundwasserschutzes sollte sich am ökosystemaren Ansatz für Oberflächengewässer in der Europäischen Wasserrahmenrichtlinie (EG-WRRL) und den Zielen der nationalen Biodiversitätsstrategie orientieren. Für das Grundwasser wird die Einführung der Begriffe „guter ökologischer Zustand“ und „Grundwasserökosysteme“ in das Umweltrecht vorgeschlagen. Grundwasserlebensräume und -arten sollten durch die Eingriffsregelung berücksichtigt und in die FFH-Richtlinie, in das Bundesnaturschutzgesetz und die Bundesartenschutzverordnung aufgenommen werden. Fachlich und rechtlich ist die Diskriminierung der Grundwasserökosysteme gegenüber Oberflächengewässern nicht zu begründen. Die Autoren argumentieren für die „Gleichberechtigung“ von Oberflächen- und Grundwasser und machen Vorschläge für die Anpassung des bestehenden Rechts im Sinne eines ökologisch begründeten Grundwasserschutzes.AbstractGroundwater is the largest and oldest continental biome. However, in the German and EU legislation, groundwater is still considered an abiotic resource rather than an ecosystem. On the other hand, the German Water Act (WHG, Wasserhaushaltsgesetz) mentions groundwaters along with other water bodies that carry the status of ecosystems. Its ecosystem status is also referred to in the preamble of the European Groundwater Directive (EC-GWD). The implementation of groundwater protection measures should be geared to the ecosystemic approach for surface waters contained in the European Water Framework Directive (EC-WFD) and to the German National Biodiversity Strategy (BMU 2007). Addition of the terms “good ecological status” and “groundwater ecosystems” into the German and EU environmental water laws is recommended. Groundwater habitats and species should be subject to impact assessment and included into the FFH directive and German nature conservation laws. There is no technical or legal argument for the discrimination of groundwater ecosystems and species in environmental legislation. The authors argue for the legal equality of ground and surface water, and propose the adaption of the existing legislation according to ecological requirements.

Uso da fauna de metazoários de subsuperfície como indicador das interacções águas subterrâneas–águas superficiais na planície aluvial do Rio Nakdong, Coreia do Sul

Hydrogeol J, 2008

Bewertung von Altlasten im Grundwasser anhand der Meiofaunagemeinschaften?erste Ergebnisse

Grundwasser, 2005