Ocean warming is an extreme environment event that has profound and lasting impacts on Symbiodiniaceae. However, their response mechanisms to elevated temperature exposure are poorly understood. In this study, the physiological and transcriptional responses of Effrenium voratum (Symbiodiniaceae) to ocean warming were examined. After exposure to 30 °C, no significant variations in growth, chlorophyll a, or photosynthetic and respiration rates were observed, while a higher temperature (34 °C) significantly reduced these physiological measurements. Meanwhile, lipid content and fatty acid composition were altered at high temperature (i.e., elevated degree of fatty acid saturation). Such biochemical constituents likely contributed to the mitigation of the negative effects of elevated temperatures. Furthermore, higher expression levels of genes related to the synthesis and elongation of fatty acids were detected at high temperature. The adjustment of lipids and fatty acid composition may be a potential mechanism by which E. voratum may survive under future global warming. The adjustment of lipids and fatty acid composition may be a potential mechanism by which E. voratum acclimate to future global warming.

Persistent organic and inorganic pollutants are among the most concerning pollutants in Australian estuaries due to their persistent, ubiquitous, and potentially toxic nature. Traditional methods of soil remediation often fall short of practical implementation due to high monetary investment, environmental disturbance, and potential for re-contamination. Phytoremediation is gaining traction as an alternative, or synergistic mechanism of contaminated soil remediation. Phytoremediation utilises plants and associated rhizospheric microorganisms to stabilise, degrade, transform, or remove xenobiotics from contaminated mediums. Due to their apparent cross-tolerance to salt, metals, and organic contaminants, halophytes have shown promise as phytoremediation species. This review examines the potential of 93 species of Australian saltmarsh halophytes for xenobiotic phytoremediation. Considerations for the practical application of phytoremediation in Australia are discussed, including mechanisms of enhancement, and methods of harvesting and disposal. Knowledge gaps for the implementation of phytoremediation in Australian saline environments are identified, and areas for future research are suggested.

Bioelectrochemical system (BES) is an emerging technology for wastewater treatment. The urgent requirement for dealing with water shortage, wastewater treatment and reuse, energy generation, and resources recovery has promoted intensive research in BES during the last decade. This review summarizes the latest typical BES configurations based on specific functions, including microbial fuel cells (MFC), microbial electrolysis cells (MEC), microbial electrosynthesis systems (MSS), microbial desalination cells (MDC), microbial recycling cells (MRC), microbial solar cells (MSC), and microbial electrochemical snorkel (MES). The removal of contaminants, particularly emerging organic, non-metallic, metallic, and metalloid contaminants, and the recovery of resources in the form of bioenergy, biofuel, nutrients, metals, and metalloids in wastewater treatment using BES technology have been reviewed in this work. Limitations of BES technology in terms of reactor performance, scale-up, and construction costs for real-world wastewater treatment applications are discussed and future research directions needed for the successful deployment of BES technology are proposed.

PM₂.₅ is one of the major air pollutants in port cities of the Yangtze River Delta (YRD) of China. Understanding the driving factors of PM₂.₅ is essential to guide air pollution prevention and control. We selected 17 major port cities in YRD to study the driving factors of PM₂.₅ in 2019 and 2020. Generalized Additive Models were built to model the non-linear effects of single, multiple and interactions of driving factors on the variations of PM₂.₅. NO₂, SO₂ and the day of year are most strongly associated with the variation of PM₂.₅ concentration when used alone. Anthropogenic emissions play complicated roles in regulating PM₂.₅ concentration. Although the effect of cargo throughput (CT) on PM₂.₅ concentration is non-monotonic, higher PM₂.₅ levels are found to be associated with higher levels of SO₂ and CT. This work can potentially provide a scientific basis for formulating PM₂.₅ prevention and control policies in the region.

Bizerte Lagoon is a vital Mediterranean ecosystem subjected to intense anthropogenic pressure. The potential ecological risk caused by certain metals (Zn, Cu, Cr, Cd, Ni, Pb and Mn) is assessed from the data carried out in the sediment and pore water at two sites along with identifying the effects of diagenetic processes on the vertical distribution of these metals and their resulting diffusive fluxes. Using various ecological indices our results reveal a high ecological risk to benthic organisms from metals chiefly Cd, Pb and Ni accumulated in the sediment at both sites. Metals derived from organic matter degradation (Cu and Cd) and/or reduction of Mn-Fe-oxyhydroxydes (Pb, Ni, Zn, Cr) due to early diagenetic processes in sediment. The resulting concentration gradients between pore water and overlying water induce diffusive fluxes of metals to the water column. The estimation of the potential ecological risk caused by dissolved metals in pore waters by application of the Interstitial Water Criteria Toxic Units index indicates a slight ecological risk by Cu and Ni that was not identified in sediment. The ecological risk posed by dissolved metals is evidenced from −6 cm depth, which reduces the possibility of contamination of benthic species living above the water-sediment interface by diffusive flux of these metals.

Plastic production is an essential part of the world economy that has mushroomed exponentially with c.9.2 billion tonnes estimated to have been made between 1950 and 2017. Now, each year c.8–11 million tonnes of plastic waste escapes into the oceans. Plastic usage is varied but the packaging industry accounts for 47%. Recycling and the circular economy are seen as keys to unlocking the plastic problem, for example, via the Extended Producer Responsibility scheme; a Deposit Return Scheme. The circular economy is a fine idea and has been around a long time, but has it made any real difference? The amount of plastic in circulation keeps getting bigger and bigger. More thought must be given to creating technologies and designs that can deal with waste management, integrate international collaboration and cut waste to a bare minimum at its source point upstream. No single solution exists, but there is a need for a legally binding global governance arrangement that would effectively and measurably limit and control plastic pollution. Many governments are in favour of this.

The present study provides a baseline assessment of the prevalence and densities of splenic melanomacrophage centres (MMCs) in 18 fish species from the NW Mediterranean Sea related to spatiotemporal and environmental factors and fish traits. Their correlation with other established health indicators, such as body condition indices (condition factor, hepatosomatic and gonadosomatic indices), parasite community descriptors and histological assessment of target organs (gills, liver and spleen) is also assessed. Despite MMCs variability is mainly attributed to the species identity and fish size, their potential use as generic biomarkers of health condition is pointed out for certain species (e.g. Spicara maena and Micromesistius poutassou) in which an increased response was identified, and whose potential drivers are discussed. Most importantly, present results provide a comprehensive assessment of MMCs in the fish community for future studies in the area.

The dispersion of oil droplets near ocean surface is important for evaluating the impact to the environment. Under breaking wave conditions, the surface oil experiences mainly two processes: the generation of oil droplets at/near the water surface, and the transport of oil droplets due to ocean dynamics. We investigated the vertical behavior by incorporating the transport equation and the VDROP model. The transport equation adopted the ocean dynamics by K-profile parameterization (KPP) and the impact of additional turbulence by imposing the energy dissipation rate on the ocean surface. The oil droplet distribution was obtained, and the entrained distribution and entrainment rate was computed. The results shows that although the entrained distribution and the entrainment rate shares certain consistency with previous studies, divergences are also noticed. Accordingly, the model that describes the physics should be adopted to avoid incorrect qualification of the oil concentration dispersed in the ocean.

Metal concentrations were concurrently quantified in seawater, phytoplankton, and zooplankton from a heavily impacted coast of southern Taiwan. Combined size and density fractionation were used to accurately quantify metal concentrations in phytoplankton. Cr, Co, Ni, Cu, As, and Pb were analyzed using an inductively coupled plasma mass spectrometer (ICP-MS). As expected, metals significantly increased with an order of seawater < phytoplankton < zooplankton (p < 0.05); but did not differ between estuarine, nearshore, and offshore sites (p > 0.05). Metals were higher along Kaohsiung Harbor and marine outfall diffusion sites, highlighting their major impacts on plankton metal contamination. Notably, phytoplankton (Cr BCF > 100; half of the sites) significantly accumulated more metals contrary to zooplankton (BAF < 10). Metal concentrations and bioaccumulation factors between phytoplankton and zooplankton showed significant negative correlations. This demonstrates a non-proportional distribution and bioaccumulation of metals in phytoplankton and zooplankton—corroborating laboratory findings on zooplankton ability to control metals, irrespective of significantly high bioaccumulation in phytoplankton.