Physical and chemical dynamics of temporary ponds on a calcareous plateau in Thuringia, Germany

AbstractTemporary ponds on calcareous hills surrounding the town of Jena (Thuringia, Germany) were investigated for one year with regard to the dynamics of their physical and chemical characteristics. The present paper concerns selected data from a vertical, diurnal and seasonal sampling program including the major physical and chemical factors. The ponds were also investigated during the dry period in summer, and in winter when they are covered with ice. A description of the emergent vegetation is also given and used for a classification of the ponds. Most of the factors investigated show strong diurnal and seasonal trends and some, — despite all ponds being shallow — were vertically stratified. The measurements emphasize that in small ponds both seasonal and diurnal changes in water-chemistry, as well as changes in vertical gradients, are affected by the vegetation succession stage, and consequently by the temporary character of the ponds. Protection and management of these ponds often involves dredging and therefore the short time response of dredging is discussed

The effects of a small low-head dam on benthic invertebrate communities and particulate organic matter storage in the Ilm stream /Thuringia/Germany)

Zahlreiche anthropogene Störungen haben die Fließgewässer-Ökosysteme in starkem Maße verändert. Die vorliegende Dissertation untersucht den Einfluß eines Wehres auf die Invertebraten-Gemeinschaft und das partikuläre organische Material (POM) in der Ilm, einem Mittelgebirgsfließgewässer in Thüringen (Deutschland). Die Untersuchung liefert als eine der ersten ein detailliertes und differenziertes Bild über die Effekte eines Wehres auf die Gemeinschaft benthischer Invertebraten und deren Hauptenergie?Ressource (POM). Die gewonnenen Informationen sind von größter Bedeutung, um neue (teilweise modifizierte und realistischere) Restaurationsziele zu definieren. Diese Ziele bilden die Grundlage für ein effizientes Management unserer Fließgewässer-Ökosysteme

Trends and patterns in surface water chemistry in Europe and North America between 1990 and 2016, with particular focus on changes in land use as a confounding factor for recovery

The report presents trends in sulphate, nitrate, chloride, base cations, ANC (acid neutralising capacity), pH and DOC at circa 500 ICP Waters sites in Europe and North America for the period 1990-2016. Time series were analysed for trends in annual median values, annual extreme values and change points, that indicate years with sudden changes in trend or level. Also provided is a brief overview of possible implications of land use change for recovery of acidified surface waters

Responses of benthic invertebrates to chemical recovery from acidification

Prosjektleder: Heleen de WitThe report provides an assessment of biological recovery from acidification in freshwater environments in Europe. The report consists of two parts, a regional data analysis based on an international dataset of biological and water chemical records, and a collection of national contributions on monitoring and assessment of biological recovery in different countries. The regional analysis showed that 47% of all included rivers (21 sites, for the period 1994-2018) and 35% percent of all lakes (34 sites, for the period 2000 to 2018) showed significant increases in species richness. Correlations between species diversity and water chemical components (ANC, pH, SO4) were found, supporting that the biological responses were related to chemical recovery. Additionally, the composition of functional traits in rivers underwent significant changes over time. Both parts of the report demonstrate ongoing biological recovery from acidification in European acid-sensitive freshwater environments.Norwegian Ministry of Climate and Environment, United Nations Economic Commission for Europe (UNECE)publishedVersio

Water Framework Directive Intercalibration: Central-Baltic Lake Fish fauna ecological assessment methods

The European Water Framework Directive (WFD) requires the national classifications of good ecological status to be harmonised through an intercalibration exercise. In this exercise, significant differences in status classification among Member States are harmonized by comparing and, if necessary, adjusting the good status boundaries of the national assessment methods. Intercalibration is performed for rivers, lakes, coastal and transitional waters, focusing on selected types of water bodies (intercalibration types), anthropogenic pressures and Biological Quality Elements. Intercalibration exercises are carried out in Geographical Intercalibration Groups - larger geographical units including Member States with similar water body types - and followed the procedure described in the WFD Common Implementation Strategy Guidance document on the intercalibration process (European Commission, 2011). The Technical report on the Water Framework Directive intercalibration describes in detail how the intercalibration exercise has been carried out for the water categories and biological quality elements. The Technical report is organized in volumes according to the water category (rivers, lakes, coastal and transitional waters), Biological Quality Element and Geographical Intercalibration group. This volume addresses the intercalibration of the Lake Central-Baltic Fish ecological assessment methods. Part A: This document comprises an overview and detailed descriptions of fish-based lake ecological assessment methods. Part B describes the construction of multiple pressure index in the Central-Baltic region. Part C describes the procedure and results of the boundary harmonisation of national fish-based lake assessment systemsJRC.D.2-Water and Marine Resource

Monitoring of Surface Waters in Germany under the Water Framework Directive—A Review of Approaches, Methods and Results

The European Commission Water Framework Directive (WFD) was established 16 years ago and forms the current basis for monitoring surface waters and groundwater in Europe. This legislation resulted in a necessary adaptation of the monitoring networks and programs for rivers, lakes, and transitional and coastal waters to the requirements of the WFD at German and European levels. The present study reviews the most important objectives of both the monitoring of surface waters and the principles of the WFD monitoring plan. Furthermore, we look at the changes water monitoring in Germany has undergone over the past sixteen years and we summarize monitoring results from German surfaces waters under the WFD. Comparisons of European approaches for biological assessments, of standards set for physical and chemical factors and of environmental quality standards for pollutants reveal the necessity for further European-wide harmonization. The objective of this harmonization is to improve comparability of the assessment of the ecological status of waters in Europe, and thus also to more coherently activate action programs of measures

Monitoring of Surface Waters in Germany under the Water Framework Directive—A Review of Approaches, Methods and Results

The European Commission Water Framework Directive (WFD) was established 16 years ago and forms the current basis for monitoring surface waters and groundwater in Europe. This legislation resulted in a necessary adaptation of the monitoring networks and programs for rivers, lakes, and transitional and coastal waters to the requirements of the WFD at German and European levels. The present study reviews the most important objectives of both the monitoring of surface waters and the principles of the WFD monitoring plan. Furthermore, we look at the changes water monitoring in Germany has undergone over the past sixteen years and we summarize monitoring results from German surfaces waters under the WFD. Comparisons of European approaches for biological assessments, of standards set for physical and chemical factors and of environmental quality standards for pollutants reveal the necessity for further European-wide harmonization. The objective of this harmonization is to improve comparability of the assessment of the ecological status of waters in Europe, and thus also to more coherently activate action programs of measures

Beyond fish eDNA metabarcoding: Field replicates disproportionately improve the detection of stream-associated vertebrate species

Fast, reliable, and comprehensive biodiversity monitoring data are needed for environmental decision making and management. Recent work on fish environmental DNA (eDNA) metabarcoding shows that aquatic diversity can be captured fast, reliably, and non-invasively at moderate costs. Because freshwater ecosystems act as sinks in the landscape, they also collect traces of terrestrial species via surface runoff or when specimens come into direct contact with water (e.g., for drinking purposes). Thus, fish eDNA metabarcoding data can provide information on fish but also on other, even terrestrial vertebrate species that live in riparian habitats. This data become available and may offer a much more comprehensive approach for assessing vertebrate diversity at no additional costs. Studies on how the sampling strategy affects species detection especially of stream-associated communities, however, are scarce. We therefore performed an analysis on the effects of biological replication on both fish as well as (semi-)terrestrial species detection. Along a 2-km stretch of the river Mulde (Germany), we collected 18 1L water samples and analyzed the relation of detected species richness and quantity of biological replicates taken. We detected 58 vertebrate species, of which 25 were fish and lamprey, 18 mammals, and 15 birds, which account for 50%, 24% and 7% of all native species to the German federal state of Saxony-Anhalt. However, while increasing the number of biological replicates resulted in only 25 % more detected fish and lamprey species, mammal and bird species richness increased disproportionately by 69 % and 84 %, respectively. Contrary, PCR replicates showed little stochasticity. We thus emphasize to increase the number of biological replicates when the aim is to improve general species detections. This holds especially true, when the focus is on rare aquatic taxa or on (semi-)terrestrial species, the so-called ‘bycatch’. As a clear advantage, this information can be obtained without any additional sampling or laboratory effort when the sampling strategy regarding biological replication is chosen carefully. With the consideration of frequent eDNA metabarcoding as part of national biomonitoring programs, the additional information provided by the bycatch can be used to further investigate the state of the environment and its biodiversity on a much broader scale

Regional assessment of the current extent of acidification of surface waters in Europe and North America

Project manager Kari AustnesThe current status of surface water acidification related to air pollution in Europe and North America has been assessed using country reports, monitoring data, critical loads and exceedance data, acid sensitivity and deposition maps, and data reported under the European Commission’s Water Framework Directive (WFD). Acidification is still observed in many countries, but the extent and severity vary. Maps of acid sensitivity and deposition suggest that surface water acidification is present in regions and countries for which no data or reports were delivered for the current assessment. Existing national monitoring varies in the ability to assess the spatial extent of acidification and the recovery responses of acidified sites. The monitoring requirements under the European Union’s National Emission Ceilings Directive are expected to reverse the recent decline in the number of monitoring sites observed in some countries. The information reported under the WFD is currently of limited value in assessing the extent of acidification of surface waters in Europe. Chemical recovery in response to reductions in acid deposition can be slow, and biological recovery can lag severely behind. Despite large and effective efforts across Europe and North America to reduce surface water acidification, air pollution still constitutes a threat to freshwater ecosystems.Norwegian Environment Agency (Miljødirektoratet) United Nations Economic Commission for Europe (UNECE)publishedVersio