Ostracods and environmental variability in lagoons and deltas along the north-western Mediterranean coast (Gulf of Lions,France and Ebro delta,Spain)

The aim of this paper is to characterize various lagoon and delta environments through the analysis of ostracod fauna. Various aquatic environments from the Mediterranean coastline of the Gulf of Lions (Languedoc-Roussillon, France) and Ebro delta (Catalonia, Spain) were studied. The sample sites (60) are different in terms of marine and fluvial influence. Environmental parameters (salinity, water depth, sedimentary texture, plant cover) were measured and compiled from available data in order to characterize the biotopes. We interpreted the species distribution as related to the degree of isolation from the sea, the hydrological internal currents and the proximity of river mouths. Moreover, the assemblage composition seems influenced by the lagoon vegetation growth. These data can be used for the palaeoenvironmental reconstructions, particularly in Holocene deltaic context where the mobility of river mouths and the forming and evolution of sand bars and lagoons are recurring issues.     

Red-backed salamander (Plethodon cinereus) as a bioindicator of mercury in terrestrial forests of the northeastern United States

Despite concerns over the widespread deposition of mercury (Hg) in remote forested areas of the northeastern United States (U.S.), little information is available on the bioaccumulation of Hg in this region's terrestrial fauna. There is a strong need to develop baseline data on appropriate bioindicator species for this area, and here we report Hg concentrations in one of the most widely distributed vertebrates in forested areas, the red-backed salamander (Plethodon cinereus). To inform the use of this species as a bioindicator of Hg accumulation, we assessed ratios of bioavailable methylmercury (MeHg) to total Hg, and techniques for non-destructive sampling along an elevational gradient of increasing forest floor Hg concentrations. Total Hg in body samples was 70% MeHg, and Hg concentrations in tail-clips, which can be collected non-lethally, were positively correlated with body concentrations. Mercury concentrations in salamanders increased 2.4-fold along an increasing elevational gradient of Hg in soils. We conclude that Hg concentrations in P. cinereus can act as a biomonitoring tool for broad areas of remote terrestrial forests, and may help identify regions and landscape characteristics of particular concern for Hg bioaccumulation.     

Shell alterations in the limpet Bostrycapulus odites: A bioindicator of harbour pollution and mine residuals

Molluscs are commonly used as bioindicators because of their abundance, low motility and the information their shells record. Although in harbour areas gastropod shell deposition would be affected at an endocrinal level, which may increase their vulnerability, studies on the shell of gastropods are scarce. Bostrycapulus odites is a limpet species that possess those characteristics as well as a wide distribution. Limpets were collected in 2001 and 2011, in a channel polluted by both, harbour activities and leaching mine residuals, to compare to a 2011 sample from an unpolluted area within San Antonio Bay. The sensitivity to pollution of this species and the possibility of it use to detect changes in the environmental situation of an area in a 10 years period were investigated. Soft body wet weight and shell morphological variables were measured while shells were also analyzed through scanning electron microscopy and energy dispersive spectroscopy for microstructure and elemental composition, respectively. Maximum likelihood ratio test showed shells from the polluted channel were thicker as well as the same shells presented microstructure malformations and changes in elemental composition (lower Ca and O levels, higher C and Fe levels). The present results indicate that B. odites can be considered a useful bioindicator species to study these kinds of pollution and the potential processes implicated in shell alterations are discussed.     

Phyllactinia fraxinicola,another Asian fungal pathogen on Fraxinus excelsior (common ash) introduced to Europe?

Since the mid-nineties Phyllactinia fraxini has become frequent in Germany. This species has hitherto been characterized by having straight conidiophore foot cells. However, we found that recent collections from Germany have conidiophores with sinuated and twisted foot cells. So far sinuated foot cells were only known from the related P. fraxinicola, another species with Eastern Asian origin. We thus hypothesized that recent collections from Germany belong to P. fraxinicola which might have been introduced to Europe. Using morphological and molecular rDNA data we found that no introduction took place and that there is only P. fraxini in Germany.