The structure of the fire fighting foam surfactant Forafac®1157 and its biological and photolytic transformation products

For several decades, perfluorooctane sulfonate (PFOS) has widely been used as a fluorinated surfactant in aqueous film forming foams used as hydrocarbon fuel fire extinguishers. Due to concerns regarding its environmental persistence and toxicological effects, PFOS has recently been replaced by novel fluorinated surfactants such as Forafac®1157, developed by the DuPont company. The major component of Forafac®1157 is a 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB), and a link between the trade name and the exact chemical structure is presented here to the scientific community for the first time. In the present work, the structure of the 6:2 FTAB was elucidated by ¹H, ¹³C and ¹⁹F nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. Moreover, its major metabolites from blue mussel (Mytilus edulis) and turbot (Scophthalmus maximus) and its photolytic transformation products were identified. Contrary to what has earlier been observed for PFOS, the 6:2 FTAB was extensively metabolized by blue mussel and turbot exposed to Forafac®1157. The major metabolite was a deacetylated betaine species, from which mono- and di-demethylated metabolites also were formed. Another abundant metabolite was the 6:2 fluorotelomer sulfonamide. In another experiment, Forafac®1157 was subjected to UV-light induced photolysis. The experimental conditions aimed to simulate Arctic conditions and the deacetylated species was again the primary transformation product of 6:2 FTAB. A 6:2 fluorotelomer sulfonamide was also formed along with a non-identified transformation product. The environmental presence of most of the metabolites and transformation products was qualitatively demonstrated by analysis of soil samples taken in close proximity to an airport fire training facility.     

Managing Mediterranean soil resources under global change: expected trends and mitigation strategies

Regional Environmental Change - The soils of the Mediterranean Basin are the products of soil processes that have been governed by a unique convergence of highly differentiated natural and...     

Extremes, plasticity, and invariance in vertebrate life history traits: insights from coral reef fishes

Life history theory predicts a range of directional generic responses in life history traits with increasing organism size. Among these are the relationships between size and longevity, mortality, growth rate, timing of maturity, and lifetime reproductive output. Spanning three orders of magnitude in size, coral reef fishes provide an ecologically diverse and species-rich vertebrate assemblage in which to test these generic responses. Here we examined these relationships by quantifying the life cycles of three miniature species of coral reef fish from the genus Eviota (Gobiidae) and compared their life history characteristics with other reef fish species. We found that all three species of Eviota have life spans of < 100 days, suffer high daily mortality rates of 7-8%, exhibit rapid linear growth, and matured at an earlier than expected size. Although lifetime reproductive output was low, consistent with their small body sizes, short generation times of 47-74 days help overcome low individual fecundity and appear to be a critical feature in maintaining Eviota populations. Comparisons with other coral reef fish species showed that Eviota species live on the evolutionary margins of life history possibilities for vertebrate animals. This addition of demographic information on these smallest size classes of coral reef fishes greatly extends our knowledge to encompass the full size spectrum and highlights the potential for coral reef fishes to contribute to vertebrate life history studies.     

Seasonal changes in habitat structure underpin shifts in macroalgae-associated tropical fish communities

Habitat shifts play an important role in structuring faunal assemblages; however, research has focused on the influence of random disturbance events and information on how regular seasonal changes to habitat affect marine fauna remains largely unexplored, especially in the tropics. We recorded seasonal changes in the structure of tropical macroalgae fields within the Ningaloo lagoon (Western Australia) and related this to the density, biomass and species richness of fishes that represent key processes: juveniles, predators of juveniles and herbivores. The extent and direction of seasonal changes in macroalgae were inconsistent among sites, creating a highly dynamic habitat matrix across time and space. Species richness and density of fishes were largely maintained where density of holdfasts from canopy-forming macroalgae and/or cover was high across seasons, but shifted markedly in areas of macroalgae habitat loss: suggesting stable habitat structure is critical for the persistence of macroalgae-associated fishes. Our results demonstrate that macroalgae fields that maintain high structural complexity across different seasons are more likely to preserve key ecological processes and therefore warrant greater conservation attention within a spatial management framework.     

The basics of acidification: baseline variability of pH on Australian coral reefs

Ocean acidification is one of the key threats facing coral reef ecosystems, but there are few estimates of spatial and temporal variability in pH among reef habitats. The present study documents levels of spatial variability in pH among coral reef habitats (9 to 10), among locations separated by 100’s km of latitude and between east (Great Barrier Reef, GBR) and west (Ningaloo Reef) coasts of Australia. Differences were found in pH between inshore and offshore waters along Ningaloo Reef (means 8.45, 8.53, respectively). Replicate assessments here ranged from 8.22 to 8.64. On the GBR, the range of values over all habitats and replicates was 0.39 pH units (7.98 to 8.37). There were minor but significant differences of 0.05 pH units between 5 consecutive days for habitats on average. Highest pH was recorded in filamentous algal beds maintained by the damselfish Dischistodus perspicillatus. Lowest pH was found in water extracted from sand-dwelling goby holes. While there were marked changes in pH over a 48-h sampling period among 4 habitats at Lizard Island (GBR), there was little evidence of a diel trend. Understanding how pH varies at scales that are relevant to organisms that live on shallow coral reefs is crucial for the design and interpretation of experiments that test the effects on organisms of the changes in water chemistry predicted to affect oceans in the future.     

Second german heavy-metal survey by means of mosses,and comparison of the first and second approach in germany and other european countries

This paper shows the geographic distribution in Germany of iron (Fe), nickel (Ni) and lead (Pb) analyzed in mosses in 1995/96 and compares it with the results of the 1990/91 pilot study within a European moss-monitoring programme. Other elements (As, Cd, Cr, Cu, Ti, V, Zn) are compared on basis of the overall element medians for Germany of the 1990/91 and 1995/96 survey. Samples of Pleurozium schreberi, Scleropodium purum, Hypnum cupressiforme and Hylocomium splendens were taken at a total of 1026 sites. In the 1995/96 monitoring campaign, 95% of the original sites of the 1990/91 study were resampled. The results from 1995/96 display local elevated values and many cases of areas affected by known sources of heavy-metal emissions. The industrialized and urban regions of Germany are shown up clearly by the 1995/96 moss-monitoring results: the Ruhr area, parts of Saarland and Baden-Württemberg, as well as areas in eastern Germany. Relatively low values for many elements were found in large areas of Lower Saxony and Bavaria. A comparison of the results of the 1990/91 and 1995/96 moss-monitoring programmes shows a fall in the concentration of the presented elements (except cadmium, copper and zinc) over the relevant period. Especially in the former GDR, chromium (Cr), iron (Fe), titanium (Ti) and vanadium (V) decreased significantly. This is, firstly, a reflection of the closure of and/or technological improvements to large power plants; secondly it is due to the fact that lignite has given way to other fuels. Vanadium (V) and nickel (Ni), typical constituents of crude oil, also show a decrease in the western part and thus document changes in the type of fuel consumed. The significant fall in lead concentration in 1995/96 as compared to 1990/91 in what used to be East and West Germany probably results from the increasing use of lead-free petrol. A comparison of the median values for 1990/91 and 1995/96 in mosses to the rate of emission of heavy metals in Germany for 1990 and 1995 shows similar trends in the case of elements such as arsenic (As), chromium (Cr), nickel (Ni), and lead (Pb). The comparison of the medians of the elements analyzed for 19 European countries indicates for most of the elements a general tendency to lower values in 1995, except for Lithuania, Netherlands, Portugal, Italy and United Kingdom.     

Remote in situ voltammetric techniques to characterize the biogeochemical cycling of trace metals in aquatic systems

The contamination of aquatic ecosystems by natural and anthropogenic metals has lead to a need to better characterize their impact in the environment. To a large extent, the fate and the (eco)toxicity of these elements in aquatic systems are related to their chemical speciation, which may vary continuously in space and time. Detailed measurements of the fraction of specific metal species or groups of homologous metal species and their variation as a function of the bio-physicochemical conditions of the natural media are thus of prime importance. To determine these metal fractions as well as redox chemical species regulating their distribution (dissolved oxygen, sulfides, iron and manganese oxides), new analytical tools capable of performing in situ, real-time monitoring in both water columns and sediments with minimum perturbation of the media are required. This paper reviews the challenges associated with metal speciation studies, and the progress made with state of the art voltammetric techniques to measure the speciation of metals in situ. More specifically, it summarizes the specific conceptual, analytical, and technical criteria that must be considered and/or fulfilled to develop rugged, field deployable, non-perturbing sensors and probes. Strategies used to satisfy these criteria are presented by describing the up-to-date most advanced voltammetric sensors, mini-/micro-integrated analytical systems, and submersible equipments developed for in situ measurements of trace metals and main redox species in aquatic systems. The spatial and temporal resolutions achieved by these news tools represent a significant advantage over traditional laboratory techniques, while simultaneously remaining cost effective. The application of these tools to aquatic systems is illustrated by several examples of unattended and remote in situ monitoring and/or profiling in water columns and sediments.     

Reproduction of the invasive slipper limpet, Crepidula fornicata, in the Bay of Brest, France

The reproduction of Crepidula fornicata was studied in the Bay of Brest in order to characterise the first step of the reproductive cycle of this invasive species. The survey was carried out from 2000 to 2003 and different parameters were measured, namely, the percentage of the different sexual stages, the straight length of the shell and the percentage of brooding females using a survey of the embryonic development and the fecundity. The juvenile frequency increases generally from mid-June or mid-August, depending on the year. In 2001 and 2003, a first peak was observed as early as May, but it was followed by a rapid disappearance of the individuals. The sex-ratio female/male increased from 0.22 to 0.46 between 2001 and 2003. The sex change between intermediates and females took place mainly in summer and was well marked in 2001 and 2003. The survey of the embryonic development in the egg capsules brooded by the females provided an annual phenology of the laying and hatching processes. The laying period extends from February to September with three to four major periods of egg-laying per year and corresponding hatching periods about 1 month later. Each female lays two to four times per year on average. The first egg-laying concerned fewer females than subsequent ones, except in 2003, and exhibited a higher fecundity. The annual mean of the number of eggs for each stage was not significantly different, thus indicating no significant mortality rate during embryonic development. For the C. fornicata population in the Bay of Brest, several reproductive characteristics tend to highlight its invasive capacity: (1) a long reproductive period, (2) reproduction in a ‘multi-trials’ process equivalent to a spreading out of the risks and (3) a relatively high fecundity.