Spatial-temporal characteristics and the importance of environmental factors in relation to algal blooms in coastal seas.

In the prediction of algal blooms with the artificial intelligence (AI) technology, the proper selection of the indices is crucial to the quality of the results. Although eutrophication and climate change have been identified as the main contributors to algal blooms, limited knowledge of the relationships among environmental factors hinders the accurate and correct AI prediction. To explore the importance of environmental factors in the occurrence of algal blooms in coastal seas and facilitate the selection of inputs for the prediction model, this study examines observed water quality data and analyzes their relationship using machine learning methods.

The MoS/rGO embed in macro-porous PAN gel as a novel DGT binding phase for the rapid and accurate detection of trace Hg(II).

The development of binding gels with a fast uptake rate, high capacity, and good selectivity could be beneficial for trace Hg(II) detection based on the DGT technology. In this study, a novel PAN@MoS/rGO-DGT was assembled by using the nanocomposite embedded in polyacrylonitrile membrane (PAN@MoS/rGO) as the binding phase. The interior regular finger-like macropore of the gel provided a convenient channel for the rapid mass diffusion of Hg(II), and the abundant sulfur offered the paramount driving force for trapping Hg(II).

Cadmium contamination in sediments from a mangrove wetland: Insights from lead isotopes.

Cadmium (Cd) pollution has gained significant attention in mangrove sediments due to its high toxicity and mobility. However, the sources of Cd and the factors influencing its accumulation in these sediments have remained elusive. In this study, we utilized lead (Pb) isotopic signatures for the first time to assess Cd contamination in mangrove sediments from the northern region of the Beibu Gulf.

Spatiotemporal distribution patterns and coupling effects of aquatic environmental factors in the dry-wet season over a decade from the Beibu Gulf, South China Sea.

Since the 21st century, the Beibu Gulf area has been affected by increasing anthropogenic activities, which makes the coastal aquatic ecosystem extremely concerning. However, the comprehensive exploration and analysis of the long-term scale behavior change characteristics of various water quality environment factors is still limited. Through comprehensively detecting coastal surface water environmental behavior information from 33 locations in the Beibu Gulf from 2005 to 2015, we revealed and quantified mutual response characteristics and patterns of various environmental indicators.

Seasonal dynamics of antibiotic resistance genes and mobile genetic elements in a subtropical coastal ecosystem: Implications for environmental health risks.

Antibiotic resistance poses a considerable global public health concern, leading to heightened rates of illness and mortality. However, the impact of seasonal variations and environmental factors on the health risks associated with antibiotic resistance genes (ARGs) and their assembly mechanisms is not fully understood. Based on metagenomic sequencing, this study investigated the antibiotic resistome, mobile genetic elements (MGEs), and microbiomes in a subtropical coastal ecosystem of the Beibu Gulf, China, over autumn and winter, and explored the factors influencing seasonal changes in ARG and MGE abundance and diversity.

The adsorption and release mechanism of different aged microplastics toward Hg(II) via batch experiment and the deep learning method.

Aged microplastics are ubiquitous in the aquatic environment, which inevitably accumulate metals, and then alter their migration. Whereas, the synergistic behavior and effect of microplastics and Hg(II) were rarely reported. In this context, the adsorptive behavior of Hg(II) by pristine/aged microplastics involving polystyrene, polyethylene, polylactic acid, and tire microplastics were investigated via kinetic (pseudo-first and second-order dynamics, the internal diffusion model), Langmuir, and Freundlich isothermal models; the adsorption and desorption behavior was also explored under different conditions.

Coupling isotopic signatures and partial extraction method to examine lead pollution in mangrove sediments.

Elevated lead (Pb) has been widely observed in mangrove sediments due to human activities, yet understanding the sources of Pb in these sediments and the factors influencing Pb accumulation is challenging. Here, we combined Pb isotopes with partial extraction methods to study Pb contamination levels in mangrove sediments from the eastern and western parts of the Maowei Sea, China. Our results showed that the Pb in the leachate and residual fraction was mainly from anthropogenic and natural sources, respectively.

Determining effect of seagrass-mediated CO flux on the atmospheric cooling potential of a subtropical intertidal seagrass meadow.

Atmospheric greenhouse gas (GHG) emissions from seagrass meadows that determine the ecosystem atmospheric cooling effect have rarely been quantified. This study measured the simultaneous fluxes direct to the atmosphere of three GHGs (CO, CH and NO) within a Halophila beccarii seagrass meadow and an adjacent unvegetated bare intertidal flat, and their relationships to seagrass abundance and relevant soil parameters. The results showed that seasonal variation in seagrass abundance was strongly linked with the CO exchange rate.

Short-Term Exposure to MPs and DEHP Disrupted Gill Functions in Marine Bivalves.

The synergistic impact of microplastics (MPs) and organic pollutants remains poorly understood in the marine environment. This study aimed to assess the toxicity of polypropylene microplastics (PS) and/or di-(2-ethylhexyl) phthalate (DEHP) on marine clams. Both and were exposed to PS and DEHP individually and combined at environmentally relevant concentrations for 48 h.

Development and validation of the DGT technique using the novel cryogel for measuring dissolved Hg(II) in the estuary.

The complex seawater matrix has significantly influenced the determination of estuarine dissolved Hg(II), hindering its monitoring and risk assessment in maricultural areas. In this work, SiO-SH-DGT assembled by the sulfhydryl-modified silica cryogel (SiO-SH cryogel) as the novel binding phase was developed to tackle this problem. The uniform dispersion of the cryogel into binding gel was advantageous for achieving remarkable and comparable capacity, which endowed the estimated diffusion coefficient (D) to be 1.

Adsorption of di (2-ethylhexyl) phthalate (DEHP) to microplastics in seawater: a comparison between pristine and aged particles.

Microplastics (MPs) are a widely distributed pollutant and have been attracting global attention. The increasing abundance of MPs in marine environments has raised concern about their adverse effects on marine organisms and influence on the fate of contaminants in seawater. In this study, we investigated the effects of natural aging on the adsorption of di (2-ethylhexyl) phthalate (DEHP), one of the most widely used phthalic acid esters (PAEs), in two types of MPs (polyethylene and polystyrene).

Mechanisms of Metal Tolerance in Halophytes: A Mini Review.

Industrialization and urbanization of coastal wetlands have caused metal pollution worldwide. Phytoremediation has been widely used for treating soil and water pollution, and halophytes are considered a promising remediation method to address metal pollution. However, application of halophytes in phytoremediation is still in its infancy.

The distribution of microplastics in water, sediment, and fish of the Dafeng River, a remote river in China.

Although rivers are one of the dominant pathways by which microplastics reach the oceans, reports on remote rivers are rare. Dafeng River is located in Guangxi Province, China, is an important water source and a habitat of a coastal dolphin, Sousa chinensis, which is a first-class national protected animal in China. In this study, we determined the distribution and characteristics of microplastics in the surface water, sediment, and fish of the river.

Control of phytoplankton by oysters and the consequent impact on nitrogen cycling in a Subtropical Bay.

Although there has been growing interest in using oysters to remediate estuarine eutrophication since the 1980s, the role of oysters in remediation remains controversial. In this study, we took advantage of the intensive oyster farming in a nutrient-enriched estuary to evaluate the control of phytoplankton blooms by oysters. Observing the phytoplankton density variations in March and October, we found that despite doubled nutrient levels in March, oysters kept the phytoplankton density low.

Pollution and ecological risk assessment, and source identification of heavy metals in sediment from the Beibu Gulf, South China Sea.

The Beibu Gulf is an important passageway between China and the Association of Southeast Asian Nations, where there has been an increase in pollution of heavy metals (HMs). High concentrations of Pb, Cr, Cd, Cu, Zn, As, and Hg in surface sediment were found in Qinzhou Bay, Fangchenggang, and other coastal areas. Stochastic geo-accumulation analyses identified the pollution to be "uncontaminated"; however, it had an 18% probability of deterioration.

Long-term trends of microplastics in seawater and farmed oysters in the Maowei Sea, China.

Microplastic pollution in marine environments and organisms has received a great deal of international attention. However, the long-term field studies of microplastics are rare. Here, we assessed annual variation in microplastic abundance in the Maowei Sea, a classic mariculture bay in southern China, and analyzed the long-term accumulation in oyster tissues.

Litterfall-derived organic matter enhances mercury methylation in mangrove sediments of South China.

Mercury (Hg) contamination in mangrove ecosystems has received increasing attention in recent years. Although many studies have investigated methylmercury (MeHg) contamination and its relationship to a number of environmental factors in mangrove sediments, the production of MeHg in this carbon-rich ecosystem has not been fully evaluated. In this study, we measured the total mercury (THg) and MeHg concentrations in the sediments collected from seven mangrove forests in China.

Isotopic Composition Reveals the Impact of Oyster Aquaculture on Pelagic Nitrogen Cycling in a Subtropical Estuary.

To offset estuarine eutrophication, interest is increasing in restoring oyster reefs and expanding oyster aquaculture. However, ecosystem-scale evidence is lacking on oyster assemblages' impacts on estuarine pelagic nitrogen (N) cycling. Using a multiple-isotope approach and isotope-mixing model, we examined the sources, transformations, and influence of intensive oyster aquaculture on N pollution in a subtropical estuary.

Bulk sedimentary phosphorus in relation to organic carbon, sediment textural properties and hydrodynamics in the northern Beibu Gulf, South China Sea.

Bulk sedimentary phosphorus (P) is studied to evaluate its source, distribution, preservation and enrichment in relation with organic carbon (OC), sediment textures and moisture contents in the northern Beibu Gulf. Approximately 80% of surface sediments in the investigated sites were composed of coarse sandy texture (>63 μm). Total P (TP), inorganic P (IP) and organic P (OP) contents were lower to medium range compared to the levels reported for other marginal seas.

Neutral monosaccharides and their relationship to metal contamination in mangrove sediments.

Mangrove sediments act as an important natural sink and a secondary source for trace metals. The main objective of this study was to investigate metal contamination and its relationship to mangrove-derived carbohydrates in mangrove sediments. Sixteen metals (Be, V, Cr, Co, Ni, Cu, Zn, Ga, As, Sr, Cd, Sn, Sb, Ba, Tl, and Pb）were analyzed in the surface sediments from four sites at different latitudes on the southeast coastline of China.

Phosphorus chemical speciation and seasonal variations in surface sediments of the Maowei Sea, northern Beibu Gulf.

This study presents the distribution, seasonal variations and factors influencing phosphorus (P) forms in surface sediments from the Maowei Sea. P forms were measured using the sequential extraction (SEDEX) procedures. Inorganic P (IP) was the predominant chemical form of total P (TP).

Microplastic pollution in the Maowei Sea, a typical mariculture bay of China.

The ingestion of microplastics by organisms presents a potential exposure route for humans via seafood consumption. Although mariculture has become an essential source of seafood worldwide, the content of microplastics in the mariculture zone has received less scrutiny than in the wild environment. The Maowei Sea is a semi-closed bay that is rich in fishery resources.

Complete mitochondrial genome of disc coral Turbinaria peltata (Scleractinia, Dendrophylliidae).

To date, no complete nucleotide sequences of the mitochondrial genome of Dendrophylliidae are yet available. In our study, the entire mitochondrial nucleotide sequence was determined for the Dendrophylliidae species Turbinaria peltata. The sequence was 18,966 bp in length and contained thirteen protein-coding genes, two ribosomal RNA genes (12S rRNA and 16S rRNA), two transfer RNA genes (tRNA(Met) and tRNA(Trp)) and a putative control region locating between Cyt b and ND2.