Rating the risks of anticoagulant rodenticides in the aquatic environment: a review

Environmental Chemistry Letters - Anticoagulant rodenticides are used worldwide to control commensal rodents for hygienic and public health reasons. As anticoagulants act on all vertebrates, risk...     

An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 1: new molecules,metabolism, fate,and transport

Environmental Science and Pollution Research - With the exponential number of published data on neonicotinoids and fipronil during the last decade, an updated review of literature has been...     

PCDDs, PCDFs, dioxin-like PCBs and indicator PCBs in soil from five selected areas in Slovakia

There is a lack of information regarding persistent organic pollutants (POPs) in soil from Slovakia. This paper reports the concentrations of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), 12 dioxin-like polychlorinated biphenyls (dl-PCBs) and 6 indicator PCBs associated with 32 soil samples collected in 2007 from areas in the vicinity up to several kilometres from four selected industrial PCDD/F sources in Slovakia and one background area.The results show that the total WHO₁₉₉₈-PCDD/F/dl-PCB-TEQ concentrations varied from 0.34 to 18.05 pg g⁻¹ dry weight (dw) and the average total TEQ concentrations in samples collected at the Šala, Košice, Krompachy and Dubová areas were 3.18, 2.64, 7.80, and 3.19 pg g⁻¹ dw respectively. The average of the total WHO₁₉₉₈-TEQ values in three soil samples representing the background Starina area was 0.66 pg g⁻¹ dw. The predominant contaminants among 2,3,7,8-substituted PCDD/Fs, dl-PCB, and indicator PCBs was OCDD, PCB 118, and PCB 153 respectively. The major contributors to the TEQ were 2,3,4,7,8-PeCDF, PCB 126, 1,2,3,7,8-PeCDD, PCB 156 and 1,2,3,4,7,8-HxCDF + 1,2,3,4,7,9-HxCDF in descending order.     

Differential routing of ‘new’ nitrogen toward higher trophic levels within the marine food web of the Gulf of Aqaba, Northern Red Sea

Mesozooplankton communities in the meso-oligotrophic Gulf of Aqaba, Northern Red Sea, were investigated over a 2 years period (2005–2007) with emphasis on the trophodynamic relations among different taxonomic groups ranging from primary consumers to carnivorous predators. Based on stable isotope analyses, we present evidence for a strong contribution of ‘new’ nitrogen mainly derived from the utilization of aerosol nitrate by unicellular cyanobacteria especially during summer stratification and the propagation of exceptionally low δ¹⁵N onto higher trophic levels. In contrast, N₂-fixation by diazotrophs seemed to play a minor role, while the utilization of deep water nitrate by cyanobacteria and eukaryotic algae might be of importance during winter mixing. Based on ¹⁵N enrichment of consumers, clear differences between exclusively herbivorous organisms (doliolids, appendicularians, pteropods) and those with omnivorous feeding modes were detected. The category of omnivores comprised a large variety of taxons ranging from small meroplanktonic larvae to non-calanoid copepods (harpacticoids, cyclopoids and poecilostomatoids) that together form a diverse and complex community with overlapping feeding modes. In addition, distinct seasonality patterns in δ¹⁵N of copepods were found showing elevated trophic positions during periods of winter mixing, which were most pronounced for non-calanoid copepods. In general, feeding modes of omnivores appeared rather unselective, and relative contributions of heterotrophic protists and degraded material to the diets of non-calanoid copepods are discussed. At elevated trophic positions, four groups of carnivore predators were identified, while calanoid copepods and meroplanktonic predators showing lowest ¹⁵N enrichment within the carnivores. The direct link between ‘new’ nitrogen utilization by primary producers and the ¹⁵N enrichment of consumers in the planktonic food web of the Gulf of Aqaba emphasizes the significant contribution of ‘new’ nitrogen to the nitrogen budget and ecosystem functions in subtropical and tropical oligotrophic oceans.     

Why do female mice mate with multiple males?

Females often show multi-male mating (MMM), but the adaptive functions are unclear. We tested whether female house mice (Mus musculus musculus) show MMM when they can choose their mates without male coercion. We released 32 females into separate enclosures where they could choose to mate with two neighboring males that were restricted to their own territories. We also tested whether females increase MMM when the available males appeared unable to exclude intruders from their territories. To manipulate territorial intrusion, we introduced scent-marked tiles from the neighboring males into males' territories, or we rearranged tiles within males' own territories as a control. Each female was tested in treatment and control conditions and we conducted paternity analyses on the 57 litters produced. We found that 46 % of litters were multiply sired, indicating that multiple paternity is common when females can choose their mates. Intrusion did not increase multiple paternity, though multiple paternity was significantly greater in the first trial when the males were virgins compared to the second trial. Since virgin male mice are highly infanticidal, this finding is consistent with the infanticide avoidance hypothesis. We also found that multiple paternity was higher when competing males showed small differences in their amount of scent marking, suggesting that females reduce MMM when they can detect differences in males' quality. Finally, multiple paternity was associated with increased litter size but only in the intrusion treatment, which suggests that the effect of multiple paternity on offspring number is dependent on male–male interactions.     

Allocation in reproduction is not tailored to the probable number of matings in common toad (<Emphasis Type="Italic">Bufo bufo</Emphasis>) males

The theory of life history evolution assumes trade-offs between competing fitness traits such as reproduction, somatic growth, and maintenance. One prediction of this theory is that if large individuals have a higher reproductive success, small/young individuals should invest less in reproduction and allocate more resources in growth than large/old individuals. We tested this prediction using the common toad (Bufo bufo), a species where mating success of males is positively related to their body size. We measured testes mass, soma mass, and sperm stock size in males of varying sizes that were either (1) re-hibernated at the start of the breeding season, (2) kept without females throughout the breeding season, or (3) repeatedly provided with gravid females. In the latter group, we also estimated fertilization success and readiness to re-mate. Contrary to our predictions, the relationship between testes mass and soma mass was isometric, sperm stock size relative to testes mass was unrelated to male size, fertilization success was not higher in matings with larger males, and smaller males were not less likely to engage in repeated matings than larger males. These results consistently suggest that smaller males did not invest less in reproduction to be able to allocate more in growth than larger males. Causes for this unexpected result may include relatively low year-to-year survival, unpredictable between-year variation in the strength of sexual selection and low return rates of lowered reproductive investment.     

The memory of spatial patterns: changes in local abundance and aggregation in a tropical forest

The current spatial pattern of a population is the result of previous individual birth, death, and dispersal events. We present a simple model followed by a comparative analysis for a species-rich plant community to show how the current spatial aggregation of a population may hold information about recent population dynamics. Previous research has shown how locally restricted seed dispersal often leads to stronger aggregation in less abundant populations than it does in more abundant populations. In contrast, little is known about how changes in the local abundance of a species may affect the spatial distribution of individuals. If the level of aggregation within a species depends to some extent on the abundance of the species, then changes in abundance should lead to subsequent changes in aggregation. However, an overall change of spatial pattern relies on many individual birth and death events, and a surplus of deaths or births may have short-term effects on aggregation that are opposite to the long-term change predicted by the change in abundance. The change in aggregation may therefore lag behind the change in abundance, and consequently, the current aggregation may hold information about recent population dynamics. Using an individual-based simulation model with local dispersal and density-dependent competition, we show that, on average, recently growing populations should be more aggregated than shrinking populations of the same current local abundance. We tested this hypothesis using spatial data on individuals from a long-term tropical rain forest plot, and find support for this relationship in canopy trees, but not in understory and shrub species. On this basis we argue that current spatial aggregation is an important characteristic that contains information on recent changes in local abundance, and may be applied to taxonomic groups where dispersal is limited and within-species aggregation is observed.     

Physiological testing of Mytilus galloprovincialis for the environmental assessing of coastal marine areas: a case study in Boka Kotorska Bay (the Adriatic Sea)

The aim of this work was to validate in the field certain measurement of the heart rate alterations of the bioindicator organism Mytilus galloprovicialis as a tool for ecotoxicological biomonitoring and assessment applications related to coastal and marine environment. The latter was determined by testing the mussels according to the method of functional loading (1-hour lowered salinity stress-exposure). The time of heart rate (HR) recovery (T_rec) and the coefficient of HR variation (CV_HR) in a group of tested animals were used as biomarkers for the assessment of their physiological state. It was found that the values of the biomarkers in mussels from our reference location were 1.3-1.5 times lower than in mussels from differently polluted coastal areas of the Bay. The study also included an investigation of the relationship between the mussel’s cardiac rhythm characteristics and the bioaccumulation of trace elements in their soft tissues, caused by chronic pollution. The conclusion was drawn that this approach to the physiological testing of mussels could be useful in developing a rapid and low-cost method for the assessment of the health of coastal ecosystems.     

Use of Animal Species Data in Environmental Impact Assessments

Environmental Impact Assessments (EIAs) should ideally help minimize adverse effects on biological diversity by considering impacts of projects on wide ranges of species. This paper investigates how recent Dutch EIAs included the species comprising animal diversity. We present results of two studies on fauna data used in the EIAs. Objectives were to determine for different taxa (a) the relative representation of species in Environmental Impact Statements (EISs); (b) the extent to which EISs referred to specific species and the accuracy of survey data referred to; and (c) apparent roles of different EIA actors in species inclusion. EIAs were found to use data on various taxa but on limited numbers of species. The frequency with which taxa were included varied significantly. Birds were most frequently included, followed by mammals, amphibians, and other species groups. The quality of data on birds exceeded that regarding other vertebrates. Our results indicate that (a) EIA working groups of independent experts were the most influential in determining the data to be used; (b) on average, proponents included data more often than required by guidelines; and (c) in 30 to 40% of the EIAs, the participation of nongovernmental organizations prompted use of data. Despite the key role of experts in data inclusion, the taxon rankings found in the EIAs showed little deviation from those observed in studies on people’s preferences for species. Given the limited ranges of species considered, it is doubtful that the EIAs examined effectively contributed to conserving animal species diversity. Edo Knegtering produced this work in his personal capacity