Effects of 17beta-estradiol on the reproduction of Java-medaka (Oryzias javanicus), a new test fish species

17β-estradiol (E2) is a female hormone which is known to be one of the strongest estrogenic chemicals in the environment. The present study investigated the effects of E2 on the reproduction of the estuarine fish, Java-medaka (Oryzias javanicus). Starting from the embryonic stages, Java-medaka was exposed for 6 months to 9.5, 16, 68, 159 and 243 ng/l of E2. The fecundity of Java-medaka exposed to E2 levels >16 ng/l was significantly lower than that of the control. The appearance of secondary sexual characteristics seemed to be inhibited by exposure to 159 and 243 ng/l E2. Vitellogenin concentrations in the liver of male fish exposed to 68, 159 and 243 ng/l were significantly higher than that of the control. Thirty-three and sixty percent of male fishes exposed to 159 and 243 ng/l, respectively, had testis-ova. These results suggest that reproduction in the Java-medaka, especially the male fish, could be affected by exposure to E2 concentrations greater than 16 ng/l.     

Peculiarities of annual variations in the concentration of iron compounds in the water-bottom sediments system of the Mozhaisk Reservoir

Annual variations in concentrations of Fe forms in the bottom water (0–70 cm from the bottom, by layers), pore water, and in solid phase of silts (25 cm, by layers) of the Krasnovidovo Pool channel area of the Mozhaisk Reservoir are studied. A drastic increase in the concentration and ratio of Fe_susp/Fe_dis in the water layer 0–20 cm from the bottom is detected. Fe(II) dominates in dissolved and suspended forms. The concentrations of Fe(III) reaching 2–3 mg/l were for the fist time revealed in the pore water of silts (Eh ～ ?120 mV). The factors responsible for this phenomenon are discussed. Fe flux from sediments is tentatively assessed as 0.2–0.6 mg Fe m²/day.     

The distribution of particulate matter in the Atlantic Ocean

We have determined the dry weight of suspended particulate matter in seawater in a section through the western Atlantic Ocean from 75°N to 52°S. The concentrations, operationally defined as that weight retained on 0.6-μm and 0.4-μm pore size Nuclepore filters, contained in 1 kg of seawater, range from 5 to 300 μg/kg and show readily explainable regional features. High concentrations are found in surface waters and in association with radpidly moving bottom waters in the Denmark Straits overflow and in Antarctic bottom waters to 15°S. Low concentrations, <12 μg/kg, characterize the mid-water regions of the sub-tropical gyres. High concentrations are seen in sinking Labrador Sea water and in a plume extending at least a kilometer off the bottom at 35°N–40°N where the cruise track intersects the North Atlantic gyre. It is doubtful whether this important phenomenon could be observed by any means other than through particulate observations, either optical or gravimetric, and this provides a unique insight into the scale of vertical turbulent processes.     

Effects of 17β-estradiol on the reproduction of Java-medaka (Oryzias javanicus), a new test fish species

17β-estradiol (E2) is a female hormone which is known to be one of the strongest estrogenic chemicals in the environment. The present study investigated the effects of E2 on the reproduction of the estuarine fish, Java-medaka (Oryzias javanicus). Starting from the embryonic stages, Java-medaka was exposed for 6 months to 9.5, 16, 68, 159 and 243 ng/l of E2. The fecundity of Java-medaka exposed to E2 levels >16 ng/l was significantly lower than that of the control. The appearance of secondary sexual characteristics seemed to be inhibited by exposure to 159 and 243 ng/l E2. Vitellogenin concentrations in the liver of male fish exposed to 68, 159 and 243 ng/l were significantly higher than that of the control. Thirty-three and sixty percent of male fishes exposed to 159 and 243 ng/l, respectively, had testis-ova. These results suggest that reproduction in the Java-medaka, especially the male fish, could be affected by exposure to E2 concentrations greater than 16 ng/l.     

Analysis of the Ecotoxicological Conditions of Amur Bay,the Sea of Japan,by Chemical and Toxicological Characteristics

Water Resources - Data on the concentrations of Cd, Cu, Pb, and Zn in bottom sediments of Amur Bay are given. The pollution of bottom sediments is especially heavy near the central part of...     

Environmental Effects of the Bottom Sediments of the Senezh Reservoir

The formation and accumulation of bottom sediments in the Senezh Reservoir are discussed on the basis of field observations. Data on the bottom sediment thickness, the rates of accumulation, and the concentrations of organic substances, metals, petroleum products, and organic pollutants are presented. The bottom sediments of the reservoir are demonstrated to be still no source of secondary pollution.     

Distribution of Heavy Metals in Lake Seliger Bottom Deposits

The distribution of some microelements in the surface and stratified layers of bottom sediments in Lake Seliger is studied. Data on the bottom deposit pollution by heavy metals is used to determine the anthropogenic load on the lake ecosystem. Cd, Zn, and Pb are shown to rapidly accumulate in thick (>1 m) bottom deposits that have formed during the period of lake existence. The concentrations of Cd and Zn are shown to correlate with the organic matter in thick bottom deposits.     

Concentrations of Heavy Metals in the Upper Volga Bottom Deposits

The distribution of heavy metals in the Volga bottom deposits is studied. According to the degree of pollution with heavy metals, three stretches are singled out within the river reach under consideration. A drastic increase in Cu and Cd concentrations in bottom deposits is established. A close statistical correlation between Cu and Pb accumulation and the organic matter content of bottom deposits is revealed.     

Metal Concentrations in the Ecosystem and Around Recreational and Fish-Breeding Pond Bugach

Data of two field studies were used to analyze the concentrations of Na, K, Ca, Mg, Fe, Mn, Zn, Cu, Al, Cr, Ni, Cd, and Pb in the water, bottom deposits, zoobenthos, fish, and macrophytes of the Pond Bugach and in the soils near the pond. It was established that the majority of metals in the soils and bottom deposits correlate and their concentrations are governed by the universal geochemical factors of the region. The heavy metals were recognized that originate from anthropogenic sources and their concentrations were found to exceed the maximum admissible values for different components of the ecosystem. Five types of heavy metals migration were recognized in the soil–bottom deposits–zoobenthos–fish chain and in macrophytes. Statistically significant difference was found to exist between the concentrations of some heavy metals in the muscles of fish species with different food types (crucian carp and perch) as well as between the correlations of metals. The recorded concentrations were compared with the concentrations of metals measured in the last decade in other limnetic ecosystems in Siberia, Europe, North America, and China.     

Aliphatic and polyaromatic hydrocarbons in bottom sediments of offshore mouth area of the Volga

Data on the concentration and composition of aliphatic and polyaromatic hydrocarbons in the surface layer and the body of bottom sediments in Volga delta and on the northern Caspian shelf are given. Volga delta sediments are shown to contain large concentrations of organic compounds. It is established that the concentrations of organic compounds is largely dependent on the dispersiveness of sediments. Anthropogenic hydrocarbons, both oil and pyrogenic, fail to pass the marginal filter of the Volga River and do not reach the open part of the sea. Therefore, the hydrocarbons contained in the bottom sediments on the Caspian Sea shelf are mostly of natural genesis. The distribution of organic compounds in the bottom sediment strata has a complex character. In some cases, their concentration increases because of the higher flux of hydrocarbons (especially, polyarenes in the 1950s).     

Phosphorus Distribution in Bottom Deposits of the Mozhaisk Reservoir

The spatial distribution and accumulation of different forms of phosphorus in bottom deposits of the Mozhaisk Reservoir are discussed with account taken of the granulometric composition and organic matter content of the soil and the hydrodynamic conditions in the reservoir. The total amount of P in the 10-cm layer of bottom deposits is calculated and the rate of P accumulation is assessed by the balance method. Data on the concentrations of P fractions in silts in the reservoir channel trough in the 1970s and currently are presented; they indicate to a considerable increase in the non-apatite fraction of P.     

226Ra behavior in the Pee Dee River-Winyah Bay estuary

Concentrations of dissolved²²⁶Ra in Winyah Bay, South Carolina, and in the adjacent Atlantic Ocean are augmented by the desorption of radium from sediments in the low-salinity area of the estuary and diffusion from bottom sediments. Desorption of²²⁶Ra is reflected by lower concentrations in suspended sediments from higher-salinity regions of the estuary. Bottom sediments from the high-salinity region have lower²²⁶Ra/²³⁰Th activity ratios than those from the low-salinity end.The shape of the dissolved²²⁶Ra vs. salinity profile is influenced by the river discharge. During average-discharge conditions, desorption of²²⁶Ra from suspended and bottom sediments increases the dissolved²²⁶Ra concentrations by a factor of 3.5 as the water passes through Winyah Bay. High river discharge produces an initial increase of dissolved²²⁶Ra by a factor of 2 to 3 and apparently reflects only desorption from suspended sediments. By driving the salt wedge down the estuary and reducing the zone of contact of salt water with bottom sediments, the high-flow conditions sharply reduce the flux of²²⁶Ra from bottom sediments.     

Heavy metals in sediments from the Athens sewage outfall area

Sediments in the upper Saronikos Gulf have been contaminated by heavy metals from the discharge of untreated industrial and domestic wastewater from the area around Athens. Neutron activation analysis indicates concentrations of antimony, arsenic, chromium, gold, mercury, silver and zinc are 8–200 times greater than in the surrounding uncontaminated sediments. The bottom area affected by increased metal concentrations is at least 13 km² and indicates a nearly radial dispersal pattern from the main outfall with higher concentrations extending to the southeast and southwest.     

Heavy Metals in Bottom Sediment in the Upper and Lower Volga

Heavy metal concentrations in bottom sediment in some reaches of the Upper (the Ivankovo Reservoir) and Lower Volga (from Volgograd to the mouth offshore area). The bottom sediment in the Ivankovo Reservoir are shown to be heavily polluted by Cu and Zn and to a lesser extent, by Co and Ni; heavy pollution with Ni and Cr and moderate pollution with Zn and Mn were recorded in the Lower Volga. Principal component procedure was used to assess bottom sediment pollution. The role of organic matter in the formation of the Ivankovo Reservoir bottom sediment pollution with heavy metals is shown to be moderate because of the weak correlation between heavy metal concentration and organic matter content of bottom sediment. The same is true for the Lower Volga because of low organic matter content of bottom sediment. The major role in the redox cycle of elements is shown to belong to Fe in the Ivankovo Reservoir and Mn in the Lower Volga.     

Persistent Organic Pollutants (POPs) in Bottom Sediments of the Vistula River,Poland

The Vistula (Wisla) river, the biggest river in Poland, is 1038 km long and has a drainage area of 168 689 km². The river is strongly polluted by wastewaters. Big industrial plants are situated mainly in the upper part of the river, where it is slow‐flowing. This paper presents the results of the analysis of bottom sediment samples gathered from different locations along the Vistula river, from Kraków to Gdansk. The study was conducted in 2005. The following parameters were determined: chloroorganic pesticides, polychlorinated biphenyls (PCBs), chlorophenols, polycyclic aromatic hydrocarbons (PAHs), total organic carbon (TOC). The sum of chloroorganic pesticides was in the range of 2.0 to 77.5 ng/g d.w. (dry wet) with the highest values in the upper part of the river. p,p′‐DDT was found in the highest concentration. The sum of PCBs was in the range of 0.9 to 64.2 ng/g d.w. The sum of chlorophenols varied from 0.48 to 14.3 ng/g d.w. 2,4‐Dichlorophenol and pentachlorophenol occurred in the highest concentration. The sum of PAHs was in the range of 1552 to 7832 ng/g d.w. Phenantren was found in the highest concentration and antracen in the lowest. TOC values varied from 4.3 to 43.9 g/kg d.w. The concentrations of pesticides and PCBs were the highest in the upper part of the river and decreased along the course of the river, but the other determined compounds did not show this trend. However, the highest values occurred always in the upper part of the river.     

Geochemical features of the silt sediment of the Novosibirsk Reservoir

Earlier data on heavy metal concentrations in bottom sediments of the Novosibirsk Reservoir are supplemented by new geochemical characteristics of fine silt sediment in the near-dam part of the reservoir with the list of chemical elements extended to 55. After the beginning of the Ob’s runoff regulation by HPP dam, a new geochemical type of sediment started forming in the new reservoir. This type of sediment features higher concentrations of chemical elements (including heavy metals), reaching the values typical of Baikal silt recorded in the central hollow of the lake.     

Seasonal Variations in the Forms of Heavy Metal Occurrence in the Kuibyshev Reservoir Waters and Bottom Deposits

Seasonal dynamics of total concentrations and the main forms of occurrence of heavy metals (HM) in the water mass and bottom deposits (BD) are studied in the Priplotinnyi (Near-dam) Pool of the Kuibyshev Reservoir. In the near-bottom and interstitial waters, heavy metals are mostly found in the form of complex compounds with organic and mineral ligands; the proportions of these complexes and the dominant form in the above media change from season to season. The hard skeleton of bottom deposits contains a large store of heavy metals that can be a source of the secondary pollution of water masses.     

Studying the Correlation between the Vegetable Pigments Content of Bottom Deposits and the Trophic Status Indices of the Gor'kovskoe Reservoir

Data on the distribution of vegetable pigments in bottom deposits and water mass is presented to characterize the ecological zones of the reservoir. The concentrations of pigments in the channel deposits are shown to increase from the reservoir head toward the dam in accordance with the difference in phytoplankton production in the zone of backwater pinching out, transient zone, and near-dam zone. It is shown that the space heterogeneity of the pigment characteristics of deposits is controlled by the soil properties and the pigments content of the top 2.5-cm layer of bottom deposits of the reservoir correspond to the average productivity level.     

Persistent organic pollutants in subarctic lakes in the extreme North of European Russia

The paper presents data on the concentrations of persistent organic pollutants in bottom sediments of subarctic lakes on Vaygach Isl. and in the Polar Cis-Urals in the Northern European Russia. Dioxin pollution is estimated at the background level, and the recorded levels of hexachlorobenzene fall within the concentration range identified in the bottom sediments of small lakes in the southwestern Arkhangelsk region. The specific character of the congener profile of polychlorinated dibenzo-p-dioxins and dibenzofurans in bottom sediments is demonstrated, suggesting a relationship between the pollution that forms under the effect of atmospheric transport of persistent organic pollutants from low latitudes in the past and present and the application of dioxin-containing organochlorine chemicals in timber industry.     

Ecological and toxicological assessment of water and bottom sediments in the Novosibirsk Reservoir

The toxicological state of individual parts of the Novosibirsk Reservoir was assessed with the help of bioassay tests of water and water extracts from bottom sediments with the use of two species of protococcus algae (Scenedesmus quadricauda (Turp.) Breb., Chlorella vulgaris Beijer) and two species of entomostracans (Daphnia magna Straus, Ceriodaphnia affinis Lillijeborg). It was found that the Ob R. near Kamenon-Ob is more polluted in terms of water and less polluted in terms of bottom sediments, compared with those in the lower part of the reservoir. The bioassay results are in agreement with the results of benthos-based bioindication and studies of chlorophyll a and pollutant concentrations in water.