Marine Surface Sediments Research Articles

Gene biomarkers in diatom Thalassiosira pseudonana exposed to polycyclic aromatic hydrocarbons from contaminated marine surface sediments

Marine diatoms have a key role in the global carbon fixation and therefore in the ecosystem. We used Thalassiosira pseudonana as a model organism to assess the effects of exposure to environmental pollutants at the gene expression level. Diatoms were exposed to polycyclic aromatic hydrocarbons mixture (PAH) from surface sediments collected at a highly PAH contaminated area of the Mediterranean Sea (Genoa, Italy), due to intense industrial and harbor activities. The gene expression data for exposure to the sediment-derived PAH mixture was compared with gene expression data for in vitro exposure to specific polycyclic aromatic hydrocarbons. The data shows that genes involved in stress response, silica uptake, and metabolism were regulated both upon exposure to the sediment-derived PAH mixture and to the single component. Complementary monitoring of silica in the diatom cultures provide further evidence of a reduced cellular uptake of silica as an end-point for benzo[a]pyrene exposure that could be linked with the reduced gene and protein expression of the silicon transporter protein. However some genes showed differences in regulation indicating that mixtures of structurally related chemical compounds can elicit a slightly different gene expression response compared to that of a single component. The paper provides indications on the specific pathways affected by PAH exposure and shows that selected genes (silicon transporter, and silaffin 3) involved in silica uptake and metabolism could be suitable molecular biomarkers of exposure to PAHs.

Polycyclic Aromatic Hydrocarbons in Dated Freshwater and Marine Sediments Along the Norwegian Coast

Polycyclic aromatic hydrocarbons (PAH) have been identified and quantified in dated layers of freshwater and marine sediments in Norway. Furthermore, profiles of the individual PAH (22 different) have been used to evaluate possible PAH sources. There is a significant increase in total PAH levels (sum of the 22 PAH) in freshwater sediments from the south-western part of Norway representing the 1800–1950 period, whereas the concentrations have decreased with a factor of approximately four since the 1950s. This pronounced trend was observed in two independent surveys. In northern Norway, the PAH levels in lake sediments have increased slightly during the past decades. In spite of this, the levels are considerably lower than in lake sediments from the south-western part of Norway. In fact, the PAH levels are decreasing northwards on the Norwegian mainland for both freshwater and marine surface sediments. Generally, the regional total PAH levels are higher (three to four times) in freshwater sites compared to the corresponding marine sites. Results of PAH source allocation indicate that pyrogenic sources are important in almost all sediment samples studied. Sediment samples were also collected at Svalbard where the local coal reserve is the major contributor to PAH.

Impact of industries in the accumulation of radionuclides in the lower part of Ebro river (Catalonia, Spain)

Ebro River extends over almost 930 km and is the main Spanish river entering the Mediterranean Sea. There are several industries located along this river course including a dicalcium phosphate factory (DCP) and two nuclear power reactors. These installations, together with other factors such as the geology, can contribute to the radiological content of the river. Therefore, this study was performed to determine some natural and also some anthropogenic radionuclide concentrations in the Ebro River ecosystem. We analysed water samples, solid samples (rice field sludge and surface marine sediment samples), and also biota samples ( Cladophora glomerata and Cynodon dactylon ). For water samples, gross alpha, gross beta, tritium, uranium, thorium and also a group of gamma-emitting isotopes’ activities were determined. The main contribution to radioactivity for these samples was due to some isotopes from the uranium and thorium chain. For the solid samples, we quantified some natural and artificial gamma radioisotopes, which may be related to the geological and/or industrial activities located in this zone. In the case of biota, the results indicate that the presence of the DCP has a significant influence, since the highest activity was observed in the surroundings of this industry (Flix), where isotopes such as 214 Bi and 214 Pb presented activity values of 105 ± 43 Bq/kg and 100 ± 58 Bq/kg, respectively.

The radiocarbon age of organic carbon in marine surface sediments

Long-term carbon cycling and climate change are strongly dependent on organic carbon (OC) burial in marine sediments. Radiocarbon ( 14C) has been widely used to constrain the sources, sinks, and processing of sedimentary OC. To elucidate the dominant controls on the radiocarbon content of total organic carbon ( 14C TOC) accumulating in surface sediments we construct a box model that predicts 14C TOC in the sediment mixed layer (measured as fraction modern, Fm). Our model defines three distinct OC pools (“degradable,” “semi-labile,” and “refractory”) and assumes that 14C TOC flux to sediments is exclusively derived from surface ocean primary productivity, and hence follows a “generic” surface ocean dissolved inorganic carbon (DIC) bomb curve. Model predictions are compared to a set of 75 surface sediment samples, which span a wide geographic range and reflect diverse water column and depositional conditions, and for which sedimentation rate and mixed-layer depth are well characterized. Our model overestimates the Fm value for a majority (65%) of these sites, especially at shallow water depths and for sites characterized by depleted δ 13C TOC values. The model is most sensitive to sedimentation rate and mixed-layer depth. Therefore, slight changes to these parameters can lead to a match between modeled and measured Fm values at many sites. Yet, in some cases, we find that measured Fm values cannot be simulated without large and unrealistic changes to sedimentation rate and mixed-layer depth. These results point to sources of pre-aged OC to surface sediments and implicate soil-derived terrestrial OC, reworked marine OC, and/or anthropogenic carbon as important components of the organic matter present in surface sediments. This approach provides a valuable framework within which to explore controls on sedimentary organic matter composition and carbon burial over a range of spatial and temporal scales.

Two diketopiperazine cyclo(pro-phe) isomers from marine bacteria Bacillus subtilis sp. 13-2

Two bioactive diketopiperazines, cyclo(S-Pro-S-Phe) and cyclo(R-Pro-S-Phe), against Bacillus subtilis (terrestrial), Staphylococcus aureus, and Escherichia coli DH5 alpha were isolated from marine surface sediment bacteria Bacillus subtilis sp. 13-2. To our knowledge, this was the first time that cyclo(S-Pro-S-Phe) and cyclo(R-Pro-S-Phe) were isolated from Bacillus subtilis, and the first time that cyclo(R-Pro-S-Phe) was isolated from a natural source. These two compounds were established on the basis of ESI-MS spectral data, as well as NMR 1D and 2D (COSY, HMQC, and HMBC) spectral data.

Impact of anthropogenic input on physicochemical parameters and trace metals in marine surface sediments of Bay of Bengal off Chennai, India

The study of heavy metal distribution in coastal surface sediments is an important component in understanding the exogenic cycling as well as in assessing the effect of anthropogenic influences on the marine ecosystem. In this study, surface sediment samples were collected from five different traverses along the innershelf of Bay of Bengal, off Chennai, India during pre- and post-monsoon seasons. The results of Spearmen correlation matrix, factor and cluster analysis, enrichment and contamination factor analysis, and geoaccumulation index of the heavy metals analyzed in the collected surface sediment were discussed. The level of both enrichment and contamination factor are shown in following order Cd > Cu > Cr > Ni > Pb > Co > Zn > Mn > Fe > Hg. The geoaccumulation index suggests that Cd and Cu are strongly to extremely pollute the sediments in both seasons. The results strongly indict anthropogenic sources for moderate input of Cd and Cu in to the innershelf of Chennai coast.

Heavy metal concentrations in the surface marine sediments of Sfax Coast, Tunisia

Sixty-seven surface marine sediment samples in the <63 μm fraction collected from the coast of Sfax (Tunisia) were analyzed by inductively coupled plasma-atomic emission spectrometry for seven heavy metals (Pb, Ni, Cu, Cr, Zn, Cd, and Fe). Metal concentrations were compared with natural values, marine sediment quality standards, and also with other results concerning sediments from several Mediterranean coasts. The study of their spatial distributions refined by complementary approaches including principal component analysis, enrichment factors, and geoaccumulation index showed a significant impact of multiple anthropogenic sources. These included industrial sources and municipal discharges of the urban Sfax and also non-controlled discharges in rural zones close to the coastline. Moderate pollution of sediments, especially by Pb, Zn, and Ni, was shown to exist in localized sites. Besides, it was shown that other sites, slightly to highly enriched in terms of Cu, Cr, and Cd, are characterized by a quality of sediments varying from unpolluted to moderately polluted.

Parâmetros físicos de sedimentos marinhos superficiais da região costeira de Caravelas, Sul da Bahia

Este trabalho combina informacoes obtidas por testemunhos de sondagem com dados adquiridos por perfilagem geofisica a fim de verificar a influencia dos parâmetros geologicos e sedimentologicos na velocidade de ondas P em sedimentos marinhos superficiais. Dados de velocidade da onda compressional (Vp), densidade gama, impedância acustica e susceptibilidade magnetica foram correlacionados com dados geologicos de quatro testemunhos coletados na zona costeira da cidade de Caravelas, estado da Bahia. As propriedades geofisicas foram obtidas utilizando como sistema de medicao o perfilador multisensor de testemunhos (MultiSensor Core Logger - MSCL). Os testemunhos foram descritos segundo a geologia, cor e grau de compactacao. Oito tipos distintos de sedimentos foram observados: conchas, areia grossa a muito grossa, areia media, areia muito fina a fina, lama arenosa, lama compacta, lama fluida e lama muito fluida. Os resultados mostram que, de maneira geral, os maiores valores de velocidade e densidade, inversamente proporcionais aos de susceptibilidade magnifica, estao associados aos sedimentos de maior granulometria. Os valores de Vp para areia muito grossa e conchas mostrou-se erratico devido a falta de compactacao desses materiais. Os graficos de impedância acustica e do coeficiente de reflexao facilitaram a identificacao de interfaces e apresentaram coerencia em relacao aos perfis de velocidade e de densidade. Medicoes de granulometria foram realizadas na secao de lama arenosa do testemunho JP-112, para ratificar a relacao da variabilidade dos parâmetros fisicos com a classificacao granulometrica utilizada para a caracterizacao dos quatro testemunhos.

Distribution of 137Cs, 40K, 232Th and 238U in coastal marine sediments of Margarita Island, Venezuela

This work presents the results of 137Cs, 40K, 232Th and 238U concentration (Bq kg−1) values in coastal marine sediments collected from 38 sites along the coastline of the island of Margarita, Venezuela. The purpose was to determine baseline values for these radionuclides in surface marine sediments and to detect if there were any anomalously high concentration values. Only three of the 38 sediments analyzed had measurable values above the detection limit of 0.9 Bq kg−1 for 137Cs and the highest only being 1.4 Bq kg−1. While, the concentration (Bq kg−1) ranges for the primordial radionuclides, 40K, 232Th and 238U were as follows: 12.2–211.7, <1.5–9.8 and <4.4–20.7, respectively. These concentration ranges for the primordial radionuclides can be considered as baseline values for surface marine sediments for areas that are considered not polluted by man or contaminated by nature. Finally, the concentration range of 137Cs can also be employed as baseline values, which only seem to have been the result of the atmospheric testing of nuclear weapons in the past.

Rare earth elements determination and distribution patterns in surface marine sediments of the South China Sea by INAA, Malaysia

Results obtained from the analysis of sediments surface samples taken from rivers mouth and polluted marine environment were analyzed for REE contents to determine the concentrations of La, Ce, Sm, Eu, Tb, Dy, Lu and Yb using instrumental neutron activation analysis. Thirty surface samples were collected from ten sites in the coastal marine sediments of the South China Sea along 957 km stretch of the east coast of Peninsular Malaysia. The samples prepared in the powdered form before irradiating them in a neutron flux of ~4 × 1012 n cm−2 s−1 at 750 kW power using the TRIGA Mark II research reactor at Malaysian Institute for Nuclear Technology (MINT). Results of the total concentration are used to establish baseline data in environmental pollution assessment and to develop the correlations between the Ce/Ce* anomalies and the distribution patterns of some the light rare earth elements (LREEs) and the heavy rare earth elements (HREEs). The Chondrite-normalized REE pattern from each site examined and used to explain the sedimentation patterns by anthropogenic activities and by natural processes such as shoreline erosion, weathering deposits. Shale-normalized (NASC) patterns suggest enrichment of LREEs relative to the HREEs with a positive Ce/Ce* anomaly. Validation of the used method was done using a Soil-7 SRM.

Distribution of phosphine in the offshore area of the Southwest Yellow Sea, East Asia

Phosphine is a natural gaseous compound in the phosphorus biogeochemical cycle. This paper studies the spatial and temporal distributions of matrix-bound phosphine (MBP) and gaseous phosphine in the offshore area of the Southwest Yellow Sea, East Asia. The results show that MBP concentrations in marine surface sediments range from 0.69 ± 0.06 ng/kg (dry) to 179 ± 29 ng/kg (dry). Higher seasonal MBP concentrations in sediments are found in fall than in spring or winter in most sites. High MBP contents are observed in two fish-breeding areas. MBP concentrations decrease with distance to the coast, except in the southeast of the sampling area. MBP levels in marine sediments are found to be higher than those at several other places: freshwater sediments and soil, except eutrophic lakes. Gaseous phosphine contents in fall range from 0.14 ± 0.00 ng/m 3 to 9.83 ± 0.97 ng/m 3. No correlation is observed between MBP and gaseous phosphine.

Polycyclic Aromatic Hydrocarbon Contamination of Recent Sediments and Marine Organisms from Xiamen Bay, China

Surface marine sediments from 12 sites within Xiamen Bay (XMB) and marine organisms (clam, crab, and fish) from a heavily polycyclic aromatic hydrocarbon (PAH)-contaminated site at Yuandang Lagoon were sampled and analyzed for 16 priority PAH content by gas chromatography/mass spectrometry. The total PAH concentrations in sediments ranged from 203.7 to 1590.5 ng/g, with an average value of 670.0 ng/g. Overall, the total PAH concentrations were relatively lower in the east coastal zone and significantly higher in Yuandang Lagoon. These concentrations were intermediate in comparison with those observed in other estuaries in China. The sources of PAH inputs to sediments in XMB were quantitatively determined by principal components analysis with multiple linear regression. The results showed that, on average, vehicle emissions, petroleum spills, and coal combustion contributed to 41, 36, and 23% of the total PAHs, respectively. Analysis of the PAH composition pattern in marine organisms showed that the total PAHs levels of fishes were lower than those of the clam and crab. The PAH burden of the crab and calm was characterized by the non-negligible occurrence of high-molecular-weight compounds, whereas the fish PAH pattern was dominated by the lower-molecular-weight compounds. In addition, the carcinogenic PAH benzo[a]pyrene was detected in all samples. Molecular indices based on isomeric PAH ratios differentiated the uptake pathway among organisms. The water soluble matter and the petroleum seemed to be the most favorable uptake pathway in fish from Yuandang Lagoon, whereas the crab and clam shared a mix uptake by the water-soluble and the particulate matter.

Historical and Geographical Trends in Sediment Chronology from Lakes and Marine Sites Along the Norwegian Coast

Sediment cores collected from 12 lakes and eight marine sites along the Norwegian and Svalbard coast as part of a project investigating polycyclic aromatic hydrocarbons (PAH) in sediments were dated radiometrically using 210Pb, 137Cs and 241Am fallout radionuclides. In all lake cores, except on Svalbard, the 137Cs activity versus depth profile appears to have been significantly modified by post-depositional migration within the sediment column. The relatively low 137Cs inventories suggest that these sites were not significantly impacted by fallout from the 1986 Chernobyl accident. All the marine cores have 137Cs inventories that are substantially lower than in lake sediments almost certainly due to leaching of 137Cs from the marine sediments due to higher solubility in the seawater. In the marine surface sediments, the unsupported 210Pb concentrations are up to an order of magnitude lower than in the corresponding lake sediments reflecting the higher (dry mass) sedimentation rate at the marine sites. Five of the cores including marine sites and lakes have unusual high 210Pb flux most likely due to sediment focusing. Most of the irregularities in the 210Pb records seem to be due to slump events but some patterns are also due to possibly increased accumulation rates. Three of the marine cores show systematic increase in their sedimentation rate from c.1960 towards the present while only one lake shows the same systematic increase.

Occurrence and Fate of 1-Chloro-2,2-bis(4-chlorophenyl)ethene in the Environment of the Pearl River Delta, South China

1-Chloro-2,2-bis(4-chlorophenyl)ethene (p,p'-DDMU), a metabolite of either 1,1-dichloro-22-bis(4-chlorophenyl)ethane (p,p'-DDD) or 1,1-dichloro-2,2-bis(4-chlorophenyl)ethene (p,p'-DDE), which is degraded from 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT), was detected in a variety of environmental matrices of the Pearl River Delta (PRD), South China, including fish, fish feeds, semidigested fish stomach contents, marine surface sediment, surface soil, atmospheric gaseous phase, and particulates, rainwater, and coastal rainwater. Forfish species,the concentrations of p,p'-DDMU were significantly higher in farmed fish than in marine wild fish, with the highest value obtained in seawater farmed fish species (mear/median values of 262/173 ng/g lipid). The relative abundance of p,p'-DDMU to total DDTs (sum of o,p'- and p,p'-DDT, DDD, and DDE) was higher in samples of marine origin (approximately 5%) than in those of terrestrial origin (approximately 2%). Because p,p'-DDD was considerably abundant in all samples and a negative linear correlation was found between p,p'-DDD/(p,p'-DDD + p,p'-DDE) and p,p'-DDMU/DDTs in the marine sediments (r2 = 0.73) and seawater farmed fish (r2 = 0.29) under investigation, it is possible that DDMU was partially dehydrochlorinated from DDD in the environment of the PRD. A fugacity-based assessment suggested that p,p'-DDMU is likely to transport from sediment to seawater and then to air and from soilto air. The ubiquity of p,p'-DDMU in the PRD indicates that it may also be widespread worldwide particularly in countries with large amounts of DDT used currently and/or historically. Given the potential risk of p,p'-DDMU to human health, more efforts should be directed toward to this previously overlooked contaminant

Dinoflagellate cyst distribution in marine surface sediments off West Africa (17–6°N) in relation to sea-surface conditions, freshwater input and seasonal coastal upwelling

An organic-walled dinoflagellate cyst analysis was carried out on 53 surface sediment samples from West Africa (17–6°N) to obtain insight in the relationship between their spatial distribution and hydrological conditions in the upper water column as well as marine productivity in the study area. Multivariate analysis of the dinoflagellate cyst relative abundances and environmental parameters of the water column shows that sea-surface temperature, salinity, marine productivity and bottom water oxygen are the factors that relate significantly to the distribution patterns of individual species in the region. The composition of cyst assemblages and dinoflagellate cyst concentrations allows the identification of four hydrographic regimes; 1) the northern regime between 17 and 14°N characterized by high productivity associated with seasonal coastal upwelling, 2) the southern regime between 12 and 6°N associated with high-nutrient waters influenced by river discharge 3) the intermediate regime between 14 and 12°N influenced mainly by seasonal coastal upwelling additionally associated with fluvial input of terrestrial nutrients and 4) the offshore regime characterized by low chlorophyll-a concentrations in upper waters and high bottom water oxygen concentrations. Our data show that cysts of Polykrikos kofoidii, Selenopemphix quanta, Dubridinium spp., Echinidinium species, cysts of Protoperidinium monospinum and Spiniferites pachydermus are the best proxies to reconstruct the boundary between the NE trade winds and the monsoon winds in the subtropical eastern Atlantic Ocean. The association of Bitectatodinium spongium, Lejeunecysta oliva, Quinquecuspis concreta, Selenopemphix nephroides, Trinovantedinium applanatum can be used to reconstruct past river outflow variations within this region.

A sequential extraction to determine the distribution of phosphorus in the seawater and marine surface sediment

The distribution of phosphorus species among environmental compartments (e.g., between water and sediment), significantly affects the bioavailability of these species to organisms. The eastern Mediterranean Sea is one of the most extreme oligotrophic oceanic regions on earth in terms of nutrient concentrations and primary productivity. The paper presents the results of inorganic and organic forms in surface sediment and seawater from NE Mediterranean Sea (Burclar Bay, Erdemli, South Anatolia of Turkey) in May 2007. Speciation of phosphorus in seawater and surface sediment using inductively coupled plasma-atomic emission spectrometer (ICP-AES) has been reported here. The method is based on sequential extractions of the seawater and sediment each releasing four forms of inorganic phosphorus: loosely sorbed phosphorus, phosphorus bound to aluminium (P–Al), phosphorus bound to iron (P–Fe) and phosphorus bound to calcium (P–Ca). The most abundant form of inorganic phosphorus in the seawater and surface sediment is calcium-bound phosphorus. Relative abundances of the remaining phosphorus forms in sediment follow the order: P–Al > P–Fe > loosely bound-P and in seawater follow the order P–Fe > P–Al > loosely bound-P.

Natural vs. anthropogenic sources of hydrocarbons as revealed through biomarker analysis: A case study in the southern Gulf of Mexico

Biological markers are organic compounds in geological samples with an unambiguous link to specific precursor molecules in living organisms. They provide information on the origin and depositional environment of fossil organic matter as well as about its thermal maturation caused by geothermal heat flow during burial. Petroleum and its refinery products carry this biomarker information into the environment when they are released during anthropogenically-induced pollution. Soils or aquatic surface sediments in contaminated areas usually contain binary mixtures of fossil hydrocarbons and recent biogenic hydrocarbons like higher-plant wax esters, together with (often olefinic) hydrocarbons from earliest diagenetic transformation of functionalized biomolecules. Surface sediments collected in the shelf area of the Campeche Sound, Gulf of Mexico, sampled in the course of environmental monitoring for possible petroleum pollution due to industrial activity, however, revealed a third group of hydrocarbons. GC-MS analysis of biomarkers in the nonaromatic hydrocarbon fractions of the sediment extracts yielded overlapping hydrocarbon assemblages indicating multiple sources. Samples taken close to known asphalt seeps exhibit biomarker patterns virtually identical to those of reference crude oils. Other sediments contain mature fossil hydrocarbons and biomarkers that are not typical of either fossil fuels or immature organic matter in marine surface sediments. Instead, they come from drill cuttings recovered during penetration of Tertiary to Cretaceous deposits that were littered on the shallow sea bottom.

Polybrominated, polychlorinated and monobromo-polychlorinated dibenzo- p-dioxins/dibenzofurans and dioxin-like polychlorinated biphenyls in marine surface sediments from Hong Kong and Korea

In this study we investigated occurrences and distribution patterns of dioxin-related compounds (DRCs) such as polybrominated dibenzo- p-dioxins/dibenzofurans (PBDD/Fs), polychlorinated dibenzo- p-dioxins/dibenzofurans (PCDD/Fs), monobromo-polychlorinated dibenzo- p-dioxins/dibenzofurans (MoBPCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in marine surface sediments collected from the coastal waters of Hong Kong and Korea. In most sampling sites, concentrations of PCDDs were the highest, followed by DL-PCBs, PCDFs, PBDFs, PBDDs, MoBPCDDs and MoBPCDFs in this order. Levels of PBDD/Fs were generally 1–2 orders of magnitude lower than chlorinated analogues. Levels of PCDDs are higher than PCDFs in Hong Kong while levels of PBDFs are higher than PBDDs in Korea ( p < 0.05). Report of PBDD/Fs and MoBPCDD/Fs in sediments from East Asian countries is novel and original. Environmental levels of PBDD/Fs are supposed to start increasing in accordance with rising production, use and disposal of brominated flame retardants (BFRs) and recycling processes of e-waste in Asian developing countries.

TWO NEW MARINE SPECIES OF THE DIATOM GENUS COCCONEIS EHRENBERG: C. MELCHIOROIDES SP. NOV. AND C. DALLMANNII SP. NOV., FROM KING GEORGE ISLAND, ANTARCTICA

Two new marine diatom species, Cocconeis melchioroides and C. dallmannii are described from Potter Cove, King George Island, Antarctica. Detailed descriptions are given based on LM and SEM images for both species and compared with the only known morphologically related taxon, Cocconeis melchiori Frenguelli and Orlando. Both C. melchioroides and C. dallmannii belong to the Cocconeis group, in which the sternum valve has very short and marginal striae. They differ from each other in the number of striae, number of areolae, central raphe endings, crista marginalis and valvocopula. A comparison with the Cocconeis costata group is provided. Both species are common inhabitants of the marine surface sediment in the Potter Cove area.

Distribution of 226Ra– 210Pb– 210Po in marine biota and surface sediments of the Red Sea, Sudan

Activity concentration levels and ratios of 226Ra, 210Pb and 210Po are presented in multicellular marine algae, molluscs, coral as well as in surface marine sediments collected from the shallower waters of the fringing reefs area extending towards north and south (Flamingo bay) of PortSudan harbour, Sudan. The analyses were performed adopting alpha-spectrometry, liquid scintillation and Cerenkov counting techniques. Surface sediments from this coastal region are poor in their radioactivity content in contrast to similar data reported from different coastal areas around the globe. There is surface enrichment of 210Pb and 210Po with respect to their progenitor 226Ra as it is evident from the activity ratios of 210Pb/ 226Ra (3.03 ± 1.79) and 210Po/ 226Ra (2.23 ± 1.56). Among marine plants and animals investigated, the green algae species, Halimeda, and coral species, Favites, show substantial concentration of radium at 8.2 Bq/kg and 21.9 Bq/kg dry weight, respectively. Similarly, the highest concentration of 210Po was met in Favites at 38.7 Bq/kg followed by brown algae, Cystoseria sp., at 32.6 Bq/kg. There is no variation seen among algal species for 210Pb uptake, however, converse to radium and polonium, Favites (coral) was found to contain the minimum concentration of lead (3.88 Bq/kg). In most species there is preferential accumulation of polonium over its parent radium as indicated by 210Po: 226Ra activity ratio with Cystoseria (brown algae) showing the highest value at 8.81. On the other hand, 210Po: 210Pb activity concentration ratio revealed that coral species Favites (9.97) and the brown algae Sargassum (1.85) have a greater tendency to accumulate 210Po over 210Pb, while in the rest of species; this ratio is less than unity.