Mitigation of agricultural nonpoint-source pesticide pollution in artificial wetland ecosystems

Contamination caused by pesticides in agriculture is a source of environmental poor water quality in some of the European Union countries. Without treatment or targeted mitigation, this pollution is diffused in the environment. Pesticides and some metabolites are of increasing concern because of their potential impacts on the environment, wildlife and human health. Within the context of the European Union (EU) water framework directive context to promote low pesticide-input farming and best management practices, the EU LIFE project ArtWET assessed the efficiency of ecological bioengineering methods using different artificial wetland (AW) prototypes throughout Europe. We optimized physical and biological processes to mitigate agricultural nonpoint-source pesticide pollution in artificial wetland ecosystems. Mitigation solutions were implemented at full-scale demonstration and experimental sites. We tested various bioremediation methods at seven experimental sites. These sites involved (1) experimental prototypes, such as vegetated ditches, a forest microcosm and 12 wetland mesocosms, and (2) demonstration prototypes: vegetated ditches, three detention ponds enhanced with technology of constructed wetlands, an outdoor bioreactor and a biomassbed. This set up provides a variety of hydrologic conditions, with some systems permanently flooded and others temporarily flooded. It also allowed to study the processes both in field and controlled conditions. In order to compare the efficiency of the wetlands, mass balances at the inlet and outlet of the artificial wetland will be used, taking into account the partition of the studied compound in water, sediments, plants, and suspended solids. The literature background necessary to harmonize the interdisciplinary work is reviewed here and the theoretical framework regarding pesticide removal mechanisms in artificial wetland is discussed. The development and the implementation of innovative approaches concerning various water quality sampling strategies for pesticide load estimates during flood, specific biological endpoints, innovative bioprocess applied to herbicide and copper mitigation to enhance the pesticide retention time within the artificial wetland, fate and transport using a 2D mixed hybrid finite element model are introduced. These future results will be useful to optimize hydraulic functioning, e.g., pesticide resident time, and biogeochemical conditions, e.g., dissipation, inside the artificial wetlands. Hydraulic retention times are generally too low to allow an optimized adsorption on sediment and organic materials accumulated in artificial wetlands. Absorption by plants is not either effective. The control of the hydraulic design and the use of adsorbing materials can be useful to increase the pesticides residence time and the contact between pesticides and biocatalyzers. Pesticide fluxes can be reduced by 50–80% when hydraulic pathways in artificial wetlands are optimized by increasing ten times the retention time, by recirculation of water, and by deceleration of the flow. Thus, using a bioremediation method should lead to an almost complete disappearance of pesticides pollution. To retain and treat the agricultural nonpoint-source po a major stake for a sustainable development.     

Advantages and limits to copper phytoextraction in vineyards

Environmental Science and Pollution Research - Copper (Cu) contamination of soils may alter the functioning and sustainability of vineyard ecosystems. Cultivating Cu-extracting plants in vineyard...     

Prenatal molecular diagnosis in RASA1-related disease

RASA1-related disease is a rare autosomal dominant disease characterized by capillary malformations, arteriovenous malformations (AVMs), and/or arteriovenous fistulas (AFVs). Penetrance is nearly complete and vascular malformations may cause serious complications such as organ injury due to oxygenation disorder, brain abscess, hemorrhage, and stroke. Early diagnosis is useful in order to discuss optimal management, including AVMs/AVFs embolization or surgical procedures, and try to prevent some of the complications. In this context, molecular testing of RASA1 gene mutation in relatives may help to better manage the family. All arteriovenous malformations are however not accessible to such procedures. In addition, these therapeutic procedures may result in potential side effects and complications. A couple was referred to our genetics unit and asked us for prenatal genetic testing about a RASA1 mutation. Here, we discuss about arguments that led our team to accept prenatal testing. To the best of our knowledge, no molecular prenatal diagnosis was reported until now in RASA1-related diseases. This first report of prenatal diagnosis in RASA1-related diseases may also offer perspectives for a more general discussion in the field of inherited arteriovenous malformations.     

Familial orofaciodigital syndrome type I revealed by ultrasound prenatal diagnosis of porencephaly

Porencephaly is a rare central nervous system (CNS) abnormality that can be caused by an intraparenchymal destructive process or a developmental defect. Here we report on a prenatal ultrasound diagnosis of complex CNS abnormalities including agenesis of the corpus callosum, agenesis of the cerebellar vermis, bilateral hydrocephaly, and bilateral porencephaly in fetus at 33 weeks' gestation. The diagnosis of familial orofaciodigital syndrome type I (OFD I) was raised after fetal autopsy, clinical examination of the family, and the X-linked dominant inheritance pattern. This is the fourth report of porencephaly in association with OFD I. We discuss the difficulties in genetic counselling since OFD I shows variable expressivity of the phenotypic features. Furthermore, we emphasize the importance of a detailed ultrasound examination after a prenatal diagnosis of porencephaly. Copyright © 2001 John Wiley & Sons, Ltd.     

How a songbird with a continuous singing style modulates its song when territorially challenged

In songbirds of the temperate zone, often only males sing and their songs serve to attract females and to deter territorial rivals. In many species, males vary certain aspects of their singing behavior when engaged in territorial interactions. Such variation may be an honest signal of the traits of the signaler, such as fighting strength, condition, or aggressive motivation, and may be used by receivers in decisions on whether to retreat or to escalate a fight. This has been studied intensively in species that sing discontinuously, in which songs are alternating with silent pauses. We studied contextual variation in the song of skylarks (Alauda arvensis), a songbird with a large vocal repertoire and a continuous and versatile singing style. We exposed subjects to simulated territorial intrusions by broadcasting conspecific song and recorded their vocal responses. We found that males sing differently if they are singing spontaneously with no other conspecific around than if they are territorially challenged. In this last case, males produced lower-frequency syllables. Furthermore, they increased the sound density of their song: they increased the proportion of sound within song. They seem to do so by singing different elements of their repertoire when singing reactively. Furthermore, they increased the consistency of mean peak frequency: they repeated syllable types with less variability when singing reactively. Such contextual variation suggests that skylarks might use low frequencies, sound density, and song consistency to indicate their competitive potential, and thus, those song features might be important for mutual assessment of competitive abilities.     

Intra-sex vocal interactions in two hybridizing seabird species (Puffinus sp.)

Hybridization between two closely related species breeding in sympatry depends on the effectiveness of both inter-sex (sexual attraction) and intra-sex (competitors’ repulsion) components of communication. As birds primarily communicate acoustically, several studies have investigated interspecific vocal interactions between the sexes and their consequences on sympatric zones with a focus on songbird species. Here, we investigate these issues on intra-sex vocal interactions occurring during incubation in two non-songbird sister species, the Yelkouan Puffinus yelkouan and the Balearic Puffinus mauretanicus shearwaters. We compared the acoustical structure of calls and the behaviors obtained in response to same-sex Yelkouan and Balearic calls across allopatric parental populations from each species and a sympatric-hybridized population. Acoustic analyses showed that, for both sexes, calls have species-specific characteristics while hybrids have intermediate acoustic features compared to their parental species. Playback experiments showed that despite their vocal differences, both species interact and reply to each other. Remarkably, incubating Yelkouan and hybrid individuals resulted in equal intra-sex responses to either species while incubating Balearic birds led to lower territorial responses to Yelkouan than to conspecific calls. Moreover, incubating Balearic males less readily responded to same-sex Yelkouan calls than Balearic females. These results may have fitness consequences: Yelkouan birds, and especially males, would be more likely to win same-sex disputes against Balearic incubating birds than against Yelkouan incubating birds.     

Patterns of sexual cohabitation and female ejaculate storage in the American lobster (<Emphasis Type="Italic">Homarus americanus</Emphasis>)

Little is known of the time and ejaculate allocation strategies during mating of American lobster, Homarus americanus. This study investigated sexual cohabitation and female ejaculate accumulation patterns in a laboratory mating experiment, as well as female seminal receptacle load in exploited populations in the waters of the Magdalen and Anticosti Islands, in eastern Canada. In the laboratory experiment, the length of sexual cohabitation was proportionate to female size for large but not for small males. Also, large males cohabited with pre- and postmolt females longer than small males. These different time investment strategies can be explained by different mutual benefits. In the field and laboratory, larger females accumulated more ejaculate than smaller ones. This suggests that male lobsters tailor ejaculate to female size, a reliable index of her reproductive potential. Moreover, similarly-sized females accumulated more ejaculate when mated with large compared to small males. Comparison of receptacle loads between wild-mated and laboratory-mated females suggests that the former were mating mainly with smaller males, although some evidence of positive size-assortative mating existed, especially at the less exploited Anticosti site. The results are discussed in the context of evolutionary theory and of proposed management measures to increase egg production in exploited populations.Communicated by T. Czeschlik     

Differential effects of increased corticosterone on behavior at the nest and reproductive output of chick-rearing Adélie penguins

Glucocorticoid hormones (GCs) are important mediators of physiological and behavioral responses to stress. While many studies have evaluated the environmental, behavioral, or physiological correlates of GCs and their effects on reproductive performances, further work is needed to clarify the relationship between GCs and fitness. Assessing the effects of increased GC levels on specific behaviors of breeding animals should improve our understanding of how GCs affect parental care. In this experimental study, we measured the effects of an experimental increase in corticosterone (CORT, the main avian GC) levels on the behavior of free-living male Adélie penguins (Pygoscelis adeliae) within the colony, their reproductive output, and the indirect consequences of both on the behavior of their partners. We show that increased CORT levels in males decreased their foraging time at sea while increased their attendance at the nest, although their attentiveness toward the nest itself decreased. In addition, treated males spent more time on comfort behaviors (e.g., preening), vocalizing, and engaging in positive social interactions relative to controls. Treatment further affected the behavior of their partners, but not chick begging and feeding rates. Penguins with increased CORT levels also exhibited decreased reproductive output. Previous studies of Adélie penguins in different life history stages and environmental conditions suggest that the consequences of CORT treatment on reproductive performance are context-dependent. In addition to the potential delay in the effects of increased CORT levels on reproduction, this context dependence should be taken into account when studying the behavior of free-living animals in relation to stress-inducing situations.