Freshwater benthic diatoms of central Europe: over 800 common species used in ecological assessment. English edition with updated and added species.

One of the most controversial societal issues today, regarding pesticide registration in the European Union (EU) may be the case surrounding re-registration of the active herbicide ingredient glyphosate. Shortly before the announcement of the conflicting views regarding the carcinogenicity status of this regulated agrochemical by EU Agencies, the European Food Safety Authority (EFSA) and the European Chemicals Agency (ECHA) on the one hand, and the International Agency for Research on Cancer (IARC) on the other hand, the Cancer Assessment Review Committee of the US Environmental Protection Agency (US EPA) also published re-evaluations. The US EPA assessment classified glyphosate into Group E, “not likely to be carcinogenic to humans”. Similar positions were reached by EFSA and ECHA, assessing glyphosate as “unlikely to pose a carcinogenic hazard to humans” and “not classified as a carcinogen”, respectively. A strongly opposing evaluation has previously been reached by IARC by classifying glyphosate into Group 2A, “probably carcinogenic to humans”. IARC identified potential cancer hazards in this case, but did not estimate the level of risk it may present, which was taken into consideration by opposing agencies. Multiple effects of glyphosate have been reported, of which carcinogenic effects are only one component. Formulated glyphosate products – especially with polyethoxylated tallowamine and related compounds – have been shown to cause stronger cytotoxic or endocrine disrupting effects than the active ingredient glyphosate alone. Questions related to hazards and corresponding risks identified in relation to this active ingredient and its formulated herbicide preparations divide scientific circles and official health and environmental authorities and organizations, and touch upon fundamental aspects of risk assessment and product regulation. The decision has to consider both hazard-based (IARC) and risk-based analysis (EFSA); the former may not be suitable to calculate practical significances, and the latter being challenged if exposure estimations are uncertain in light of new data on residue levels. The results of current analytical surveys on surface water are particularly worrisome. In turn, the precautionary principle appears to be the optimal approach in this case for regulation in the EU.

/pdf/re-registration-challenges-of-glyphosate-in-the-european-tqquh2yxxx.pdf

Re-registration Challenges of Glyphosate in the European Union

https://digital.csic.es/bitstream/10261/176544/1/Meta-analysis%20of%20glyphosate%20contamination%20in%20surface%20waters%20and%20dissipationby%20biofilms.pdf

Meta-analysis of glyphosate contamination in surface waters and dissipation by biofilms.

/pdf/functional-diversity-of-phytoplankton-highlights-long-term-30b5jejisc.pdf

Functional diversity of phytoplankton highlights long‐term gradual regime shift in the middle section of the Danube River due to global warming, human impacts and oligotrophication

Our understanding on phytoplankton diversity has largely been progressing since the publication of Hutchinson on the paradox of the plankton In this paper, we summarise some major steps in phytoplankton ecology in the context of mechanisms underlying phytoplankton diversity Here, we provide a framework for phytoplankton community assembly and an overview of measures on taxonomic and functional diversity We show how ecological theories on species competition together with modelling approaches and laboratory experiments helped understand species coexistence and maintenance of diversity in phytoplankton The non-equilibrium nature of phytoplankton and the role of disturbances in shaping diversity are also discussed Furthermore, we discuss the role of water body size, productivity of habitats and temperature on phytoplankton species richness, and how diversity may affect the functioning of lake ecosystems At last, we give an insight into molecular tools that have emerged in the last decades and argue how it has broadened our perspective on microbial diversity Besides historical backgrounds, some critical comments have also been made

/pdf/freshwater-phytoplankton-diversity-models-drivers-and-2as3uf5ioe.pdf

Freshwater phytoplankton diversity: models, drivers and implications for ecosystem properties.

Phytoplankton of rhithral rivers: Its origin, diversity and possible use for quality-assessment

Dissipation of the herbicide active ingredient glyphosate was investigated in natural waters. To assess combined effects, glyphosate was applied in its pure form (glyphosate isopropylammonium salt) and in preparation Roundup Classic® formulated with polyethoxylated tallowamines (POEA). Standing and running surface water samples originated from Lake Balaton and River Danube between early May and mid-June of 2015. The kinetics of dissipation of glyphosate, measured by high-performance liquid chromatography combined with UV-VIS absorbance detection or tandem mass spectrometry, was investigated under laboratory conditions in aquaria with or without the presence of biofilms. The quantity and the biofilm structure of algal biomass were determined by in vivo fluorimetry and scanning electron microscopy. The presence of POEA affected the dissipation of glyphosate, and dissipation profiles differed in the investigated natural waters. Significantly higher initial concentrations of glyphosate were measured i...

/pdf/dissipation-of-the-herbicide-active-ingredient-glyphosate-in-590xkcq6dw.pdf

Dissipation of the herbicide active ingredient glyphosate in natural water samples in the presence of biofilms

The spatial response of epiphytic diatom communities to environmental stress was studied in a moderately saline wetland area located in the plain of Danube-Tisza Interfluve, Hungary. The area is characterised by World War II bomb crater ponds and can be regarded as an excellent ecological model system where the dispersion of species is slightly limited by distance. To study the effect of environmental variables on the communities, canonical correspondence analysis was applied. Salinity, pH, total suspended solids, total phosphorous and depth proved to be significant environmental drivers in this analysis. The ecological status of the ponds was assessed with Ziemann's halobity index, as the trophity-depending metric cannot be applied to these habitats (due to the naturally high phosphorus content). Ponds in "good" ecological status significantly differed from those appertaining to water quality category of "not-good" ecological status considering characteristic of natural astatic soda pans (e.g. salinity, pH, ammonium, total phosphorous concentration, nitrogen:phosphorous ratio and turbidity). The differences between epiphytic diatom communities inhabiting the ponds were detected using non-parametric multidimensional scaling. The samples formed three groups according to the types of ponds ("transparent", "transitional" and "turbid") based on the width of the macrophyte belt around them. Indicator species related to the ecological status of the ponds and diatom communities contributing to the separation of groups of ponds were identified. One of the indicator species differed from species already described. Light and scanning electron microscopy features and phylogenetic analyses based on three genes (18S and 28S rRNA genes, rbcL) proved that it was a new species of Nitzschia genus, closely related to Nitzschia frustulum and Nitzschia inconspicua. Therefore, description of a new species, Nitzschia reskoi Acs, Duleba, C.E.Wetzel & Ector is proposed. We concluded that the increasing abundance of Nitzschia reskoi was a signal of the degradation of the intermittent saline wetlands.

/pdf/unexpected-consequences-of-bombing-community-level-response-3ngk73zxad.pdf

Unexpected consequences of bombing. Community level response of epiphytic diatoms to environmental stress in a saline bomb crater pond area.

(1) Urbanization significantly influences the ecosystems of rivers in various ways, including the so-called loading effect of wastewater production. Benthic diatoms are used in ecological status assessments of waters. Beside species composition, traits can be used as indicators. We aimed to evaluate how the loading of the large city of Budapest manifests in the physico-chemical variables of the River Danube and what species composition and trait response this loading results in for the benthic diatom communities. (2) Weekly samplings were performed at points upstream and downstream of Budapest on both riverbanks. Samples were compared, based on general physical-chemical variables and the concentration of thirty-four elements, as well as species composition and seven traits of species of diatom communities. Ecological status was assessed using the Specific Pollution Sensitivity Index (IPS). (3) Only a few measured environmental variables showed differences between the sampling points, suggesting that the nutrient loading has significantly decreased due to the installation of several efficiently working wastewater treatment plants since the introduction of the European Union Water Framework Directive. In contrast, the species composition and traits of species showed the effect of land use. Benthic diatoms indicate the environmental changes caused by land use in the longer-term, while chemical measurements reflect instantaneous status.

https://www.mdpi.com/2073-4441/12/2/479/pdf

Effect of Land Use on the Benthic Diatom Community of the Danube River in the Region of Budapest

/pdf/comparison-of-the-utility-of-a-frequently-used-diatom-index-3zxy31qj1j.pdf

Zsuzsa Trábert

Papers

Phytoplankton of rhithral rivers: Its origin, diversity and possible use for quality-assessment

Dissipation of the herbicide active ingredient glyphosate in natural water samples in the presence of biofilms

Unexpected consequences of bombing. Community level response of epiphytic diatoms to environmental stress in a saline bomb crater pond area.

Effect of Land Use on the Benthic Diatom Community of the Danube River in the Region of Budapest

Comparison of the utility of a frequently used diatom index (IPS) and the diatom ecological guilds in the ecological status assessment of large rivers