Elements In Surface Sediments Research Articles

Abundance, distribution and bioavailability of major and trace elements in surface sediments from the Cai River estuary and Nha Trang Bay (South China Sea, Vietnam)

Major (Si, Al, Fe, Ti, Mg, Ca, Na, K, S, P), minor (Mn) and trace (Li, V, Cr, Co, Ni, Cu, Zn, As, Sr, Zr, Mo, Cd, Ag, Sn, Sb, Cs, Ba, Hg, Pb, Bi and U) elements, their chemical forms and the mineral composition, organic matter (TOC) and carbonates (TIC) in surface sediments from the Cai River estuary and Nha Trang Bay were first determined along the salinity gradient. The abundance and ratio of major and trace elements in surface sediments are discussed in relation to the mineralogy, grain size, depositional conditions, reference background and SQG values. Most trace-element contents are at natural levels and are derived from the composition of rocks and soils in the watershed. A severe enrichment of Ag is most likely derived from metal-rich detrital heavy minerals such as Ag-sulfosalts. Along the salinity gradient, several zones of metal enrichment occur in surface sediments because of the geochemical fractionation of the riverine material. The parts of actually and potentially bioavailable forms (isolated by four single chemical reagent extractions) are most elevated for Mn and Pb (up to 36% and 32% of total content, respectively). The possible anthropogenic input of Pb in the region requires further study. Overall, the most bioavailable parts of trace elements are associated with easily soluble amorphous Fe and Mn oxyhydroxides. The sediments are primarily enriched with bioavailable metal forms in the riverine part of the estuary. Natural (such as turbidities) and human-generated (such as urban and industrial activities) pressures are shown to influence the abundance and speciation of potential contaminants and therefore change their bioavailability in this estuarine system.

Distribution of major and trace elements in surface sediments of the western Gulf of Thailand: Implications to modern sedimentation

In this study, we analyze major and trace elements (SiO2, Al2O3, Fe2O3, CaO, K2O, MgO, Na2O, TiO2, P2O5, MnO, Cu, Pb, Ba, Sr, V, Zn, Co, Ni, Cr, and Zr) and grain size of 157 surface sediment samples from the western Gulf of Thailand (GoT). On the basis of the space distribution characteristics, the study area can be classified into three geochemical provinces. Province I covers the northern and northwestern coastal zones of the GoT, including the whole upper GoT and thus the sediments from the rivers in the area. It contains high contents of SiO2. Province II is located in the middle of the GoT and has similar geochemistry composition as the South China Sea (SCS). It contains sediments that are characterized by higher contents of Na2O, TiO2, Ba, Cr, V, Zn, Zr, and Ni. Province Ш is located in the lower GoT, close to Malaysia. Major and trace elements in this area showed complex distribution patterns, which may be due to terrestrial materials from Malay rivers combining with some sediments from the SCS in this province. The results also indicate that grain size is the controlling factor in elemental contents, and that the hydrodynamic environment and mineral composition of the sediments play an important role in the distribution of these elements. The anthropogenic impact of heavy metal introduction (especially Cr, Zn, Cu, and Pb) can be seen in surface sediments from the nearshore region of Chantaburi province and north of Samui Island.

The distribution characteristics of rare metal elements in surface sediments from four coastal bays on the northwestern South China Sea

The distribution of rare metal elements (Zr, Sn, Ti, Y, Nb, Ta, Ce, La, Nd and Th) in surface sediments from four bays along the northwestern coast of the South China Sea allowed infer their main controlling factors and their mineralization potential as metals placer. The results revealed that their contents in surface sediments are very variable but show a clear geographic regularity. The average content of all elements in those areas decreases from the East to the West, with the minimum value of all elements in Leizhou Bay, the maximum value of Zr, Y, La, Ce, Nd and Th in Zhanjiang Bay, and the maximum values of Sn, Ti, Nb and Ta in Hailing Bay. The relative enrichment of these elements in two easternmost bays (Hailing Bay and Shuidong Bay) are attributed to the southwest alongshore current, which drain and transport terrigenous sediments from the granite region of the South China into these two bays. The correlation results between all element contents and fine sediment fraction (<63 μm) suggested that the main factors controlling the distribution of Ti, Nb and Sn should be the fine fraction of the sediment, but alternatively Zr, Y, La, Ce, Nd and Th are rich in heavy minerals and/or bioclasts, and Ta maybe affected by both. Detail analysis shows that sediments from Hailing Bay may contain abundant zircon, cassiterite, ilmenite (or rutile), xenotime, monazite, niobium tantalite and other rare metal minerals, with a good prospect as a rare metal placer resource, and the zircon, xenotime and monazite may also have good metallogenic prospects in Shuidong Bay and in the local area of Zhangjian Bay.

Apportionment of geochemistry, texture's properties, and risk assessment of some elements in surface sediments from Bardawil Lagoon, Egypt

ABSTRACTGranulometric and geochemical analyses of surface sediment samples collected from twelve sites along Bardawil Lagoon [water content (A%; 15.88–71.38%), total organic carbon (TOC%; 0.12–6.76%), total carbonate (TCO3%; 10.00–67.34%), total phosphorus (TP; 54.00–482.58 μg/g), sodium (Na; 2.65–8.99 mg/g), potassium (K; 0.63–2.54 mg/g), calcium (Ca; 23.33–201.20 mg/g), magnesium (Mg; 7.04–57.02 mg/g), fluoride (F; 1.00–680.47 μg/g), boron (B; 5.67–63.45 μg/g), Lithium (Li; 0.00–355.62 μg/g), Cobalt (Co; 0.00–15.48 μg/g), and bismuth (Bi; 2.12–15.09 μg/g)] were evaluated. The average results of the elements of geochemical parameters in the sediments gave a descending order of Ca > Mg > Na > K > F > Li > B > Bi > Co. The sediment pollution status was assigned by computing the enrichment factor with two methods concerning the usage of the crust's elements levels and a normalized element (Mg) and median of background values. The latter method reflected that the lagoon is still an uncontaminated region. The human health risk description was performed in the sediments using the exposure assessment of ingestion [(ExpIng), dermal contact (ExpDerm) and ingestion while swimming (ExpSwim)], hazard quotient (HQ), and hazard index (HI) for child and adult. The calculated Exp, HQ, and HI values reflected that the lagoon did not pose any risk to the populations.

Occurrence, source identification and ecological risk evaluation of metal elements in surface sediment: toward a comprehensive understanding of heavy metal pollution in Chaohu Lake, Eastern China.

In the present study, surface sediment samples from 48 sites covering the whole water area and three main estuaries of Chaohu Lake were collected to determine the concentrations of 25 metal elements using microwave-assisted digestion combined with ICP-MS. Spatial variation, source appointments, and contamination evaluation were examined using multivariate statistical techniques and pollution indices. The results show that for the elements Cd, Pb, Zr, Hf, U, Sr, Zn, Th, Rb, Sn, Cs, Tl, Bi, and Ba, which had higher coefficients of variation (CV), the concentrations were significantly higher in the eastern lake than in the western lake, but other elements with low CV values did not show spatial differences. The accumulation of Cu, Zn, Rb, Sr, Zr, Cd, Sn, Cs, Ba, Hf, Ta, Tl, Pb, Bi, U, and Th in the surface sediments was inferred as long-term agricultural cultivation impact, but that of Ti, V, Cr, Mn, Co, and Ni may have been a natural occurrence. The contribution from industrial and municipal impact was negligible, despite the rapid urbanization around the studied area. Principal component analysis-multiple linear regression (PCA-MLR) predicted the contribution from agricultural activities to range from 0.45 ± 1.31% for Co to 92.7 ± 17.7% for Cd. The results of the pollution indices indicate that Chaohu Lake was weakly to moderately affected by Ti, V, Cr, Mn, Co, and Ni but was severely contaminated by Hf and Cd. The overall pollution level in the eastern lake was higher than that in the western lake with respect to the pollution level index (PLI). Therefore, our results can help comprehensively understand the sediment contamination by metals in Chaohu Lake.

Seasonal variation in element concentrations in surface sediments of three rivers with different pollution input in Serbia

Purpose The main objective of this study was to evaluate the concentrations and seasonal variations of trace elements in surface sediments of three major rivers in Serbia—the Danube, the Zapadna Morava (ZM), and the Južna Morava (JM)—according to sediment quality guidelines. The ZM and the JM create the Velika Morava River, one of the most important tributaries of the Danube, which has been characterized as a source of heavy metal pollution.

Rare earth elements in surface sediments of a marine coast under heavy anthropogenic influence: The Bohai Bay, China

Surface sediments along four river-to-sea transects from the coastal Bohai Bay were assessed using a four-step sequential extraction procedure to determine the concentrations of rare earth elements (REEs) and the geochemical fractions in which those elements were present. The concentrations of light REEs were slightly depleted than those of the middle REEs and the heavy REEs. No significant Ce anomaly was observed whereas slight Eu-positive anomaly was found. The sequential extraction results revealed that the geochemical fractions of REEs followed the order of residual > reducible > oxidizable > acid soluble. The residual fraction accounted for the majority of the total concentrations of REEs. Middle REEs were more easily leached than other REEs. No obvious river-to-sea transportation was observed and the concentrations of REEs in surface sediments of the coastal Bohai Sea were consistent with the data from the Post-Archean Australian Shale. This study further demonstrated on the basis of our previous inference that the geochemical features of REEs in coastal sediments were generally unaffected by heavy anthropogenic effects.

Rare metal elements in surface sediment from five bays on the northeastern coast of the South China Sea

We studied the distribution of rare metal elements (RME) (Zr, Sn, Ti, Y, Nb, Ta, Ce, La, Nd, and Th) in surface sediments from five bays along the northeastern coast of the South China Sea. The results of the study elucidated the main controlling factors and the mineralization potential of these bays as metals placers. The RME contents of surface sediments are highly variable but show clear geographic regularities. The content of all studied elements in this area decreases from east to west, with the maximum average content in Shantou (ST) bay, which also contains the overall maximum element content. The minimum overall contents were found in Daya (DY) bay. The weak correlation between the fine sediment fraction and these elements suggests that they occur mainly in the form of metallic minerals. The relative abundance of these elements in the two easternmost bays [ST and Zhelin (ZL) bays] is attributed to the large amounts of terrigenous material input by the Hanjiang River, and other small rivers. ST and ZL bays sediments are rich in zircon, cassiterite, ilmenite (or rutile), xenotime, monazite, niobium tantalite, and other rare metal minerals. Thus, these bays are good prospects as rare metal placer resources. Shanwei (SW) and Dapeng (DP) bays show mineralization potential mostly for zircon and ilmenite (or rutile), respectively.

Biogeochemistry of bulk organic matter and biogenic elements in surface sediments of the Yangtze River Estuary and adjacent sea

This study investigated the distribution and roles of total organic carbon (TOC), biogenic silicon (BSi), various forms of nitrogen (N) and phosphorus (P), and the stable carbon isotope (δ13C) in surface sediments of the Yangtze River Estuary (YRE) and adjacent sea. Terrestrial input accounted for 12–63% of total organic matter in the study area. The distribution of biogenic elements was affected by the Changjiang Diluted Water, the Jiangsu Coastal Current, human activities, marine biological processes, and the sediment grain size. Potentially bioavailable N and P accounted for an average 79.6% of the total N (TN) and 31.8% of the total P (TP), respectively. The burial fluxes for TOC, BSi, TN and TP were 39.74–2194.32, 17.34–517.48, 5.02–188.85 and 3.10–62.72μmolcm−2yr−1, respectively. The molar ratios of total N/P (1.2–5.0), Si/P (5.0–14.8) and Fe/P (21–61) indicated that much of the P was sequestered in sediments.

Trace Elements in the Marine Sediments of the La Paz Lagoon, Baja California Peninsula, Mexico: Pollution Status in 2013.

To determine the actual concentrations of trace elements in surface sediments from the La Paz Lagoon, as well as their associations and possible origins, 91 sediment samples were analyzed for more than 50 elements using a combination of ICP-MS and ICP-AES. The results of a principal component analysis are used to distinguish four associative groups within the elements. Natural enrichment of As, Cd and U occurs due to the supply of weathered phosphorites from the El Cien formation located to the north-west of the lagoon. Sediment quality indices for potentially toxic trace elements do not show any probable impact on the biota of the lagoon. Only the concentrations of As in 30 % of the stations and Cu in 20 % of them exceed related effect range low levels. The highest concentration of Pb (36.8 mg kg(-1)) was measured in the sediments near the City of La Paz.

Spatial distribution and environmental risk of major elements in surface sediments associated Manwan Dam in Lancang River, China

Bulk elements and grain sizes in sediments collected at upstream and downstream of Manwan Dam were studied to demonstrate the spatial distribution of heavy metals in the sediments and to assess their risk. Correlation analysis showed that the spatial distribution of Cd, Zn and Mg were significantly affected by dam construction. PCA analysis demonstrate that Cd and Zn were both controlled by Ca, As, Pb, organic matter and clay. Mg was controlled by silt, Al, P and K. The risk assessment demonstrated that the pollution of Cd, As, Zn were more serious than other heavy metals. Fine-grained sediments with higher risk level were found in the section near the upstream of dam, while coarse-grained ones with lower risk level were found in the section far away from the downstream of dam. The sections in tributary were lower in risk than those in the main stream. Heavy metal concentrations in the mainstream sediments were influenced by dam construction and those in tributary were influenced by both dam construction and human activities in locality. Unusual high concentrations of Cd, As, and Zn in both sections implied that more pollution prevention measures are needed in the Manwan Dam in order to prevent increased heavy metal pollutions in the Lancang-Mekong River.

Occurrence, distribution, and ecological risk assessment of potentially toxic elements in surface sediments of Lake Awassa and Lake Ziway, Ethiopia

Microwave-assisted acid digestion and modified aqua regia (HNO3:HCl:HF:H3BO3) leaching techniques were used for the determination of 15 potentially toxic elements (V, Cr, Fe, Mn, Co, Ni, Cu, Zn, As, Se, Ag, Cd, Sn, Hg and Pb) in sediment samples from Lake Awassa and Lake Ziway, Ethiopia. The digests were subsequently analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectrometry (ICP-OES). Mercury was directly determined in the solid samples using an elemental mercury analyzer. The precision and accuracy of the digestion procedures were verified using certified reference materials. The experimental results were in good agreement with the certified values (P < 0.05) and the recoveries were quantitative (>90%). The average relative standard deviations were below 10%. There is significant correlation between the two lakes at the 0.01 level (2-tailed). Using the sediment quality guidelines, both lakes are heavily polluted with Zn and some of the sites are heavily polluted with Cu, Ni and Pb. Based on effect range low (ERL) – effect range medium (ERM), in both lakes for Ag were greater than the ERM, indicating that the areas could be toxic to aquatic organisms, while for Cr, Cu, As and Hg the values were less than ERL.

Speciation study of trace elements in surface sediment of Winam Gulf, Lake Victoria, by sequential extraction, aqua-regia acid digestion, and ICP-OES

The speciation of trace metals in surface sediment in Kisumu Carwash area of Winam Gulf, was studied and results compared with those found at Usoma beach which was found to be several orders of magnitude less polluted. High proportions of the metals were bioavailable (fractions 1–6) with BA% ranging from 21.7% (Al) to 94.5% (Pb) at Carwash and 19.6% (Al) to ∼100% (for Cd and Pb) at Usoma beach. The readily mobilizable fraction (fractions 1–4) decreased in the order: Pb > Mn > Sn > Cu > Co > Zn > Mg > Cd > Mo > Ni > Cr > Fe > Al at Carwash and Mn > Mo > Sn > Pb > Cd > Mg > Cu > Zn > Co > Ni > Fe > Cr > Al at Usoma beach. The total Zn, Cd, Cr, and Cu sediment concentrations at Carwash were higher than the threshold effect concentrations (TECs), although their bioavailable concentrations were lower than these limits. Both the total and bioavailable concentrations of Pb in surface sediment at Kisumu Carwash area were higher than the TEC threshold limit indicating significant contamination from this heavy metal. Although there was a general good agreement on data obtained by sequential extraction as compared with those obtained by direct aqua-regia digestion, there were large discrepancies for some specific metal analytes which could be accounted for in terms of analytical variations and lack of uniformity in physical and chemical composition of the sediment samples analyzed.

Analysis of trace elements in surface sediments, mussels, seagrass and seawater along the southeastern Adriatic coast – a chemometric approach

AbstractSurface sediments, mussels, seagrass, surface and bottom seawater samples were collected from the costal area of the southeastern Adriatic Sea and analyzed in order to determine the concentration and origin of the following elements: Fe, Mn, Zn, Ni, Cu, Ni, Co, As, Cd, Cr and Hg. The complexity of the obtained data was reduced by principal component analysis (PCA) and cluster analysis (CA), methods well known and accepted for the identification of the quality of marine environments. Both PCA and CA analysis were used to discriminate groups of samples according to the similarity of their chemical composition. The results revealed good diversity between the various samples, expressed by their distinctive positions of points in factor space. PCA indicated that the first two PC components explained about 73, 48, 43, 48, and 50 % of the total variance of the data for sediments, mussels, seagrass, and surface and bottom water, respectively. The results showed good discrimination capabilities between the samples taken from different locations, and also different seasons, which was especially evident in the surface and bottom water samples. Simultaneously, PCA/CA analysis of the amounts of trace elements found in the marine organisms could explain the manner of their bioaccumulation.

Analysis of major, minor and trace elements in surface sediments by X-ray fluorescence spectrometry for assessment of possible contamination of Boka Kotorska Bay, Montenegro

&lt;p class="prvred"&gt;Boka Kotorska Bay is on the UNESCO’s World Heritage List. There are no published papers related to the surface sediment pollution of the Bay. For the first time, elements were measured in surface sediments at nine locations in the Bay by the energy dispersive X-ray fluorescence spectrometry (ED-XRF) technique. Si, Fe, Ca, K, Ti, Mn, P, Ba, Cr, Sr, Zn, Rb, Ni, Cu, Pb, As, Sn, Sb, Hg and Cd were quantified in the surface sediments. Sediments were classified as non-polluted or polluted by counting the enrichment factor (&lt;em&gt;EF&lt;/em&gt;), metal loading index (&lt;em&gt;MLI&lt;/em&gt;) and geo-accumulation index (&lt;em&gt;I&lt;sub&gt;geo&lt;/sub&gt;&lt;/em&gt;) based on the elemental background level of the analyzed elements in the literature, or by the Sediment Quality Guidelines (&lt;em&gt;SQGs&lt;/em&gt;) of USEPA (United States Environmental Protection Agency). Based on USEPA’s &lt;em&gt;SQG&lt;/em&gt;s, the surface sediment in the entire Bay can be classified as heavily polluted by As and Cr, and non-polluted by Cd and Hg, and, related to the sites, the surface sediment at the Tivat-Arsenal site was heavily polluted and at the Orahovac site was not polluted at all. The &lt;em&gt;PLI&lt;/em&gt; (pollution load index) values for the locations of Tivat-Arsenal and Orahovac are in agreement with the conclusion based on USEPA’s&lt;em&gt; SQG&lt;/em&gt;s. The results in this paper will establish an initial view of sediment pollution and the state of the Bay’s environment.&lt;/p&gt;

Distribution, chemical speciation and source of trace elements in surface sediments of the Changjiang Estuary

To evaluate biogeochemical characteristics, eco-environmental risks and sources of trace elements (TEs: As, Hg, Se, Sb, Te, Sn, Bi and Ge), their total concentrations and chemical speciation in surface sediments collected from the Changjiang Estuary were determined. Total concentrations for As, Hg, Se, Sb, Te, Sn, Bi and Ge were 4.57–30.20, 0.01–0.40, 0.04–0.38, 0.36–1.48, 0.02–0.10, 0.48–6.58, 0.13–0.64 and 0.83–2.43 μg/g, respectively, with higher values at the estuary. This distribution pattern was attributed to the riverine input and high clay and total organic carbon contents. The sequential extraction suggested that TEs mainly occurred in residual fractions. The risk assessment code suggested that As, Hg and Sn were at low risk, whereas Bi, Se, Sb, Te and Ge were at medium risk. The geoaccumulation index (Igeo) and principal component analysis indicated that Se and Sn mainly came from the natural input (crustal and biological inputs), whereas As, Sb, Hg, Bi and Te came from both of the crustal and anthropogenic inputs via atmosphere and rivers. In addition, Ge possibly came from the natural (crustal and biological inputs) and anthropogenic inputs.

Effect of seasonal variations on the surface sediment heavy metal enrichment of a lake in South India

Environmental effects due to continuous accumulation of hazardous materials like heavy metals in the surface sediments of lake systems can stress fragile ecosystems. Elucidating the mechanisms influencing the concentration and distribution of heavy metals becomes vital in formulating lake management strategies to preserve the quality of the water environment. Studying of the effect of seasonal variations on surface sediments will help in understanding the different factors and sources contributing and diluting these persistent pollutants. In this study, heavy metal pollution in a tropical shallow lake (Akkulam-Veli) in South India was investigated by monitoring the seasonal variations of heavy metals and major elements in surface sediments. The metallic pollutants (Cr, Ni, Co, Cu, Zn, Pb, Fe, and Mn) and major elements (Si, Ti, Al, Ca, Mg, Na, K, and P (measured as oxides) in the surface sediments of this lake were monitored during four consecutive seasons. The results were subjected to correlation analysis and principal component analysis to study the interrelationships of different parameters as well to determine the possible origin of pollutants. Although metal concentrations were found to be unaffected by seasonal variations, the factors contributing to occurrence of these heavy metals were found to be affected by seasonal fluctuations.

Pollution characteristics and possible sources of seldom monitored trace elements in surface sediments collected from Three Gorges Reservoir, China.

A geochemical study of Three Gorges Reservoir (TGR) sediments was carried out to analyze the concentrations, distribution, accumulation, and potential sources of the seldom monitored trace elements (SMTEs). The mean concentrations of Li, B, Be, Bi, V, Co, Ga, Sn, Sb, and Tl were 47.08, 2.47, 59.15, 0.50, 119.20, 17.83, 30.31, 3.25, 4.14, and 0.58 mg/kg, respectively. The concentrations of total SMTEs, together with their spatial distribution, showed that the SMTEs were mainly due to anthropogenic inputs in the region of TGR. The assessment by Geoaccumulation Index indicates that Tl, Be, V, Co, and Fe are at the unpolluted level; Bi, Li, Ga, and Sn were at the “uncontaminated to moderately contaminated” level. However, B was classified as “moderately contaminated” level and Sb was ranked as “strongly contaminated” level. The pollution level of the SMTEs is Sb > B > Bi > Li > Ga > Sn > Tl > Be > V > Co > Fe. The results of Correlation Analysis and Principal Component Analysis indicated Be, V, Co, Ga, Sn, Tl, Bi, and Fe in sediments have a natural source. B and Li were positively correlated with each other and mainly attributed into similar anthropogenic input. In addition, Sb has less relationship with other SMTEs, indicating that Sb has another kind of anthropogenic source.

Environmental significance of biogenic elements in surface sediments of the Changjiang Estuary and its adjacent areas

Biogenic elements and six phosphorus (P) fractions in surface sediments from the Changjiang Estuary and adjacent waters were determined to investigate the governing factors of these elements, and further to discuss their potential uses as paleo-environment proxies and risks of P release from sediment. Total organic carbon (TOC) and leachable organic P (Lea-OP) showed high concentrations in the estuary, Zhejiang coast and offshore upwelling area. They came from both the Changjiang River and marine biological input. Biogenic silicon (BSi) exhibited a high concentration band between 123 and 124°E. BSi mainly came from diatom production and its concentration in the inshore area was diluted by river sediment. Total nitrogen (TN) was primarily of marine biogenic origin. Seaward decreasing trends of Fe-bound P and Al-bound P revealed their terrestrial origins. Influenced by old Huanghe sediment delivered by the Jiangsu coastal current, the maximum concentration of detrital P (Det-P) was observed in the area north of the estuary. Similar high concentrations of carbonate fluorapatite (CFA-P) and CaCO3 in the southern study area suggested marine calcium-organism sources of CFA-P. TOC, TN and non-apatite P were enriched in fine sediment, and Det-P partially exhibited coarse-grain enrichment, but BSi had no correlation with sediment grain size. Different sources and governing factors made biogenic elements and P species have distinct potential uses in indicating environmental conditions. Transferable P accounted for 14%–46% of total P. In an aerobic environment, there was low risk of P release from sediment, attributed to excess Fe oxides in sediments.

Impact evaluation of the industrial activities in the Bay of Bakar (Adriatic Sea, Croatia): Recent benthic foraminifera and heavy metals

The Bay of Bakar is one of the most heavily polluted bays at the Eastern Adriatic. Three major industrial companies potentially endanger the bay. The concentration of major, minor and trace elements in surface sediments from thirteen stations was discussed in relation to the sediment type and foraminiferal assemblages. The distribution of major elements in the bay is influenced by geological nature of surroundings. Heavy metal distribution depends on pollution sources and on amount of mud fraction: fine-grained sediments are enriched by them in comparison with coarse-grained ones. Different sediment quality criteria complicate the pollution assessment in the bay. Heavy metal concentrations generally fall into allowed depositional values for marine environments; only area in front of the coke plant and the City of Bakar harbor is heavily polluted. Stress-tolerant foraminiferal species dominate at stations with higher concentrations of heavy metals and coarse-grained sediments consist of larger number of epifaunal taxa.