Short-term effects of sucralose on Calanus finmarchicus and Calanus glacialis in Disko Bay,Greenland

The potential effects of sucralose on the Arctic copepods Calanus finmarchicus and Calanus glacialis were studied in Disko Bay, Greenland. Sucralose is a non-calorie sweetener and chlorine derivate of sucrose containing three chlorine atoms. Scandinavian screening studies of sucralose in 2007, revealed sucralose in all effluent samples. To investigate whether sucralose is harmful to the Arctic aquatic ecosystems, possible short-term effects were investigated on egg production, hatching rate, food intake and mortality of two species of Arctic copepods. The copepods were exposed to six different concentrations (0–50,000 ng · L^?1) of sucralose, which spans the range of concentrations found in the screening studies. Exposure led to no mortality among the copepods. Food intake by C. glacialis increased with increasing concentrations of sucralose. In C. finmarchicus, food intake did not differ with increasing concentrations. No effect of sucralose was observed on egg production of C. finmarchicus. Despite increased food intake with increasing concentrations of sucralose, C. glacialis did not increase its egg production. The results show that both species responded weakly to sucralose, but with C. glacialis being possibly slightly more sensitive to sucralose than C. finmarchicus.     

Distribution and trophic links of gelatinous zooplankton on Dogger Bank,North Sea

The ecology of small, gelatinous zooplankton is not integrated into management of Dogger Bank (54° 00′ N, 3° 25′ E to 55° 35′ N, 2° 20′ E). In pursuit of this goal, gelatinous zooplankton and their potential prey were sampled along a transect across the bank on June 10–16, 2007. Eleven species of small medusae and ctenophores were collected, with six abundant taxa occurring in greater numbers below the thermocline and in the shallower, southeastern portion of the bank. There were no statistically significant diel changes in distribution. In contrast, potential prey were distributed more evenly across the bank and throughout the water column. Isotopic analyses revealed that gelatinous zooplankton fed on both smaller (100–300 μm) and larger (>300 μm) mesozooplankton, but also potentially on each other. These ecological insights suggest that small medusae and ctenophores should be integrated into sustainable management of Dogger Bank.     

Environmental problems and environmental regulations in Western Europe, 1980–1989

Environmental problems are a function of the process of economic development and the ability to mitigate the problems through regulation. An historical analysis helps to show how the problems have been solved thus far. The objective of this investigation is to present an overview of environmental problems and the corresponding regulations in Western Europe during the 1980s. Environmental problems for 18 Western European countries were identified from abstracts from a data base on environmental literature. The 1977 findings were systematized on the basis of 20 key words according to source and impact, and a new data base was established. The data showed that the main environmental problems in Western Europe were: energy production/acid rain, nuclear power/waste, air pollution/climate, heavy metals, pesticides, water pollution, solid waste, and unforeseen accidents. Many environmental problems are common to most European countries. Regulatory measures differ significantly. In some countries environmental regulations are largely limited to the implementation of European Economic Community (EEC) directives. We have supplemented the national analyses with an examination of existing and proposed EEC regulations along with interviews with civil servants in the EEC Commission. In the 1980s, EEC environmental regulations were similar to environmental regulations in some member states. It is expected that future EEC regulations will be less reflective of those of individual member states.     

Evolution of variation in male secondary sexual characteristics

Summary The male pied flycatcher Ficedula hypoleuca exhibits sexual dimorphism in its plumage colour, varying from a female-like brown to jet black. The evoltution of this variation in male plumage colour can be explained by at least eight hypotheses viz., (I) neutral mutation; (II) individual recognition; (III) three forms of inter-sexual selection; (IIIa) mate selection for phenotypes, (IIIb) Fisherian selection, (IIIc) handicap selection; (IV) intrasexual selection; (V) delayed maturation; and (VI) female mimicry. The assumptions and predictions derived from all these hypotheses were tested by analysing the observed variation in male plumage colour in relation to age, body size, physical condition, survival rate, aggressivity in territorial defence, territorial quality, female choice of mate, sex ratio, and reproductive success. We found that: males became blacker with age; black males were larger than browner ones; however, browner males survived better between breeding seasons than did blacker ones; black males were more aggressive against black than brown intruders; blacker males occupied better territories; blacker males were paired earlier than browner males; and finally blacker males produced heavier offspring than did brown males. A reasonable conclusion from the results of these analyses is that four of the hypotheses considered, viz. mate selection for phenotypes (IIIa), Fisherian selection (IIIb), handicap selection (IIIc), and intra-sexual selection (IV) could not be rejected. We therefore suggest that the evolution of the observed variation in the secondary sexual characteristics of the male pied flycatcher can be explained by a combination of these hypotheses.     

Disruption of a belowground mutualism alters interactions between plants and their floral visitors

Plants engage in diverse and intimate interactions with unrelated taxa. For example, aboveground floral visitors provide pollination services, while belowground arbuscular mycorrhizal fungi (AMF) enhance nutrient capture. Traditionally in ecology, these processes were studied in isolation, reinforcing the prevailing assumption that these above- and belowground processes were also functionally distinct. More recently, there has been a growing realization that the soil surface is not a barrier to many ecological interactions, particularly those involving plants (who live simultaneously above and below ground). Because of the potentially large impact that mycorrhizae and floral visitors can have on plant performance and community dynamics, we designed an experiment to test whether these multi-species mutualisms were interdependent under field conditions. Using benomyl, a widely used fungicide, we suppressed AMF in a native grassland, measuring plant, fungal, and floral-visitor responses after three years of fungal suppression. AMF suppression caused a shift in the community of floral visitors from large-bodied bees to small-bodied bees and flies, and reduced the total number of floral visits per flowering stem 67% across the 23 flowering species found in the plots. Fungal suppression has species-specific effects on floral visits for the six most common flowering plants in this experiment. Exploratory analyses suggest these results were due to changes in floral-visitor behavior due to altered patch-level floral display, rather than through direct effects of AMF suppression on floral morphology. Our findings indicate that AMF are an important, and overlooked, driver of floral-visitor community structure with the potential to affect pollination services. These results support the growing body of research indicating that interactions among ecological interactions can be of meaningful effect size under natural field conditions and may influence individual performance, population dynamics, and community structure.     

Promise and performance of agricultural nutrient management policy: Lessons from the Baltic Sea

Following decades of international collaboration to restore the Baltic Sea, we provide an assessment of the domestic implementation of measures agreed to limit diffuse agricultural pollution and the patterns of policy instruments applied. Despite the Helsinki Convention being unusually specific in detailing what measures countries should introduce, we find many shortcomings. These are most pronounced in the larger countries (Poland, Germany and Russia), while smaller countries perform better, notably Sweden and Estonia. The patterns of policy instruments applied differ, influenced by domestic politics. The limited use of complementary policy instruments suggests that other priorities overrule full and effective implementation, with engagement mirroring the advantages that a restored Baltic Sea can bring to countries. Using the European Agricultural Fund for Rural Development to support farmers in managing nutrients, particularly advisory services and investments in modern manure management technologies, represents a significant opportunity for reducing agricultural pollution in most countries.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01549-3.     

The potential of willow for remediation of heavy metal polluted calcareous urban soils

Growth performance and heavy metal uptake by willow (Salix viminalis) from strongly and moderately polluted calcareous soils were investigated in field and growth chamber trials to assess the suitability of willow for phytoremediation. Field uptakes were 2-10 times higher than growth chamber uptakes. Despite high concentrations of cadmium (≥80 mg/kg) and zinc (≥3000 mg/kg) in leaves of willow grown on strongly polluted soil with up to 18 mg Cd/kg, 1400 mg Cu/kg, 500 mg Pb/kg and 3300 mg Zn/kg, it is unsuited on strongly polluted soils because of poor growth. However, willow proved promising on moderately polluted soils (2.5 mg Cd/kg and 400 mg Zn/kg), where it extracted 0.13% of total Cd and 0.29% of the total Zn per year probably representing the most mobile fraction. Cu and Pb are strongly fixed in calcareous soils.     

Painted surfaces--important sources of polychlorinated biphenyls (PCBs) contamination to the urban and marine environment

A study of a large number of samples of flaking old paint from various buildings in Bergen, Norway (N = 68) suggests that paint may be the most important contemporary source of PCBs in this urban environment with concentrations of PCB₇ up to 3.39 g/kg. Twenty-three of the samples were collected from a single building, and the concentrations were found to vary over 3 orders of magnitude. In addition, 16 concrete samples from a large bridge previously coated with PCB-containing paint were collected and separated into outer- and inner samples indicating that PCBs are still present in high concentrations subsequent to renovation. PCBs were found in several categories of paint from wooden and concrete buildings, potentially introduced to the environment by natural weathering, renovation, and volatilization. Consequently, this dispersion may lead to increased levels of PCBs in urban atmospheres, soils, and harbor sediments where high concentrations have resulted in Governmental advice against consumption of certain seafood.