Offshore Sediments Research Articles

Export and dispersal of coastal macrophyte-derived organic matter to deep offshore sediment around the Tokara and Yaeyama Islands, southwest Japan: Evaluation using quantitative DNA probing techniques

Export and dispersal of coastal macrophyte-derived organic matter to deep offshore sediment around the Tokara and Yaeyama Islands, southwest Japan: Evaluation using quantitative DNA probing techniques

First assessment of microplastics in offshore sediments along the Lebanese coast, South-Eastern Mediterranean

Few studies on microplastics (MPs) in the marine environment have been conducted along the Eastern part of the Mediterranean Sea and even fewer along the Lebanese coast. This study aims to determine MPs contamination for the first-time in coastal and continental shelf sediments collected along the Lebanese shores, South-Eastern Mediterranean Sea. Sediments were collected as transects in 10 sites with a total of 23 samples between 2 and 120 m depth and suspected MPs were assessed by moving farther from land-based sources. Microplastics concentrations ranged between 0 and 4500 MPs/kg of dry sediment (1126 ± 1363 MPs/kg). Polypropylene, polyethylene, polyethylene terephthalate and polystyrene were the polymers identified on micro-Raman. Coastal landfills and raw sewage effluents were identified as the main sources and routes for MPs into the Lebanese coastal marine environment. This study serves as the first database reporting MPs in continental shelf sediments in the South-Eastern Mediterranean.

Enhanced bioremediation of cyclohexaneacetic acid in offshore sediments with green synthetic iron oxide and Pseudoalteromonas sp.

Naphthenic acids (NAs) have been found to exert serious threats on offshore sediment ecosystems and human health in recent years, which entails us the urgent need for NAs remediation. Bioremediation is considered an ideal method for sediment remediation due to ecological sustainability and economic feasibility. However, current bioremediation efficiency of offshore sediments suffers from relatively slow and there has never any attempts to bioremediate offshore sediment NAs contamination hitherto. In this study, the green synthetic iron oxides (gFeOx) based on Laminaria extracts was employed to enhance the biodegradation of NAs (Cyclohexylacetic acid, CHAA) in offshore sediments by Pseudoalteromonas sp. JSTW (an indigenous microorganism). The results showed that CHAA (20mg·kg-1) in offshore sediments was removed almost 100% within 7days at 30mg·kg-1 gFeOx and 0.6mg·kg-1 Strain JSTW. High-throughput sequencing results revealed that the structure and function of sediment microbial community were essentially restored to uncontaminated levels after bioremediation, highlighting the joint remediation approach is an efficient and eco-friendly method. Overall, this work has firstly provided insights into the application for NAs in situ bioremediation in offshore sediments.

Nghiên cứu ảnh hưởng của công trình tới trường sóng, trường dòng chảy khu vực Cửa Tùng – Quảng Trị bằng mô hình số

For many years, Cua Tung area has suffered from the effects of rising water and waves, especially during storms. That situation leads to changes in water environment and coastal erosion, directly affecting people's lives and properties; affect the development of tourism, economy - society. The presence of the works here has led to a change in the hydrodynamic regime (waves, currents) and negatively affects the coast and water environment. Confirmed results show that wave height and flow rate are 73.6% and 55.2% according to Nash criteria, at a satisfactory level or higher. Before and after two constructions, the Southern Embankment and the North Embankment of Cua Tung, have shown a clear change in wave regime and flow, causing the waves to be strengthened and causing severe coastal erosion important. The author has proposed a breakwater construction measure off Cua Tung beach, through simulations, it has been shown that the breakwater has a great effect on breaking waves and protecting the coast. Wave height has decreased markedly at the rear of the breakwater. In addition, the barrier dyke also causes the sediment moving from the shore to the sea to be deposited inside the dyke and in the middle of the dyke there is a gap where the offshore sediment enters. The research results contribute to the assessment of the current status of the coastal zone and serve as a basis for ensuring the stability of the water environment, minimizing coastal erosion in order to develop tourism and promote socio-economic development.

Detection and analysis of microplastics in offshore sediment by microscopic differential Raman spectroscopy.

In view of the problems of low pre-screening efficiency, a weak Raman signal, and strong fluorescence interference in the detection of microplastics by traditional Raman spectroscopy, a set of rapid detection system and research methods for microplastics, including fluorescence imaging technology, differential Raman spectroscopy technology, and confocal microscopic Raman technology, are constructed in this paper. A 784/785nm dual-wavelength laser was used as the excitation light source in the rapid detection system for microplastics. The sediment in the coastal waters of Qingdao Shilaoren was taken as the research object. Polycarbonate and high-density polyethylene with a particle size of 40µm in the samples were accurately detected and analyzed. The research method for microplastics proposed in this study breaks through relevant key technologies, which we believe will help promote the development of microplastic monitoring technology in the global marine environment and provide strong technical support for the healthy development of the global marine ecological environment.

A probabilistic Bayesian methodology for the strain-rate correction of dynamic CPTu data

Dynamic Cone Penetration Test (CPTu) profile offshore sediments by impact penetration. To exploit their results in full, the measured data are converted to obtain a quasi-static equivalent profile. Dynamic CPTu conversion requires calibrated correction models. Calibration is currently done by using paired (i.e., very close) quasi-static and dynamic tests. It is shown here that paired test data, which may be inconvenient to acquire offshore, are not strictly necessary to convert dynamic CPTu data. A new probabilistic methodology is proposed to call upon quasi-static results from a much wider area in the conversion procedure. Those results feed the prior distribution of a converted profile, within a Bayesian updating scheme where strain-rate coefficient and correction model error are also described by updated stochastic variables. The updating scheme is solved numerically using the Transitional Markov Chain Monte Carlo sampling algorithm. To avoid undue influence of local profile heterogeneity, the statistic treatment of the quasi-static CPTu data takes place in the frequency domain, using a discrete cosine transform. The new procedure is applied to a CPTu campaign offshore Nice (France): dynamic tests are converted with equal precision using quasi-static data acquired at distances orders of magnitude larger than what was previously employed.

Genomic Analysis of a Novel Heavy Metal Resistant Isolate from a Black Sea Contaminated Sediment with the Potential to Degrade Alkanes: Plantactinospora alkalitolerans sp. nov.

Microorganisms that grow in poorly studied environments are of special interest when new biotechnological applications are searched. The Melet river offshore sediments at the Black Sea have been described to contain an important number of contaminants from upstream industries which have been accumulating for years. Bacteria of such habitats must be adapted to the presence of those compounds and in some cases, are able to use them as carbon sources. In the analysis of some samples recovered from this environment, an actinobacterial strain was isolated, named as S1510T, and its taxonomic position was determined using a combination of phenotypic and genotypic properties. Strain S1510T presented phenotypic properties typical of members of the family Micromonosporaceae and was assigned to the Plantactinospora genus, based on the phylogenetic analyses of the 16S rRNA gene and whole-genome sequences. Low dDDH (digital DNA-DNA hybridization) values with other members of the genus confirmed that Plantactinospora sp. S1510T represents a novel species, and is proposed with the new name Plantactinospora alkalitolerans. The strain presented characteristics not previously described for other species in the genus, such as its high tolerance to alkaline pHs, the presence of genes related to the production and degradation of alkanes (oleABCD, ssuAD, almA), the degradation of several aromatic compounds, and the tolerance to high heavy metal concentrations. In addition, Plantactinospora sp. S1510T presents several bioclusters to produce nonribosomal peptide-synthetases, terpenes, polyketide synthases, and bacteriocins, that possess low similarities with known compounds.

Greigite Formation Modulated by Turbidites and Bioturbation in Deep‐Sea Sediments Offshore Sumatra

AbstractAuthigenic greigite may form at any time within a sediment during diagenesis. Its formation pathway, timing of formation, and geological preservation potential are key to resolving the fidelity of (paleo‐)magnetic signals in greigite‐bearing sediments. In the cored sequence of the International Ocean Discovery Program Expedition 362 (Sumatra Subduction Margin), multiple organic‐rich mudstone horizons have high magnetic susceptibilities. The high‐susceptibility horizons occur immediately below the most bioturbated intervals at the top of muddy turbidite beds. Combined mineral magnetic, microscopic, and chemical analyses on both thin sections and magnetic mineral extracts of sediments from a typical interval (∼1,103.80–1,108.80 m below seafloor) reveal the presence of coarse‐grained greigite aggregates (particles up to 50–75 μm in size). The greigite formed under nonsteady state conditions caused by the successive turbidites. Organic matter, iron (oxy)(hydr)oxides, Fe2+, and sulfides and/or sulfate were enriched in these intensively bioturbated horizons. This facilitated greigite formation and preservation within a closed diagenetic system created by the ensuing turbidite pulse, where pyritization was arrested due to insufficient sulfate supply relative to Fe (oxy)(hydr)oxide. This may represent a novel greigite formation pathway under conditions modulated by turbidites and bioturbation. Paleomagnetic analyses indicate that the early diagenetic greigite preserves primary (quasi‐)syn‐sedimentary magnetic records. The extremely high greigite content (0.06–1.30 wt% with an average of 0.50 wt% estimated from their saturation magnetization) implies that the bioturbated turbiditic deposits are an important sink for iron and sulfur. Mineral magnetic methods, thus, may offer a window to better understand the marine Fe–S–C cycle.

A new approach for incorporating sea-level rise in hybrid 2D/one-line shoreline models

Hybrid 2D/one-line shoreline models, which typically apply a finite volume approach to simulate sediment transport and the one-line theory to update the shoreline morphology, are being increasingly applied over meso timescales (101 to 102 years) to inform coastal management. The one-line theory assumption of a constant closure depth prevents these models from considering the effects of sea-level rise in the shoreline morphology update. Sea-level rise, an endogenous driving factor of meso timescale coastal behaviour, influences the closure depth through its effects on the wave climate. This paper presents a new hybrid 2D/one-line approach that enables a time-varying closure depth in response to annual variations in wave climate as a solution for mirroring the effects of sea-level rise on the coastal profile and associated shoreline evolution. This new hybrid approach is applied to hindcast meso timescale shoreline evolution in a sandy coastal system and compared against the traditional hybrid 2D/one-line approach. Results show that the traditional hybrid approach gives the most accurate predictions whereas the new hybrid approach overpredicts shoreline erosion. However, this overprediction is attributed to net closure depth overestimation. This attribution gives confidence that the shoreline response to the time-varying closure depth specified is within expectations since closure depth overestimation increases offshore sediment transport in shoreline models. Therefore, it is likely that enabling a time-varying closure depth in hybrid 2D/one-line models may improve meso timescale shoreline predictions under sea-level rise if closure depths can be accurately prescribed over time.

Sediment transport and morphological responses of a silty coast to a cold front event in the southwest Bohai Bay of China

Silty coast, as a transitional state between muddy coast and sandy coast, possesses a considerable percentage of the overall coast in China. Huanghua-Binzhou coast in the southwest Bohai Bay in the northeastern China is a typical silty coast which is vulnerable to cold fronts when its seabed is prone to suffer suddenly drastic erosion and deposition due to the sediment there with relatively low incipient velocity and high settling velocity. In this study, a multi-sediment fraction model was established and two-way coupled with the wave-tide-surge model to investigate the responses of the sediment transport and morphodynamics of Huanghua-Binzhou coast to a cold front event during 10–13th Oct. 2003. The model results demonstrate that three sediment fractions, i.e. mud, silt and sand, showed different responses to the storm due to their different spatial percentages and distinct physical properties. The silt fraction, as the primary fraction, played a leading role in the suspension and transport of the total sediment, and showed a pattern of “deposition-erosion-deposition” in the cross-shore direction like the total morphological change. The fine sediment was transported westward and offshore during the storm, which indicated the sediment coarsening in the study area. The depth-induced wave modulation considerably enhanced the resuspension ability of the nearshore waves for sediment and thus played a critical role in intensifying the erosion. The Huanghua waterway siltation mainly resulted from the resuspension of the offshore sediment by the strong wind waves and its westward transport by the wind-induced currents during the storm. The construction of two long jetties in 2006 can significantly reduce the deposition in the waterway by 75%, and the additional large-scale construction in 2016 can further lessen the waterway siltation by intercepting the westward sediment transport and reduce the suspended sediment concentration by 30% by the land reclamation in the study area.

The Occurrence of Vanadiferous Titanomagnetite in Offshore Sediments, Gulf of Khambhat, West Coast of India

The Occurrence of Vanadiferous Titanomagnetite in Offshore Sediments, Gulf of Khambhat, West Coast of India

Global distribution, genesis, exploitation, applications, production, and demand of industrial heavy minerals

Heavy minerals (HMs) are used in many high-tech applications (e.g. nuclear reactors, photovoltaic cells, electronics, green, and nano- and space technology), and thus global demand is increasing day by day. This review article is focused on the global distribution, genesis, economic geology, exploration and exploitation, demand (i.e. past, present, and future status of annual global production, consumption, and price), applications (geological and industrial uses), and major environmental issues mostly related to the HM sand industry. Heavy mineral deposits are distributed in more than 45 countries. Major HM deposits are located in Australia, Asia, and Africa, as secondary coastal placers bordering the Indian Ocean. Onshore and offshore deposits in the Americas, Europe, and other countries also contribute to the global HM market. Heavy mineral deposits are categorised as primary (magmatic, hydrothermal, metamorphic) or secondary (weathered, eroded, and transported sediments) deposits. Titanium, zirconium, and rare earth element (REEs) bearing minerals are key industrial commodities in the current global market. The heavy mineral industry has experienced healthy growth in unit price and global production due to increased demand generated by rapidly expanding economies such as those of China and India. Global production of zircon, ilmenite, and rutile has gradually increased over the last few decades. Global apparent consumption of ilmenite declined slightly from 1970 to 1995, in part due to introduction of stringent regulatory measures and government environmental policies in Europe and North America, as the main consumers of HMs at present. Mining and utilisation planning following the United Nations Sustainable Development Goals are highly appropriate for the sustainability of the HM industry, and to overcome ecological challenges, health issues, and social resistance towards HM exploitation. Finally, we forecast changes in production and price of three HMs (ilmenite, rutile, and zircon) for the decade from 2020 to 2030, assuming there are no disturbances in production due to external factors such as the Covid-19 global pandemic or unfavourable geopolitical interventions.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12517-022-10874-0.

On the assessment of the diversity of coefficients of oil recovery from developed objects


 
 
 Based on the geological and commercial material collected and systematized by the offshore fields of Azerbaijan, the article discusses the reasons for the varying degrees of use of their reserves. For this purpose, the identification of deposits was carried out accord- ing to the natural regime, as a complex factor affecting oil recovery. Oil recovery models have been obtained for offshore reservoirs, draining mainly in two types of mechanisms: mixed and solution gas drives. Based on these regression equations and geological-economical analysis, a comparative analysis of the factors influencing oil recovery was carried out. Study of the different nature of the implementation of reserves of deposits characterized by different natural mechanisms so as to determine the degree to which the geological and technological parameters at various stages of development influence oil recovery. Objects: Offshore deposits of the Republic, characterized mainly by the solution gas and mixed drives. Application of the methods of mathematical statistics (Student’s and Fisher’s criteria) for the comparative analysis of the parameters of the mined deposits, confined to different natural conditions, allowing the revelation of the degree to which they are different and various patterns of the use of the reserves. In order to determine the influence of various factors on oil recovery, we used the method of correlation-regression analysis. It was found that a wide range of changes in oil recovery factors is associated with the internal structure of the deposits, with varying degrees of activity of the energy of the reservoirs and the fluids saturating them. It is known that each of the geological and technolog- ical parameters to one degree or another affects oil recovery, this influence is complex and subject to certain changes in the process of reservoir mining. In order to study the influence of parameters on oil recovery, we developed matrices of averaged values of a number of parameters of offshore deposits draining by mixed and solution gas drives. Using multivariate correlation-regression analysis and appropriate software, we obtained models for each of the above types of the mechanisms. A comparative analysis of those models, as well as geological and field studies of the parameters included in the obtained regression equations, make it possible to correct the oil production process in a timely manner, and can also be used in designing projects for the additional mining of those objects.
 
 

Sedimentary carbon on the continental shelf: Emerging capabilities and research priorities for Blue Carbon

Continental shelf sediments store large amounts of organic carbon. Protecting this carbon from release back into the marine system and managing the marine environment to maximize its rate of accumulation could both play a role in mitigating climate change. For these reasons, in the context of an expanding “Blue Carbon” concept, research interest in the quantity and vulnerability of carbon stored in continental shelf, slope, and deep ocean sediments is increasing. In these systems, carbon storage is physically distant from carbon sources, altered between source and sink, and disturbed by anthropogenic activities. The methodological approaches needed to obtain the evidence to assess shelf sea sediment carbon manageability and vulnerability within an evolving blue carbon framework cannot be transferred directly from those applied in coastal vegetated “traditional” blue carbon habitats. We present a toolbox of methods which can be applied in marine sediments to provide the evidence needed to establish where and when marine carbon in offshore sediments can contribute to climate mitigation, focusing on continental shelf sediments. These methods are discussed in the context of the marine carbon cycle and how they provide evidence on: (i) stock: how much carbon is there and how is it distributed? (ii) accumulation: how rapidly is carbon being added or removed? and (iii) anthropogenic pressures: is carbon stock and/or accumulation vulnerable to manageable human activities? Our toolbox provides a starting point to inform choice of techniques for future studies alongside consideration of their specific research questions and available resources. Where possible, a stepwise approach to analyses should be applied in which initial parameters are analysed to inform which samples, if any, will provide information of interest from more resource-intensive analyses. As studies increasingly address the knowledge gaps around continental shelf carbon stocks and accumulation – through both sampling and modelling – the management of this carbon with respect to human pressures will become the key question for understanding where it fits within the blue carbon framework and within the climate mitigation discourse.

Grain size distribution and fluvial environmental implications of Sebou estuary (Morocco)

The hydrodynamics and grain size distributions of sediment in estuarine and coastal environments provide important information on the material source, environmental events, and so forth. According to our knowledge, there is no research on the sediment characteristics of the entire Sebou estuary (Morocco), particularly, on the correlation between hydrodynamics and sediment properties. Grain-size analysis of estuary sediments along Sebou estuary (Morocco) has been carried out to reveal the depositional environment condition, energy and hydrodynamic conditions, as well as the mode of transportation along the study area. Linear discriminate analysis technique and bivariate plotting of grain size parameters are used to explain and understand the environment of sediment deposition. Hydrodynamic processes working during the deposition of sediments have been identified by CM plotting. As the mean grain size increased, sorting improved, and skewness became more positive and leptokurtic to very leptokurtic nature was observed in both periods. The spatial distribution indicates majority of sample fall in silt and clay category in both periods (i.e., spring and neap). Based on the CM pattern it was inferred that the sediment fall in rolling and suspension field. The sediments may be derived from offshore and catchment area deposits of the clay and silt, and evidence was found to suggest that these deposits are being eroded by tidal currents.

Effect of PCBs Extracted from Offshore Sediment of South China Sea (Zhanjiang) on Histological Structure and Inflammation of Zebrafish Intestine

As ubiquitous environmental pollutants, polychlorinated biphenyls (PCBs) can cause significant health risks to various organisms, including humans. Meanwhile, PCBs exhibit various properties such as biological toxicity, high fat solubility, and accumulation in sediments and bioaccumulation in the food chain. In this study, the concentration of PCBs in Zhanjiang offshore sediment and the histopathological changes and the mRNA expression of cytokines in intestines of zebrafish (Danio rerio) exposed to environmentally relevant concentrations of PCBs were investigated. Among the six sites selected, PCB28 was found in the sediments of Lakeside Park (BHP) and Seashore Park (HBP), with concentrations of 35.0 and 27.0 μg/kg, respectively. On the other hand, PCB81 was discovered in the sediments of Jinsha Bay (JSW) with a total amount of 29.0 μg/kg. Adult zebrafish were exposed to different PCB concentrations through water, with control (no PCB exposure), positive control (PCB 81 at 10 μg/L), low (5 μg/L), medium (10 μg/L), and high (15 μg/L) PCB doses. The fish were euthanized on days 1, 3, 5, and 7. The intestinal epithelial cells of the zebrafish exposed to PCB extracts proved the dose-responsive lesions. With the increase of concentration and time (P < 0.05), the relative expression of IL-1β, IL-8, and TNF-α mRNA increased significantly. The results showed that intestinal lesions and inflammation were dependent on exposure dose.

Distribution and dynamics of U.S. continental shelf ridge sediment and morphology: A brief review

The U.S. continental shelf is an important sediment source for beach nourishment and restoration efforts that mitigate erosion, increase resilience to storm impacts, provide habitat, and support the economy. The continental shelf is the preferred source for borrow sediment to closely match the native grain size distribution and composition of the site being restored. However, spatiotemporal variability of continental shelf sediment ranges in size and composition, resulting from previous sea levels and contemporary variability such as normal shelf processes, storm waves, and anthropogenic activities. Understanding the nature and distribution of continental shelf ridge sediment changes over time should reduce costs of efforts required to explore offshore sediments for coastal restoration projects. This review examines the present state of knowledge on the availability, distribution, and characteristics of continental shelf sediment under normal conditions and potential variability after storms and dredging. Under normal conditions sediment on the shelf is easily located and characterized as potential borrow areas. However, storms can induce enough sediment transport to change the boundaries of sediment borrow areas and the location of known sand ridges. Dredging can also influence sediment infilling of the dredged borrow areas, which impact benthic infauna and introduce potential onshore impacts depending on the geometry and nearshore proximity of the excavation. The results of this summary have identified gaps in the present knowledge such as a need for additional sand searches in under-investigated regions, a better understanding of storm impacts on hydrodynamic-driven ridge migration and continuing to review best management practices when new research of dredging practices and impacts are presented. A brief review of the present state of knowledge on the distribution and dynamics of continental shelf sedimentology and morphology are presented here to aid in advancing the scientific and coastal management community’s knowledge of shelf sediments and dynamics as well as highlight potential future research needs.

Particle-scale understanding sorption of phenanthrene on sediment fractions amended with black carbon and humic acid

Black carbon (BC) and humic acid (HA) have been proposed to dominate the sorption behavior of phenanthrene in sediment. Nevertheless, little is known about the sorption mechanism that related to particle-scale by spiking of BC and HA in sediment particle size fractions. In this study, sorption isotherms for phenanthrene were determined in four particle-size sediment fractions (<2 μm, 2–31 μm, 31–63 μm and >63 μm) that amended with BC and HA, or not. The fitting results by Freundlich model indicated that the sediment particle size fractions amended with BC increased the sorption capacity and affinity for phenanthrene. Sediment coarser size fractions (31–63 μm and >63 μm) by spiking of BC contributed higher to sorption capacity factor (KF) and nonlinearity factor (n) than the finer size fractions (2–31 μm and <2 μm). By contrast, the sediment particle size fractions amended with HA enhanced the sorption distribution coefficient (Kd), but reduced the sorption affinity for phenanthrene. All these phenomena are obviously affected by the distribution of heterogeneous organic matter that related to sediment particle-scale. Results of this work could help us better understand the impact of increased BC and HA content in sediments on the sorption of hydrophobic organic pollutants (HOCs) and predict the fate of HOCs in offshore sediments due to tidal action.

Differences in the methanogen community between the nearshore and offshore sediments of the South Yellow Sea.

The differences in methanogen abundance and community composition were investigated between nearshore and offshore sediments in the South Yellow Sea (SYS). Shannon, Simpson, and Chao1 indices revealed a higher diversity of methanogens in the nearshore sediments than in the offshore sediments. The Mann-Whitney U test demonstrated that the relative abundance of Methanococcoides was significantly higher in the offshore sediments, while the relative abundances of Methanogenium, Methanosarcina, Methanosaeta, Methanolinea, and Methanomassiliicoccus were significantly higher in the nearshore sediments (P < 0.05). The abundance of the mcrA gene in the nearshore sediments was significantly higher than that in the offshore sediments. Furthermore, a similar vertical distribution of the methanogen and sulfate-reducing bacteria (SRB) abundances was observed in the SYS sediments, implying there is potential cooperation between these two functional microbes in this environment. Finally, total organic carbon (TOC) was significantly correlated with methanogen community composition.

Geological evolution of offshore pollution and its long-term potential impacts on marine ecosystems

Populations and metropolitan centers are accumulated in coastal areas around the world. In view of the fact that they are geographically adjacent to coasts and intense anthropogenic activities, increasing global offshore pollution has been an important worldwide concern over the past several decades and has become a very serious problem that needs to be addressed urgently. Due to offshore pollution, various geological disasters occur in high frequency, including intensified erosion and salinization of coastal soils, frequent geological collapses and landslides and increasing seismic activities. Moreover, offshore pollution shows increasingly serious impacts on the topography and geomorphology of offshore and coastal areas, including coastal degradation, retreating coastlines and estuary delta erosion. Offshore sedimentation processes are strongly influenced by the pH changes of terrestrial discharges, and sedimentary dynamics have become extremely acute and complex due to offshore pollution. The seabed topography and hydrodynamic environment determine the fate and transport of pollutants entering offshore regions. Coastal estuaries, port basins and lagoons that have relatively moderate ocean currents and winds are more likely to accumulate pollutants. Offshore regions and undersea canyons can be used as conduits for transporting pollutants from the continent to the seabed. It is particularly noteworthy that the spatial/temporal distribution of species, community structures, and ecological functions in offshore areas have undergone unprecedented changes in recent decades. Due to increasing offshore pollution, the stable succession and development trend of marine ecosystems has been broken. It is thus important to identify and regulate the quantity, composition and transportation of pollutants in offshore regions and their behavior in marine ecosystems. In particular, crucial actions for stabilizing marine ecosystems, including increasing species and biodiversity, should be implemented to enhance their anti-interference capabilities. This review provides an overview of the current situation of offshore pollution, as well as major trends of pollutant fate and transportation from continent to marine ecosystems, transformation of pollutants in sediments, and their bioaccumulation and diffusion. This study retrospectively reviews the long-term geological evolution of offshore pollution from the perspective of marine geology, and analyses their long-term potential impacts on marine ecosystems. Due to ecological risks associated with pollutants released from offshore sediments, more research on the influence of global offshore pollution based on marine geology is undoubtedly needed.