Measures taken - the Swiss national action plan for bee health

The annual winter losses of honey bees in Switzerland vary between 9% and 23% during the years 2008 to 2019 and are exceeding the as normal defined 10% level. The causes for the losses can have several reasons. However, one of the main reasons is the infection of the honeybees with the Varroa mite. Therefore, a health services for bees was founded to offer education programs for beekeepers and to support beekeepers in preventing and combating diseases. Switzerland further decided in 2014 to implement an action plan to promote the health of bees. Measures have been taken in the areas of disease prevention, promotion of food supply and reduction of risks from plant protection products. Immediate measures have been implemented such as the inclusion of a flowering strip in the Direct Payments Ordinance and measures to protect bees from plant protection products. Switzerland is actively involved in the development of new OECD test guidelines to evaluate the acute and chronic risk to honey- and wild bees. Honey and wild bees play an important role in pollination of agricultural crops and wild plants. The current situation is in evaluation to decide if further measures are needed.The annual winter losses of honey bees in Switzerland vary between 9% and 23% during the years 2008 to 2019 and are exceeding the as normal defined 10% level. The causes for the losses can have several reasons. However, one of the main reasons is the infection of the honeybees with the Varroa mite. Therefore, a health services for bees was founded to offer education programs for beekeepers and to support beekeepers in preventing and combating diseases. Switzerland further decided in 2014 to implement an action plan to promote the health of bees. Measures have been taken in the areas of disease prevention, promotion of food supply and reduction of risks from plant protection products. Immediate measures have been implemented such as the inclusion of a flowering strip in the Direct Payments Ordinance and measures to protect bees from plant protection products. Switzerland is actively involved in the development of new OECD test guidelines to evaluate the acute and chronic risk to honey- and wild bees. Honey and wild bees play an important role in pollination of agricultural crops and wild plants. The current situation is in evaluation to decide if further measures are needed

Comparing growth development of Myriophyllum spp. in laboratory and field experiments for ecotoxicological testing

Background, goals and scope: Risk assessment of herbicides and the evaluation of contaminated sediments based on algae and the macrophyte Lemna sp. alone may underestimate the potential hazard of certain compounds. Therefore, various test systems with Myriophyllum spp. have been developed recently to assess the phytotoxicity in surface waters and natural sediments. In the present study, experiments investigating the growth development of Myriophyllum spp. were performed in the laboratory under defined conditions and in mesocosms under environmentally realistic exposure conditions to evaluate the suitability of these species as potential standard test organisms in ecotoxicological testing. This study provides data on the endpoints biomass, plant length and root development. Materials and methods: Six independent experiments were performed to investigate the plant development of Myriophyllum spp. under control conditions. The main difference in the experiments was the complexity of the test systems ranging from simple laboratory experiments to complex outdoor mesocosm studies. At the start of each experiment, uniform cuttings of Myriophyllum spp. were placed in vessels with or without sediments to reduce variability between replicates. The endpoints considered in this investigation were biomass (fresh weight of the whole plant), length of the main shoot, length of the side shoots, total length of the plant (calculated from the length of the main and side shoots) and root formation. Root to shoot ratios were calculated as a further measure for plant development. Relative growth rates (RGR) based on plant length (RGLR) and on biomass (RGBR) were calculated. Results: Despite the various experimental conditions, comparable growth was obtained in all test systems and the variability of endpoints, such as total length and biomass of plants, was low. It was observed that the RGR of M. spicatum in the simple laboratory test system with sediment were comparable to growth data obtained for M. verticillatum and M. spicatum grown in indoor and outdoor mesocosms, thus indicating that Myriophyllum growth tends to increase by the addition of sediment. High variability was determined for the endpoints length of the side shoots, total root length and biomass of roots. Discussion: One challenge for a test design to investigate phytotoxicity on aquatic plants is to obtain good growth of the plants. From the results, it can be concluded that the experimental conditions in the various test systems were suitable to study the plant development of Myriophyllum spp. because obtained growth rates were comparable between laboratory and field investigations. Another challenge for developing a plant biotest system is the definition of sensitive endpoints. Low variability is preferred to detect minor effects of chemicals or polluted sediments on plant development. In our studies, the variability of the endpoints biomass and total length of plant was low and, therefore, they have much potential as endpoints for assessing toxicity. Conclusions: The methodologies presented in this study have applications within the risk assessment for aquatic plants and have the advantage of assessing effects taking into account the relevant exposure pathways via water and/or sediment for compounds under investigation. Recommendations and perspectives: Setting safe quality criteria for surface water and sediments is one of the challenges authorities are facing today. Myriophyllum spp. is recommended as suitable test species to investigate phytotoxicity in surface water and sediments. These results, thus, might serve as a basis for the compilation of a new harmonised guideline for ecotoxicological testing with aquatic macrophyte

Evaluating the necessity of additional aquatic plant testing by comparing the sensitivities of different species

At present, at least three and up to five plant species are required to assess the potential risks of herbicides to non-target aquatic plants. Several regulatory authorities are considering whether there should be further requirements based on concerns about the possible selectivity of herbicides (e.g., specific modes of action against dicotyledonous plants). The relative sensitivity of a range of aquatic plants is assessed in our work in order to evaluate the implications of differences in species sensitivity for aquatic risk assessment of herbicides. We therefore present results from ecotoxicological tests performed at Syngenta Crop Protection AG on various aquatic plants and compare them to available studies and results in literature. The criterion used for sensitivity ranking is the EC50 (median effect concentration) value, which allows a better comparison of values from different testing methods and conditions. The overall results obtained in the present work show that the aquatic risk assessment procedure for herbicides based on Lemna sp. and algae is sufficiently protective while identifying potential toxicity to non-target plants. Only few exceptions concerning herbicides with selective modes of action (e.g., auxin simulators) may require additional species testing for proper risk assessmen

Blühstreifen für Bestäuber und andere Nützlinge - Wertvolle Nahrungsquellen im Ackerbau

Das Merkblatt hilft Beratungskräften, Landwirtinnen und Landwirten sowie weiteren landwirtschaftlichen Akteuren bei der Umsetzung der neuen Biodiversitätsförderfläche Blühstreifen für Bestäuber und andere Nützlinge. Das Dokument beschreibt den kulturspezifischen Nutzen der Flächen, deren Anlage, Pflege und Aufhebung. Zudem werden Empfehlungen zur optimalen Umsetzung formuliert, damit die erwartete Leistung der Bestäuber und Nützlinge auch langfristig erbracht werden kann

AMEG: the new SETAC advisory group on aquatic macrophyte ecotoxicology

Introduction and background Primary producers play critical structural and functional roles in aquatic ecosystems; therefore, it is imperative that the potential risks of toxicants to aquatic plants are adequately assessed in the risk assessment of chemicals. The standard required macrophyte test species is the floating (non-sediment-rooted) duckweed Lemna spp. This macrophyte species might not be representative of all floating, rooted, emergent, and submerged macrophyte species because of differences in the duration and mode of exposure; sensitivity to the specific toxic mode of action of the chemical; and species-specific traits (e.g., duckweed's very short generation time). Discussion and perspectives These topics were addressed during the workshop entitled “Aquatic Macrophyte Risk Assessment for Pesticides” (AMRAP) where a risk assessment scheme for aquatic macrophytes was proposed. Four working groups evolved from this workshop and were charged with the task of developing Tier 1 and higher-tier aquatic macrophyte risk assessment procedures. Subsequently, a SETAC Advisory Group, the Macrophyte Ecotoxicology Group (AMEG) was formed as an umbrella organization for various macrophyte working groups. The purpose of AMEG is to provide scientifically based guidance in all aspects of aquatic macrophyte testing in the laboratory and field, including prospective as well as retrospective risk assessments for chemicals. As AMEG expands, it will begin to address new topics including bioremediation and sustainable management of aquatic macrophytes in the context of ecosystem services

The 2015 Annual Meeting of SETAC German Language Branch in Zurich (7-10 September, 2015): ecotoxicology and environmental chemistry-from research to application

This report provides a brief review of the 20th annual meeting of the German Language Branch of the Society of Environmental Toxicology and Chemistry (SETAC GLB) held from September 7th to 10th 2015 at ETH (Swiss Technical University) in Zurich, Switzerland. The event was chaired by Inge Werner, Director of the Swiss Centre for Applied Ecotoxicology (Ecotox Centre) Eawag-EPFL, and organized by a team from Ecotox Centre, Eawag, Federal Office of the Environment, Federal Office of Agriculture, and Mesocosm GmbH (Germany). Over 200 delegates from academia, public agencies and private industry of Germany, Switzerland and Austria attended and discussed the current state of science and its application presented in 75 talks and 83 posters. In addition, three invited keynote speakers provided new insights into scientific knowledge ‘brokering’, and—as it was the International Year of Soil—the important role of healthy soil ecosystems. Awards were presented to young scientists for best oral and poster presentations, and for best 2014 master and doctoral theses. Program and abstracts of the meeting (mostly in German) are provided as Additional file 1

Adsorption of fulvic acid on algal surfaces and its effect on carbon uptake

Adsorption of Suwannee River fulvic acid (SRFA) to algal surfaces of three green algae was studied at environmentally relevant pH values (4–7) and SRFA concentrations (5–100 mg·L −1 ). The influence of adsorbed SRFA on carbon uptake of Scenedesmus subspicatus Chodat was also examined. Although no adsorption was observed at neutral pH values (pH 6 and 7), at pH 4 up to 31 mg SRFA·m −2 and at pH 5 up to 4 mg SRFA·m −2 was adsorbed to the algal surfaces. Electrophoretic mobility measurements of S. subspicatus demonstrated an increase in the negative surface charge of the alga in the presence of SRFA at pH 4. The adsorbed SRFA also influenced 14C uptake in S. subspicatus; in this case, enhanced carbon uptake could be related to the amount of adsorbed SRFA. The binding of humic substances by algal surfaces was interpreted as the result of hydrogen bonding and hydrophobic interactions.</p

Copper-induced Oxidative Stress in Rainbow Trout Gill Cells

Copper is known to pose a serious threat to aquatic organisms. However, the mechanisms of its toxicity still remain unclear. Cu is known to exert its toxicity partly due to the formation of reactive oxygen species (ROS). The purpose of this work was therefore to link the exposure to copper at pH 6 and 7 to cellular formation of ROS and effects like cell viability and genotoxicity using the rainbow trout gill cell line RTgill-W1. To relate effects to bioavailable copper, free Cu2+ concentrations in the medium were calculated using the programm ChemEQL 3.0. H2DCF-DA (2¿,7¿-Dichlorodihydrofluorescein-Diacetate) was used as cell-permeant indicator of ROS formation. Cell viability was assessed using the fluorogenic probe CFDA-AM (5-carboxyfluorescein diacetate acetoxymethyl ester). DNA strand breaks were assessed using the comet assay, and lipid peroxidation was investigated using the thiobarbituric acid-reactive substances assay (TBARS). Copper treatment resulted in a dose-dependent elevation in cytotoxicity and formation of cellular ROS. Cell vitality was significantly reduced at total copper (CuT) concentrations of 5 µM (corresponding to a free Cu2+ of 0.11 µM at pH 7) and higher, resulting in an EC50 of CuT = 29.2 µM (Cu2+ = 0.63 µM, pH 7). Neither an impairment concerning the viability of control cells due to growth at pH 6 was observed, nor significant differences for cytotoxicity in cells exposed to the same nominal CuT concentrations at pH 6 compared to pH 7. Cellular ROS concentrations increased significantly and decreased with loss of cell vitality. After normalizing ROS formation to cell viability, ROS induction up to 25-35 fold compared to the control was detected, but mainly for rather high concentrations (CuT = 100 µM; Cu2+ = 2.2 µM, pH 7). ROS formation rates were slightly higher when cells were exposed to Cu at pH 6 compared to pH 7, correlating with the higher free Cu2+ concentrations. A significant induction of DNA strand breakages was noted at CuT of 1 and 2.5 µM with greater effects at pH 6 due to higher free Cu2+ concentrations than at pH 7. No effects on lipid peroxidation were observed. These results lead to the hypothesis that copper-induced loss in viability and genotoxicity in trout gill cells are partially triggered by the generation of ROS and related to the free Cu2+.JRC.H.5-Rural, water and ecosystem resource

The influence of particles on bioavailability and toxicity of pesticides in surface water

Environmental risk assessment is an essential part of the approval process for pesticides. Exposure concentrations are compared with ecotoxicological data obtained from standardized laboratory studies and, if available, from field studies to determine the risk of a substance or formulation for aquatic communities. Predicted concentrations in surface waters are derived using, for example, the European FOrum for the Co-ordination of pesticide fate models and their USe (FOCUS) or the German Exposit models, which distinguish between exposure to dissolved and particle-associated pesticide concentrations, because the dissolved concentration is thought to be the best predictor of bioavailability and toxicity. Water and particle-associated concentrations are estimated based on the organic carbon-water partitioning coefficient (K-OC). This review summarizes published information on the influence of natural suspended solids on bioavailability and toxicity of pesticides to aquatic organisms (algae, invertebrates and fish), and the value of log K-OC and log K-OW (octanol-water coefficient) as sole predictors of the bioavailable fraction is discussed. The information showed that: 1) the quality and origin of suspended solids played an important role in influencing pesticide bioavailability and toxicity; 2) a decrease in toxicity due to the presence of suspended solids was shown only for pyrethroid insecticides with log K-OW greater than 5, but the extent of this reduction depended on particle concentration and size, and potentially also on the ecotoxicological endpoint; 3) for pesticides with a log K-OW less than 3 (e.g., triazines, carbamates, and organophosphates), the impact of particles on bioavailability and toxicity is small and species dependent; and 4) pesticide bioavailability is greatly influenced by the test species and their physiology (e.g., feeding behavior or digestion). We conclude that exposure of aquatic organisms to pesticides and environmental risk of many pesticides might be underestimated in prospective risk assessment, when predicted environmental concentration is estimated based on the K-OC of a compound. Integr Environ Assess Manag 2017;13:585-600. (c) 2016 SETA