This study aimed to compare the contamination levels of various organohalogenated compounds in two migratory fish species in the Vilaine River in western France. Organochlorinated pesticides, polychlorinated biphenyls (PCBs), dioxins (polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/Fs)), and polybrominated diphenyl ethers (PBDEs) were analyzed in two diadromous species from the Vilaine estuary, the grey mullet (Liza ramada)-an amphihaline species, and the allis shad (Alosa alosa)-an anadromous species. Fish were collected in spring 2004 and spring 2005, upstream and downstream of the Arzal Dam. PCB contamination varied from 27 to 200 ng g(-1) dry weight (d.w.). PCDDs/Fs, expressed in toxicity equivalent quantity (TEQ) varied from 0.4 to 2.8 pg g(-1) d.w. Dioxins and dioxin-like PCBs expressed in total TEQ varied from 1.4 to 18.8 pg g(-1) d.w. PBDE47 was present at around 2-10 ng g(-1) d.w. and concentrations of the insecticide dichlorodiphenyltrichloroethane breakdown product p,p'-dichlorodiphenylchloroethylene varied from 1 to 14 ng g(-1) d.w. For both species, specimens collected upstream were more contaminated. The grey mullet specimens were less contaminated than the allis shad when taken downstream of the dam but were more contaminated upstream. The allis shads presented intermediate contaminant concentrations with a less pronounced difference between upstream and downstream specimens. However, it is thought that shads do not feed when they spawn in the upstream parts of rivers, which should modify the contaminant concentrations. However, measurements in upstream shad samples show an unexpected increase of the contamination, which remains unexplained.

We assessed the capacity of real-time PCR markers to identify the origin of contamination in shellfish. Oyster, cockles or clams were either contaminated with fecal materials and host-associated markers designed from Bacteroidales or Catellicoccus marimammalium 16S RNA genes were extracted from their intravalvular liquid, digestive tissues or shellfish flesh. Extraction of bacterial DNA from the oyster intravalvular liquid with FastDNA spin kit for soil enabled the selected markers to be quantified in 100% of artificially contaminated samples, and the source of contamination to be identified in 13 out of 38 naturally contaminated batches from European Class B and Class C areas. However, this protocol did not enable the origin of the contamination to be identified in cockle or clam samples. Although results are promising for extracts from intravalvular liquid in oyster, it is unlikely that a single protocol could be the best across all bacterial markers and types of shellfish. (C) 2013 Elsevier Ltd. All rights reserved.

The most important oyster farming area in Europe is in a close proximity of two medium size merchant ports. Cargo ships deballast in this area before loading, releasing unwanted or noxious marine species. During a sampling campaign aboard these arriving ships, we found in some ballast water samples a huge number of potentially toxic dinoflagellates and some potentially pathogenic bacteria. A model was applied to find the potential geographical spread of the discharged ballast water. This model predicts the water to reach highly vulnerable shellfish farmed areas in six to eight days.

Although present in a low concentration in the atmosphere, mercury in particulate matter (PHg) plays an important role in the biogeochemical process of mercury. In this study, the mercury concentrations in three size fractions of airborne particulate matters collected from 14 sites (12 urban sites, 1 rural site and 1 remote site) in the southeast coastal cities of China during different seasons in 2010–2011 were investigated. Most of PHg (46.8–71.9%) was concentrated in the finer particles, i.e. PM2.5 (particulate matter ≤2.5 µm in aerodynamic diameter). The average mercury concentrations in PM2.5 were 141.2±128.1 (range of 7.6–956.5), 37.0±19.2 (5.6–89.4), and 24.0±14.6 (3.2– 59.9) pg m–3 at urban, rural, and remote sites during the whole sampling period, respectively. The PHg concentrations were almost at the same level in spring, autumn, and winter, approximately two times of that in summer. PHg concentrations in the atmosphere displayed a significant spatial variation with far higher values in urban areas than those at rural and remote sites. The dry deposition fluxes of total PHg estimated by a theoretical model were 38.3, 47.7, and 58.7 µg m–2 y–1 at Ji’an (JA), Jimei (JM), and Longwen (LW), respectively. The backward air trajectory analysis revealed that the atmospheric PHg concentrations were mainly influenced by air masses from ocean sources that diluted PHg in summer and on contrary from continental sources in other seasons.

Certain coral reef systems north of the Arabian Gulf are characterized by corals with a unique ability to thrive and flourish despite the presence of crude oil continuously seeping from natural cracks in the seabed. Harboring oil-degrading bacteria as a part of the holobiont has been investigated as a potential mechanism of adaptation and survival for corals in such systems. The use of conventional and molecular techniques verified a predominance of bacteria affiliated with Gammaproteobacteria, Actinobacteria and Firmicutes in the mucus and tissues of Acropora clathrata and Porites compressa. These bacteria were capable of degrading a wide range of aliphatic (C9–C28) aromatic hydrocarbons (Phenanthrene, Biphenyl, Naphthalene) and crude oil. In addition, microcosms supplied with coral samples and various concentrations of crude oil shifted their bacterial population toward the more advantageous types of oil degraders as oil concentrations increased.

Total-Hg, monomethylmercury (MMHg), and mercury isotopic composition was determined in sediment from a cold seep and background sites in the northern Gulf of Mexico (nGoM). Total-Hg averaged 50ng/g (n=28), ranged from 31 to 67ng/g, and decreased with depth (0–15cm). MMHg averaged 0.91ng/g (n=18), and ranged from 0.2 to 1.9ng/g. There was no significant difference for total-Hg or MMHg between cold seep and background sites. δ202Hg ranged from −0.5 to −0.8‰ and becomes more negative with depth (r=0.989). Mass independent fractionation (Δ199Hg) was small but consistently positive (0.04–0.12‰); there was no difference between cold seeps (Δ199Hg = +0.09±0.03; n=7, 1SD) and background sites (Δ199Hg=+0.07±0.02; n=5, 1SD). This suggests that releases of hydrocarbons at the cold seep do not significantly alter Hg levels, and that cold seeps are likely not major sources of MMHg to nGoM waters.

Ratios of sucrose-negative to sucrose-positive vibrios on TCBS agar (suc−/suc+) indicate the abundance of potential human pathogenic non-cholera vibrios in coastal mariculture environments of the Lingayen Gulf (Philippines. In guts of adult maricultured milkfish (Chanos chanos) of suc− vibrios reached extreme peak values ranging between 2 and 545millionperg wet weight. Suc− vibrios outnumbered suc+ vibrios in anoxic sediments, too, and were rarely predominant in coastal waters or in oxidized sediments. Suc−/suc+ ratios in sediments increased toward the mariculture areas with distance from the open sea at decreasing redox potentials. There is circumstantial evidence that suc− vibrios can be dispersed from mariculture areas to adjacent environments including coral reefs. An immediate human health risk by pathogenic Vibrio species is discounted, since milkfish guts contained mainly members of the Enterovibrio group. A representative isolate of these contained proteolytic and other virulence factors, but no genes encoding toxins characteristic of clinical Vibrio species.

We investigated the influence of salinity on sediment inorganic nitrogen dynamics in three Portuguese estuaries (Cávado, Ave and Douro). Anaerobic slurry experiments were run at different salinity treatments (0, 10, and 25) and net changes in concentration of nitrate, nitrite, ammonium, and nitrous oxide were monitored. Salinity-induced NH4+ sediment desorption was observed at all sites. No significant salinity driven changes in NO3- concentrations were observed, except for Ave estuarine sediments, where NO3- consumption increased 10 times as the salinity rose from 0 to 10. In the upper stretches of the three estuaries, N2O production increased sharply as salinity rose. Although no stimulation of N2O production was observed in higher salinity areas, the salinity-driven changes in N2O production are of major concern given the greenhouse characteristics of the gas. The global trend of decreasing freshwater discharge, and therefore increase in salinity, to estuarine systems could thereby exacerbate N2O production and global warming.

Eggs from egrets (Egretta thula) were collected from Cartagena Bay and Totumo Marsh, two sites at the north of Colombia with different pollution background, and measured their morphometric parameters as well as total mercury (T-Hg) and calcium levels in eggshell. Statistically significant differences were observed for egg weight and size between the two sampling locations. T-Hg and calcium concentrations in eggshell were greater in eggs from Cartagena Bay, the industrial site, compared to Totumo Marsh, a non-industrial location. The opposite was observed for eggshell thickness (3.6% less in the bay). Pearson correlation analysis showed eggshell T-Hg negatively correlated with eggshell weight in eggs from the marsh (R=−0.795, P<0.006), but not from the bay (R=0.387, P=0.269), probably suggesting greater susceptibility to Hg in birds from the non-polluted site. In short, results suggest eggs from E. thula at Cartagena Bay have greater T-Hg concentrations and less eggshell thickness than those from Totumo Marsh.