Information on the occurrence of organobrominated compounds in bivalves from Tunisia is scarce. To the best of our knowledge, this is the first report of these compounds in clams from Tunisia. The aim of this study is to measure natural and synthetic organobrominated compound concentrations and evaluate congener distribution and pollution sources in a clam species (Ruditapes decussatus) from three sites of the Bizerte Lagoon. Total synthetic organobrominated pollutant levels in clam ranged from 34.8 to 188ngg−1lw. For natural organobrominated compounds, concentrations varied from 18.2 to 49.5ngg−1lw. Total PBDE and MeO-PBDE concentrations in clams from the Bizerte Lagoon were similar or slightly lower than those reported for other species from other locations around the world. The health risks associated with the consumption of this species were assessed and posed no threat to public health concerning PBDE intakes.

Selected trace elements (As, Cr, Zn, Cu, Cd, Co, Pb and Ni) in 76 surface sediment samples collected from the rivers and the intertidal zone of Jiaozhou Bay (JZB) were evaluated to assess their environmental background values in the JZB catchment. Overall, the sediment quality in the area meets the China Marine Sediment Quality criteria. The background values (ranges) of the elements As, Cr, Zn, Cu, Cd, Co, Pb and Ni were, respectively, 8.28 (4.10–12.46), 67.96 (38.40–97.52), 56.80 (16.42–196.51), 19.13 (5.71–64.06), 0.10 (0.02–0.42), 6.51 (2.08–20.40), 17.97 (12.26–55.84) and 20.69 (10.43–30.95)mg/kg. The background values of most of the trace elements were lower than those in Chinese soil, the upper continental crust, global shales and global preindustrial sediments. The results may assist in defining future coastal and river management measures specifically targeted at monitoring trace element contamination in the JZB catchment.

Increasing sediment inputs are recognised as an important factor leading to coral reef degradation. However, the role of sediments in ecological processes is poorly understood. This study used paired-choice trials to quantify the effects of sediment grain size and chemical composition on feeding by the abundant detritivorous reef fish, Ctenochaetus striatus. The size of sediments from algal turfs were also compared to those ingested by reef-dwelling C. striatus. Algal turfs containing coarser sediments were preferred by C. striatus, while sediment composition (reefal carbonates vs. riverine silicates) had little effect. On the reef, C. striatus ingested finer sediments than those present in algal turfs. C. striatus appears to prefer algal turfs with coarser sediments as this facilitates ingestion of fine detrital particles, while finer sediments prevent selective feeding on detritus. These findings suggest that fine sediments from terrestrial runoff or dredging may be detrimental to feeding by detritivorous species.

Marine debris (litter) is a complex problem that affects human activities and the marine environment worldwide. The Clean Coast Program in Israel has had some success in keeping most of the coasts clean most of the time, but without understanding the mechanisms of accumulation of marine debris on the coasts of Israel. In 2012, we initiated a study to characterize the types of marine debris, its origins and spatial distribution. Nineteen surveys were done from June 2012 to March 2015 on eight beaches that spanned the coast of Israel. Average debris density was 12.1 items per 100m2 and 90% of the items were plastic. The top debris categories were food wrappers and disposables, plastic bags and cigarette butts. However, there was variation in the top debris categories among the beaches indicating that a flexible approach with multiple options will be important when addressing the marine debris problem.

Plans to exploit an offshore source of iron sand in South Taranaki Bight (STB), New Zealand, caused concerns that such exploitation may expose benthic and pelagic biota to elevated trace metal concentrations. We conducted dilute-acid extractions and standard elutriate tests to investigate the potential of this exploitation to (1) create a new seafloor with elevated trace metal content, (2) mobilise trace metals during iron sand extraction and, (3) enrich the returning process seawater, which feeds iron sand through mills, with trace metals. We found that recruits of freshly uncovered sediment may encounter higher-than-natural concentrations of cadmium, nickel and chromium (but not of copper, lead, and zinc) and propose to investigate the bioavailability of these metals. Elutriate test with raw and milled iron sand revealed that, for nickel and copper, dilution of the process seawater may be required to meet the local water quality guideline. We argue that this dilution can be achieved by adjustment of the mass and seawater balance of the offshore extraction process.

This study investigated Enterobacteriales and their antimicrobial resistance in green sea turtles captured adjacent to the central Great Barrier Reef (GBR) and proximate to urban development. Cloacal swabs were taken from 73 green turtles between 2015 and 2016. A total of 154 out of 341 Gram-negative bacterial isolates were identified as Enterobacteriales that represent 16 different species from 9 different genera. The dominant isolates were Citrobacter (30.52%), Edwardsiella (21.43%) and Escherichia (12.34%). The resistance against 12 antibiotics belonging to 6 different classes was determined. The isolates showed highest resistance to β-lactam antibiotics (78.57%) followed by quinolone (50%) and tetracycline classes (46.1%). Approximately one-third (37.7%) of the isolates identified exhibited multidrug-resistance. Isolates recovered from rehabilitated turtles were significantly multidrug resistant (p<0.009) compared to isolates from other study sites. These results provide baseline information on antimicrobial resistance while revealing gaps for further research to evaluate the level of pollution in the GBR.

The aerosol color ratio, depolarization ratio and aerosol optical depth (AOD) were measured by a two-wavelength-depolarization lidar at Wuhan, China during the period from May 2015–July 2016. The annual average AOD at Wuhan was about 0.33 during the period 2015–2016. The seasonal average AOD is small (0.26 ± 0.25) during the winter (December–February) season and large (0.4 ± 0.1) during the summer (June–August) season. The monthly average color ratio is small (0.23 ± 0.09) in January and large (0.76 ± 0.21) in August with an annual average value 0.54. The maximum monthly mean depolarization ratio (0.2 ± 0.07) occurred in the month of October, while the minimum (0.06 ± 0.02) occurred in the month of September, and the annual mean depolarization ratio was about 0.17. An analysis of temporal variations of color ratio and depolarization ratio suggests the presence of coarse and non-spherical particles during the autumn. The aerosol color ratio between 0.3 and 2.0 km was large (0.65), suggesting a large number of coarse particles in this range. The vertical distribution of the depolarization ratio is uniform. Finally, the spatial aerosol distribution under different weather conditions and its relationship with the color ratio is investigated in detail. The color ratio value of 0.74 could be used as a threshold for distinguishing polluted weather from clean weather. The aerosol optical and physical properties are investigated to provide a comprehensive understanding of aerosol radiative forcing and environmental problems in this region.

There is scientific evidence that beach sands are a significant contributor to the pathogen load to which visitors are exposed. To develop beach quality guidelines all beach zones must be included in microbiological evaluations, but monitoring methods for beach sand quality are relatively longstanding, expensive, laborious and require moderate laboratory infrastructure. This paper aimed to evaluate the microorganism activity in different beach zones applying and comparing a classical method of membrane filtration (MF) with two colorimetric screening methods based on fluorescein (FDA) and tetrazolium (TTC) salt biotransformation to evaluate a new rapid and low-cost method for beach sand microbiological contamination assessments. The colorimetric results can help beach managers to evaluate rapidly and at low cost the microbiological quality of different beach zones in order to decide whether remedial actions need to be adopted to prevent exposure of the public to microbes due to beach sand and/or water contamination.

The effect of urbanization on the environmental quality of two sandy beaches was evaluated using metrics such as pH, dissolved oxygen, coliforms and solid waste. Urbanization effects on physicochemical metrics (pH and dissolved oxygen) were not significant. The coliforms concentration was below the established limit for primary contact, but it was significantly higher on beaches with highest recreational potential. Similarly, the abundance of solid waste was significantly higher in urbanized areas (~4.5 items/m2), and it was higher than what was found for 106 beaches worldwide. Plastic represented 84% of the total number of items and recreational activities were the main sources of debris (80%). Therefore, a balance between recreation and conservation actions, based on short-term (e.g. fines) and long-term measures (e.g. educational policies) is recommended. We demonstrate that the use of multiple metrics provides more robust estimates of the environmental quality of sandy beaches than a single impact metric.

Toxic heavy metals are an important group of emerging chemical contaminants in seafood. Heavy metal concentrations in commercially important and most commonly eaten 10 fish species from Thondi fish landing, southeast coast of India, were determined by atomic absorption spectrometry. The concentrations of heavy metals significantly varied within and between the investigated fish species (P<0.05). The results of this study showed best significant correlations among the toxic heavy metals in the fish samples. It was revealed that Cd, Pb, Cu, and Zn metals were present in the fish samples at various levels. The residual levels of toxic heavy metals were less than the permissible levels specified for human consumption by the European Union, Food and Agriculture Organization and World Health Organization guidelines. Therefore, the fish species found in the Thondi fish landing and their fishery products can be considered safe for human consumption and can be exported worldwide.