Monitoring plastic ingestion by the northern fulmar Fulmarus glacialis in the North Sea

The abundance of plastics in stomachs of northern fulmars from the North Sea is used in the OSPAR Ecological Quality Objective (EcoQO) for marine litter. The preliminary EcoQO defines acceptable ecological quality as the situation where no more than 10% of fulmars exceed a critical level of 0.1 g of plastic in the stomach. During 2003-2007, 95% of 1295 fulmars sampled in the North Sea had plastic in the stomach (on average 35 pieces weighing 0.31 g) and the critical level of 0.1 g of plastic was exceeded by 58% of birds, with regional variations ranging from 48 to 78%. Long term data for the Netherlands since the 1980s show a decrease of industrial, but an increase of user plastics, with shipping and fisheries as the main sources. The EcoQO is now also used as an indicator for Good Environmental Status in the European Marine Strategy Framework Directive.     

The use of environmental metabolomics to determine glyphosate level of exposure in rapeseed (Brassica napus L.) seedlings

Metabolic profiling in plants can be used to differentiate between treatments and to search for biomarkers for exposure. A methodology for processing Ultra-High-Performance Liquid Chromatography-Diode-Array-Detection data is devised. This methodology includes a scheme for selecting informative wavelengths, baseline removal, retention time alignment, selection of relevant retention times, and principal component analysis (PCA). Plant crude extracts from rapeseed seedling exposed to sublethal concentrations of glyphosate are used as a study case. Through this approach, plants exposed to concentrations down to 5 μM could be distinguished from the controls. The compounds responsible for this differentiation were partially identified and were different from those specific for high exposure samples, which suggests that two different responses to glyphosate are elicited in rapeseed depending on the level of exposure. The PCA loadings indicate that a combination of other metabolites could be more sensitive than the response of shikimate to detect glyphosate exposure.     

Transport modes and pathways of the strongly sorbing pesticides glyphosate and pendimethalin through structured drained soils

Leaching of the strongly sorbing pesticides glyphosate and pendimethalin was evaluated in an 8-month field study focussing on preferential flow and particle-facilitated transport, both of which may enhance the leaching of such pesticides in structured soils. Glyphosate mainly sorbs to mineral sorption sites, while pendimethalin mainly sorbs to organic sorption sites. The two pesticides were applied in equal dosage to a structured, tile-drained soil, and the concentration of the pesticides was then measured in drainage water sampled flow-proportionally.The leaching pattern of glyphosate resembled that of pendimethalin, suggesting that the leaching potential of pesticides sorbed to either the inorganic or organic soil fractions is high in structured soils. Both glyphosate and pendimethalin leached from the root zone, with the average concentration in the drainage water being 3.5 and 2.7 μg L⁻¹, respectively. Particle-facilitated transport (particles >0.24 μm) accounted for only a small proportion of the observed leaching (13-16% for glyphosate and 16-31% for pendimethalin). Drain-connected macropores located above or in the vicinity of the drains facilitated very rapid transport of pesticide to the drains. That the concentration of glyphosate and pendimethalin in the drainage water remained high (>0.1 μg L⁻¹) for up to 7 d after a precipitation event indicates that macropores between the drains connected to underlying fractures were able to transport strongly sorbing pesticides in the dissolved phase. Lateral transport of dissolved pesticide via such discontinuities implies that strongly sorbing pesticides such as glyphosate and pendimethalin could potentially be present in high concentrations (>0.1 μg L⁻¹) in both water originating from the drainage system and the shallow groundwater located at the depth of the drainage system.     

Treatment of municipal landfill leachate by catalytic wet air oxidation: Assessment of the role of operating parameters by factorial design

The wet air oxidation (WAO) of municipal landfill leachate catalyzed by cupric ions and promoted by hydrogen peroxide was investigated. The effect of operating conditions such as WAO treatment time (15-30 min), temperature (160-200 °C), Cu²⁺ concentration (250-750 mg L⁻¹) and H₂O₂ concentration (0-1500 mg L⁻¹) on chemical oxygen demand (COD) removal was investigated by factorial design considering a two-stage, sequential process comprising the heating-up of the reactor and the actual WAO. The leachate, at an initial COD of 4920 mg L⁻¹, was acidified to pH 3 leading to 31% COD decrease presumably due to the coagulation/precipitation of colloidal and other organic matter. During the 45 min long heating-up period of the WAO reactor under an inert atmosphere, COD removal values up to 35% (based on the initial COD value) were recorded as a result of the catalytic decomposition of H₂O₂ to reactive hydroxyl radicals. WAO at 2.5 MPa oxygen partial pressure advanced treatment further; for example, 22 min of oxidation at 200 °C, 250 mg L⁻¹ Cu²⁺ and 0-1500 mg L⁻¹ H₂O₂ resulted in an overall (i.e. including acidification and heating-up) COD reduction of 78%. Amongst the operating variables in question, temperature had the strongest influence on both the heating-up and WAO stages, while H₂O₂ concentration strongly affected the former and reaction time the latter. Nonetheless, the effects of temperature and H₂O₂ concentration were found to depend on the concentration levels of catalyst as suggested by the significance of their 3rd order interaction term.     

Growth and development rates of Calanus finmarchicus nauplii during a diatom spring bloom

Growth and development rates were determined for nauplii of Calanus finmarchicus (Gunnerus) in the near-shore waters of a western Norwegian fjord from in situ mesocosm incubations. The major food source for the nauplii was diatoms, but Phaeocystis sp., dinoflagellates and ciliates were also part of the diet. At local temperatures ranging from 4.8 to 5.2 °C the cumulative median development time from hatching to Nauplius VI was 19 d. The time taken to molt to the next naupliar stage was approximately constant (3 d) from Stages IV to VI, but Stage III needed the longest development time (5 d). The instantaneous growth rate in terms of body carbon was negative from hatching to Nauplius Stage II, but as high as 0.25 to 0.30 d⁻¹ from Stage III to V. Enhancement of food resources by nutrient addition led to no significant change in specific growth rates. Additionally, the cohorts from different nutrient regimes showed almost equal development time, size and body carbon within stages. Length–weight relationships of nauplii from the two different food resources were: W _{low resources} = 4.17 × 10⁻⁶ × L ^2.03 (r ² = 0.84) and W _{high resources} = 4.29 × 10⁻⁶ × L ^2.05 (r ² = 0.92), where weight (W) is in micrograms of C and body length (L) in micrometers. The natural body morphology of naupliar stages I to VI is illustrated with digital images, including the final molt from Nauplius VI to Copepodid Stage I. In general, development of the nauplii was faster than that of the copepodids of C. finmarchicus, and structural growth was exponential from naupliar stages III to VI. This study validates our earlier results that nauplii of C. finmarchicus can obtain high growth and nearly maximal developmental rates at relatively low food levels (∼50 μg C l⁻¹), suggesting that nauplii exhibit far less dependence on food supply than copepodids. Received: 30 July 1999 / Accepted: 7 March 2000     

Relative Costs and Benefits of a Continuous and a Periodic Forest Inventory in Minnesota

We show that the Annual Forest Inventory System (AFIS) being developed by the USDA Forest Service and tested in the state of Minnesota is no more costly than the periodic Minnesota forest inventory (12 year measurement cycle). Since very useful results could be generated with AFIS every 4 years in addition to the results from the periodic survey, a continuous inventory would be cost effective. Periodic surveys yield more precise estimates within the first few years of the full survey but afterwards the annual survey would be more precise. Where the changeover in precision occurs still needs to be determined. This cost-neutral advantage of AFIS is quite important to note since the USFS has decided to go to annualized inventories such as AFIS this year.     

Teil I: Stoffstromanalysen landwirtschaftlicher Produktionsverfahren

When discussing strategies for realising an environmental friendly agricultural production, there are methods for quantifying environmental effects which do not originate in agricultural contexts. For instance, the methodology of Life Cycle Assessment is mainly developed from analyses of industrial production lines and products. Substance flow analyses in agriculture contain a complete analysis of agriculturally caused substance and energy flows, to which certain environmental effects are assigned, and also an assessment of these effects. For the provision of production means, balancing agricultural production procedures includes the extraction of energy sources and mineral resources from their reservoirs. The growth phase of the crops regarded (cereals, sugar beet, rape) is described depending on the nutrients nitrogen, phophor, potassium and calcium. The nitrogen flux within the system plant-soil-atmosphere is recorded referring to its temporal dynamic. In the framework of this study, selected environmental effects of agricultural production procedures of winter wheat are calculated regarding different conditions of locations and are supplemented by declining scenario simulations. Essential features of the structure of the substance flow net, which is implemented for the calculation and which can be used completely or as for single modules for further studies, are explained. Basing on selected categories of effectiveness, ecological optimisation potentials of varying agricultural provision of production means and procedures are estimated within the whole context of provision. Thereby, the effects of a reduced employment of fertilisers, of a change as for the kind of fertiliser and of the region of origin of the N-fertiliser, as well as variations concerning mechanical work in the fields are outlined for the cultivation of winter wheat.     

Do males and females differ in the feeding of large and small siblings? An experiment with the bluethroat

Males and females have been reported to differ in their feeding of large and small siblings in several species of birds. According to recent hypotheses, this phenomenon may be related to a sexual conflict over avian hatching patterns. We designed an experiment to test for the existence of such a sex difference by manipulating nestling size hierarchies of the bluethroat (Luscinia s. svecica) in two directions; half the broods were “asynchronized” to yield large size-differences within broods and the other half were “synchronized” to yield small size-differences. In all broods, nestlings were categorized as being either large or small according to body mass. We recorded male and female food distribution by video early (day 4 after hatching) and late (day 8) in the nestling period. Males and females did not differ in their distribution of food among different-sized nestlings. With large size-differences, both males and females fed large nestlings nearly twice as often as small ones. In contrast, when the size-differences were small, food was more evenly distributed among nestlings. Early in the nestling period, males fed more nestlings during each feeding visit than did females. Our finding that male and female bluethroats do not differ in the feeding of large and small siblings is in contrast to most previous studies. Variation in costs and benefits to males and females from feeding different-sized nestlings, and restrictions to parental choice due to nestling interactions, may explain interspecific variation. Received: 27 June 1997 / Accepted after revision: 26 January 1998     

Microbial degradation pathways of the herbicide dichlobenil in soils with different history of dichlobenil-exposure

This is the first detailed study of metabolite production during degradation of the herbicide 2,6-dichlorobenzonitrile (dichlobenil). Degradation of dichlobenil and three potential metabolites: 2,6-dichlorobenzamide (BAM), 2,6-dichlorobenzoic acid (2,6-DCBA) and ortho-chlorobenzamide (OBAM) was studied in soils either previously exposed or not exposed to dichlobenil using a newly developed HPLC method. Dichlobenil was degraded in all four soils; BAM and 2,6-DCBA were only degraded in soils previously exposed to dichlobenil (100% within 35-56 days and 85-100% in 56 days, respectively), and OBAM in all four soils (25-33% removal in 48 days). BAM produced from dichlobenil was either hydrolyzed to 2,6-DCBA or dechlorinated to OBAM, which was further hydrolyzed to ortho-chlorobenzoic acid. BAM was rapidly mineralized in previously exposed soils only. All potential metabolites and the finding that BAM was a dead-end metabolite of dichlobenil in soils not previously exposed to dichlobenil needs to be included in risk assessments of the use of dichlobenil.     

Composition of source-sorted municipal organic waste collected in Danish cities

Source-sorted municipal organic waste from different dwelling types in five Danish cities was sampled during one year. The samples were from permanent, full-scale systems or temporary, experimental systems for collection of source-sorted municipal organic waste. Pre-treatment of the organic waste prior to biological treatment was used in all cities to remove foreign objects and provide size reduction. All sampling was performed after pre-treatment in order to obtain more homogeneous and representative samples. The sampling included both the pre-treated waste and the reject from the pre-treatment allowing for estimation of the composition of the original waste. A total of 40 waste samples were chemically characterised with respect to 15 parameters. The waste generally consisted of around 88% VS of which an average of 80% was easily degradable. The average content of N, P and K in the dry matter of the organic waste was 2.5%, 0.4% and 0.9%, respectively. A general analysis of variance was applied to show the influence of the collection system, dwelling type and annual season on the waste composition. The content of plastic and crude fibres in the waste differed the most among the samples, probably due to use of different bag types (plastic and paper) in the different collection systems. Variations in the ash content and the calorific value might be explained by differences in the sorting instructions (whether soil and cat litter are allowed in the organic fraction). Significant seasonal variations were seen for ash, S and Cl. Dwelling type showed no statistically significant influence on any waste components. A test for uniform distribution of the p-values from the analysis of variance (Kolmogorov-Smirnov test) showed that the overall composition of the collected waste was strongly affected by the collection system (city) and season, while dwelling type had no significant influence.