Metal contamination of estuaries is a severe environmental problem, for which phytoremediation is gaining momentum. In particular, the associations between halophytes-autochthonous rhizobacteria have proven useful for metal phytostabilization in salt marshes. In this work, three bacterial strains (gram-negative and gram-positive) were used for Spartina densiflora inoculation. All three bacteria, particularly Pantoea strains, promoted plant growth and mitigated metal stress on polluted sediments, as revealed from functionality of the photosynthetic apparatus (PSII) and maintenance of nutrient balance. Pantoea strains did not significantly affect metal accumulation in plant roots, whereas the Bacillus strain enhanced it. Metal loading to shoots depended on particular elements, although in all cases it fell below the threshold for animal consumption. Our results confirm the possibility of modulating plant growth and metal accumulation upon selective inoculation, and the suitability of halophyte-rhizobacteria interactions as biotechnological tools for metal phytostabilization in salt marshes, preventing metal transfer to the food chain.

Three to six-month-old juveniles of Acropora tenuis, A. millepora and Pocillopora acuta were experimentally co-exposed to nutrient enrichment and suspended sediments (without light attenuation or sediment deposition) for 40days. Suspended sediments reduced survivorship of A. millepora strongly, proportional to the sediment concentration, but not in A. tenuis or P. acuta juveniles. However, juvenile growth of the latter two species was reduced to less than half or to zero, respectively. Additionally, suspended sediments increased effective quantum yields of symbionts associated with A. millepora and A. tenuis, but not those associated with P. acuta. Nutrient enrichment did not significantly affect juvenile survivorship, growth or photophysiology for any of the three species, either as a sole stressor or in combination with suspended sediments. Our results indicate that exposure to suspended sediments can be energetically costly for juveniles of some coral species, implying detrimental longer-term but species-specific repercussions for populations and coral cover.

The multiple-contamination of heavy metals and nutrients worsens increasingly and Ulva sp. green tide occurs almost simultaneously. To reveal the biological mechanism for outbreak of the green tide, Ulva pertusa was exposed to seven-day-multiple-contamination. The relation between pH variation (VpH), Chl a content, ratio of (Chl a content)/(Chl b content) (Rchla/chlb), SOD activity of U. pertusa (ASOD) and contamination concentration is VpH=1.72±0.38+1.68±0.72×10−4×Cammonia2 (p<0.05), Cchla=0.88±0.09−0.01±0.00×CCd (p<0.05), Rchla/chlb=0.72±0.04−0.35±0.08×10−4×CCd2 (p<0.05), and ASOD=25.64±2.35−0.41±0.09×10−2×CZn2+0.54±0.10×CZn (p<0.05), respectively. Cammonia, CCd and CZn is concentration of ammonia, Cd2+ and Zn2+, respectively. Comparing the contamination concentrations of seawaters where Ulva sp. green tide occurred and the contamination concentrations set in the present work, U. pertusa can adapt to multiple-contaminations in these waters. Thus, the adaption to multiple-contamination may be one biological mechanism for the outbreak of Ulva sp. green tide.

In La Paz Bay conspicuous macroalgal blooms of Ulva spp. are recurrent in the waterfront of the city; studies relate its growth to seasonality and nutrient enrichment but their relative influence is not known. We use the δ15N to discern amongst nitrogen sources at three sites with different substratum and anthropogenic activities. Ulva blooms were monitored monthly at San Juan de la Costa (SJC), Casa del Marino (CM) and El Tecolote (TE). Species presence varied between sites and months. At SJC Ulva displayed the highest signal of δ15N associated with fishing products and local mining wastewaters (19.5‰). CM showed isotopic values related to sewage waters (13‰). The δ15N of species at TE were the lowest. We found higher isotopic signatures than in other tropical/subtropical regions, associated with nutrient rich water masses. Ulva species can be used to trace and discern amongst different sources of nitrogen from natural or anthropogenic sources.

Seawater, sediment and fish (anchovy) samples consumed in the Rize province of the Eastern Black Sea region of Turkey were collected from five different stations. The radioactivity levels (226Ra, 232Th, 40K and 137Cs) were determined in all the samples using a high-purity germanium detector. While 226Ra, 232Th and 40K radionuclides were detected in all samples, the radionuclide concentration of 137Cs, except for the sediment samples (mean activity is 9±1.4Bqkg−1), was not detected for the seawater and fish samples. The total annual effective dose rates from the ingestion of these radionuclides for fish were calculated using the measured activity concentrations in radionuclides and their ingested dose conversion factor. Also, the concentrations of some heavy metals in all the samples were determined. The activity and heavy metal concentration values that were determined for the seawater, sediment and fish samples were compared among the locations themselves and with literature values.

A 3D coupled physical-biogeochemical model is developed and applied to Bizerte Lagoon (Tunisia), in order to understand and quantitatively assess its hydrobiological functioning and nutrients budget. The biogeochemical module accounts for nitrogen and phosphorus and includes the water column and upper sediment layer. The simulations showed that water circulation and the seasonal patterns of nutrients, phytoplankton and dissolved oxygen were satisfactorily reproduced. Model results indicate that water circulation in the lagoon is driven mainly by tide and wind. Plankton primary production is co-limited by phosphorus and nitrogen, and is highest in the inner part of the lagoon, due to the combined effects of high water residence time and high nutrient inputs from the boundary. However, a sensitivity analysis highlights the importance of exchanges with the Mediterranean Sea in maintaining a high level of productivity. Intensive use of fertilizers in the catchment area has a significant effect on phytoplankton biomass increase.

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Although anthropogenic oil spills vary in size, duration and severity, their broad impacts on complex social, economic and ecological systems can be significant. Questions pertaining to the operational challenges associated with the tactical allocation of human resources, cleanup equipment and supplies to areas impacted by a large spill are particularly salient when developing mitigation strategies for extreme oiling events. The purpose of this paper is to illustrate the application of advanced oil spill modeling techniques in combination with a developed mathematical model to spatially optimize the allocation of response crews and equipment for cleaning up an offshore oil spill. The results suggest that the detailed simulations and optimization model are a good first step in allowing both communities and emergency responders to proactively plan for extreme oiling events and develop response strategies that minimize the impacts of spills.

This study reports the occurrence of some endocrine disrupting chemicals in red mullet samples and sediments collected in two representative sites of the northern Sicilian coast (Italy). For this purpose, an improved method, using solid extraction and high-performance liquid chromatography analyses for the simultaneous determination of bisphenol A (BPA), 4-nonylphenol (4-NP) and 4-t-octylphenol (4-t-OP) in fish tissues and sediments, has been developed and validated. Method performance was demonstrated over the concentration range 0.1–200ng/mL, with detection limits from 0.06 to 0.1ng/mL. Recoveries ranged from 83.4% to 102.6%, with relative standard deviations of 7.7–14.0% for the entire procedure.Results showed that BPA, 4-t-OP and 4-NP were detected in all fish samples and sediments from two sampling sites, indicating that these chemicals have contaminated Mediterranean aquatic ecosystem and have accumulated in fish. The study provided more comprehensive fundamental data for risk assessment and contamination control of phenolic EDCs in aquatic environment.

Under the background of growing greenhouse gas emissions and the resulting global warming, researches about the spatial-temporal variation analysis of the concentration of carbon dioxide in the regional and global scale has become one of the most important topics in the scientific community. Simulating and analyzing the spatial-temporal variation of the carbon dioxide concentration on a global scale under limited observation data has become one of the key problems to be solved in the research field of spatial analysis technology. A new research approach based on high accuracy surface modeling data fusion (HASM-DF) method was proposed in this paper, in which the output of the CO2 concentration of the GEOS-Chem model were taken as driving field, and the observation values of CO2 concentration at ground observation station were taken as accuracy control conditions. The new approach's objective is to fulfill the fusion of the two kinds of CO2 data, and obtain the distribution of CO2 on a global scale with a higher accuracy than the results of GEOS-Chem. Root mean square error (RMSE) was chosen as the basic accuracy index, and the experimental analysis shows that the RMSE of the result of the proposed approach is 1.886 ppm, which is significantly lower than that of the GEOS-Chem's 2.239 ppm. Furthermore, compared with the results created by the interpolation methods used the observation values at stations; the fusion results keep a good spatial heterogeneity similar to the results of GEOS-Chem. This research analyzed the spatial distribution and time series variation of the near-surface CO2 based on the fusion result on a global scale. And it can found that areas such as East Asia, Western North American, Central South America and Central Africa and other region show a relatively high value of the near-surface CO2 concentration. And we also found that the near-surface CO2 concentration changes with season, especially in North America and Eurasia, the near-surface CO2 in summer was significantly lower than winter in these areas.