Trace metals in sediments of Raritan bay

Marine sediments are the ultimate recipient of nearly all trace metals introduced by man into aquatic ecosystems. This study examined the amounts and distribution of six trace metals (Cd, Cr, Cu, Ni, Pb, Zn) in sediments of Raritan Bay, apolluted estuary. The highest levels of these metals found in Raritan Bay were: Cd-15, Cr-260, Cu-1230, Ni-50, Pb-985, Zn-815. Three metals regimes within Raritan Bay are readily apparent. An area of high values extends across the Bay from the mouth of the Raritan Riverand Arthur Killinto Sandy Hook Bay. This is bounded on the south and northeast by areas of somewhat lower concentrations. An area of relatively low concentrations, near background values, occupies the region at the mouth of the Bay between Sandy Hook peninsula and Coney Island, New York. Metals values from Raritan Bay are compared with other areas and with a few exceptions, the Raritan Bay maximum levels were similar in magnitude to those of areas in Corpus Christi Harbour (U.S.A), Severn Estuary (U.K.), Deep Sea and Florida Lakes, River Blyth (U.K.), dump sites off New York City, various basins off South California, and in Long Island Sound.     

Statistical analysis of trend monitoring data of heavy metals in flounder (Platichthys flesus)

Six years trend monitoring data of mercury, cadmium, copper, lead, and zinc in flounder from the Sound and the Great Belt (Danish coastal waters) are statistically assessed using a series of multilinear, regressive models in terms of the measurements of metal levels and various biological parameters (e.g. length) for individual fish. With the exception of zinc in females from the Great Belt, each element exhibited no significant differences in relation to biological parameters from year to year at the two areas. Linearly increasing trends in the concentrations were found for cadmium without sex dependance from the two areas and for zinc and copper in females from the Sound and zinc in males from the Great Belt. Zinc is, in both areas, significantly correlated with the sex as is copper in the flounder from the Sound. The statistical models used have been found very useful and easy to interpret.     

Organic pollutants (PAHs, PCBs) in sediments from the Mar Piccolo in Taranto (Ionian Sea, Southern Italy)

Polychlorinated biphenyls (PCBs) and 17 parent polycyclic aromatic hydrocarbons (PAHs) were determined in surface sediments from nine stations in the Mar Piccolo of Taranto (Ionian Sea, Southern Italy). Total PAH concentrations ranged from 380 to 12,750 microg/kg d.w., while total PCB levels ranged from 2 to 1684 microg/kg d.w.; this values were higher than those found in others marine coastal areas of the Mediterranean Sea. For PAHs, low molecular weight/high molecular weight, phenanthrene/anthracene and fluoranthene/pyrene ratio were used for discriminating between pyrolitic and petroleum origin. Results showed that PAHs were mainly of pyrolitic origin. PCB and PAH levels in sediments were compared with Sediments Quality Guidelines (ERM-ERL, TEL-PEL indexes) for evaluation probable toxic effects on marine organism. Finally, ERM and PEL quotients were used to evaluate the degree to which chemicals exceed guidelines. Results suggest an ecotoxicological risk for benthic organisms mainly in the first inlet, where high concentrations of PCBs were found in sediments influenced by harbour activities.     

Evaluations of heavy metal pollution in sediment and Mullus barbatus from the Izmir Bay (Eastern Aegean) during 1997-2009

Izmir Bay is one of the great natural bays of the Mediterranean. The surface sediment and fish samples were collected during 1997-2009. The sediment concentrations of inner bay showed significant enrichments during sampling periods. Outer and middle bays exhibited low levels of metal enrichments except the estuary of Gediz River. The concentrations were generally higher than the background levels from the Mediterranean and Aegean except Cd and Pb levels gradually decreased. Metal EF is used as an index to evaluate anthropogenic influences of metals in sediments. Maximum metal enrichment was found for Hg in the outer bay, while Pb indicated maximum enrichment in the middle-inner bays. Metal levels were evaluated in sediments in accordance with the numerical SQG of the USEPA. The levels of fish tissues were lower than the results reported from polluted areas of the Mediterranean. The highest BAFs were detected for Hg and Cd in fish.     

Coprostanols in Antarctic marine sediments: A biomarker for marine mammals and not human pollution

The first analysis of sterols in Antarctic marine sediment cores (Bransfield Strait and McMurdo Sound) is reported here. The isolated sterols in the sediments from Bransfield Strait are comprised mainly of dinosterol (4,23,24-trimethyl-5cholest-22-en-3β-ol), coprostanol (5β-cholestan-3β-ol) and epicoprostanol (5β-cholestan-3-ol) and trace amounts of cholesterol (cholest-5-en-3β-ol). The sediment cores of McMurdo Sound also contain small quantities of coprostanols in addition to large amounts of marine sterols. Dinosterol is a known dinoflagellate chemical marker, whereas coprostanols are currently being used as tracers for sewage contamination. However, sterol composition in Antarctic sediments is expected to be atypical of sewage input and probably different from those of temperate and tropical zones. The coprostanols must therefore arise from the feces of marine mammals, most probably whales which use the region for feeding and spawning. Based on the results of this study, caution should be exercised in the use of coprostanol to estimate the amount of sewage-derived organic matter transported away from impacted coastal areas.     

Dissolved trace metals in the surface waters of Puget Sound

Employing clean and quantitative techniques, a marine monitoring programme succeeded in detecting large surface elevations in the concentrations of dissolved Cu, Zn and Pb in the marine surface waters of Puget Sound adjacent to Seattle and Tacoma, Washington. Physical mixing with cleaner waters was the controlling factor in reducing the dissolved concentrations of Cu downstream of these contaminated regions. Comparisons between Puget Sound waters and coastal waters adjacent to Puget Sound suggest that a portion of this Cu, Zn and Pb pollution is being advected out of Puget Sound. The low Ni and Cd concentrations found in this study indicate that these trace metals are not a significant pollution problem in the main basin of Puget Sound.     

Heavy metal contamination from gold mining recorded in Porites lobata skeletons, Buyat-Ratototok district, North Sulawesi, Indonesia

Shallow marine sediments and fringing coral reefs of the Buyat-Ratototok district of North Sulawesi, Indonesia, are affected by submarine disposal of tailings from industrial gold mining and by small-scale gold mining using mercury amalgamation. Between-site variation in heavy metal concentrations in shallow marine sediments was partially reflected by trace element concentrations in reef coral skeletons from adjacent reefs. Corals skeletons recorded silicon, manganese, iron, copper, chromium, cobalt, antimony, thallium, and lead in different concentrations according to proximity to sources, but arsenic concentrations in corals were not significantly different among sites. Temporal analysis found that peak concentrations of arsenic and chromium generally coincided with peak concentrations of silica and/or copper, suggesting that most trace elements in the coral skeleton were incorporated into detrital siliciclastic sediments, rather than impurities within skeletal aragonite.     

Dissolved metal contamination in the East River-Long Island sound system: potential biological effects

A suite of dissolved trace metals (Ag, Cd, Cu and Pb), inorganic nutrients (NO(3), PO(4)), and chlorophyll a was measured along a 55 mile transect from the East River into western and central Long Island Sound. The main objectives of this study were to determine the relative levels of contamination from sewage, and to assess its possible biological impact on local waters. The East River-Long Island Sound system receives large volumes of treated sewage and industrial effluent as a result of the heavy urbanization of the area. Despite these strong environmental pressures, this study is among the first to report dissolved metal levels from that region. Consistent with the locations of anthropogenic sources, a strong east-west concentration gradient was observed for Ag, Pb, NO(3) and PO(4) with the highest levels found in the East River. In contrast, dissolved Cd and Cu were relatively constant throughout the area of study, suggesting that sewage sources have a more limited influence on the levels of those metals. Remobilization from contaminated sediments may represent the primary source of Cd and Cu to the Long Island Sound under low-runoff conditions in summer. Chlorophyll a concentrations, used as an indicator of total biomass, were also low in the East River. These low chlorophyll concentrations could not be explained by nutrient or light limitation, water column stratification, or to advection of phytoplankton out of the river during tidal flushing. These preliminary results suggest a potential toxic effect of sewage on the biological communities of the East River.     

Organic pollutants (PAHs,PCBs) in sediments from the Mar Piccolo in Taranto (Ionian Sea,Southern Italy)

Polychlorinated biphenyls (PCBs) and 17 parent polycyclic aromatic hydrocarbons (PAHs) were determined in surface sediments from nine stations in the Mar Piccolo of Taranto (Ionian Sea, Southern Italy). Total PAH concentrations ranged from 380 to 12,750 μg/kg d.w., while total PCB levels ranged from 2 to 1684 μg/kg d.w.; this values were higher than those found in others marine coastal areas of the Mediterranean Sea. For PAHs, low molecular weight/high molecular weight, phenanthrene/anthracene and fluoranthene/pyrene ratio were used for discriminating between pyrolitic and petroleum origin. Results showed that PAHs were mainly of pyrolitic origin. PCB and PAH levels in sediments were compared with Sediments Quality Guidelines (ERM–ERL, TEL–PEL indexes) for evaluation probable toxic effects on marine organism. Finally, ERM and PEL quotients were used to evaluate the degree to which chemicals exceed guidelines. Results suggest an ecotoxicological risk for benthic organisms mainly in the first inlet, where high concentrations of PCBs were found in sediments influenced by harbour activities.     

Trace metal fluxes to nearshore Long Island Sound sediments

Sediments are very important as trace metal ‘sinks’ in coastal areas. In this paper we present data on the concentrations and calculated fluxes of the trace metals, Fe, Mn, Cu, Pb, Zn, Cd and Ag at nearshore sites in Long Island Sound. In both areas a percentage of the metal accumulation can be ascribed to local human activities with the highest anthropogenic metal fluxes occurring closest to their source.     

Anthropogenic influences on heavy metals across marine habitats in the western coast of Venezuela

Concentrations of ten metals were measured in waters and sediments at 14 sites during four sampling periods (1996–1997). These sites include various marine ecosystems that are highly influenced by industry, tourism and river discharges, nine of which are within the Morrocoy National Park. Spatially, metal concentrations in water were homogenous, whereas in sediments their distributions were related to grain size. Maximum concentrations of cadmium (Cd) and mean concentrations of copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) in water were above the guideline values proposed by NOAA, indicating the potential of these metals for producing chronic effects in marine biota. Sheltered sites showed the highest metal concentrations in sediments; with Cd and Zn above these guidelines. Enrichment factors and geo-accumulation indexes suggested that metals in sediments were largely of natural origin except for Pb, Cd and vanadium (V), which were apparently associated with industrial effluents. A disruption of the spatial distribution of metals after heavy rainfall, when exposed sites reached concentrations as high as those in sheltered sites, showed the influence of nearby rivers. The potential increase of such climatic events could represent additional stress for natural protected areas in the Caribbean.     

Natural and anthropogenic heavy metals in estuarine cohesive sediments: geochemistry and bioavailability

The geochemistry, mineralogy, and grain size distribution of several estuarine cohesive sediment samples from potentially human-influenced areas without such an influence were analyzed to determine the natural heavy metal content and evaluate its impact on the Bahía Blanca estuarine environment. The data were compared with different ranges of concentrations for heavy metals in marine sediments established by the NOAA Screening Quick Reference Tables in which values range from background levels to those considered toxic to the marine environment. Our total heavy metal contents were below the established hazardous levels in all the analyzed samples, even though the potentially human-influenced areas (harbors, industry, urban spread) showed the highest total concentration values as well as greater percentages of bioavailable compounds. This would imply a low and not extensive anthropogenic input into the environment. The relatively high proportions in which Cd, Pb, and Cr appear as bioavailable compounds at some sites not influenced by human activity suggest the presence of a natural source for these elements. This could be attributed to the weathering of naturally occurring volcanic minerals, indicating that special care must be taken when monitoring of sediment for anthropogenic activity is carried out within this environment. According to the results obtained, and in order to minimize the environmental impact caused by periodic water injection dredging, relocation of sewage outfalls from vessel mooring areas into open waters is strongly recommended.     

Matrix bound phosphine in sediments of the yellow sea and its coastal areas

Matrix bound phosphine (MBP), a kind of chemically reduced phosphorus, has received limited attention in prevailing modeling of the phosphorus biogeochemical cycle. MBP has been found to occur in marine sediments. MBP in the sediments of the Yellow Sea and its coastal areas was measured by gas chromatography from 2004 to 2007. MBP levels in surface sediments were 0.19–38.24 ng kg⁻¹ in the shelf of the Yellow Sea, 0.34–17.15 ng kg⁻¹ in the Jiaozhou Bay, 2.11–71.79 ng kg⁻¹ in the Sanggou Bay and 0.28–319.32 ng kg⁻¹ in the rivers around the Jiaozhou Bay. High levels of MBP occurred in the northern and middle areas of the Yellow Sea. Obvious seasonal variation of MBP was observed in surface sediments of the Sanggou Bay, with the highest MBP level occurring in summer and the lowest in winter. MBP in surface sediments of the inner Jiaozhou Bay was higher than those in the outer region. MBP levels increased with depth in the top 5–10 cm sediments of the Jiaozhou Bay and on the intertidal flats. Environmental factors such as type of sediments, temperature, organic matter and human activity were found to affect the concentrations and distribution of MBP in marine sediments.     

Metals in Sediments of the Upper Laguna Madre

The Laguna Madre system is the largest hypersaline coastal basin in the United States. Surface sediments from 22 Upper Laguna Madre (ULM) sites were analyzed for grain size and metals (Cd, Cu, Ba, Cr, Mn, Ni, Pb, V, Zn, Fe, and Al) to assess the extent of contamination in the area. Sediments were found to consist mainly of sand texture. Clay and silts were minor constituents (<10%) of the sediments. Anomalies in metal concentrations were found at some sites and were related to probable sources, i.e., recreational and industrial activities. Concentrations of metals were normalized to grain size, Al, and Fe to distinguish natural and anthropogenic sources. Most metals showed positive correlations (p < 0.001) with Fe and Al, suggesting a natural variability of metal concentrations in sediments. Concentrations of metals, except Cd and Pb, at most sites were found to be below threshold concentrations thought to produce toxic effects in marine and estuarine organisms.     

Pesticides in Sediments From Queensland Irrigation Channels and Drains

Pesticide concentration in sediment from irrigation areas can provide information required to assess exposure and fate of these chemicals in freshwater ecosystems and their likely impacts to the marine environment. In this study, 103 sediment samples collected from irrigation channels and drains in 11 agricultural areas of Queensland were analysed for a series of past and presently used pesticides including various organochlorines, synthetic pyrethroids, benzoyl ureas, triazines and organophosphates. The most often detected compounds were endosulphans (, β and/or endosulphan sulphate) which were detectable in 78 of the 103 samples and levels ranged from below the limit of quantification (0.1 ng g⁻¹ dw) up to 840 ng g⁻¹ dw. DDT and its metabolites were the second most often detected pesticide investigated (74 of the 103 samples) with concentrations up to 240 ng g⁻¹ dw of ∑DDTs. Mean ∑endosulphan and ∑DDT concentrations were 1–2 orders of magnitude higher in sediments from the irrigation areas which are dominated by cotton cultivation compared to those which are dominated by sugarcane cultivation. In contrast to these insecticides, the herbicides diuron, atrazine and ametryn were the compounds which were most often detected in sediments from irrigation drains in sugarcane areas with maximum concentrations in areas of 120, 70 and 130 ng g⁻¹ dw, respectively. In particular during flood events, when light is limiting, transport of these photosynthesis inhibiting herbicides from the sugarcane cultivation areas to the marine environment may result in additional stress of marine plants.     

The distribution of mercury in the surficial sediments of the northern Tyrrhenian sea

Marine sediments are the ultimate recipient of mercury introduced into aquatic ecosystem either by man or by weathering. In the surficial sediments of the northern Tyrrhenian sea high concentrations of this metal were found in an area close to the effluent of a chlor-alkali plant and in the bays of La Spezia and Leghorn, which receive wastes from numerous industries and from port activities.The sediments of a much larger marine area off the mouths of the Ombrone, Albegna and Fiora rivers also contain high levels of Hg, part of which derives from the weathering of the rich cinnabar deposits of Mount Amiata and part from mining and processing the cinnabar.     

Trace metal concentrations and fluxes in Bermuda sediments

Concentrations and calculated fluxes of trace metals into Bermuda nearshore marine and lake sediments are presented. In areas affected by anthropogenic activity, metal profiles show surface sediment enrichments similar to those observed in North American and European lacustrine and estuarine sediments. Atmospheric fluxes of Cu, Zn and Pb into the lake sediments are higher than those of rural areas in North America. These high fluxes are assumed to be due to jet-fuel combustion. Sediment profiles in the Hamilton City area indicate increased anthropogenic input of Cu and Pb compared to other marine locations.     

An assessment of marine pollution in Puget Sound

The Marine Ecosystems Analysis (MESA) Puget Sound Project was initiated to determine the existing levels, sources, fates and effects of toxic chemicals in Puget Sound, Washington. An approach was developed to assess the concentrations of a suite of contaminants and to measure a suite of biological parameters known to be responsive to contaminants. Metals, aromatic hydrocarbons and synthetic organics were found throughout the Sound. Highest concentrations were in bays near urban areas, particularly Elliott Bay near Seattle and Commencement Bay near Tacoma. A variety of biological disorders, including liver tumors in flatfish, and benthic community parameters were correlated with elevated contaminant levels. Because of the high contaminant concentrations there, and the high potential for exposure of humans to them, Commencement Bay has been identified by the US Environmental Protection Agency as a high priority toxic dump site in the United States, and remedial action is planned.     

Setting sediment quality guidelines: a simple yet effective method

Deriving sediment quality guidelines (SQGs) for marine sediments is a difficult task. It will often be a trade off between reproducibility and relevance. One of the fundamental questions in ecotoxicology is to decide what one should measure to detect response in ecosystems exposed to human disturbance. In this paper we use field data to estimate threshold levels eliciting effects on soft bottom macrobenthos collected at different sediment types and depths on the Norwegian Continental Shelf and test these against natural levels occurring levels in reference conditions. SQGs are presented from multivariate analyses based on 121 gradients (represented with Ba, THC, Cd, Cu, Pb and Zn) incorporating more than 2000 species. Clear clusters with slightly disturbed communities related to contamination loadings were evident in 35% of the gradients. We found large variations in naturally occurring contamination concentrations and in the threshold levels electing effects on the fauna at different sediment types and depths. For example, an increase in depth of only 100 m can triple the Cu and Zn concentrations that elicit effects. Lowest background and threshold levels were found in shallow, sandy sediment. Our results suggest that current SQGs are too high. We hypothesised that setting a SQG of 4-times background concentrations will give sufficient protection for the fauna from metal contamination. The overall background concentration eliciting effects on metal was 3.6x.     

Trace metals in sediment cores from Deception and Penguin Islands (South Shetland Islands, Antarctica)

This paper presents information on the levels of trace elements in sediments collected at Deception and Penguin Islands and tracks the sources of natural and anthropogenic inputs of metals into this sub-Antarctic region. The results suggest that natural processes, such as volcanic activity, hydrothermal processes and sediment transport, are more important than anthropogenic inputs in accounting for the metal concentrations measured in sediments at Deception Island. The higher levels of trace metals recorded in sediments at Penguin Island seem to reflect the composition of the source rocks of the island, which are dominated by the olivine-basalt group. Our findings show that human activities in the study areas may contribute to negligible levels of trace metals associated with anthropogenic inputs (e.g., Cr and Zn) in sediments, and these results can be used in the future as background levels related to low anthropogenic impacts.