Microplastics (MP) are a pervasive environmental pollutant that enter coastal water bodies, posing an ingestion risk to marine biota. This study quantified the ability of the Eastern oyster (Crassostrea virginica) to egest MP in-situ in their biodeposits - feces and pseudofeces. Oysters of all sizes were able to egest environmental MP at a mean rate of 1 MP per 1 h through feces, and 1 MP per 2 h through pseudofeces. Smaller C. virginica were more efficient at egesting MP, and efficiency decreased by 0.8% per 1-g increase in tissue weight, with C. virginica of harvestable size being much less efficient. These findings are of relevance to resource managers for C. virginica populations as it further contributes to our understanding of MP accumulation in wild populations and has implications for not just C. virginica but also for their consumers.

Understanding the effects of habitat heterogeneity on the functioning of macrobenthic communities is essential to the conservation of biodiversity in coastal ecosystems. However, the effects of habitat heterogeneity on the functional trait composition and diversity of seagrass bed macrobenthos are as scarce. In the present study, functional diversity indices (i.e., functional dispersion, functional richness, and Rao's quadratic entropy), RLQ analysis, and fourth-corner analysis indicated that macrobenthic functional trait composition and diversity differ among seagrass bed microhabitats (interior, edge, and bare sediment). More specifically, functional traits were more evenly distributed in the seagrass bed interior and edge habitats, when compared to bare sediment, and functional diversity was significantly higher (p < 0.01). Functional trait distributions were influenced by environmental parameters (e.g., total organic carbon, organic matter, and grain size). Suspension-feeding and burrowing bivalves preferentially inhabited bare sediment with high sand content and low TOC, whereas herbivorous, small, and sensitive species mainly inhabited muddy sediments with higher organic supply.

Polycyclic Aromatic Hydrocarbons (PAHs) are among the main persistent organic pollutants in the Arcticwhich enter the polar region from lower latitudes by air transport and ocean currents and accumulate in marine sediments. This work represents the first study in 25 years of the least studied and hard-to-reach areas of Siberian arctic seas. Sixteen priority PAHs as well as 1- and 2-methylnaphthalenes were analyzed by gas chromatography – tandem mass spectrometry in the twenty-four sediment samples taken from Kara, Laptev and East Siberian Seas in October 2020. The obtained sum concentrations ranged from 31 to 223 ng/ g with the greatest contribution of phenanthrene, benzo[b]fluoranthene, benzo[k]fluoranthene, as well as naphthalene and its methyl derivatives while the greatest PAH levels were observed in Laptev Sea. No correlations between sum PAH concentration, total organic carbon and black carbon contents were found. The toxic equivalent in benzo[a]pyrene units was from 2.2–18.2 ng/ g that shows the general safe environmental situation in the region. The overall PAH level is comparable with the data obtained in 1990s which indicates a long-term persistence of pollution despite an overall decline in global PAH emissions. The main sources of PAHs involve mainly coal/biomass and liquid fuel combustion with weaker contribution of petroleum sources.

The presence of microplastics in the world's oceans and their effects on marine habitats are highly concerning. As suspension-feeders, corals are very exposed to microplastics, compromising the health of coral reef ecosystems. In this study we surveyed for the first time the presence of microplastics in Maldivian reef-building corals. Aiming to determine the influence of exposure and depth on microplastic distribution, analyses were carried out on 38 individuals belonging to three different species. 58% of the investigated colonies resulted contaminated with particles within the 25–150 μm size range. The maximum concentration was encountered in a Pocillopora verrucosa colony sampled from a shallow inner reef (8.9 particles/g of coral). No significant differences in microplastic concentration were observed between different depths, exposures, sites and species. Overall, this study confirmed microplastic presence in coral reefs of the Maldivian archipelago including foundation species.

PURPOSE OF REVIEW: Organic solid wastes (OSWs) have great potential for resourceful applications. However, individual treatment technologies are difficult to effectively recover their resources. This review aims to describe the development of solid-state anaerobic digestion (SS-AD), digestate aerobic composting, and their hybrid technology (SSADAC) for OSWs treatment to maximize resource recovery from OSWs. RECENT FINDINGS: SSADAC exhibits high potential for OSW treatment in energy and nutrient recovery. As individual treatment technologies, SS-AD and digestate composting recover energy and nutrients in terms of methane and compost, respectively. However, some deficiencies of these individual treatment technologies are hard to be ignored, such as energy loss and liquid digestate/leaching discharge. SSADAC can alleviate these issues with fully synergizing the characteristics of two treatment units for multi-target products. Thus, recent studies have proposed that the regulation of digestion duration can improve SSADAC performance, and other potential methods can also improve the value of SSADAC, such as raw material regulation and exogenous additives, to achieve zero waste discharge and maximum resource recovery. This review presents the applications of SS-AD and digestate composting for OSW treatment and illustrates the development and potential improvements of SSADAC as an integrated process. Key issues and their potential counter-measurements were displayed to provide the further development of SSADAC.

Water is the material basis for living organisms and one of the primary resources to maintain the sustainable development of the earth’s ecological environment. As a water purification method, nanofiltration (NF) separation technology has been widely considered by researchers in recent years. However, most of the studies on NF in the literature focus on membrane modification, and there are only a few reviews available. In this paper, the latest research progress of NF is reviewed, and the processes of NF membrane preparation using phase inversion, layer by layer, and interfacial polymerization are described. Polymer materials used for NF membrane preparation are reviewed and the main types of nanofillers to generate thin film nanocomposite membranes, including metal organic frameworks, boron nitride, Ti₃C₂TX, graphene oxide, SiO₂, and iron oxide are discussed. Membrane fouling is inevitable during NF operation and this paper analyzes the mechanisms of fouling and summarizes key pretreatment and cleaning methods required to remediate the long-term effects of cake layer formation. The steric hindrance effect, Donnan effect, and dielectric exclusion are analyzed, and some common characterization methods are summarized. The practical applications of NF are briefly introduced including groundwater, pharmaceutical wastewater, and textile wastewater treatment. Finally, the shortcomings and prospects of the existing research progress are put forward.

Motorized vessels are a major source of anthropogenic noise and can have adverse effects on species relying on sound for communication and feeding. Monitoring noise levels received by endangered southern resident killer whales (SRKWs) requires knowing the number, distance, and speed of surrounding vessels, including small boats that do not have Automatic Identification Systems (AIS). A method for estimating their speed is required to predict received noise levels and compliance with vessel regulations. We compared theodolite and photogrammetry methods to estimate the number, distance, and speed of vessels in SRKW Salish Sea summertime critical habitat. By treating AIS as “truth”, we found photogrammetry-derived ranges and speeds were more variable than theodolite estimates. Error in photogrammetry-derived speeds increased with range. Overall, we found time saved in the field using photogrammetry was more than offset by long analysis time. Theodolite data were relatively easy to collect, and produced accurate and precise results.

Off-flavours in fish products generated from recirculating aquaculture systems (RAS) are a major problem in the fish farming industry affecting the market demand and prices. A particular concern is the muddy or musty odour and taste in fish due to the presence of secondary metabolites geosmin and 2-methylisoborneol (2-MIB), produced by actinobacteria (mainly Streptomyces), myxobacteria and cyanobacteria. Off-flavours have deteriorated the quality of fish, rendering their products unfit for human consumption. The process of odour removal requires purification for several days to weeks in clean water; thus this leads to additional production costs. Geosmin and 2-MIB, detected at extremely low odour thresholds, are the most widespread off-flavour metabolites in aquaculture, entering through fish gills and accumulating in the fish adipose tissues. In this review, we aimed to determine the diversity and identity of geosmin- and 2-MIB-producing bacteria in aquaculture and provide possible strategies for their elimination.

Various oil spill cleanup sorbents have good hydrophobicity and oil separation efficiency, but their practical use has been limited due to the difficult and costly fabrication procedure. The research aims towards material development using the consumption of lignocellulosic agricultural residue for isolating cellulose nanofiber and its forward use to construct a 3D porous structure. A simple freeze-drying technique was used to assemble low-density porous structure. The biodegradable polylactic acid coating was used to alter the wettability from hydrophilic to hydrophobic and the maximum water contact angle value was around 120°. The prepared coated samples were testified for a series of oil/organic solvents-water mixtures. The sorption capacity was in the range of 28–70 g/g. The prepared aerogels were efficiently reused for at least 10 cycles. Developed material was used in continuous oil-water separation to remove oil from the water's surface. The cost analysis was estimated for scaleup production in the future.

Interactions of microplastics and persistent organic pollutants (POPs) associated with Atlantic salmon farming were studied to assess the potential role of microplastics in relation to the environmental impact of aquaculture. HDPE, PP, PET and PVC microplastics placed for 3 months near fish farms sorbed POPs from aquafeeds. PET and PVC sorbed significantly higher levels of dioxins and PCBs compared to HDPE, while the levels sorbed to PP were intermediate and did not differ statistically from PET, PVC or HDPE. In addition, the composition of dioxins accumulated in caged blue mussels did not reflect the patterns observed on the microplastics, probably due to polymer-specific affinity of POPs. In conclusion, the results of this study show that microplastics occurring near fish farms can sorb aquafeed-associated POPs and, therefore, microplastics could potentially be vectors of such chemicals in the marine environment and increase the environmental impact of fish farming.