Oil Spill Simulation and Validation in the Arabian (Persian) Gulf with Special Reference to the UAE Coast

The use of numerical modeling in oil spill incidents is a well established technique that has proven to provide cost-effective and reasonable estimates of oil surface drift. Good predictability of such models depends highly on the quality of the input data of the incident and on the model calibration effort. This paper presents the results of simulating oil spillage trajectory in the Arabian (Persian) Gulf. The study employed a 3-D rectilinear hydrodynamic model combined with oil spill model. Typical representative environmental conditions of the Arabian Gulf were first setup into a hydrodynamic circulation model using data from various sources. The performance of the hydrodynamic model was then tested against measurements of tidal fluctuation and sea currents at selected locations. The spill analysis model was setup using the flow field produced from the hydrodynamic simulation and its performance was further validated against documented events of Al-Ahmadi historical oil spill crisis in the Gulf. The comparison of the actual and simulated oil spill drift was found reasonably acceptable allowing for further application in risk assessment studies in UAE Coastal water and in the entire Arabian Gulf as well.     

Evaluation of Heavy Metal Pollution in the Arabian Gulf Using the Clam Meretrix meretrix Linnaeus, 1758

The present study is an attempt to assess the heavy metal contamination in the marine environment of the Arabian Gulf of Saudi Arabia. The concentrations of heavy metals in water and the soft tissues of the bivalve species Meretrix meretrix Linnaeus, 1758, from different stations along the Arabian Gulf coastline, were determined during the summer season of 2008. Bioaccumulation of some heavy metals (Cd, Pb, Cu, and Zn) in fresh parts of the clam (M. meretrix) was measured by an atomic absorption spectrophotometer. The average concentrations of heavy metals in the clam tissues were 0.224?C0.908, 0.294?C2.496, 3.528?C8.196, and 12.864?C24.56 mg/kg wet weight for Cd, Pb, Cu, and Zn, respectively. In water, the mean concentration values of these metals were arranged in the following descending order: Pb > Cu > Zn > Cd. The heavy metal concentrations in tissues of M. meretrix were within the acceptable standards set by the US Environmental Protection Agency, the Commission Européenne, and the Food and Drug Administration of the USA. From the human public health point of view, these results seem to show no possibility of acute toxicities of Cd, Cu, Pb, and Zn if the edible clam is consumed. It is recommended that relevant authorities should carry out a continual assessment on the levels of these pollutants in the studied area.     

Pelagic longlines: A threat to sea turtles in the Equatorial Eastern Atlantic

Pelagic longlines are widely known to interact with several species of sea turtles, and there is an increasing concern about the by-catch of turtles in commercial fisheries and its impact on their populations. However, information on sea turtle by-catch in the South Atlantic Ocean is scarce, and there are no quantitative by-catch data available on olive ridleys for the Equatorial Eastern Atlantic. In this paper we analyze data collected by observers on board an Uruguayan long-liner targeting swordfish in two areas in the Equatorial Eastern Atlantic: off the Gulf of Guinea and north of Saint Helenaa Island. Specimens of Lepidochelys olivacea and Dermochelys coriacea were hooked or entangled in 26 longline sets. All registered interactions with olive ridleys took place off the The Gulf of Guinea, with captures ranging from 1 to 3 specimens in a single set. The captured specimens, though not measured directly, appeared to be juveniles. In addition, the examination of the stomach contents of one female mako shark showed dermal scutes, vertebrae and the complete head of a sea turtle identified as L. olivacea, allowing us to estimate its curved carapace length. In contrast, adult specimens of D. coriacea were caught in the two fishing areas. The capture of 10 individuals in a single set was recorded. Due to the high rate of sea turtle by-catch observed off the The Gulf of Guinea (1.02 ind/1000 hooks) conservation programs in the area should take into consideration the possible existence of a developmental and feeding area in this zone. Accordingly, longline fisheries in this area should be monitored and mitigation measures put in place to avoid or minimize damage to the pelagic phase of African populations of sea turtles.     

Sewage Sludge Application and Soil Properties Effects on Short-Term Zinc Leaching in Soil Columns

Eight soils from the Gulf of Kalloni in Lesvos Island, Greece, most of which were of low clay and low organic matter content, were used in a series of leaching experiments. The aim was to investigate the role of sewage sludge on Zn leaching and determine the soil properties that affect it. It was found that sludge addition at a low application rate (10 t ha^?1) decreased Zn leaching significantly by 30%. From a regression analysis it was found that eluted Zn was reduced with increasing Fe oxides content, probably due to Zn adsorption onto them, and that Zn transport increased with clay content. This indicates that Zn leaching was facilitated by the downward movement of clay particles, which was also suggested by the erratic Zn breakthrough observed in many soils. This was further confirmed by the fact that colloid concentrations increased with clay content in the soils (R?=?0.85, P?<?0.05). The results show that the addition of sewage sludge to low organic matter and clay content soils at moderate application rates enhances soil organic carbon and increases metal retention capacity.     

Influence of Salinity in the Bioavailability of Zn in Sediments of the Gulf of Cádiz (Spain)

This study assesses the effect of salinity in bioavailability and toxicity of Zn by means of laboratory bioassays by observing contamination in both sediment and water, accumulation of Zn in biological tissues, and histopathological damage in the gills and guts tissues of Ruditapes philippinarum clams, which were exposed to different types of sediments from the Gulf of Cádiz (SW Spain) as well as two dilutions of toxic mud coming from an accidental mining spill. With this objective, the coefficients of distribution (K _D) for Zn between overlying water and sediments were calculated, the histopathological frequencies in the tissues of the gills and guts of clams were determined, and the biota-sediment bioaccumulation factors as well as the bioaccumulation factors were quantified in the different stations. Results showed that the greatest histopathological damages appeared when the salinity values decreased. Statistical results showed that salinity was inversely correlated with histopathological damage (p?<?0.01) for the lesion index for gills. The most outstanding results were observed in the two dilutions of toxic mud (0.3% and 7.9%) at a salinity value of 10. Salinity was inversely correlated with the concentration of Zn in biological tissues (p?<?0.05) and inversely correlated with the concentration of Zn in water and sediment. Zn mobilization to the overlying water is produced when salinity values decrease.     

Bioaccessibility of Zinc in Estuarine Sediment Contaminated by Tire Wear Particles

The bioaccessibility of Zn in tire wear particles (TWP) has been studied in incubations in the presence of estuarine sediment and solutions that mimic the digestive chemistry of sediment-ingesting invertebrates. Sea water solutions of the protein bovine serum albumin (BSA), a surrogate for digestive amino acids, released about 2?% of total Zn from sediment?CTWP preparations (in ratios of 100:1, 12:1 and 6:1) after a 5-h period. Although sodium taurocholate, a surrogate of digestive surfactancy, released quantities of Zn that were not always greater than those released by a sea water control, addition of taurocholate to BSA in sea water enhanced Zn release by solutions of the protein alone. Time courses of Zn release by BSA, with or without taurocholate, conformed to a diffusion-controlled reaction, with rate constants ranging from about 0.1 to 2?mg?L^?1?h^?1/2. Results of the study suggest that sediment-ingesting invertebrates inhabiting coastal environments impacted by urban runoff are instrumental to the mobilisation of Zn.     

Do circle hooks reduce the mortality of sea turtles in pelagic longlines? A review of recent experiments

Circle hooks have been proposed as a means of reducing the by-catch mortality of sea turtles in pelagic longline fisheries to sustainable levels. I examine the efficacy of circle hooks as a sea turtle conservation measure by examining the results of field trials conducted in the western North Atlantic, the Azores, the Gulf of Mexico, and Ecuador. These experiments employed more than a million and a half hooks between 2000 and 2004 and, in general, were well designed, conducted and analyzed. Four of five experiments demonstrated a significant reduction in capture rate and/or hooking location, indicating that circle hooks would reduce overall mortality. In one trial, however, circle hooks reduced catches of target species to such a degree that their use was impractical. I conclude, therefore, that circle hooks have the potential to reduce the mortality of sea turtles captured in many (but not all) pelagic longline fisheries, but that they should be field tested in a rigorous experiment before they are required in any fishery. Circle hooks will not reduce mortality rates of sea turtles in every pelagic longline fishery; each case needs to be tested before this measure is adopted. Circle hooks reduce turtle mortality because of their shape and size and the ways that these parameters interact with the size of turtles interacting with the fishery. Circle hooks may cause a reduction in turtle mortality by decreasing the incidence of hook ingestion as well as reducing capture rate, particularly for loggerhead sea turtles.     

大沽河湿地表层沉积物重金属分布特征及污染评价

胶州湾属半封闭海湾,水体交换能力较弱,受多条河流入海影响,污染日趋加重,通过大沽河的径流量、输沙量和溶解污染物占到胶州湾入海河流的首位。根据区域特征,于2009年2、5、8、11月对大沽河湿地48个采样点表层沉积物中的Cu、Zn、Pb、Cd、Hg、As、有机碳、粒度进行测定,探讨了重金属含量和污染特征与总有机碳、粒度的关系,利用污染评价法和潜在生态风险评价法进行污染和风险分析。结果表明：胶州湾大沽河湿地表层沉积物重金属含量较低,大部分测站符合海洋沉积物质量（GB 18668—2002）Ⅰ类标准的要求。表层沉积物中Cu、Pb、Zn含量8月份最高、2月份次之、5月份最低。Pb、Hg、As 3种重金属含量在2月份最高。Cu、Pb、Zn和Cd重金属之间存在显著正相关关系,Hg与As存在明显的相关关系;除Cd和As外的4种重金属与沉积物粘土、有机碳含量之间也存在显著正相关性。重金属单因子污染程度总体较轻,属于低污染水平,污染程度依次为Hg〉Cd〉Pb〉Cu〉As〉Zn。大沽河河口区表层沉积物重金属潜在生态风险总体处于较低水平,风险程度依次为Hg〉Cd〉Pb〉Cu〉As〉Zn。     

Determination of the Lability Characteristics of Lead,Cadmium and Zinc in a Polluted Mediterranean Brackish-Marine Interface System

Labile and non-labile fractions of zinc, lead and cadmium are studied throughout the mixing process of the waters of a small brackish, polluted lake (Koumoundouros lake) with the seawaters of the adjacent Elefsis Bay, employing Differential Pulse Anodic Stripping Voltammetry (DPASV) and Chelex-100 resins. The metal fractions were classified according to their relative lability as: very labile, moderately labile, slowly labile andinert. Their distribution is determined mainly by their affinity to complexation to organic and inorganic ligands and the changes of pH and salinity. Furthermore, the impact of salinity and pH on lability was also studied using laboratory simulation experiments. Interesting observations on the phenomena recorded include: (a) positive correlation between salinity and the very labilefraction of the metals, attributed to the formation of ion pairs and complexes of metals with chlorine ions; (b) increase of the presence of the less labile metal species by increasing pH; (c) relatively strong correlation of the dissolved organic carbon with the slowly labile and inert fractions of Pb and Zn, respectively.     

Le dugong [Dugong dugon (Müller, 1776) sirenia,dugongidae] en république de djibouti

In 1979 and 1980 strandings, accidental captures and observations of animals at sea established the regular occurrence of the dugong in inshore waters of the Republic of Djibouti. Aerial surveys conducted at the end of 1980 located a small group of some 30 individuals, the largest herd ever recorded in the Red Sea and the Gulf of Aden.     

Cumulative estimates of sea turtle bycatch and mortality in USA fisheries between 1990 and 2007

Sea turtles interact with a variety of fishing gears across their broad geographic distributions and ontogenetic habitat shifts. Cumulative assessments of multi-gear bycatch impacts on sea turtle populations are critical for coherent fisheries bycatch management, but such estimates are difficult to achieve, due to low fisheries observer effort, and a single-species, single-fishery management focus. We compiled the first cumulative estimates of sea turtle bycatch across fisheries of the United States between 1990 and 2007, before and after implementation of fisheries-specific bycatch mitigation measures. An annual mean of 346,500 turtle interactions was estimated to result in 71,000 annual deaths prior to establishment of bycatch mitigation measures in US fisheries. Current bycatch estimates (since implementation of mitigation measures) are ∼60% lower (137,800 interactions) and mortality estimates are ∼94% lower (4600 deaths) than pre-regulation estimates. The Southeast/Gulf of Mexico Shrimp Trawl fishery accounts for the overwhelming majority of sea turtle bycatch (up to 98%) in US fisheries, but estimates of bycatch in this fishery are fraught with high uncertainty due to lack of observer coverage. Our estimates represent minimum annual interactions and mortality because our methods were conservative and we could not analyze unobserved fisheries potentially interacting with sea turtles. Although considerable progress has been made in reducing sea turtle bycatch in US fisheries, management still needs improvement. We suggest that sea turtle bycatch limits be set across US fisheries, using an approach similar to the Potential Biological Removal algorithm mandated by the Marine Mammal Protection Act.     

Cyclic influences on the heavy metal chronology in a Central Mediterranean area (Palermo Gulf,Italy)

Purpose  

The evaluation of long-term heavy metal concentrations in the Gulf of Palermo (Italy) has been carried out in order to investigate how changes of pollution levels in the last 50 years can be reflected in marine sediments. Measurements of Cr, Cu, Hg, Pb, and Zn concentrations were performed on dated fractions of a sediment core. Time series analysis has allowed to obtain information on the chronology of the heavy metal pollution of the area and to identify seasonal components and trends.     

贝类产品镉铜铅锌的含量特征与风险分析

根据2007年和2009年对广东、广西沿海部分海域近江牡蛎（Crassostrea rivularis）、太平洋牡蛎（Crassostrea gigas）、翡翠贻贝（Perna viridis）、菲律宾蛤仔（Ruditapes Philippinarum）和文蛤（Meretrix meretrix）的监测资料,分析了贝类产品中镉（Cd）、铜（Cu）、铅（Pb）、锌（Zn）的含量特征及其季节差异,并采用点估计方法对贝类产品中的Cd、Cu、Zn、Pb进行了风险分析。结果表明,贝类品种的差异决定了其体内Cd、Cu、Pb、Zn含量的差异,近江牡蛎样品中Cd、Cu、Zn的含量远远高于另外4种贝类,文蛤样品中Cd、Cu、Pb的含量明显低于其他4种贝类。贝类产品中Cd、Cu、Pb、Zn的含量存在一定的季节差异,这可能与海水的温度、盐度、溶解氧等因子的季节变化有关。与《无公害食品水产品中有毒有害物质限量》标准的限量值相比,贝类产品中Cd、Cu、Pb的合格率分别为65%、67.7%和100%。与其他海域贝类产品的调查结果相比,此次贝类样品Cd、Cu、Pb、Zn的含量处于正常的波动范围内;与世界卫生组织/联合国粮农组织的食品添加剂联合专家委员会推荐的暂定每周耐受摄入量相比,太平洋牡蛎、翡翠贻贝、菲律宾蛤仔和文蛤的Pb、Cd的膳食暴露量处于安全范围内,而近江牡蛎的Cd膳食暴露量可能存在风险。     

Trace Metals in the Water Columns of the Red Sea and the Gulf of Aqaba,Egypt

Seawater samples were collected from the northern Red Sea and the Gulf of Aqaba at different depths during February 1999 and analyzed for iron, zinc, manganese, nickel, copper, cadmium, cobalt and lead to determine the existing concentration of these metals, their distribution patterns and where contamination has occurred. The concentrations of Fe, Zn, Mn, Ni, Cu, Cd, Co, Pb were scatteredin the ranges: (0.56–4.44; mean 1.67±0.9 μg L^-1), (0.13–1.17; mean 0.24±0.12 μg L^-1), (0.06–0.21; mean 0.13±0.03 μg L^-1), (0.05–0.52; mean 0.16±0.06 μg L^-1), (0.07–0.29; mean 0.14±0.06 μg L^-1), (0.02–0.78; mean 0.49±0.14 μg L^-1), (0.06–0.29; mean 0.15±0.04 μg L^-1), and (0.02–0.68; mean 0.31±0.13 μg L^-1), respectively. The results revealed a small range of variation and regional irregularities. It also indicated significant higher concentrations for Fe, Cd and Pb compared to other metals. Compared to the northern Red Sea, significant higher concentrations for Ni and Cd are measured at the Gulf of Aqaba. Other metals, i.e. Fe, Zn, Mn, Cu, Co, and Pb are not significantly different in both areas indicating no distinct concentration gradients. Except for Pb, the distribution patterns indicated significantly lower concentrations at surface layer in both regions, then increasing to their maximum values at the sub-surface layers which followed by a decrease in deep water. The study indicated also that the mean concentrations of trace metals examined here are much lower than those reported for the Mediterranean Sea and typical of open ocean water.     

三峡库区消落区表层土壤重金属污染评价及源解析

三峡库区是我国重要的水源地, 研究库区水陆交错带消落区内土壤重金属污染程度并解析其来源,对水库的水环境和土壤环境具有重要意义。本研究采用地质累积指数, 对三峡库区消落区175 m 水位蓄水前12 个采样区表层68 个土样的土壤重金属Cu、Pb、Zn、Cd、Hg、As 和Cr 污染进行评价, 结果表明: 整个研究区不受Cr 污染, 研究区70%以上面积不受Pb、Cu 和Zn 污染; 研究区As 污染最严重, 其次为Cd 和Hg。利用因子分析法对这7 种重金属来源进行解析的结果表明, 库区消落区土壤重金属源可分为2 大类别:“自然因子”类别元素(Cr、Pb、Cu 和Zn)和“工业污染因子”类别元素(Hg、As 和Cd)。消落区表层土壤重金属污染评价及源解析可为消落区生态环境的综合治理提供参考。     

Aluminum effects on micronutrient uptake by annual ryegrass

Abstract

Four ryegrass (Lolium multiflorumLam.) cultivars were grown in 1/5 Steinberg nutrient solution supplemented with six Al levels (0, 37, 74, 148, 296, or 592 umol L^‐1) at pH initially adjusted to 4.2. Average net Fe influx was stimulated at low nutrient solution Al levels. This stimulation was larger for more Al‐tolerant cultivars Marshall and Gulf. Decreases in average net Mn and Zn influxes were brought about by increasing Al levels in the nutrient solution. The average net influx of Fe, Mn, and Zn was positively correlated with the root tolerance index (relative root yield of plants grown with and without Al added to the nutrient solution). For more Al‐tolerant cultivars, increased total uptake of Fe and Cu was brought about by increased nutrient solution Al levels up to 74 umol L^‐1. Decreases in total uptake of Mn and Zn were generally noted with increased nutrient solution Al levels. Percentage inhibition of total Fe, Mn, Zn, and Cu uptake was negatively correlated with the mean pH of the Al‐containing nutrient solutions. The higher average net influx and the smaller percentage inhibition of total Fe uptake at nutrient solution Al levels up to 74 umol L^‐1can be used as indicators in ranking ryegrass cultivars as more Al‐tolerant     

Levels and Distribution of Petroleum Hydrocarbons in the Coastal Waters and Sediments of the United Arab Emirates in the Arabian Gulf and the Gulf of Oman

The levels and distributions of petroleum hydrocarbons incoastal waters and sediments of the United Arab Emirates (U. A. E.) along theArabian Gulf and the Gulf of Oman were investigated. Oil concentrations in the waters ofthe U. A. E. were below the 15 μg L^-1 and ranged from 1.6 to 13 μg L^-1.Petroleum hydrocarbons showed different pattern of distribution in the Arabian Gulf and the Gulf of Oman withmore or less similar values. Horizontal distribution of petroleum hydrocarbons atthe Arabian Gulf showed significant differences between most sites. At the Gulf ofOman, similar oil concentrations were measured at different sites. Meanwhile,vertical distributions of petroleum hydrocarbons indicated higher concentrations atsurface layers of the Arabian Gulf compared to bottom layers. Whereas, more or less similarconcentrations were measured at the Gulf of Oman. The concentration of petroleum hydrocarbons in marinesediments varied from 2.5 to 8.2 μg g^-1 (dry sediment weight), with higher concentrations at theArabian Gulf compared to the Gulf of Oman. The pattern of distribution for petroleumhydrocarbons in marine sediments resembled to some extent the distribution of organiccarbon in marine sediments. The study revealed that the concentrations ofpetroleum hydrocarbons in waters and sediments of the investigated area are not highcompared to other areas of the world.     

平武野生天麻生态环境与土壤地球化学研究

采用野外调查与室内分析相结合的方法,对四川平武野生天麻产区的自然地理、气候、植被、土壤营养成分、土壤及天麻中微量元素含量等进行了研究。研究表明平武野生天麻主要分布于海拔800-1900m范围,该区气候温和、降雨充沛,林木以青冈树为主,草本植物以蕨类为主,成土母质为志留系千枚岩。野生天麻多生长于壤土中,土壤为弱酸性,有机质含量丰富,土壤中速效氮、速效钾含量中等,速效磷较缺乏,土壤有效铜、有效锌和活性锰含量较高,未遭受到重金属污染。天麻对铜、锌具有选择性吸收作用。     

Heavy Metal Contents and Distribution in Coastal Sediments of the Gulf of Trieste (Northern Adriatic Sea, Italy)

A set of ten heavy metals (Al, As, Cd, Cr, Cu, Hg, Ni, Pb, V, and Zn) was investigated in surface sediments (0–5 cm) collected in 21 sites of the Gulf of Trieste, Northern Adriatic Sea (Italy). The aim of this work was to obtain a preliminary assessment about the levels and spatial distribution of these selected elements. Ancillary parameters such as grain size, total organic carbon, and total nitrogen were also determined. The enrichment factor was calculated to discriminate if a natural condition or a status of anthropogenic contamination occurs. In addition, a set of sediment quality guidelines, mean effect low range and effect medium range quotients, was also applied in order to predict the probability of adverse biological effects on the benthic community.     

Properties of humic substances from the baltic sea and lake ermistu mud

Scope and Goal  Humic substances (HSs) are the product of microbial degradation, chemical polymerisation and oxidation of organic matter. HSs can be divided into different fractions: humic acid (HA), hymatomelanic acid (HMA), fulvic acid (FA) and humin. HSs play a fundamental role in accumulation and exchange processes of chemical compounds (metals and organic pollutants) in the environment. HSs can form soluble complexes that migrate long distances or precipitate, carrying bound cations with them. The migration/precipitation abilities depend on the metal ion, the ion charge, the degree of ionisation of the organic molecule, the ionic strength of the media, and the location of the metal ion. Objective  Estonia is rich in the Baltic Sea and lake sediments. Historically, mud has been used in human treatment as a curative mud. High-molecular HSs are an important part of curative mud and they have a strong effect on its properties. The curative mud which is used in human therapy may not be polluted with different organic and inorganic contaminants. The aim of this work is to characterise and compare HSs isolated from the Baltic Sea mud (Haapsalu Bay) and from the sediments of Lake Ermistu (Estonia). Results and Conclusions  We determined the yield of basic extraction of different HSs components from mud in the course of separation. We found that acid pre-treatment of mud increased the amount of extracted HSs more in the sea mud than in the lake mud. These results show that HSs are bound to the inorganic/organic structure of mud and are released during prolonged treatment with an acid. We performed elemental analysis of the different fractions of HS extracts. HMA fractions had the highest carbon content and the lowest nitrogen content. HMA contains more polysaccharides than amino acid residues. These subunits may cause a better solubility of HMA in water as compared to HA. Acid pre-treatment of the natural sea and the lake mud diminished the content of carbon in most of the HS fractions. The content of nitrogen in the sea and in lake FA diminished by about two times. We determined the metal content in the mud and its HS fractions. We found that the concentration of heavy metals Pb and Cr is lower than <0.08 mg/kg. As expected, the total metal concentration is considerably lower in the lake than in the sea mud. Acid pre-treatment of mud shows that the sea HA forms more stable Fe and Mg complexes, while the sea HMA contains more stable Zn and Cu complexes. The lake HSs result in more stable Mg complexes with HA and HMA fractions. Sea FA binds Cu and Mg better, but lake FA is more effective in binding Zn. To compare the amount of metals extracted from HA, HMA, FA (with that, remains in HS fractions), the metal concentration in the alkaline full extract of the sea mud was determined. Alkaline treatment removed 0.8% Mg, 7.9% Cu, 5.2% Zn and 3.8% Fe together with HSs from the sea mud, the rest remained in humin and in the mineral part of the mud. The following work-up was additionally carried out for most of the metals. So, we found that there was only 1.7% of Fe, 2.1 % of Mg, 23.2% of Zn and 45.2% of Cu left in HA, HMA and the FA fraction (as a sum) from the total amount of those metals in HSs. This means that Cu is the metal most strongly bound to HSs. On the bases of HS separation data we found that the order of stability of the metal-humate complexes is Cu>Zn>Mg>Fe. The ultraviolet spectra of HA, HMA and FA revealed that HMA had the biggest molar absorption and calculated aromaticity. Recommendations and Outlook. The characteristics of HSs, isolated from the Baltic Sea and Lake Ermistu mud reveal the difference of HSs from the sea and the lake mud. Also, different properties of HS fractions are observed. Metals are concentrated variously in different HS fractions. In all cases the content of Pb and Cr was low, meaning that the mud preparations are nontoxic in respect to these metals. The order of stability of metal-humate complexes is Cu>Zn>Mg>Fe. The order of affinity of metals to HS fractions obtained have to be extended to other metals of environmental interest. The ability of HSs to bind metals may make them a candidate for natural, environmentally safe substances to concentrate hazardous metals and to remove them from natural water reservoirs.