Few studies to date have investigated the effects of ocean acidification on non-reef forming marine invertebrates with non-feeding larvae. Here, we exposed adults of the bryozoan Bugula neritina and their larvae to lowered pH. We monitored spawning, larval swimming, settlement, and post-settlement individual sizes at two pHs (7.9 vs. 7.6) and settlement dynamics alone over a broader pH range (8.0 down to 6.5). Our results show that spawning was not affected by adult exposure (48 h at pH 7.6), larvae swam 32% faster and the newly-settled individuals grew significantly larger (5%) at pH 7.6 than in the control. Although larvae required more time to settle when pH was lowered, reduced pH was not lethal, even down to pH 6.5. Overall, this fouling species appeared to be robust to acidification, and yet, indirect effects such as prolonging the pelagic larval duration could increase predation risk, and might negatively impact population dynamics.

Concentrations of neutral poly- and perfluoroalkyl substances (PFASs), such as fluorotelomer alcohols (FTOHs), perfluoroalkane sulfonamides (FASAs), perfluoroalkane sufonamidoethanols (FASEs), and fluorotelomer acrylates (FTACs), have been simultaneously determined in surface seawater and the atmosphere of the North Sea. Seawater and air samples were taken aboard the German research vessel Heincke on the cruise 303 from 15 to 24 May 2009. The concentrations of FTOHs, FASAs, FASEs, and FTACs in the dissolved phase were 2.6-74, <0.1-19, <0.1-63, and <1.0-9.0 pg/L, respectively. The highest concentrations were determined in the estuary of the Weser and Elbe rivers and a decreasing concentration profile appeared with increasing distance from the coast toward the central part of the North Sea. Gaseous FTOHs, FASAs, FASEs, and FTACs were in the range of 36-126, 3.1-26, 3.7-19, and 0.8-5.6 pg/m**3, which were consistent with the concentrations determined in 2007 in the North Sea, and approximately five times lower than those reported for an urban area of Northern Germany. These results suggested continuous continental emissions of neutral PFASs followed by transport toward the marine environment. Air-seawater gas exchanges of neutral PFASs were estimated using fugacity ratios and the two-film resistance model based upon paired air-seawater concentrations and estimated Henry's law constant values. Volatilization dominated for all neutral PFASs in the North Sea. The air-seawater gas exchange fluxes were in the range of 2.5 × 103-3.6 × 105 pg/m**2 for FTOHs, 1.8 × 102-1.0 × 105 pg/m**2 for FASAs, 1.1 × 102-3.0 × 105 pg/m**2 for FASEs and 6.3 × 102-2.0 × 104 pg/m**2 for FTACs, respectively. These results suggest that the air-seawater gas exchange is an important process that intervenes in the transport and fate for neutral PFASs in the marine environment.

Marine CO2 seeps allow the study of the long-term effects of elevated pCO2 (ocean acidification) on marine invertebrate biomineralization. We investigated the effects of ocean acidification on shell composition and structure in four ecologically important species of Mediterranean gastropods (two limpets, a top-shell snail, and a whelk). Individuals were sampled from three sites near a volcanic CO2 seep off Vulcano Island, Italy. The three sites represented ambient (8.15 pH), moderate (8.03 pH) and low (7.73 pH) seawater mean pH. Shell mineralogy, microstructure, and mechanical strength were examined in all four species. We found that the calcite/aragonite ratio could vary and increased significantly with reduced pH in shells of one of the two limpet species. Moreover, each of the four gastropods displayed reductions in either inner shell toughness or elasticity at the Low pH site. These results suggest that near-future ocean acidification could alter shell biomineralization and structure in these common gastropods.

Persistent organic pollutants like organochlorine pesticides continue to contaminate large areas worldwide raising questions concerning their management. We designed and tested a method to link soil and water pollution in the watershed of the Galion River in Martinique. We first estimated the risk of soil contamination by chlordecone by referring to past use of land for banana cultivation and took 27 soil samples. We then sampled surface waters at 39 points and groundwater at 16 points. We tested three hypotheses linked to the source of chlordecone pollution at the watershed scale: (i) soils close to the river, (ii) soils close to the sampling point, (iii) throughout the sub-watershed generated at the sampling point. Graphical and statistical analysis showed that contamination of the river increased when it passed through an area with contaminated plots and decreased when it passed through area not contaminated by chlordecone. Modeling showed that the entire surface area of the watershed contributed to river pollution, suggesting that the river was mainly being contaminated by the aquifers and groundwater flows. Our method proved to be a reliable way to identify areas polluted by chlordecone at the watershed scale and should help stakeholders focus their management actions on both hot spots and the whole watershed. (Résumé d'auteur)

A biopurification system (BPS) is used on-farm to clean pesticide-contaminated wastewater. Due to high pesticide loads, a BPS represents a hot spot for the proliferation and selection as well as the genetic adaptation of discrete pesticide degrading microorganisms. However, while considerable knowledge exists on the biodegradation of specific pesticides in BPSs, the bacterial community composition of these systems has hardly been explored. In this work, the Shannon diversity, the richness and the composition of the bacterial community within an operational BPS receiving wastewater contaminated with various pesticides was, for the first time, elucidated over the course of an agricultural season, using DGGE profiling and pyrosequencing of 16S rRNA gene fragments amplified from total community DNA. During the agricultural season, an increase in the concentration of pesticides in the BPS was observed along with the detection of significant community changes including a decrease in microbial diversity. Additionally, a significant increase in the relative abundance of Proteobacteria, mainly the Gammaproteobacteria, was found, and OTUs (operational taxonomic units) affiliated to Pseudomonas responded positively during the course of the season. Furthermore, a banding-pattern analysis of 16S rRNA gene-based DGGE fingerprinting, targeting the Alpha- and Betaproteobacteria as well as the Actinobacteria, indicated that the Betaproteobacteria might play an important role. Interestingly, a decrease of Firmicutes and Bacteroidetes was observed, indicating their selective disadvantage in a BPS, to which pesticides have been introduced.

Long-term drainage and intensive agricultural use of peatlands make it unlikely that the original sink functions for nutrients and carbon as well as low-nutrient conditions can be re-established within a human time perspective. The data presented here consists of i) soil characteristics, ii) water quality, and iii) mobilization rates for phosphate, dissolved organic matter and methane from soil cores of altogether 12 rewetted inundated peatlands. In addition we included data from a rewetted non-inundated peatland ("Lehstseemoor"). All studied sites are representative of calcareous rich, i.e. groundwater charged peatlands (= fens) found in the lowlands of NE Germany, as well as in other parts of Europe such as Great Britain, the Netherlands or Poland. All sites developed as fens with peat forming small-sedge-brown moss plant communities in their central parts, with sedge and reed stands at the margins, and occurring either at the edge of areas of mineral soils or close to a water course. Approx. 300 years ago the sites were drained for peat excavation or agriculture. The study sites' climate is continental, with a mean annual precipitation of 582-596 mm. The mean daily temperature is 0.7-1.2 °C in January and 18.1-19.1 °C in July (mean of 1991-2007 from the nearby meteorological stations at 'Deutscher Wetterdienst'). Field measurements and an incubation experiment in the laboratory were performed to study the effect of top soil removal on: i) soil and water quality; ii) P mobilisation from soil to porewater; iii) net fluxes of P and dissolved organic matter at the soil-surface water interface; and iv) potential methane production.

It is an open question whether adverse habitat conditions, characteristic for many anthropogenically impacted coastal habitats, can determine resistance to abiotic stress in populations of residing invertebrates. We tested experimentally for differences in stress tolerance between individuals of the Asian green mussel Perna viridis stemming from the heavily impacted Jakarta Bay and from two natural sites, Lada Bay and Pelabuhan Ratu, West Java. Mussel performance under hyposalinity and hypoxia was assessed in laboratory assays by measuring fitness-related response variables, e.g. body condition index, relative shell weight, byssus production, respiration rates and survival. We found stress-specific and population-specific differences in mussel resistance to adverse conditions: Individuals from the impacted Jakarta Bay performed better under hypoxia than their conspecifics from the natural sites, whereas the latter were more resistant to hyposalinity. We explain these differences by differential acclimation to environmental conditions in the respective habitats and by diverging degrees of food supply.

Organic and metal contaminants and biological effects were investigated in flounder, mussels, and sediments in the southern Baltic Sea coastal area in order to assess environmental quality status in that area. Four sites were selected, including two within the Gulf of Gdańsk (GoG). In biota and sediment at each site, DDTs dominated over PCBs and PBDEs were the least abundant among organic contaminants. Their concentrations decreased progressively outward from GoG. Among metal contaminants, the levels of Hg, Pb, and Cd were elevated in GoG. Biomarkers in flounder, EROD activity and DNA SB, showed moderate positive correlations with organic and metal contaminants. In flounder, the integrated biomarker index (IBR/n) presented a spatial trend coherent with chemical pollution index (CPI), but there was no clear spatial correspondence between IBR/n and CPI in mussels nor between sediment toxicity index (STI) and sediment CPI. The integrated assessment of contaminant and biological effect data against available assessment criteria indicated that in biota, the contaminant assessment thresholds were most often exceeded by CB-118, heptachlor, PBDE, and Hg (in the GoG sediments by p,p′-DDT, Hg and Cd), while of the biological determinants, the threshold was breeched by AChE activity in mussels in GoG. Applying the ICES/OSPAR traffic-light approach showed that of the 50 parameters assessed at each site, there were 18% of determinants in the red color category in the two GoG sites and 8% of determinants in the two sites outside GoG, which indicated that none of the four investigated sites attained good environmental status (GES).

We conducted shipboard microcosm experiments at both off-shore (SEATS) and near-shore (D001) stations in the northern South China Sea (NSCS) under three treatments, low temperature and low pCO2 (LTLC), high temperature and low pCO2 (HTLC), and high temperature and high pCO2 (HTHC). Biomass of phytoplankton at both stations were enhanced by HT. HTHC did not affect phytoplankton biomass at station D001 but decreased it at station SEATS. HT alone increased net primary productivity by 234% at station SEATS and by 67% at station D001 but the stimulating effect disappeared when HC was combined. HT also increased respiration rate by 236% at station SEATS and by 87% at station D001 whereas HTHC reduced it by 61% at station SEATS and did not affect it at station D001. Overall, our findings indicate that the positive effect of ocean warming on phytoplankton assemblages in NSCS could be damped or offset by ocean acidification.