The Red Sea is a unique ecosystem with high biodiversity in one of the warmest regions of the world. In the last five decades, Red Sea coastal development has rapidly increased. Sediments from continental margins are delivered to depths by advection and diffusion-like processes which are difficult to quantify yet provide invaluable data to researchers. Beryllium-7, lead-210 and ceseium-137 were analyzed from sediment cores from the near-coast Red Sea near Jeddah, Saudi Arabia. The results of this work are the first estimates of diffusion, mixing, and sedimentation rates of the Red Sea coastal sediments. Maximum chemical diffusion and particle mixing rates range from 69.1 to 380cm−2y−1 and 2.54 to 6.80cm−2y−1, respectively. Sedimentation rate is constrained to approximately 0.6cm/yr via multiple methods. These data provide baselines for tracking changes in various environmental problems including erosion, marine benthic ecosystem silting, and particle-bound contaminant delivery to the seafloor.

The levels and distribution of tris-(2,3-dibromopropyl) isocyanurate (TBC) and hexabromocyclododecanes (HBCDs) of surface sediments in the Yellow River Delta wetland had been investigated. The concentrations of TBC and ∑HBCDs ranged from 0.20 to 29.03ng·g−1dw and below limits of detections (LODs) to 20.25ng·g−1dw. The average composition profile of three HBCDs isomers were 10.1%, 6.1% and 83.8% for α-, β- and γ-HBCD, respectively. Moreover, correlation analysis indicated there are similar sources among three isomers and positive correlations between total organic carbon (TOC) content and concentrations of TBC and HBCDs. The mass inventory of TBC,α-, β-, γ-HBCD, ΣHBCDs in surface sediments of Yellow River Delta wetland were estimated about 725.50, 72.76, 44.29, 548.34, 665.39kg. Therefore, further investigations on potential human health and environmental risk assessments of TBC and HBCDs were needed.

Release and microbial degradation of dissolved organic matter (DOM) and chromophoric dissolved organic matter (CDOM) from the macroalgae Ulva prolifera were studied in laboratory incubation experiments. The release of DOM and CDOM from Ulva prolifera was a rapid process, and hydrolysis played an important role in the initial leaching of the organic compounds from the algae. Bacterial activity enhanced the release of DOM and CDOM during degradation of the algae and utilization of the released organic compounds. It is calculated that 43±2% of the C and 63±3% of the N from Ulva prolifera's biomass were released during the 20-day incubation, and 65±3% of the released C and 87±4% of the released N were utilized by bacteria. In comparison, only 18±1% of the algae's C and 17±1% of its N were released when bacterial activities were inhibited. The fluorescence characteristics of the CDOM indicate that protein-like DOM was the major organic component released from Ulva prolifera that was highly labile and biodegradable. Bacteria played an important role in regulating the chemical composition and fluorescence characteristics of the DOM. Our study suggests that the release of DOM from Ulva prolifera provides not only major sources of organic C and N, but also important food sources to microbial communities in coastal waters.

Antifouling paints are widely used to avoid organisms settling on boat hulls. The active ingredients in the paints have differed over the years where lead, TBT, irgarol and diuron have been deemed too harmful to non-target organisms and subsequently been banned within the EU. Most of these compounds however are persistent in the environment and can cause problems long after they are deposited.We have examined if present-day and banned substances used in antifouling paints can be found in sediments in a national park on the Swedish west coast. Sampled locations include waterways, natural harbours and small marinas for leisure crafts to investigate if number of visiting boats affect the concentration of antifouling compounds in sediments.Few significant differences were found when comparing the different locations types, suggesting that overall boat presence is more important than specific mooring sites, however, several banned antifouling compounds were found in the surface sediments.

Bioaerosols were collected between April and November 2015 on land (Gdynia) and at sea (Southwestern Baltic), using six-step microbiological pollutant sampler. It was determined that picoplanktonic cyanobacteria of the genus Synechococcus, Synechocystis, Aphanocapsa, Aphanothece, Microcystis, Merismopedia, Woronichinia and Cyanodictyon were the most commonly found in aerosols both over land and at sea. Chlorophyta were also numerous (Chlorella vulgaris, Stichococcus bacillaris), as were Bacillariophyta and Ochrophyta (Phaeodactylum sp., Navicula cf. perminuta and Nannochloropsis cf. gaditana). As primary production and phytoplankton concentration in sea water grew, so did the diversity of the microorganisms identified in bioaerosols. Over the sea cyanobacteria and microalgae occurred more often in large aerosols (>3.3μm). Over land they were mainly the components of smaller particles. In respirable particles species both capable of producing harmful secondary metabolites and potentially toxic ones were identified. We assume that bioaerosols pose the actual threat to human health in Baltic Sea region.

The performance of a portable x-ray fluorescence spectrometer configured in a test stand and coupled to a laptop has been evaluated for the determination of various elements (including Br, Cd, Cl, Cr, Cu, Fe, Pb and Zn) in beached microplastics. Under laboratory conditions, analysis of samples that covered the 3-mm x-ray beam returned concentrations that, on average, were within 20% of concentrations determined by ICP following acid digestion. Analysis of progressively smaller offcuts (to <1mm) resulted in corresponding concentrations that were comparable to those determined in original samples but errors and detection limits that progressively increased. When the configuration was deployed in situ with two operators, up to 35 microplastics counted for 60s each could be processed per hour. Advantages of immediate measurements include the development of an iterative study strategy, rapid compliance-evaluation, and identification of specific materials for further characterisation or study in the laboratory.

This work is an evaluation of metal contamination degree in Phorcus turbinatus and a monitoring of metals impact on metallothioneins functioning. The gastropod was sampled from six stations along the northeastern and eastern coasts of Tunisia during four seasons (2014–2015). Our results suggested that sedimentological metallic contents (Copper, Zinc and Cadmium) vary significantly depending on stations and not significantly according to seasons except for copper. Nevertheless, differences were no significant between stations and significant between seasons as for ambient factors, metallic intrinsic contents and metallothioneins rates. The monodonta tissue seems to be enriched in the four analyzed metals (Cu, Zn, Cd and Hg) and this species seems to have an ability to accumulate metals. Metal effect on the protein induction may be linked to physicochemical factors (temperature, O2 and Cu contents in sediment). In fact, metallothioneins levels were positively correlated to the dissolved oxygen rates and negatively linked to temperature.

In the present study, we determined the common morphological characteristics of the feces of Mytilus galloprovincialis to develop a method for visually discriminating the feces of this mussel in deposited materials. This method can be used to assess the effect of mussel feces on benthic environments. The accuracy of visual morphology-based discrimination of mussel feces in deposited materials was confirmed by DNA analysis. Eighty-nine percent of mussel feces shared five common morphological characteristics. Of the 372 animal species investigated, only four species shared all five of these characteristics. More than 96% of the samples were visually identified as M. galloprovincialis feces on the basis of morphology of the particles containing the appropriate mitochondrial DNA. These results suggest that mussel feces can be discriminated with high accuracy on the basis of their morphological characteristics. Thus, our method can be used to quantitatively assess the effect of mussel feces on local benthic environments.

Biotic indices for monitoring marine ecosystems are mostly based on the analysis of benthic macroinvertebrate communities. Due to their high sensitivity to pollution and fast response to environmental changes, bacterial assemblages could complement the information provided by benthic metazoan communities as indicators of human-induced impacts, but so far, this biological component has not been well explored for this purpose. Here we performed 16S rRNA gene amplicon sequencing to analyze the bacterial assemblage composition of 51 estuarine and coastal stations characterized by different environmental conditions and human-derived pressures. Using the relative abundance of putative indicator bacterial taxa, we developed a biotic index that is significantly correlated with a sediment quality index calculated on the basis of organic and inorganic compound concentrations. This new index based on bacterial assemblage composition can be a sensitive tool for providing a fast environmental assessment and allow a more comprehensive integrative ecosystem approach for environmental management.

Understanding how pollution affects populations is critical for targeted environmental risk assessments and adequate protection of the environment. However, the vast majority of ecotoxicology studies still have a traditional focus of identifying effects on individual organisms and do not measure the effects at the population-level. Modelling tools that measure population effects of pollution are available and would add value to current ecotoxicology studies by aligning outcomes more closely to what needs to be protected. In this paper I outline three possible reasons why this knowledge gap still exists and consider how they could be adopted more broadly, including better considerations about what endpoints should be measured at the initial study design phase. The purpose of highlighting this knowledge gap is to assist in facilitating the integration of population-level endpoints into routine pollution monitoring programs and progress of ecologically relevant ecotoxicology research.