Marine sediments

The mid-Holocene (ca. 8200-4200 cal BP) brought about important climatic changes and environmental shifts to land and coastal systems , globally. Many of the human groups existing at that time were affected in various degrees by such important modifications to their foraging areas, including shorelines. Higher sea-levels (þ1-3 m) were a prominent factor reshaping coastal landscapes and thus affecting coastal foraging in one or more ways. Hot and dry weather and relatively higher sea levels along the central west coast of South Africa impacted substantially on local coastal hunter-gatherer groups. These challenges were thought once to have been unsurmountable because of an apparent absence of sites dated to this period. Recently dated mid-Holocene assemblages allow us to gain insight into coastal resource procurement and overall subsistence, and also to derive more detailed coastal paleoecological data. The results show a predominantly terrestrial diet, while shellfish collection persisted amid prevailing environmental factors affecting mussel growth by supplementing their reduced mollusk takes with additional prey. Sizeable crustaceans were also procured in relatively large numbers in some localities, but not in all. This is the most-up-to date mid-Holocene subsistence record for the central west coast of South Africa which, apart from reconstructing changes in procurement strategies, reveals a trajectory of persistence in the face of climate change. ARTICLE HISTORY

The present study deals with quantification of accumulated toxic heavy metals in sediments of Mithi River of Mumbai. The study was performed at three different sampling locations along the flow of Mithi River for two years from 2009-12. The different heavy metals studied were Al, As, Cd, Cr, Hg, Ni, Pb, Sr and Mn. The results of our study indicate that the concentration level of these toxic heavy metals for the two assessment years increases by the factor of 1.2-5.8 µg/g. The result is a clear indication of day by day increasing pollution level of the Mithi River, which is creating negative environmental impact on biological life of the river. The results emphasises the need of regular scientific monitoring of different pollutants adversely affecting the environment and to reframe the pollution control strategies already in existence.

Purpose Plastic pollution in the world has led to an abundance of microplastics (MPs) and has been identified as a potential factor that can lead to serious environmental problems, especially in oceans and seas. Information on the current status of MPs pollution along the Montenegrin coast is insufficiently investigated. This study monitors the abundance, distribution, and sources of MPs, and identifies present polymers in the surface sediment of the Montenegrin coast, as well as comparison with previous research. Materials and methods Ten sampling sites along the Montenegrin coast were selected to collect surface sediment samples. The upper layer of sediment (0-5 cm) was collected by a Petite ponar grab. The samples were dried, and density separation was performed using a NaCl solution. The abundance and morphological characteristics of MPs were determined using an optical microscope (DP-Soft software), while FT-IR analysis was done to identify the polymer type. Results and discussion Microplastics were identified in all sediment samples with an average abundance of 307 ± 133 (SD) MPs/kg in dry sediment. The highest abundance of MPs was found in locations in the vicinity of highly populated areas, near wastewater discharges, and areas with high fishing and tourist activities. The most dominant shape types of MPs in all samples were filaments and fragments. The most common colors of MPs were blue and red, while the dominant MPs sizes were 0.1-0.5 mm and 0.5-1.0 mm. Of the eight identified polymers, PP, PE, and PET were the most common. Conclusion This study reveals MPs characteristics (abundance, distribution, shape type, colors, size, polymers type) in surface sediment along the Montenegrin coast, as well as the most significant sources of MPs pollution, and provides important data for further research on MPs to identify the effects of MPs pollution on the quality, health, and functionality of the marine environment.

The wetland of Thane Creek, located at Thane, Mumbai, India, has attracted much attention of environmental biologists over the last few decades, as this creek has been subjected to a lot of pollution from the Asia's biggest Thane–Belapur industrial complex located at the south of Mumbai harbour along the west coast of India. This paper advocates ecological studies with special reference to the pollution due to heavy metals in the sediments along the Thane Creek area. The sediment samples were analysed for their heavy metal contents. These heavy metals have a marked effect on the aquatic flora and fauna which through biomagnification enter the food chain and ultimately affect the human beings as well. The experimental data on heavy metal content in sediment samples collected from Thane Creek points out to the need of regular monitoring of water resources and further improvement in the industrial waste treatment methods.

Thane Creek is one of the most important ecosystems around Mumbai and Thane, and the mangroves surrounding the ecosystem form the vital green lung for the residents. It is also an important feeding and breeding ground for fishes. Locals have been living in harmony amidst this ecosystem for ages, but in recent past, man has misused this ecosystem by way of releasing sewage, dumping solid waste, etc., and has succeeded in choking the ecosystem. This paper advocates habitat conservation and ecological studies with special reference to the physico-chemical characteristics of the sediment samples collected from six different sampling sites along the Thane Creek area. The constituents monitored included bulk density, moisture content, pH, EC, alkalinity, and chlorinity. The objective of the present work is to throw light on deteriorating condition of Thane Creek, suggesting the need for regular scientific studies, which will help to gauge the extent of pollution.

Thirteen persistent organic pesticides were investigated in the sediments of Vasai Creek near Mumbai to evaluate their pollution levels and potential risks. It was observed that ΣOCPs level was in the range of 597–1538 ng/g dw, with an average value of 1115.25 ng/g dw. The level of ΣOPPs was in the range of 492–1034 ng/g dw, with an average value of 798.15 ng/g dw. The values o,p′-DDT/p,p′-DDT ratio gives an indication of use of technical DDT as the prime source of DDT, while the α/γ-BHC ratio indicate that BHCs in study area might have been received from fresh lindane. The results of an ecological risk assessment showed that sediment bound organic pesticides are of more ecotoxicological concern as they might create adverse ecological risk to the marine breeding habitats. These pesticides residues may get remobilize and released to overlying waters creating adverse effects on terrestrial and aquatic organisms.

The activities of 226Ra, 232Th and 40K were measured
using gamma ray spectrophotometer in the marine sediments at industrial regions along the Red Sea coast; oil and gas industry at Rasel Behar and phosphate mining, milling and shipping at Hamrawin. Ra-226, 232Th and 40K at Rasel Behar recorded the average activities of, 15.2±6.3, 16.2±8.7 and 330.7±107.1 Bq/kg and at Hamrawin were; 114.2±134.5, 14.8±17.2 and 253.9±78.1 Bq/kg respectively. The averages of absorbed dose rates (D), the annual effective dose rate mSv/y), radium equivalent (Raeq), the external hazard index Hex), the internal hazard index (Hin) and the representative level index (Ir) at Rasel Behar were; 30.7 nGy/h, 0.04 mSv/y, 63.8 kg, 0.2, 0.5 and 0.2 and at Hamrawin were; ; 72.35 nGy/h, mSv/y, 154.9 Bq/kg, 0.42, 0.73 and 1.08 respectively. The calculated radiation hazard parameters at Rasel Behar were lower than the global average and most studies in the Red Sea, while at Hamrawin were higher than the calculated averages in Red Sea. Some radiological parameters; (Hex, Hin and Ir) were exceeded the unity and out of the safe limit of the human health therefore it may be harmful to the peoples in the region.

The Engineering-geological research relates to the development of concepts for the reconstruction and extension of an existing harbor for small vessels on St. Anastasia Island in order to protect the water area from dangerous geological and meteorological conditions. It is confirmed that in connection with the construction of future hydrotechnical facilities, the studied area is presented of Upper Cretaceous volcanic rocks and Quaternary marine sediments, subjected to the active impact of lithodynamic processes in Burgas Gulf. The performed Engineering geological studies included sampling, sample analysis, strength-deformation and physico-mechanical characteristics of lithological varieties and foundation conditions. The conditions for the foundation of the designed pier with a fenced mall are favorable for two types of hydrotechnical constructions: gravity and pilot.

Настоящото изследване е свързано с изготвяне на концепции за реконструкция и разширяване на съществуващ пристан за малки плавателни съдове на остров Света Анастасия с цел защита на акваторията от опасни геоложки и метеорологични условия. Проведените инженерногеоложки проучвания включваха вземане и селекция на проби, анализ на пробите, якостно-деформационни и физико-механични характеристики на литоложките разновидности и условията на фундиране. Условията за фундиране на проектирания пристан с ограден мол са благоприятни за два типа хидротехнически конструкции: гравитационна и пилотна.

Sedimentological studies have been used to decipher the provenance of the sediment samples. Granulometric analysis of sediments in the region from Kanyakumari coast, eight
sandy beaches have been selected and studied for analyzing the textural parameters namely mean, sorting, skewness, and kurtosis. Abundance of medium sand and low fine sand
deposits prevails in postmonsoon, summer and SW monsoon seasons, only medium sand deposits are available in NE monsoon. The presence of medium sand indicates that the
deposition might have been formed under a high-energy condition and fine sands correspond to moderately low-energy conditions. The Linear Discriminant Functions of the sediment
samples (Y1, Y2 and Y3) indicate beach, shallow agitated, and fully shallow marine environment in the coast and less influence of aeolian, beach process in all the seasons.
Bivariate plot means vs standard deviation and sorting vs skewness show that majority of the samples fall in beach environment and few samples fall in riverine environments. CM diagram of SW coast sediments implies that overall deposition takes place by optimum grain size for the rolling process sector. The seasonal wave response associated with grain size
variation clearly reflects the predominant transport rate higher in SW monsoon than the rest of the period. The post monsoon and summer season have the similar characteristics of the
sediment origination. On the other side, SW monsoon and NE monsoon have akin relationship one among the others. The results show that seasonal action implies sediment
dynamics except in Kanyakumari, and Kadiapattinam due to the presence of rocky cliffs, estuaries and anthropogenic activities. The present work provides an insight on the depositional feature of sediment in selected stations of the SW coast, India.

In this study, we analysed metagenomes along with biogeochemical profiles from Skagerrak (SK) and Bothnian Bay (BB) sediments, to trace the prevailing nitrogen pathways. NO 3 − was present in the top 5 cm below the sediment-water interface at both sites. NH 4 + increased with depth below 5 cm where it overlapped with the NO 3 − zone. Steady-state modelling of NO 3 − and NH 4 + porewater profiles indicates zones of net nitrogen species transformations. Bacterial protease and hydratase genes appeared to make up the bulk of total ammonification genes. Genes involved in ammonia oxidation (amo, hao), denitrification (nir, nor), dis-similatory NO 3 − reduction to NH 4 + (nfr and otr) and in both of the latter two pathways (nar, nap) were also present. Results show ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) are similarly abundant in both sediments. Also, denitrification genes appeared more abundant than DNRA genes. 16S rRNA gene analysis showed that the relative abundance of the nitrifying group Nitrosopumilales and other groups involved in nitrification and denitrification (Nitrobacter, Nitrosomonas, Nitrospira, Nitrosococcus and Nitrosomonas) appeared less abundant in SK sediments compared to BB sediments. Beggiatoa and Thiothrix 16S rRNA genes were also present, suggesting chemolithoautotrophic NO 3 − reduction to NO 2 − or NH 4 + as a possible pathway. Our results show the metabolic potential for ammonification, nitrification, DNRA and denitrification activities in North Sea and Baltic Sea sediments.

The granulometric characteristics, the bio-available heavy metals and the natural radionuclide activities in the surface sediments were investigated semi-annually in Timsah Lake at the middle district of the Suez Canal, Egypt. The average percentages of mud and fine grained sediments recorded in summer were (4.17% and 33.89%) much higher than in winter (1.43% and 22.70%) attributed to the relatively high dispersing of the fine sediment fractions in winter by wave action and the fine sediments drifting towards Suez Canal. The average carbonate percentage was 19.72% in summer increased to 22.71% in winter, inversely, the average total organic matter (TOM) in summer was 7.52% decreased to 6.32% in winter. The highest averages of the bio-available heavy metals; Zn, Cu, Pb, Cd, Mn, Co, Ni and Fe were; 65.51, 18.06, 27.76, 0.78, 260.64, 4.10, 17.16 and 2087.71μg/g were recorded summer and the highest average activities of 238U, 232Th and 40K were 23.79, 23.72and 221.35Bqkg-1 were recorded in winter. The recoded heavy metals and radionuclides were attributed to multi anthropogenic sources; untreated wastewater drains, agriculture drains, industrial runoff and shipyards. The high values of TOM and bioavailable heavy metals in summer are related to the highest fine sediment percentages, while the radionuclides may tend to associate with the coarse sediments. The significant positive correlations of TOM and Fe with heavy metals and radionuclides indicated to two essential metal phases, one with organic matter in the highly reducing conditions and the other associated and/or adsorbed by Fe-oxides and hydroxide particles in addition to the other independent metal phases. The recorded bioavailable metals are lower than the excepted because of suspended matters and water drift toward Suez Canal dilute the metal accumulation in the lake sediments.

One sentence summary: This study gives insight into the bacterial community composition related to iron-cycling in suboxic marine sediments based on 16S rRNA gene pyrosequencing. ABSTRACT To gain insight into the bacterial communities involved in iron-(Fe) cycling under marine conditions, we analysed sediments with Fe-contents (0.5–1.5 wt %) from the suboxic zone at a marine site in the Skagerrak (SK) and a brackish site in the Bothnian Bay (BB) using 16S rRNA gene pyrosequencing. Several bacterial families, including Desulfobulbaceae, Desulfuromonadaceae and Pelobacteraceae and genera, including Desulfobacter and Geobacter, known to reduce Fe were detected and showed highest abundance near the Fe(III)/Fe(II) redox boundary. Additional genera with microorganisms capable of coupling fermentation to Fe-reduction, including Clostridium and Bacillus, were observed. Also, the Fe-oxidizing families Mariprofundaceae and Gallionellaceae occurred at the SK and BB sites, respectively, supporting Fe-cycling. In contrast, the sulphate (SO 4 2−) reducing bacteria Desulfococcus and Desulfobacterium were more abundant at greater depths concurring with a decrease in Fe-reducing activity. The communities revealed by pyrosequencing, thus, match the redox stratification indicated by the geochemistry, with the known Fe-reducers coinciding with the zone of Fe-reduction. Not the intensely studied model organisms, such as Geobacter spp., but rather versatile microorganisms, including sulphate reducers and possibly unknown groups appear to be important for Fe-reduction in these marine suboxic sediments.

The aim of this study is to elucidate the characteristics of marine environmental geochemistry from Ha Tinh-Quang Nam (60-100m water depth) based on analysis of geochemical parameters of seawater and surface sediments. Surface sediments that are high in absorbed capacity of toxic substances mainly accumulated in northern study area. Seawater dominantly characterized by weak alkaline-weak oxidation and contained biodegradable organic materials. Almost anion and chemical element concentrations in seawater tended to decrease with depth, with an exception for SO 4 2-, Br-, I-concentrations that had an opposite trend, increasing with depth and B, Hg concentrations displayed a complex variation. Sedimentary environments were highly predominant by weak alkaline-strong oxidizing features and carbonate-rich materials. Concentrations of anions and chemical elements tended to be higher in central area in comparison to northern and southern regions, and positively correlated with fine sediment compositions. Organochlorine pesticides (OCPs) concentration decreased with sediment depth, whilst polychlorinated biphenyls (PCBs) concentration had no clear trend. The organic material, heavy metal, OCPs and PCBs concentrations in seawater and sediments were all lower than environmental standards. The present results have provided important baseline data for monitoring marine environment quality and protecting the marine ecosystem of Ha Tinh-Quang Nam Sea.

The present study is concerned with the pollution load monitoring along Vasai Creek of Mumbai with reference to the physico-chemical parameters of sediments. The study was carried for a span of two years from 2009-11 at four sampling stations namely Vasai bundar, Bhayandar west side below Railway Bridge, Bhayandar east side near Retibundar and Ghodbundar site along the flow of Vasai Creek. It was observed that most of the physico-chemical parameters like electrical conductivity, chloride, sulfate, sulfide and phosphate content in the sediment samples were higher during the assessment year 2010-11 as compared to that during the year 2009-10. However the pH values recorded during the year 2009-10 were higher than that recorded during the year 2010-11. The results of present investigation suggest that the present increasing pollution load along the Vasai Creek may affect sediment dwelling organisms and fish resulting in decrease survival, reduced growth, or impaired reproduction and lowered species diversity.

Stable Pb isotope ratios (206Pb/207Pb, 208Pb/206Pb), 210Pb, Pb, Al, Ca, Fe, Mn and Si concentrations were
measured in 7 sediment cores from the west coast of the Iberian Peninsula to assess the Pb contamination
throughout the last 200 years. Independently of their locations, all cores are characterized by increasing
Pb/Al rends not related to grain-size changes. Conversely, decreasing trends of 206Pb/207Pb were found
towards the present. This tendency suggest a change in Pb sources reflecting an increased proportion
derived from anthropogenic activities. The highest anthropogenic Pb inventories for sediments younger
than 1950s were found in the two shallowest cores of Cascais and Lisboa submarine canyons, reflecting
the proximity of the Tagus estuary. Lead isotope signatures also help demonstrate that sediments contaminated
with Pb are not constrained to estuarine–coastal areas and upper parts of submarine canyons,
but are also to transferred to a lesser extent to deeper parts of the Portuguese Margin.

Many studies have investigated the impacts of marine cage fish farming on seabed sediments. Most of these studies have focused on organic loading or toxic chemicals used for the treatment of disease, normally for a single or a small number of sites over short time periods. Only very rarely has there been the opportunity to use large data sets consisting of a large number of fish farm sites over a long time scale. In Scotland, localised nutrient impacts have been well documented for marine cage salmon farms, but mixed effects of nutrient and chemicals such as SLICE (the active ingredient of which is emamectin benzoate) have not been investigated in the long term. The aim of this project was to investigate the ecological impacts on sediments from farming activities using very large spatial and temporal data to investigate the long term effects of nutrient and chemical waste.

This was achieved using a metadata set collected from 403 sampling stations at 31 fish farms on the west coast of Scotland over a 9 year period. Data consisted of sediment macrofauna, carbon and nitrogen levels, redox potential, particle size for sediment characterisation and sediment concentrations of SLICE. The data was analysed for trends using statistical and multivariate analysis to look for changes in sediment community and related conditions, and the relationships between these parameters were investigated. At sampling stations that were less than 50 metres from the sea cages, 72% of the macrofauna communities were correlated with regard to their species composition and abundance. A significant relationship between the concentration of SLICE and sediment characteristics was represented as:

SLICE= 0.000644*(median size particle size) + 0.0311*(C %) – 0.00213*(redox potential) + 1.453.
Annelids were the most sensitive to the presence of emamectin benzoate, with the sipunculid Phascolion strombi, the echinoderm Ophiura affinis, and the custaceans Iphinoe, Diastylis and Iphimedia also showing sensitivity. During the data period, there was a clear change in species composition associated with improved seabed conditions. This correlated with biomass changes at the relevant sites, where there was a consequent decrease in nutrient input and SLICE usage.
The statistical comparison of the AMBI and ITI indices indicated a 68.9% correlation, but they differed in their ability to indicate levels of organic disturbance. AMBI was shown to correlate more closely with conditions and thus a more reliable index when working with large databases. Univariate and multivariate analysis indicated that a combination of abundance (N), Shannon Wiener (H’) and AMBI, as biological indices for describing the status of the ecological level associated with the carbon percentage and redox potential of sediments gave the most reliable representation of environmental change over a series of sampling stations.

In conclusion, the overall results suggest that, in the long-term, sampling stations which contained significant levels of SLICE had a higher impact status than those affected only by nutrient inputs. The accuracy of multiple regression models were increased by adding biotic and abiotic parameters, though fish biomass at the sites were not considered be as important factor for the prediction of impacts. However, this model could be sensitive to natural environmental conditions and variations. In light of these results and conclusions, recommendations can be made both for updating the existed environmental regulation of marine fish farms and in the development of meaningful models to relate sediment conditions to accurate estimations of overall environmental impacts.

Numerous radiocarbon (14C) dating organic material of mollusk and bottom sediments were made. Objective of the research was absolute age determinination for geocatastrofic occurense and the beginning of sapropele formation. It took place in geochronological interval 8-9 thousand years. Holocene and Late Pleistocene strata is stratified.

КиберЛенинка: https://cyberleninka.ru/article/n/radiocarbon-dating-14c-of-the-shelf-and-deep-see-sediments-of-the-black-sea

This study investigated the levels, sources and potential risks of 17 polycyclic aromatic hydrocarbons in surface sediment samples collected along the Mithi River of Mumbai. The concentration level of ΣPAHs found in the present study was in the range of 1206–4735 ng/g dw. The composition patterns of PAHs by ring size in sediment were surveyed which indicate the dominance of four rings followed by five and three ring PAHs. In the study it was observed that the high molecular weight PAHs (HMW PAHs) made greater contributions of 90.83% as compared to that of low molecular PAHs (LMW PAHs) contributing to 9.17% to the total PAH concentrations. Toxicity and biological risk were assessed using toxic equivalent quantity and sediment quality guideline quotient. It is feared that the pollution level of PAHs in the sediments might increase in coming times resulting in an unconspicuous risks for the environment and humans through food chains.

This bachelor's thesis is intended to lay the ground for future osteological documentation and analysis of the skeletal remains from the naval ship Mars, and is conducted with the project Skeppet Mars (1564). The main purpose of this thesis is to examine and problematise the possibility to analyse digitally documented skeletal remains in a marine context. In order to evaluate the possibilities and limitations of performing an osteological analysis, a small analysis was conducted on the digitally documented skeletal remains collected from the naval ship Mars so far. The analysis showed that an osteological analysis can be performed on digitally documented skeletal remains, there are, however, limitations of performing an analysis on a two dimensional documentation. The secondary purpose of this thesis is to discuss and highlight how skeletal remains are affected by marine sediment and brackish/saltwater over a long period of time. An additional goal for this thesis is to discuss how a hypothetical retrieval and conservation of the skeletal remains of the naval ship Mars should preferably be performed.

The problems that exist in Semarang waters are erosion and deposition. This is related to current flow patterns that are closely related to sediment transport patterns. An alternative solution to this problem is to study the sediment transport patterns suspended by the dynamics of the ocean such as ocean waves and ocean currents. The purpose of this study was to determine the pattern of suspended sediment distribution that occurred in the waters of Semarang. In this study, the ocean current and total suspended sediment data were taken when the sea tides and the sea recedes at a depth of 0.2d, 0.6d, 0.8d. Data processing uses a numerical modeling approach. After processing and analyzing the data, an overview of suspended sediment transport patterns that occur in the Semarang Sea is affected by the dynamics of the sea, especially ocean currents.

The geological and geomorphological research is related to the construction of the fishing port "Karantinata", located in Asparuhovo district in the southern part of Varna Gulf. It is confirmed that in connection with the construction of future hydrotechnical facilities, the studied area is presented of Miocene and Quaternary sediments, subjected to the active impact of lithodynamic processes in Varna Gulf. - Keywords: Varna gulf, marine sediments, Miocene, Quaternary

Globally, seagrass ecosystems are considered major blue carbon sinks and thus indirect contributors to climate change mitigation. Quantitative estimates and multi-scale appraisals of sources that underlie long-term storage of sedimentary carbon are vital for understanding coastal carbon dynamics. Across a tropical–subtropical coastal continuum in the Western Indian Ocean, we estimated organic (Corg) and inorganic (Ccarb) carbon stocks in seagrass sediment. Quantified levels and variability of the two carbon stocks were evaluated with regard to the relative importance of environmental attributes in terms of plant–sediment properties and landscape configuration. The explored seagrass habitats encompassed low to moderate levels of sedimentary Corg (ranging from 0.20 to 1.44% on average depending on species- and site-specific variability) but higher than unvegetated areas (ranging from 0.09 to 0.33% depending on site-specific variability), suggesting that some of the seagrass areas (at tropical Zanzibar in particular) are potentially important as carbon sinks. The amount of sedimentary inorganic carbon as carbonate (Ccarb) clearly corresponded to Corg levels, and as carbonates may represent a carbon source, this could diminish the strength of seagrass sediments as carbon sinks in the region. Partial least squares modelling indicated that variations in sedimentary Corg and Ccarb stocks in seagrass habitats were primarily predicted by sediment density (indicating a negative relationship with the content of carbon stocks) and landscape configuration (indicating a positive effect of seagrass meadow area, relative to the area of other major coastal habitats, on carbon stocks), while seagrass structural complexity also contributed, though to a lesser extent, to model performance. The findings suggest that accurate carbon sink assessments require an understanding of plant–sediment processes as well as better knowledge of how sedimentary carbon dynamics are driven by cross-habitat links and sink–source relationships in a scale-dependent landscape context, which should be a priority for carbon sink conservation.

Mangrove swamps have unique biogeochemical interaction between the plant and the underlying sediments. The bioactive heavy metals; Zn, Cu, Fe, Mn, Pb, Ni, Cd and Co were measured using Atomic Absorption Spectrophotometer (AAS) in the bulk sediment samples and the fine fractions; 125µ, 63µ and <63µ and slack water as well as different parts of the Avicennia marina mangrove (fruits, leaves and roots) collected from 9 mangrove swamps at the nearshore zone of the Red Sea. The average percentage of the fine sediment group (125µ + 63µ + <63µ) was varied between 18.78% and 51.22% from the total sediments with recognized occurrences for the fractions 125µ and 63µ. The bulk sediments recorded the highest averages of the bioactive Zn (69.91µg/g), Mn (186.91µg/g) and Ni (19.49µg/g), the fraction 125µ recorded the highest average of Pb (16.92 µg/g), while <63µ fraction showed the highest averages of Cu and Fe (26.45 and 2744.84µg/g). In the mangrove stands, the highest averages of Zn and Cu were recorded in fruits (Avs. ≈116.41 and 15.20 µg/g), Mn in leaves (Av. ≈ 43.72 µg/g) and the highest Pb was recorded in roots (Av. ≈ 30.14 µg/g). The bio-accumulation sequence of heavy metals in the fruits and roots was Fe>Zn>Pb>Cu>Mn>Ni and in leaves was Fe>Zn>Mn>Pb>Cu>Ni. The low contents heavy metals recorded in the slack water of the mangrove swamps attributed to the reducing nature of the underlying sediments that accumulate the heavy metals in insoluble sulphide forms. The effects of the elevated metal contents in the fruits, leaves and the roots of A. marina were at the studied forests were reflected in the ramified and shorten roots, pale yellowish colour and reduction the leaves number in many of the mangrove stands.

The regeneration of pore water (PW) nutrients was investigated and the contribution of benthic
nutrient fluxes to the overlying bottom water (BW) was examined. Dissolved inorganic nutrients
( 2 NO− , 3 NO− , 3
4 PO − and 44
SiO − ) were measured in PW and BW in El Mex Bay and surround drains
during spring 2010. Nutrient concentrations gradiance in PW with overlying seawater were evaluated
according to Fick’s Law. Average inorganic nutrient fluxes were estimated using the pore
water gradient concentration across the sediment-water interface. Calculated nutrient fluxes had
averages of −7.24, −1.36, −7.86 and −1.33 in El Mex Bay. Additionally, the fluxes in the drains were
−34.39, −32.28, −53.20 and −117.6 mg⋅m−2⋅day−1 for 3 NO− , 2 NO− , 3
4 PO − and 44
SiO − , respectively.
Mineralogical studies of sediment samples by using IR, X-ray analysis were carried out to identify
the chemical structure of sediments. The results revealed that calcite, aragonite and quartz are the
dominant minerals. On the other hand, differential thermal analysis (DTA) was used to evaluate
and discuss different kinetic parameters such as Ea#, ΔG#, ΔH#, ΔS#, Z and Tm support the view of
the extra stability of these sediments.

The geochemical and mineralogical characteristics of pelagic sediments collected from the Interoceanmetal Joint Organization (IOM) claim area, located in the eastern part of the Clarion-Clipperton Fracture Zone (CCFZ; eastern tropical Pacific), are described in this paper. The concentrations of rare earth elements (REE), as well as other selected critical elements contained in 135 sediment samples of siliceous clayey silts, are presented. The vertical and spatial variabilities of elements, with particular emphasis on REE as well as metals of the highest economic interest such as Cu, Ni, and Co, are detailed. The applied methods include grain size analysis by laser diffraction, geochemistry examination using ICP-MS, XRF, AAS, and CNS spectrometry, and XRD analysis of mineral composition (Rietveld method). Additionally, statistical methods such as factor analysis (FA) and principal components analysis (PCA) were applied to the results. Finally, a series of maps was prepared by geostat...

Multivariate geostatistical methods were employed to describe the local facies of surface pelagic sediments from the Interoceanmetal IOM H11 and H22 perspective areas. Using these methods, we analyze spatial variability in seafloor features, sediment grain size, and mineralogical and geochemical composition. The data were acquired from the seafloor sediments sampled by box corer. Laboratory methods included laser grain size analysis, X-Ray diffractometry and Inducted Coupled Plasma Mass Spectrometry. Universal kriging was applied in order to generate lithofacies maps, following the “classification probability kriging” concept based on a Bayesian theorem. Under this concept, the class membership probabilities are regarded regionalized variables, so that methodical tool of geostatistics can be applied. The final result is a series of thematic maps, showing the spatial distribution of classified sediments facies, expressed by class membership probabilities, which provide information on reliability of mapping. The applied models can be useful for geological exploration of Clarion-Clipperton polymetallic nodules deposit and beyond. The lithofacies maps presented here provide information on formation processes of sediments, induced by several factors, such as diagenetic transformation of sediments and pathways of biogenic, hydrogenous or hydrothermal material.

The present paper deals with assessment of physico-chemical properties of sediments samples collected along Mithi River of Mumbai. The study was carried for the period of two years i.e. 2009-10 and 2010-11 at three different sampling stations namely Jarimari near airport, CST Kalina road and Taximen's colony at Bandra Kurla Complex (BKC). It was observed that pH values at the above three sampling stations recorded during 2009-10 were 6.75, 6.63 and 4.30 respectively, which decreases to 4.95, 4.06 and 4.02 respectively during 2010-11. The above pH values were lower than that reported by Maharashtra Pollution Control Board (MPCB) in 2004.The chloride content recorded at three sampling stations during 2009-10 were 3177 mg/L, 2849 mg/L and 1825 mg/L which increases to 3256 mg/L , 3176 mg/L and 2148 mg/L respectively during the year 2010-11. Similarly sulfate values recorded were 2204 mg/L, 3545 mg/L and 5811 mg/L during the year 2009-10 which increases to 4682 mg/L, 4266 mg/L and 5318 mg/L respectively for the three sampling stations during the year 2010-11. The above observed chloride and sulfate values were higher than that reported by MPCB in 2004. The other physico-chemical parameters like electrical conductivity, sulphide and phosphate contents were also found to be higher in 2010-11 as compared to that in 2009-10.

Holocene Black Sea basin sediments were formed in our opinion in happened geocatastrofic event on the border Pleistocene-Holocene (8-9 thousand years ago). As a result on the Upper Pleistocene lake sediments occur organogenicmineral (sapropel diatoms and coccolith) marine sediments. The characteristic features of happened catastrophe is the occurrence of hydrogen sulfide charging that conserved the organic matter and protect it from decomposition. Chemical composition and properties of deep water organogenic mineral deposits give us reason to Tip of the raw material as an integrated multi purpose and most notably in agriculture.

- КиберЛенинка: https://cyberleninka.ru/article/n/sapropelic-diatomaceous-and-coccolith-sediments-units-ib-ia-of-the-black-sea-bottom-genesis-composition-and-properties

Identification of Tsunami deposits has long been a controversial issue among geologists. Although there are many identification criteria based on the sedimentary characteristics of unequivocal Tsunami deposits, the concept still remains ambiguous. Apart from relying on some conventional geological, sedimentological, and geoscientific records, geologists need some alternative “proxies” to identify the existence of Tsunami backwash in core sediments. Polycyclic aromatic hydrocarbons (PAHs) are a class of very stable organic molecules, which can usually be presented as complex mixtures of several hundred congeners; one can assume that the “Tsunami backwash deposits” possess different fingerprints of PAHs apart from those of “typical marine sediments.” In this study, three-dimensional plots of PAH binary ratios successfully identify the Tsunami backwash deposits in comparison with those of global marine sediments. The applications of binary ratios of PAHs coupled with HCA are the basis for developing site-specific Tsunami deposit identification criteria that can be applied in paleotsunami deposits investigations.

Petroleum hydrocarbon profiles of water and sediment samples of Algoa Bay in the Eastern Cape Province of South Africa were assessed using standard analytical procedures. Water (from surface and bottom levels) and sediment samples were collected from five locations in the bay from February to June 2016. Extraction of the petroleum hydrocarbons from the water and sediment samples collected was achieved using liquid-liquid and Soxhlet extraction techniques, respectively, followed by column clean up. Target compounds were analytically determined with gas chromatography-flame ionization detector (GC-FID) and quantified by integrating the areas of both the resolved and unresolved components. Physicochemical properties of the water samples were also determined on site using a SeaBird 19plusV2 CTD SBE 55 device. Estimated limit of detection, limit of quantitation and relative standard deviation for the 35 n-alkane standards ranged from 0.06 to 0.13 μg/L, 0.30 to 0.69 μg/L and 3.61 to 8.32%...

Sediments are solid, fragmented particulate matter (silt, sand, and gravel), which are transported and deposited by physical processes such as water, wind, and ice. Sediments consist of loose, solid particles originating from the weathering and erosion of rocks, or chemical precipitation from solution, including secretion by organisms in water.

Abstract: Florida Bay is a shallow lagoonal estuary divided into basins by a latticework of mud banks, which exert a disproportionate influence on the bay ecosystem. Prevailing northeasterly winds resulted in distinct sheltered and exposed sides on narrow banks, the ...

The long biological half lives, non-biodegradable nature and accumulative properties of trace and toxic heavy metals in aquatic environment has attracted great attention of environmental scientists and ecologist in recent years. Therefore, in the present investigation, we have selected Kalwa Bridge and Balkum sites along the Thane Creek to investigate pollution load due to trace and toxic heavy metals in aquatic environment. The distribution coefficient (K d) values of metals were calculated for soil and sediment samples. It was observed that the K d values were higher for sediment as compared to that obtained for soil samples. Also the K d values of metals for soil and sediments were found to be lower in rainy and maximum in summer seasons.