Population responses of Daphnia magna, Chydorus sphaericus and Asellus aquaticus in pesticide contaminated ditches around bulb fields.

The goal of this study was to investigate the effects of ambient concentrations of pesticides combined with abiotic factors on the key aquatic species Daphnia magna, Chydorus sphaericus and Asellus aquaticus by means of 21 days field exposure experiments. In situ bioassays were deployed in ditches around flower bulb fields during spring and autumn 2011-2012. The results showed that phosphate was the most variable parameter followed by pesticides expressed as toxic units, as the main factors explaining differences between sites. Variation in reproduction and growth of cladoceran D. magna was largely explained by nutrients, whereas dissolved oxygen contributed mostly to variations in reproduction of C. sphaericus. Dissolved organic carbon contributed to variations in growth of the detrivore A. aquaticus. It is concluded that abiotic stressors rather than pesticides contributed significantly to the performance of aquatic invertebrates.

A review of the ecological effects of radiofrequency electromagnetic fields (RF-EMF).

OBJECTIVE: This article presents a systematic review of published scientific studies on the potential ecological effects of radiofrequency electromagnetic fields (RF-EMF) in the range of 10 MHz to 3.6 GHz (from amplitude modulation, AM, to lower band microwave, MW, EMF). METHODS: Publications in English were searched in ISI Web of Knowledge and Scholar Google with no restriction on publication date. Five species groups were identified: birds, insects, other vertebrates, other organisms, and plants. Not only clear ecological articles, such as field studies, were taken into consideration, but also biological articles on laboratory studies investigating the effects of RF-EMF with biological endpoints such as fertility, reproduction, behaviour and development, which have a clear ecological significance, were also included. RESULTS: Information was collected from 113 studies from original peer-reviewed publications or from relevant existing reviews. A limited amount of ecological field studies was identified. The majority of the studies were conducted in a laboratory setting on birds (embryos or eggs), small rodents and plants. In 65% of the studies, ecological effects of RF-EMF (50% of the animal studies and about 75% of the plant studies) were found both at high as well as at low dosages. No clear dose-effect relationship could be discerned. Studies finding an effect applied higher durations of exposure and focused more on the GSM frequency ranges. CONCLUSIONS: In about two third of the reviewed studies ecological effects of RF-EMF was reported at high as well as at low dosages. The very low dosages are compatible with real field situations, and could be found under environmental conditions. However, a lack of standardisation and a limited number of observations limit the possibility of generalising results from an organism to an ecosystem level. We propose in future studies to conduct more repetitions of observations and explicitly use the available standards for reporting RF-EMF relevant physical parameters in both laboratory and field studies.

Morphological markers for the detection of introgression from cultivated into wild carrot (Daucus carota L.) reveal dominant domestication traits.

Hybridisation and subsequent introgression have recently received much attention in the context of genetically modified crops. But crop-wild hybrid detection in the field can be difficult, as most domestication traits seem to be recessive, and the hybrid phenotype may also depend on the direction of the cross or environmental factors. Our aim was to develop a reliable set of morphological markers that differ between two wild and 13 cultivated carrots (Daucus carota L.) and to evaluate their inheritance in hybrid lines. We then examined these morphological markers in four F1 hybrids obtained by fertilising plants from the two wild accessions with pollen from two common carrot cultivars. Of the 16 traits that differed between the two carrot subspecies, three took intermediate values in the hybrids, eight resembled the cultivar parent (dominant domestication traits), two resembled the wild parent (domestication traits recessive), and three were not significant or growth condition-dependent. Root:shoot ratio was seven times higher for cultivars than for wild plants, while still attaining equivalent total dry weight, which shows that dry matter production by the shoot is much higher in cultivars than in wild plants. High root:shoot ratios were also present in the hybrids. While we found no maternal effects, the type of cultivar used for pollination had an impact on hybrid characteristics. The morphological markers developed here provide insights into the mode of inheritance of ecologically relevant traits and can be useful for pre-screening wild populations for hybrid detection prior to genetic analysis.

Linking land use with pesticides in Dutch surface waters.

Compared with other European countries The Netherlands has a relatively high level of pesticide consumption, particularly in agriculture. Many of the compounds concerned end up in surface waters. Surface water quality is routinely monitored and numerous pesticides are found to be present in high concentrations, with various standards being regularly exceeded. Many standards-breaching pesticides exhibit regional patterns that can be traced back to land use. These patterns have been statistically analysed by correlating surface area per land use category with standards exceedance per pesticide, thereby identifying numerous significant correlations with respect to breaches of both the ecotoxicological standard (Maximum Tolerable Risk, MTR) and the drinking water standard. In the case of the MTR, greenhouse horticulture, floriculture and bulb-growing have the highest number as well as percentage of standard-breaching pesticides, despite these market segments being relatively small in terms of area cropped. Cereals, onions, vegetables, perennial border plants and pulses are also associated with many pesticides that exceed the drinking water standard. When a correction is made for cropped acreage, cereals and potatoes also prove to be a major contributor to monitoring sites where the MTR standard is exceeded. Over the period 1998-2006 the land-use categories with the most and highest percentage of standards-exceeding pesticides (greenhouse horticulture, bulb-growing and flower cultivation) showed an increase in the percentage of standards-exceeding compounds.

The contribution of neighbouring countries to pesticide levels in Dutch surface waters.

Compared with other European countries, Dutch consumption of pesticides is high, particularly in agriculture, with many of the compounds found in surface waters in high concentrations and various standards being exceeded. Surface water quality is routinely monitored and the data obtained are published in the Dutch Pesticides Atlas. One important mechanism for reducing pesticide levels in surface waters is authorisation policy, which proceeds on the assumption that the pollution concerned has taken place in the Netherlands. The country straddles the delta of several major European rivers, however, and as river basins do not respect national borders some of the water quality problems will derive from neighbouring countries. Against this background the general question addressed in this article is the following: To what extent do countries neighbouring on the Netherlands contribute to pesticide pollution of Dutch surface waters? To answer this question, data from the Pesticides Atlas for the period 2005-2009 were used. Border zones with Belgium and Germany were defined and the data for these zones compared with Dutch data. In the analyses, due allowance was also made for authorised and non-authorised compounds and for differences between flowing and stagnant waters. Monitoring efforts in the border zones and in the Netherlands were also characterised, showing that efforts in the former are similar to those in the rest of the country. In the border zone with Belgium the relative number of non-authorised pesticides exceeding the standards is clearly higher than in the rest of the Netherlands. These exceedances are observed mainly in flowing waters. In contrast, there is no difference in the relative number of standard-exceeding measurements between the border zones and the rest of the Netherlands. In the boundary zones the array of standard-exceeding compounds clearly deviates from that in the rest of the Netherlands, with compounds authorised in the neighbouring countries but not in the Netherlands, such as flufenacet, featuring prominently. The share of the neighbouring countries in the total number of exceedances in the Netherlands is roughly proportional to the relative area of the border zones. Although there is a certain influx of pesticides from across national borders, the magnitude of the problem appears to be limited.

Similarities and differences between measured and predicted concentrations of pesticides in Dutch surface waters.

In order to have a thorough evaluation of the progress and effectiveness of Dutch crop protection policy, both model predictions and measured pesticide concentrations in surface waters are considered. To this purpose, monitoring data obtained by various water boards and other monitoring institutes were processed. Data were aggregated over a two year time period and over space (at 1x1 km-grid). A geographic view is given in the Dutch Pesticides Atlas (www.pesticidesatlas.nl). The model used for the predictions was the Dutch National Environmental Indicator NMI version 2 (www.nmi.alterra.nl) that has input data regarding spray drift data, crop interception, soil and climate and many more. Information on aggregation steps over time and space, grid sizes, information on crop areas was geared to one another for both instruments. Results on measured pesticide concentrations in surface waters and model predictions were compared to each other at the national scale. For this study, 10 different cases were selected covering a large range of pesticides' characteristics and pesticides' use. In 60% of the cases, the results were largely in agreement with each other when expressed as absolute numbers of measurements exceeding the environmental quality standard. This is very accurate and useful for policy purposes. Based on concentrations and on the order of magnitude, no significant agreement between measurements and model predictions was found. Differences were explained by various factors, and an overview of predominant systematic differences between the measurements and the model predictions was presented. Using both measurements and model predictions in supporting environmental policy evaluations is warranted, because of higher Weight-of-Evidence. Combining both can assist in optimizing the knowledge on pesticides behaviour, fate and ecological problems and therefore this is the preferred evaluation method.

Ecological impacts of early 21st century agricultural change in Europe--a review.

The impacts of agricultural land use are far-reaching and extend to areas outside production. This paper provides an overview of the ecological status of agricultural systems across the European Union in the light of recent policy changes. It builds on the previous review of 2001 devoted to the impacts of agricultural intensification in Western Europe. The focus countries are the UK, The Netherlands, Boreal and Baltic countries, Portugal, Hungary and Romania, representing a geographical spread across Europe, but additional reference is made to other countries. Despite many adjustments to agricultural policy, intensification of production in some regions and concurrent abandonment in others remain the major threat to the ecology of agro-ecosystems impairing the state of soil, water and air and reducing biological diversity in agricultural landscapes. The impacts also extend to surrounding terrestrial and aquatic systems through water and aerial contamination and development of agricultural infrastructures (e.g. dams and irrigation channels). Improvements are also documented regionally, such as successful support of farmland species, and improved condition of watercourses and landscapes. This was attributed to agricultural policy targeted at the environment, improved environmental legislation, and new market opportunities. Research into ecosystem services associated with agriculture may provide further pressure to develop policy that is targeted at their continuous provisioning, fostering motivation of land managers to continue to protect and enhance them.

Risk mapping of pesticides: the Dutch atlas of pesticide concentrations in surface waters: www.pesticidesatlas.nl.

Many pesticides are being measured in surface water. To promote the use of monitoring data in the process of risk mapping, post-registration, and improvement of water quality, a free available Internet tool has been developed to present all measurements of pesticides in surface water on the level of individual active ingredients in a spatial framework: the Dutch pesticides atlas (www.pesticidesatlas.nl). With this communication tool one can easily get maps concerning where a pesticide is being measured, observed and possibly constitutes a problem over the years. Pesticide concentrations are being compared with environmental standards and maps can been made of each pesticide at a national level. The pesticide maps have been linked with GIS land use data. At present statistical correlations can be made between crop areas and pesticides concentrations in the water. Moreover, predictions can be made where a pesticide might be exceeding environmental standards. Policy makers, chemical industry (product stewardship), NGO's and farmers can use the maps as a tool for communication and improving environmental quality. The atlas is also being used to evaluate the effectiveness of pesticide policy over the years. In this contribution the methodological background of the pesticides atlas is presented.

Characterization of grit in arable birds to improve pesticide risk assessment.

To describe the grit in bird gizzards, we examined the gizzard content of some 200 birds of varying size and diet (e.g., granivores and nongranivores). Grit use (frequency, size, amount, and shape) was characterized for 27 bird species that forage, at least part of the year, on arable land in the Netherlands. Three different groups could be recognized: the nongranivores with predominantly small "grit" particles (the result of inadvertent ingesting soil while foraging), the granivores with larger grit particles (the result of intentionally selecting soil particles), and the group in between (omnivores), which shows features of both other groups. Sample calculations made in this article show a probability of 3-277 in 1000 times for unintentionally consuming one granule. Therefore, attention should also be paid to nongranivorous birds when assessing the hazard or risk of the use of granular pesticide formulations. A risk assessment model is presented in the Appendix.

Benchmarking farmer performance as an incentive for sustainable farming: environmental impacts of pesticides.

Pesticide use in The Netherlands is very high, and pesticides are found across all environmental compartments. Among individual farmers, though, there is wide variation in both pesticide use and the potential environmental impact of that use, providing policy leverage for environmental protection. This paper reports on a benchmarking tool with which farmers can compare their environmental and economic performance with that of other farmers, thereby serving as an incentive for them to adopt more sustainable methods of food production methods. The tool is also designed to provide farmers with a more detailed picture of the environmental impacts of their methods of pest management. It is interactive and available on the internet: www.agriwijzer.nl. The present version has been developed specifically for arable farmers, but it is to be extended to encompass other agricultural sectors, in particular horticulture (bulb flowers, stem fruits), as well as various other aspects of sustainability (nutrient inputs, 'on-farm' biodiversity, etc.). The benchmarking methodology was tested on a pilot group of 20 arable farmers, whose general response was positive. They proved to be more interested in comparative performance in terms of economic rather than environmental indicators. In their judgment the benchmarking tool can serve a useful purpose in steering them towards more sustainable forms of agricultural production. The benchmarking results can also be used by other actors in the agroproduction chain, such as food retailers and the food industry.

Atlas of pesticide concentrations in Dutch surface waters: a pilot study.

A pilot study was conducted to explore the potential for geographically mapping concentrations of individual pesticides in Dutch surface waters and compiling these maps into a National Pesticide Atlas. This atlas could be used for various purposes: 1) To see where specific pesticides are monitored, observed and find out whether these are problematical. 2) To explore the relationship between environmental pesticide levels and land use, using the results as feedback to improve national pesticide admission procedures (post-registration review) 3) To review the quality of the present Dutch pesticide monitoring system. For the study we used measured data for the years 1997 and 1998, preparing maps for six illustrative pesticides. The data are presented on a grid scale of 5x5 km2. Pesticide concentrations are compared with three standards: the EU drinking water standard, the maximum tolerable risk (MTR) level and the admission standard set by the Dutch Pesticide Admission Board (CTB). The results show that all these pesticides can be satisfactorily mapped at the national level and that for most of the compounds investigated a useful relationship can be established between environmental concentration and land use. The maps also serve to show up gaps in the present pesticide monitoring system. The study yielded several new insights, among them that standards were found to be exceeded in areas and at times of the year not anticipated on the basis of land use and pesticide use statistics. As a follow-up to this pilot study a new project has been started to develop an internet version of the pesticide atlas for all measured pesticides in The Netherlands.

Environmental labelling in The Netherlands: a framework for integrated farming.

This article compares four Dutch environmental certification schemes for agricultural food crops, analysing their methodology and the completeness of their criteria on five aspects: pesticide use, nutrient use, water management, energy and materials consumption, and habitat management. The least stringent of the labels, the MBT ('Environmentally Aware Cultivation') certificate, serves mainly to increase farmers' awareness of nutrient and pesticide use. With regard to both administrative obligations and actual management practices, the MBT label largely mirrors the terms of standing Dutch legislation. The CC ('Controlled Cultivation') and AMK ('Agro-Environmental') labels comprise more and more stringent criteria. With their restrictions on nutrient and pesticide use, these two labels serve as the two principal labels in the field of integrated agriculture. There is little difference between the two and it is recommended that they be merged, on the basis of a standardised definition of integrated agriculture. The EKO ('Organic Agriculture') label proceeds from different principles, but as a minimum should also comply with Dutch legislation without exception. For both integrated and organic agriculture, in addition to criteria on pesticide and nutrient use, criteria should also be developed for water management, energy and materials use and habitat management. The relationship between the criteria and their respective thresholds and Dutch legislation is also addressed. Existing criteria are frequently specified in such a way that the environmental benefits cannot be ascertained. This is a serious drawback for the parties further down the chain: auctioneers, retailers and consumers. It is recommended to develop qualitative guidelines for an Agricultural Stewardship Council at international level, like the Forest Stewardship Council, and a separate label for integrated agriculture per country comprising quantitative criteria for all relevant aspects of farming operations.

Effects of glufosinate-ammonium on off crop vegetation--interim results.

In 2000 a field study was conducted at four different locations concerning the effects of low dosages of glufosinate-ammonium, a leaf acting herbicide, on off crop vegetation. Therefore species rich road verges and ditch banks not adapted to a history of herbicide use were sprayed twice with different dosages of glufosinate-ammonium, simulating drift (0, 2, 4, 16, 32 and 64% of the maximum field dose: 800 g a.i./ha). The parameters studied were short term phytotoxic effects and the effects on biomass, species cover and number of species in autumn (Braun-Blanquêt relevés). The results show significant phytotoxic effects at all dosages of glufosinate-ammonium on the non-target vegetation. The low concentrations (2 and 4%) had most impact when applied early in the season (9% average at the 2% dosage and 22% at 4% dosage, after the first spraying. At high dosages (32 and 64%) a decrease of the biomass of the vegetation was found in August. A comparison between treatments in August shows a small decrease in species number and cover in the 64% compared to the control. In the comparison between the spring and August relevés, the decrease in the mean number of species was significantly stronger in the treated plots than in the untreated ones of 4% and higher. For monocotyledons in all treatments except 16%, a significantly stronger decrease in species number was found compared to the untreated. For dicotyledons only the 64% dosage differed from the untreated. Only at the 64% treatment the total cover of species decreased more than in the untreated plots. Since drift percentages of 2-4% can be expected at 1-2 m from a treated plot it can be concluded that the use of glufosinate-ammonium could result in visible short term phytotoxic effects (max 22%) on off-crop vegetation such as ditch banks and verges. There are also indications that effects on the number and cover of species in autumn can occur. Because in future glufosinate-ammonium could be used on a large scale in herbicide resistant crops like maize, which will be cultivated on the same field for many years, this study will be continued in 2001 in order to investigate if there are--whether or not--sustainable effects on the off crop vegetation.

Trends of pesticide use in The Netherlands.

In 1991, a policy plan was adopted in the Netherlands, one of whose aims was a 50% reduction in pesticide use by 2000. The present paper surveys pesticide sales since 1974 and the use of such compounds in different crops per hectare as well as for the country as a whole. The results show that by the mid-1990s, pesticide consumption in kilogram terms had been reduced by about 50% compared to the mid-1980s. This reduction, however, was almost totally caused by the reduction in the use of soil disinfectants, while reduction targets for herbicides and fungicides were not met at all. Arable crops, especially potatoes and maize, which cover large areas in the Netherlands, contributed most to total consumption, while apples, tulips and lilies also made considerable contributions. On a per hectare per year basis, pesticide consumption was highest in ornamental plants like roses, chrysanthemums, lilies and hyacinths, followed by vegetables grown in greenhouses, apples and pears and mushroom cultivation. A remarkable feature is that the majority of the 20 most commonly used compounds (in terms of total consumption in kilograms of active ingredient or area sprayed) had already been introduced before 1980. On a kilogram basis, fungicides and soil disinfectants were used in the largest quantities, together with mineral oil and followed by herbicides. On a per hectare basis, herbicides played a more important role, while one insecticide also featured.

Pesticide residues in human food and wildlife in The Netherlands.

Several monitoring programmes for pesticide residues in food are currently operative in the Netherlands, some of which are related to EU directives. These programmes cover a range of products. This paper reviews the 1997 and 1998 data for fruit and vegetables, meat, milk, livestock and fish, as well as presenting data on pesticide residues in wildlife. The aim of the paper is to provide an overview of what is known about pesticide residues in the Netherlands, including indications of the origins of the compounds found. A total of 281 different compounds were monitored on fruit and vegetables. Of these compounds, 45% were actually found on products and 28% exceeded the standard. Expressed as percentages of the number of measurements, the data show that 0.3% of the measurements detected a compound, and standards were exceeded in 0.02% of the measurements. Some of the cases in which standards were exceeded concerned the use of compounds in minor crops, for which their use is not permitted. Other cases involved excessive dosages or application within the safety interval before harvest. In meat, milk and livestock, 10 persistent organochlorine compounds were measured. Most of these compounds, with the exception of lindane, are no longer in use, but are still being found as residues. The concentrations found were very low and have not exceeded standards for human consumption since 1993. No assessment was made, however, of products currently in use. Organochlorine compounds have also frequently been found in fish (eel), in higher concentrations than in meat, but in nearly all cases in quantities below the standards for human consumption. Ecological standards for accumulation in the food chain were exceeded on a larger scale and indications of exposure effects on piscivorous birds (cormorants) were found. No data on pesticide residues in wildlife are known for terrestrial organisms.

Ecological impacts of arable intensification in Europe.

Although arable landscapes have a long history, environmental problems have accelerated in recent decades. The effects of these changes are usually externalized, being greater for society as a whole than for the farms on which they operate, and incentives to correct them are therefore largely lacking. Arable landscapes are valued by society beyond the farming community, but increased mechanization and farm size, simplification of crop rotations, and loss of non-crop features, have led to a reduction in landscape diversity. Low intensity arable systems have evolved a characteristic and diverse fauna and flora, but development of high input, simplified arable systems has been associated with a decline in biodiversity. Arable intensification has resulted in loss of non-crop habitats and simplification of plant and animal communities within crops, with consequent disruption to food chains and declines in many farmland species. Abandonment of arable management has also led to the replacement of such wildlife with more common and widespread species. Soils have deteriorated as a result of erosion, compaction, loss of organic matter and contamination with pesticides, and in some areas, heavy metals. Impacts on water are closely related to those on soils as nutrient and pesticide pollution of water results from surface runoff and subsurface flow, often associated with soil particles, which themselves have economic and ecological impacts. Nitrates and some pesticides also enter groundwater following leaching from arable land. Greatest impacts are associated with simplified, high input arable systems. Intensification of arable farming has been associated with pollution of air by pesticides, NO2 and CO2, while the loss of soil organic matter has reduced the system's capacity for carbon sequestration. International trade contributes to global climate change through long distance transport of arable inputs and products. The EU Rural Development Regulation (1257/99) provides an opportunity to implement measures for alleviating ecological impacts of arable management through a combination of cross-compliance and agri-environment schemes. To alleviate the problems described in this paper, such measures should take account of opportunities for public/private partnerships and should integrate social, cultural, economic and ecological objectives for multifunctional land use.

Buffer zones for reducing pesticide drift to ditches and risks to aquatic organisms.

Pesticide drift from field sprayers fitted with different types of spray nozzles was investigated under various wind speed conditions. Droplet drift was measured adjacent to the sprayed field, on the ditch bank, and in the ditch. Measurements were carried out in the normal sprayed situation and with an unsprayed buffer zone 3 or 6 m wide. The results indicate that there are major differences between spray nozzles. Drift deposition increases with wind speed. In the sprayed situation and with a wind speed of 0.5 m/s, there was a maximum of 6.0% drift deposition halfway down the ditch bank and no drift deposition in the ditch. At 3 m/s wind speed these figures are 25.1 and 2.2%, respectively. At 5 m/s wind speed, 7.2% drift deposition was measured in the ditch. Risk assessment (cf. SLOOTBOX model) carried out with 17 pesticides used in the study area indicated that at this wind speed, 8 of the 17 pesticides investigated posed a risk to aquatic organisms. Creation of a 3-m buffer zone decreases drift deposition in the ditch by a minimum of 95%. Adjacent to the buffer zone only 4 of the 17 pesticides investigated posed a (minor) risk to aquatic organisms. With a 6-m buffer zone no drift deposition in the ditch could be measured (wind speed maximum, 4.5 m/s). Creating unsprayed crop edges offers good possibilities for the protection of aquatic ecosystems. Socioeconomic research among farmers indicates that buffer zones, such as unsprayed cereal edges and unsprayed grass strips, could well be adopted in agricultural practice.

Chemical threat to birds and mammals in The Netherlands.

This article reviews the impact of xenobiotic substances on wild birds and mammals in The Netherlands, as recorded in the field over the past 25 yr. First, a brief survey is given of population trends during this period, using a few illustrative examples to indicate the role played by "environmental policy themes" other than diffusion. The present review of the policy theme diffusion is not intended to be exhaustive, but to provide a broad summary of the nature of the problems involved. Based on this review, conclusions are drawn about the ecological compatibility of various groups of xenobiotics with respect to birds and mammals. Because policy-makers are interested in the relative significance of both the various groups of substances and the various environmental themes for the decline of bird and mammal populations in The Netherlands, a provisional estimate of these contributions is also presented. The main conclusion is that, in the context of the policy theme diffusion, PCBs and pesticides have the greatest impact on birds and mammals. PCBs have an impact up to the species level, whereas the main impact of pesticides today is probably ecological, that is, foraging and habitat changes. It is also concluded that the share of the theme diffusion in the sum total of negative environmental influences is approximately one-quarter.