A model for assessing habitat fragmentation caused by new infrastructures in extensive territories – Evaluation of the impact of the Spanish strategic infrastructure and transport plan

The aim of the present work is to design a model for evaluating the impact of planned infrastructures on species survival at the territorial scale by calculating a connectivity index. The method developed involves determining the effective distance of displacement between patches of the same habitat, simplifying earlier models so that there is no dependence on specific variables for each species. A case study is presented in which the model was used to assess the impact of the forthcoming roads and railways included in the Spanish Strategic Infrastructure and Transport Plan (PEIT, in its Spanish initials).This study took into account the habitats of peninsular Spain, which occupies an area of some 500,000 km². In this territory, the areas deemed to provide natural habitats are defined by Directive 92/43/EEC. The impact of new infrastructures on connectivity was assessed by comparing two scenarios, with and without the plan, for the major new road and railway networks. The calculation of the connectivity index (CI) requires the use of a raster methodology based on the Arc/Info geographical information system (GIS). The actual calculation was performed using a program written in Arc/Info Macro Language (AML); this program is available in FragtULs (Mancebo Quintana, 2007), a set of tools for calculating indicators of fragmentation caused by transport infrastructure (http://topografia.montes.upm.es/fragtuls.html).The indicator of connectivity proposed allows the estimation of the connectivity between all the patches of a territory, with no artificial (non-ecologically based) boundaries imposed. The model proposed appears to be a useful tool for the analysis of fragmentation caused by plans for large territories.     

Optimisation of a PMAxx™-RT-qPCR Assay and the Preceding Extraction Method to Selectively Detect Infectious Murine Norovirus Particles in Mussels

Human noroviruses are a major cause for gastroenteritis outbreaks. Filter-feeding bivalve molluscs, which accumulate noroviruses in their digestive tissues, are a typical vector for human infection. RT-qPCR, the established method for human norovirus detection in food, does not allow discrimination between infectious and non-infectious viruses and can overestimate potentially infectious viral loads. To develop a more accurate method of infectious norovirus load estimation, we combined intercalating agent propidium monoazide (PMAxx™)-pre-treatment with RT-qPCR assay using in vitro-cultivable murine norovirus. Three primer sets targeting different genome regions and diverse amplicon sizes were used to compare one-step amplification of a short genome fragment to three two-step long-range RT-qPCRs (7 kbp, 3.6 kbp and 2.3 kbp amplicons). Following initial assays performed on untreated infectious, heat-, or ultraviolet-inactivated murine noroviruses in PBS suspension, PMAxx™ RT-qPCRs were implemented to detect murine noroviruses subsequent to their extraction from mussel digestive tissues; virus extraction via anionic polymer-coated magnetic beads was compared with the proteinase K-dependent ISO norm. The long-range RT-qPCR process detecting fragments of more than 2.3 kbp allowed accurate estimation of the infectivity of UV-damaged murine noroviruses. While proteinase K extraction limited later estimation of PMAxx™ pre-treatment effects and was found to be unsuited to the assay, magnetic bead-captured murine noroviruses retained their infectivity. Genome copies of heat-inactivated murine noroviruses differed by 2.3 log₁₀ between RT-qPCR and PMAxx™-RT-qPCR analysis in bivalve molluscs, the PMAxx™ pre-treatment allowing a closer approximation of infectious titres. The combination of bead-based virus extraction and PMAxx™ RT-qPCR thus provides a more accurate model for the estimation of noroviral bivalve mollusc contamination than the conjunction of proteinase K extraction and RT-qPCR and has the potential (once validated utilising infectious human norovirus) to provide an added measure of security to food safety authorities in the hazard assessment of potential bivalve mollusc contamination.

     

Wax perception in honeybees: contact is not necessary

In social insects, much progress has been made in identifying variations in the cuticular signatures of sexes, castes, kin and reproductive status. In contrast to this, we still do not know how the receivers perceive these recognition cues. This study was designed to investigate whether honeybees use contact-chemosensory or olfactory sensilla to perceive wax components. To answer this question in a behavioral assay, we combined classical conditioning of the proboscis extension reaction and a recently established method using zinc sulfate to selectively block antennal contact-chemosensory sensilla. Comparison of the responses to sucrose, wax and geraniol before and after antennal zinc sulfate treatment revealed that the sucrose response is lost after treatment but the responses to wax and geraniol are maintained. As sucrose is perceived by the contact-chemosensory sensilla, the retention of the wax response indicates that contact-chemosensory sensilla are not necessary for wax perception.     

Microsatellite Analysis of Population Structure in the Endangered Hawaiian Monk Seal

Abstract: The endangered Hawaiian monk seal breeds at six locations in the northwestern Hawaiian Islands. To determine whether significant genetic differentiation exists among these sites, we used microsatellite loci to examine the monk seal population structure at the five largest breeding colonies. Of 27 loci isolated from other seal species, only 3 were polymorphic in an initial screening of one individual from each breeding site. Only two alleles were found at each of these 3 loci in samples of 46–108 individuals. This extremely low variation is consistent with other measures of genetic variability in this species and is probably the result of a recent severe population bottleneck, combined with a long-term history of small population sizes. Although the smallest monk seal subpopulation in this study ( Kure Atoll) showed some evidence of heterozygote deficit, possibly indicative of inbreeding, the next smallest ( Pearl and Hermes Reef) had an apparent excess of heterozygous individuals. Genetic differentiation was detected between the two subpopulations at extreme ends of the range ( Kure and French Frigate Shoals). This trend was significant only at the microsatellite locus for which we had the largest sample size ( Hg6.3: R _ST = 0.206, p = 0.002; allelic goodness of fit G _h = 15.412, p < 0.005). French Frigate Shoals is the source population for translocated animals that have been released primarily at Kure Atoll. Differentiation between these sites consisted of allele frequency differences (with the same allele predominant in each location at all three loci), rather than the preservation of alternative alleles. Although the translocations have had positive demographic effects, we recommend continued genetic monitoring of both the source and recipient populations because translocated individuals are now entering the breeding population.     

Adenylate cyclase of Mytilus galloprovincialis posterior adductor muscle: basal properties and sensitivity to serotonin

The presence and characteristics of a membrane-bound adenylate cyclase from Mytilus galloprovincialis Lmk posterior adductor muscle have been investigated. The enzyme has a Michaelis constant (K _m) of 0.38 mM at 20°C and requires divalent cations (Mg²⁺/Mn²⁺) for its activity. Optimal GTP concentrations are between 10^-5 and 10^-4 M. The non-hydrolizable GTP-analogues GMPpNHp and GTPS increase the activity of the enzyme four- to ten-fold. Sodium fluoride stimulates the enzymatic activity seven- to eight-fold. Forskolin increases the enzymatic activity two- to three-fold. Serotonin stimulates the adenylate cyclase activity in a dose-dependent manner. These experiments were performed with mussels collected from the estuary of Muros, Spain, in 1990.     

Modeling kelp forest distribution and biomass along temperate rocky coastlines

We address the global deficit of data describing kelp forest distribution, relative covers and biomass by testing the ability of species distribution models to predict these attributes at locations where data are currently limited. We integrated biological ground truth data with high-resolution environmental datasets to develop generalized additive models that accurately predict the structure of Laminaria forests within the Bay of Morlaix (48°42′42″N, 3°55′40″W). Forest distribution and proportional covers were predicted using water depth, light availability, wave exposure and sediment dynamics. The biomass of individual kelp species was modeled by supplementing these same variables with measures of seafloor slope and benthic position. Biomass predictions for Laminaria digitata and Laminaria hyperborea contrast the physiological tolerances of these species to light and wave exposure gradients. As a direct management output, we produced high-resolution maps (25 m² grids) that closely match independent field data and provide vital information for marine spatial planning.     

Modelling the impacts of land-use and drainage density on the water balance of a lowland–floodplain landscape in northeast Germany

This study presents the modelling approach and impact assessment of different strategies for managing wetland water resources and groundwater dynamics of landscapes which are characterised by the hydrological interactions of floodplains and the adjacent lowlands. The assessment of such impacts is based on the analysis of simulation results of complex scenarios of land-use changes and changes of the density of the drainage-network. The method has been applied to the 198 km² Lower Havel River catchment as a typical example of a lowland–floodplain landscape. The model used consists of a coupled soil water and groundwater model, where the latter one is additionally coupled to the surface channel network. Thus, the hydrological processes of the variable saturated soil zone as well as lateral groundwater flow and the interactions between surface water and groundwater are simulated in an integrated manner. The model was validated for several years of significantly different meteorological conditions. The comparison of lateral and vertical water balance components showed the dominance of lateral flow processes and the importance of the interactions between surface water and groundwater for the overall water balance and the hydrological state of that type of landscape.The simulation of land-use change scenarios showed only minor effects of land-use change on the water balance and groundwater recharge. Changes of groundwater recharge were particularly small within the wetland areas being part of the floodplain where interactions between surface water and groundwater are most pronounced. Alterations in vertical groundwater recharge were counter-balanced by the lateral interaction between groundwater and surface water. More significant deviations in groundwater recharge and storage were observed in the more peripheral areas towards the catchment boundaries which are characterised by greater groundwater distance from the surface and less intense of ground water–surface water interactions.However, the simulation results assuming a coarsening of the drainage network density showed the importance of drainage structure and geometry for the water balance: The removal of the artificial draining ditches in the floodplain would result in significant alterations of total groundwater recharge, i.e., less recharge from winter to early summer and an increase of groundwater recharge during summer and autumn. Furthermore the different effects of groundwater recharge alterations on the dynamics of groundwater stages within the wetland areas close to the floodplains compared to the more peripheral areas could be quantified. Finally, it will be discussed that a well-adjusted co-ordination of different management measures is required to reach a sustainable water resources management of such lowland–floodplain landscapes.     

Bewertung der Umweltrelevanz von Arzneistoffen

Aim The aim of this work was to investigate, which human and veterinary pharmaceuticals are of high ecological relevance due to the input into the environment as well as with regard to the effects and behaviour in the environment. Furthermore, the state of knowledge concerning the ecologically relevant substances and the need of research was evaluated. Methods A two-step approach considering the criteria quantity of sold pharmaceuticals, concentrations, effects and fate in the environment was developed to identify the pharmaceuticals of potential ecological relevance. In a second step the identified individual substances and groups of substances were considered in more detail concerning metabolism, environmental behaviour and ecological effects. Results In a first step 29 out of approximate 2,700 licensed human pharmaceuticals and seven substances as well as three substance groups used in veterinary medicine were identified as potentially ecologically relevant. The detailed assessment in a second step lead to the conclusion, that of the human pharmaceuticals 9 substances as well as two substance groups concerning the environmental behaviour and seven substances concerning the effects are of high environmental relevance. Concerning the environmental behaviour six out of seven veterinary pharmaceuticals as well as three substance groups and only three substances concerning the ecological effects were classified as relevant for the environment. Discussion By means of the presented method it was possible to limit the scope of a wide spectrum of pharmaceuticals, so that a detailed assessment of only relevant active agents was possible. Nevertheless, it is a precondition that investigations concerning the occurrence, fate and effects of the individual compounds in the environment have been already carried out and published in the literature. Conclusions The method is suitable for a comprehensive assessment of the ecological relevance of pharmaceuticals, but for a lot of human and veterinary pharmaceuticals the data available in the literature are insufficient. Recommendations For a final extensive assessment of the environmental relevance for some of the human and veterinary pharmaceuticals more studies are necessary. Especially data concerning the environmental behaviour in water and soils, data from long-term-studies for the assessment of ecological effects and data concerning metabolites and mixtures of pharmaceutical compounds are lacking.