Marine Sediments Research Articles

Influence of Rhamnolipids Biosurfactant on the Anodic Electrochemical Performance in Marine Sediment Microbial Fuel Cell and the Acceleration Degradation of Crude Petroleum

Influence of Rhamnolipids Biosurfactant on the Anodic Electrochemical Performance in Marine Sediment Microbial Fuel Cell and the Acceleration Degradation of Crude Petroleum

Mitigating anthropogenic climate change with aqueous green energy

Reaching net zero emissions and limiting global warming to 2 °C requires the widespread introduction of technology-based solutions to draw down existing atmospheric levels and future emissions of CO2. One such approach is direct air CO2 capture and storage (DACCS), a readily available, yet energy-intensive process. The combination of DACCS and ocean thermal energy conversion (OTEC) allows for independently powered carbon capture plants to inject concentrated carbon into deep marine sediments where storage is generally safe and permanent. OTEC is a form of electricity production that exploits the temperature difference between deep and shallow ocean waters, and can power DACCS on floating platforms at a price competitive with coal-generated electricity. Here we highlight the scale of the challenge facing society. We show that a safe and sustainable level of OTEC-generated electricity powering DACCS for 70 years could result in up to a 35% decrease in the relative global mean temperature warming compared to a business-as-usual emissions scenario.

Responses of microbial communities in coastal sediments exposed to triclocarban and triclosan.

Triclocarban (TCC) and triclosan (TCS) are applied in a wide range of pharmaceutical and personal care products to prevent or reduce bacterial growth. Due to their extensive application, they are frequently detected in marine environments. In this study, marine sediment systems exposed to different concentrations of TCC and TCS were established to evaluate their effects on microbial communities. It was found that TCC and TCS increased catalase and protease activities on Day 1, but inhibited after 15days. Microbial activity, as indicated by increased dehydrogenase activity and polysaccharide production, should be enhanced after a 15-day adaptation period. High-throughput sequencing revealed resilient α-diversity but significant shifts in community structures were observed, particularly on Day 15. Function prediction analysis confirmed that most functional profiles remained stable, and network analysis indicated that TCC and TCS enhanced the complexity of the microbial community. This study provides new insights into the impacts and risks of TCC and TCS on the marine environment.

Quantitative Determination of Pyridine Content in Crustacean Tissues and Marine Sediments by Headspace Gas Chromatography/Tandem Mass Spectrometry (HS-GC-MS/MS)

Here, a method for the accurate quantification of pyridine in crustacean tissue using head space and gas chromatography - tandem mass spectrometry (GC-MS/MS) has been validated. Recoveries obtained - using pyridine d5 for quantification - were between 89-101%. The method limit of detection (mLOD) and the method limit of quantification (mLOQ) for the crustacean matrix were 0.0060 mg/kg and 0.020 mg/kg, respectively. This approach applied to the analysis of sediments gave an mLOD and an mLOQ of 0.0023 mg/kg and 0.0076 mg/kg. The developed method was used for the analysis of marine biota (<.020 mg/kg to 2.36 mg/kg) and sediments (<0.0076 mg/kg to 0.014 mg/kg) from the UK.

Structure of a Sulfated Capsular Polysaccharide from the Marine Bacterium Cobetia marina KMM 1449 and a Genomic Insight into Its Biosynthesis

Some marine and extremophilic microorganisms are capable of synthesizing sulfated polysaccharides with a unique structure. A number of studies indicate significant biological properties of individual sulfated polysaccharides, such as antiproliferative activity, which makes them a promising area for further research. In this study, the capsular polysaccharide (CPS) was obtained from the bacterium Cobetia marina KMM 1449, isolated from a marine sediment sample collected along the shore of the Sea of Japan. The CPS was isolated by saline solution, purified by a series of chromatographic procedures, and studied by chemical methods along with 1D and 2D 1H and 13C NMR spectroscopy. The following new structure of the CPS from C. marina KMM 1449 was established and consisted of sulfated and simultaneously phosphorylated disaccharide repeating units: →4)-α-L-Rhap2S-(1→3)-β-D-Manp6PGro-(1→. To elucidate the genetic basis of the CPS biosynthesis, the whole genomic sequence of C. marina KMM 1449 was obtained. The CPS biosynthetic gene cluster (BGC) of about 70 genes composes four regions encoding nucleotide sugar biosynthesis (dTDP-Rha and GDP-Man), assembly (GTs genes), translocation (ABC transporter genes), sulfation (PAPS biosynthesis and sulfotransferase genes) and lipid carrier biosynthesis (wcb operon). Comparative analysis of the CPS BGCs from available Cobetia genomes showed the presence of KMM 1449-like CPS BGC among strains of all three Cobetia species. The study of new natural sulfated polysaccharides, as well as the elucidation of the pathways of their biosynthesis, provides the basis for the development of potential anticancer drugs.

Seawater effects on ground granulated blast furnace slag (GGBS)-stabilized marine deposits in land reclamation

Seawater effects on ground granulated blast furnace slag (GGBS)-stabilized marine deposits in land reclamation

East-Siberian Sea–Chukchi Sea Prograded Margin Tectono-Sedimentary Element and Makarov Oceanic Basin Composite Tectono-Sedimentary Element, Siberian and Central Arctic

The East Siberian Sea–Chukchi Sea Prograded Margin (ESCPM) and Makarov Oceanic Basin (MOB) include interconnected sedimentary accumulations with gradual facies transitions that occupy a significant part of the Amerasia Basin and the adjacent Siberian Arctic continental margin. The ESCPM contains a succession of Cenozoic clinothem featuring shelf-margin progradation caused by a rapid influx of siliciclastic material from NE Asia into the adjacent Amerasia Basin and represents a single tectono-sedimentary element (TSE) as per the volume's terminology. The MOB is a most distant and isolated from continental depositional systems part of the Arctic Ocean. It consists of two first-order sedimentary accumulations with distinct depositional styles and provenances. The lower, Passive margin TSE is composed of a fragment of the presumably Paleozoic-Mesozoic Barents and North Kara passive continental margin. The upper, Synoceanic TSE was formed following the separation of continental block of the Lomonosov Ridge from the Eurasian continental margin at ∼ 56 Ma and during the opening of the Eurasian Basin. It includes mostly Eocene to Holocene hemipelagic and pelagic deposits and ice-rafted sediments. Each of these accumulations is characterised as a TSE, and the MOB itself is considered as a composite TSE (CTSE). Assessments of petroleum potential in both elements rely on regional geological constraints, sedimentary architecture, and modelling. Direct hydrocarbon indicators have been detected in seismic profiles in both ESCPM and MOB. In the latter, petroleum generation likely began in the Jurassic or Late Cretaceous, peaking in the Paleocene and possibly extending into the Miocene. Reservoir rocks are inferred in Cretaceous and Cenozoic strata. In ESCPM TSE, Paleocene-middle Eocene sedimentary successions are considered to include potential source rocks, associated with main flooding surfaces and clinothem bottomset deposits.

Clostridium sediminicola sp. nov., a crude oil aggregation-forming anaerobic bacterium isolated from marine sediment.

A crude oil aggregation-forming, strictly anaerobic, Gram-stain-positive, spore-forming, rod-shaped, motile and mesophilic bacterium, named strain SH18-2T, was isolated from marine sediment near Sado Island in the Sea of Japan. The temperature, salinity and pH ranges of this strain for the growth were 15-40 °C (optimum 35 °C), 0.5-6.0% NaCl (w/v; optimum 2.0%) and pH 6.0-8.0 (optimum 7.5), respectively. A phylogenetic analysis of the 16S rRNA gene sequence showed that this strain belongs to the genus Clostridium. It was most closely related to Clostridium grantii A-1T (97.02% homology). The draft genome size was 5616089 bp, with a G+C content of 29.7 mol%. The digital DNA-DNA hybridization values determined using the Genome-to-Genome Distance Calculator and the average nucleotide identity between this strain and C. grantii A-1T were 20.30 and 78.24%, respectively. Whole-organism hydrolysates of strain SH18-2T contained meso-diaminopimelic acid; the major fatty acid was C16:0, and the polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol, glycolipid and three unidentified polar lipids. From the results of genotypic, phenotypic and chemotaxonomic analyses, SH18-2T (=NBRC 116030T=DSM 115762T) is the type strain and represents a novel species of the genus Clostridium, and the name Clostridium sediminicola sp. nov. is proposed.

Investigation of multiple resistance frequencies (antibiotic and heavy metal) of bacteria isolated from Gökçeada Island coastal marine sediment

Marine sediments are important reservoirs for antibiotics and heavy metals. Bacteria play a key role in polluted sedimentary habitats. This study aimed to identify heavy metal and antibiotic resistance in marine sediment bacteria isolated from Gökçeada Island in Turkiye. The samples were collected seasonally from 10 different sampling stations in 2015. Ninety isolates determined by VITEK 2 were tested against seven antibiotics using the disk diffusion method. The minimum inhibitory concentration values were measured against four heavy metal salts. The antibiotic resistance frequency rates were ordered as sulphonamides compound (93.3%), cefotaxime (78.9), ampicillin (77.8%), oxacillin (67.8%), rifampicin (57.8%), imipenem (1.1%), and oxytetracycline (0%). The heavy metal resistance ratios against ZnCl2, CuSO4, Pb(CH3COO)2, and HgCl2 were measured as 100%, 100%, 96.7%, and 73.3% respectively. The multiple heavy metal resistance index values were ranged from 0.75 (22.2%) to 1.0 (77.8%). The results show significant heavy metal and antibiotic contamination in the sediments of the Gökçeada Island. It is recommended that measures be taken against antibiotics and heavy metal pollution, as well as identifying and monitoring critical control points.

Benthic copepod guts as a selective microbial microhabitat in marine sediments

Benthic copepod guts as a selective microbial microhabitat in marine sediments

A new approach to high conversion CO2 hydrate sequestration by CO2/water emulsion injection into marine sediments

A new approach to high conversion CO2 hydrate sequestration by CO2/water emulsion injection into marine sediments

Preservation of organic carbon in marine sediments sustained by sorption and transformation processes

Controls on organic carbon preservation in marine sediments remain controversial but crucial for understanding past and future climate dynamics. Here we develop a conceptual-mathematical model to determine the key processes for the preservation of organic carbon. The model considers the major processes involved in the breakdown of organic carbon, including dissolved organic carbon hydrolysis, mixing, remineralization, mineral sorption and molecular transformation. This allows redefining of burial efficiency as preservation efficiency, which considers both particulate organic carbon and mineral-phase organic carbon. We show that preservation efficiency is almost three times higher than the conventionally defined burial efficiency and reconciles predictions with global field data. Kinetic sorption and transformation are the dominant controls on organic carbon preservation. We conclude that a synergistic effect between kinetic sorption and molecular transformation (geopolymerization) creates a mineral shuttle in which mineral-phase organic carbon is protected from remineralization in the surface sediment and released at depth. The results explain why transformed organic carbon persists over long timescales and increases with depth.

The transport, distribution, and budget of anthropogenic 129I in the Bohai and North Yellow Seas, China.

The potential release of radionuclides threatens marine ecosystems with the rapid development of coastal nuclear power plants in China. However, transport, dispersion, and final budget of anthropogenic radionuclides remain unclear, especially in the Bohai and North Yellow Seas, which are semi-enclosed marginal seas with poor water exchange. This study analyzed anthropogenic 129I concentration (a typical product of nuclear power plant operations) in seawater samples from this area. 129I/127I ratios (1.61-6.71 × 10-10) fall within the typical background range from similar latitudes, indicating the safe operation of nuclear power plants currently. Direct atmospheric deposition from European nuclear fuel reprocessing plants accounted for 66 % of the total 129I, which far exceeded riverine inputs (34 %). Riverine 129I acts as a clear tracer, depicting that high 129I concentrations were primarily confined within 50 km of the shore, and strong seawater dilution occurred at 50-100 km. Marine sediment serves as the largest sink (59 %) of 129I, while 27 % of 129I is retained in the water column. Additionally, surface outflow and deep-layer inflow occur in autumn in the southern strait of the Bohai Sea. These findings enhance understanding of the diffusion of water-soluble radioactive contaminants in semi-enclosed marginal seas and provide a quantitative perspective for tracing marine environmental processes.

Identification of sulfur species in coastal marine sediments collected from the Seto Inland Sea, Japan in summer

Identification of sulfur species in coastal marine sediments collected from the Seto Inland Sea, Japan in summer

Heavy metals in sediments and fishery catches from the Beibu Gulf, China: Bioaccumulation, potential risks, and human

In this study, 3 species of fishey catches (Pennahia macrocephalus, Saurida tumbil, and Upeneus sulphureus) and sediments were collected from the Beibu Gulf to identify the residual levels, human health risk, and ecological risk of HMs (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn). The average concentrations (dry weight) of As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn in the three species of fish were recorded as follows: 10.94, 0.11, 0.55, 2.00, 5.80, 0.47, 0.39, and 41.70 mg/kg, respectively. The health risk assessment results indicated that adults who consume these organisms could encounter carcinogenic health hazards, while children consuming these species may experience notable negative health effects. The contents of studied HMs reached China’s national first-class benchmark of marine sediment quality. The ecological risk index (RI) of HMs from surface sediments ranged from 17.77 to 133.88, with a mean value of 56.45, which portrayed minor potential.

Niche Partitioning and Intraspecific Variation of Thaumarchaeota in Deep Ocean Sediments.

Deep-sea sediments contain a large number of Thaumarchaeota that are phylogenetically distinct from their pelagic counterparts. However, their ecology and evolutionary adaptations are not well understood. Metagenomic analyses were conducted on samples from various depths of a 750-cm sediment core collected from the Mariana Trench Challenger Deep. The abundance of Thaumarchaeota and archaeal amoA generally decreased with depth, except for an unexpected peak midway through the core. The thaumarchaeotal metagenome-assembled genomes were classified into diverse phylogenetic clusters associated with amoA-NP-γ, amoA-NP-θ, and amoA-NP-δ of ammonia-oxidising Thaumarchaeota and non-ammonia-oxidising lineages. The most abundant group was within amoA-NP-γ, which is usually found in coastal and shallow habitats, indicating potential niche expansion from marine shallow to hadal environments. This benthic group showed within-species genomic variations compared to the previously identified Hadal water group, suggesting microdiversification of hadal Thaumarchaeota along with niche separation between benthic and pelagic environments. Evolutionary adaptations associated with the benthic-to-pelagic transition included reduced genome size, loss of motility/cell adhesion, altered energy metabolism, and different mechanisms for substrate acquisition and regulation (e.g., ammonium). These findings offer new insights into the evolution of hadal Thaumarchaeota and demonstrate, for the first time, intraspecies-level genomic variation in Thaumarchaeota related to the benthic-versus-pelagic niche partitioning in the deep ocean.

Fibre Optic Method for Detecting Oil Fluorescence in Marine Sediments.

The aim of this study is to verify the possibility of detecting oil in the bottom sediment using a fibre optic system. The presence of oil is assessed on excitation-emission spectra obtained from spectral fluorescence signals of the sediment sample. A factory spectrofluorometer coupled with an experimental fibre optic measurement system was used. During the determination of spectra, the fibre optic system is set at a 45° angle to the sediment surface and placed above its surface. The light exciting the fluorescence and the light emitted by the sediment are transmitted in a combined bundle of fibre optic threads. The analysis of excitation-emission spectra of sediments contaminated with oil shows variability of the shapes of fluorescence spectra depending on the type and degree of oil contamination, which indicates the feasibility of the sensor design for detecting oil in the sediment in situ.

The landscapes of the Aral physical-geographical region and their zoning experiments

In this article, new lands formed in the drainage zone of the Aral Sea and areas where marine deposits are widespread in the Eastern Aral Sea area were identified as a separate physical geographical unit – the Aral physical-geographical region. The article also describes the landscapes and physical-geographical districts of the Aral physical-geographical region. It has been studied that the units of physical-geographical zoning are classified differently by different researchers, and the units of zoning of the Aral physical-geographical region have been described. A map of landscapes and physical-geographic zoning of the Aral physical-geographical region with a medium scale (1: 500.000) has been compiled.

Huajuapan Lithostratigraphic Map, Puebla and Oaxaca states, Mexico (E14-D14)

ABSTRACT This paper presents a 1:50,000 scale map and lithostratigraphic synthesis of the Huajuapan region, which has one of Mexico's most complete geological records. The region represents a critical area for understanding the marine flooding process after the breakup of Pangea. This process formed small extensional basins, such as the Ayuquila basin, and dismantled a primary fluvial system that drained the ancient central Pacific slope of Pangea. In the Huajuapan region, the Ayuquila basin developed in a tectonic SSE–NNW extension framework that prevailed from the Middle Jurassic to the Turonian. In its beginnings, this basin developed a thick siliciclastic fluvial deposit during the Middle Jurassic. Later, during the Late Jurassic, although with local unconformities, the deposition of marine successions began. Marine deposits continued throughout the Cretaceous. During the Cenozoic, continental conditions were re-established with clastic-evaporite successions and volcanic activity.

Microplastic occurrence and fate in the South African environment: a review

This review examines the occurrence and fate of microplastics (MPs) in freshwater, marine, and terrestrial environments in South Africa. MPs were found in Tshwane and Johannesburg in drinking water samples, with concentrations as high as 0.189 particles/L. Concentrations in freshwater bodies were greater, sometimes reaching 0.33–56 particles/L. MP levels in marine sediments were greater than many worldwide averages, particularly along the southeast coast (up to 45,867 particles/kg) and the MP levels in air were 1–5 particles/m3. These values are in line with figures around the globe which stand at 0.1–10 particles/L, and 0.3–10 particles/m3 for water, and air respectively. Low-density PE, PP, and PE-HD were the most prevalent polymers identified. Although there is little data, inappropriate disposal of waste is a major cause of soil contamination, which is a serious concern. The study highlights how important it is to conduct more research to close knowledge gaps, especially regarding MPs in groundwater and their impact on human health. The findings emphasise the necessity of improved wastewater treatment technologies, public awareness initiatives, and stronger laws governing single-use plastics. Standardizing MPs detection techniques, improving our knowledge of MPs fate and transport, and estimating the effects of MPs exposure to human health should be the main goals for future research. Effective cooperation between researchers, legislators, and industry is necessary for mitigation initiatives to be successful.