Although it has previously been shown that bisphenol (BP) analogues may interfere with the normal hormonal regulation by acting as endocrine disrupting chemicals (EDCs), little information is available on effects of BP analogues in invertebrates, particularly on cladocerans. In the present study, we identified estrogen-related receptors (EER), vitellogenin (VTG), and VTG receptor (VtgR) from the brackish water flea Diaphanosoma celebensis, and examined the effects of BPA and the substitutes, BPF and BPS, in different sublethal concentrations. Gene expression varied with time well matched with brooding, suggesting that DcEER, DcVTG, and DcVtgR play a role in reproduction in D. celebensis. qRT-PCR analysis showed that BPA and its substitutes differently modulated mRNA expressions of DcEER, DcVTG, and DcVtgR, indicating that these compounds adversely affect the normal reproduction-related pathway. This study facilitates better understanding of the molecular mode of action of BP analogues on the reproductive system of D. celebensis.

A review of 80 papers on microplastic (MP) particles in marine sediments was conducted for different sedimentary environments. The papers were assessed for data on average MP concentration, MP morphotype (fibres, fragments, films, etc.), MP particle size distribution, sediment accumulation rates and correlations with total organic carbon (TOC) and sediment grain size. The median concentration of MP particles is highest in fjords at 7000 particles kg⁻¹ dry sediment (DS) followed by 300 in estuarine environments, 200 in beaches, 200 in shallow coastal environments, 50 on continental shelves and 80 particles kg⁻¹ DS for deep sea environments. Fibres are the dominant MP type and account for 90% of MP on beaches (median value) and 49% of particles in tide-dominated estuaries. In order to advance our understanding of the fate of MP in the ocean, quantitative assessments are needed of MP flux rates (g m⁻² year⁻¹) in a range of sedimentary environments.

Different phosphorus fractions, including total dissolved P (TDP), dissolved inorganic P (DIP), total particulate P (TPP), and particulate inorganic P (PIP), were analyzed in the Danshuei River Estuary (DRE), northern Taiwan to study the P partitioning within the estuary. Relatively higher concentrations of TDP (4.3–12.4 μM) and TPP (2.3–8.7 μM) were generally found in the upper estuary, salinity <5 region, during the four surveys. The DIP concentration generally dominated the total P pool (TDP + TPP) within the estuary. However, dissolved organic P (DOP) became the important fraction in the salinity >25 region, probably attributed to phytoplankton production because the higher DOP concentration was generally accompanied with a higher Chl. a concentration. The TPP concentrations generally correlated well with the total particulate Fe and Mn concentrations, suggesting that particulate Fe and Mn played crucial roles influencing the P distribution within the DRE.

This article investigates sediments collected from the banks of the Subaé River located in Todos os Santos Bay in the state of Bahia, Brazil, in 2018, twenty-five years after the closing of a former lead alloy processing plant. Ten sediment samples were collected at different points of the course of the river and its estuarine region. Chemometric tools were used to determine geochemical correlations between the organic matter content and concentration of sulfides and potentially toxic metals. The inorganic geochemical variables (enrichment factor [EF]) used in this evaluation were concentrations of the Pb, Cd, Cu, Zn, and Ni. Chemical element analyses were performed using ICP-OES. To assess the interaction between metals and sulfide or metals and organic matter, concentrations of Pb, Cd, Cu, Zn, Ni, sulfide, and the silt-clay fraction constituted the organic geochemical parameters selected to characterize the amount of organic matter present in Subaé River sediment samples, determining the carbon content (%TOC) to compose the matrix of the principal component analysis (PCA) and hierarchical cluster analysis. PCA showed that 88.3% of the samples were representative for assessing correlations between geochemical variables. A tendency toward binding was found among Cu, Cd, Ni, and sulfide, as well as the silt-clay fraction. The concentrations (mg kg⁻¹) of lead, zinc, and copper were higher in both collection campaigns, ranging from 4.72 to 31.34, 12.76 to 54.24, and 5.34 to 31.37, respectively. Pb and Zn were presented in elemental form when assessed as a function of the pH and Eh of the environment. Except for Cd (EF: 0.51 to 5.49), the other elements exhibited little or no potential pollution in the aquatic environment of the Subaé River.

The aim of this research was to assess marine litter abundance and its effects on the benthic fauna in an area of the central Mediterranean Sea exploited by fisheries using fish aggregating devices (FAD). The study was carried out by means of a remotely-operated vehicle (ROV). Derelict fishing gear, mainly FAD ropes, represented the main source of marine debris, contributing 96.2% to the overall litter. About 47% of debris items (mostly FAD ropes) entangled colonies of the protected black coral Leiopathes glaberrima. The results of this research will assist in the monitoring of “impact/harm” to the coral and other benthic communities, as recommended by the Marine Strategy Framework Directive and by the Integrated Monitoring and Assessment Programme. Preventive and mitigation measures (i.e., biodegradable fishing gear, onboard technology to locate and retrieve gear, reception and/or payment for old/retrieved gear, and introduction of no-take zones) to reduce the problem are discussed.

Tributyltin (TBT) was a commonly used biocide in anti-fouling paints for marine vessels, however, it had negative impacts on non-target species, including causing imposex in dogwhelks (Nucella lapillus). Since the 1980s, legislation has been introduced to curtail its usage, culminating in a ban by the International Maritime Organisation (IMO) in 2008. In 2004 a national imposex monitoring network was established in Northern Ireland to determine the level and extent of TBT pollution. The level of imposex in N. lapillus was assessed according to the degree of male sexual development in the female using three measures: percentage of imposex-affected females (%I), the relative penis size index (RPSI), and the vas deferens sequence index (VDSI). All sites showed improvement since the initial survey with a reduction in imposex and an improvement in ecological quality under the classification of the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR).

Functional diversity can reflect the overall differences in functional traits and indicate their response to environmental disturbance. Macrofaunal feeding functional groups and functional diversity were studied in the adjacent waters of the Yangtze River Estuary. The detritivorous group had the highest species number, abundance and secondary productivity while the canivorous group had the highest biomass. Pearson correlation analysis showed that functional evenness was negatively correlated with species number and Shannon-Wiener index. Functional divergence was negatively correlated with Simpson dominance index. Functional dispersion was positively correlated with species evenness, Shannon-Wiener index and Simpson dominance index. High values of functional diversity mainly cooccurred with high species diversity, uniform trait distribution and small niche overlap, indicating weak interspecific competition and high resources utilization. The dominant species were miniaturized and their biological traits analysis indicated that the study area has been disturbed for long time, resulting in the decline of the benthic ecosystem stability.

The main environmental variables of bottom seawater and macrobenthic invertebrates were investigated from February 2015 to January 2016 to evaluate the benthic ecological status in adjacent areas of the Yangtze River Estuary, China. Diverse ecological assessment results were given by the AZTI Marine Biotic Index (AMBI), multivariate-AMBI (M-AMBI) and benthic opportunistic polychaetes amphipods (BOPA) index, showing that the M-AMBI was the most suitable in the study area. A clear spatial distribution pattern related to the distance from the estuary and the coasts was found both for the benthic ecological status and the eutrophication-related bottom seawater environmental variables, indicating that the study area was under eutrophication pressure. Two major disturbed regions (one was east of the Yangtze River Estuary, and the other was east of Zhejiang Province) were discovered, which was probably mainly caused by the Changjiang Diluted Water (CDW). No significant seasonal changes were found in the ecological status.