On sediment pollution in selected german coastal waters of the Baltic Sea

In order to determine and assess their status sediments from the German coastal waters of the baltic sea were analyzed for structural parameters and for several groups of harmful substances. Regarding all groups of harmful substances, i.e. nutrients, heavy metals and organic toxicants the sediments of the eastern sections investigated (Strelasund, Peenestrom and Stettin Lagoon) are generally more polluted than the sediments of the other ones.The sediments of the examined sections of the Baltic coast compare with North Sea sediments by factors of between 0.05 and 4 with regard to heavy metals.Because of the variability of the concentration of harmful substances in the various coastal sections, it is imperative to make a differentiated assessment of the polluted sediments and to set district-related targets for the various sections of the Baltic coast.     

Heavy metals in Baltic herring and cod

The monitoring programme of harmful substances in selected species in the Baltic Sea was started in 1979. In the present study, three-year averages of Zn, Cu, Cd and Pb in cod liver (Hg in cod muscle) and herring muscle are reported. The concentrations of heavy metals in cod show areal differences roughly in accordance with the concentrations of heavy metals in sea water. No significant differences between heavy metal concentrations in North Atlantic and Baltic Sea species were found, except for mercury, for which values in the Baltic Sea species are lower than in those from the North Atlantic.     

The Pollution Load from the River Odra in Comparison to That in Other Polish Rivers in 1988–1997

The discharge of organic matter, nutrients, and heavy metals from the river Odra into the Baltic Sea is compared with the combined discharge of the same substances from other Polish rivers into the Baltic during 1988–1997. The impact of the summer flood of 1997 is also discussed. The discharges of organic matter, nitrogen and phosphorus compounds were closely correlated with the flow rate. The annual loads of these nutrients measured in 1988 and 1996 under similar flow conditions decreased by 15 to 40% in these rivers as a result of the reduction of point sources. A steady decrease in the heavy metal load, independent of weather conditions, has been recorded during the past decade. Zinc decreased by up to 85% in the Odra and 99% in the Wisła. Although the water outflow from the Odra was half that of the Wisła, it transported a proportionally higher load of chemical compounds. Despite the differences in flow rates, the contribution of both rivers to the total riverine phosphorus discharge was approximately the same. The total water outflow during the flood (from 1 July to 28 August 1997) increased by 65% near the mouth of the Odra in comparison to 1996. The phosphate discharge increased by 34%, that of nitrite nitrogen by 88%     

The Flood in the Odra River 1997 – Impact of Suspended Solids on Water Quality

The flood in the Odra river in 1997 has led to considerable additional pollution of the Stettin Lagoon and the Baltic Sea with contaminated suspended solids. For some priority substances, the pollutant entries via suspended solids during the flood period are estimated to be approximately 1/3 of the usual annual load. Among these priority pollutants there are total organic carbon (TOC), nitrogen, and the heavy metals Cu, Pb and Zn. For the concentrations of the priority pollutants in suspended solids accumulation factors from 2 to 4 in the comparison with normal conditions were observed. On the basis of the analysis of sediments sampled after the flood, main sources of the pollutants should be evaluated. As reference area with an industrial background as well as a typical pollutant pattern the region around Glogow/Legnica is proposed.     

Ecological Conditions of Watercourses in the Middle Amur Lowland in the Areas of Drainage Reclamation

The effect of land reclamation on the migration and accumulation of heavy metals and some pollutants in small rivers is determined. The study was conducted in the Middle Amur lowland in different phases of hydrological regime and at different extent of floodplain inundation. The formation of the hydrological regime in small rivers in this area is governed by the irregular annual runoff distribution. The seasonal character of flood periods requires water samples to be taken before spring flood (April) and after floods have passed (September–October), and at various extent of floodplain inundation. The field studies of water-courses were carried out in 2009–2014. The water samples were analyzed to determine the concentrations of heavy metals (iron, manganese, copper, nickel, cobalt, lead and zinc), suspended substances, organic carbon (total, dissolved, and suspended), humic and fulvic acids, and volatile organic compounds. The mobility of heavy metals in surface watercourses was shown to reflect the effect of drainage and surface runoff from soil horizons, an increase in the concentrations of suspended and organic compounds, especially, fulvic acids, which enhance their geochemical mobility. During floods, an increase in heavy metals washout from floodplain soils and the dilution of their concentrations causes the formation of a single-type concentration series of heavy metals. In addition, the processes of pollutants migration show an effect of changes in the geomorphological characteristics of floodplain–channel complexes and a decrease in flow velocity in watercourses in the areas where land reclamation was applied. Thus, all factors mentioned above lead to a decrease in water pollution index in the river.     

Eutrophication and heavy metal pollution in the Flensburg Fjord: A reassessment after 30 years

A study of surface sediment organic matter and heavy metal content (e.g. Cu, Zn, Pb and Sn) was carried out in 2006 to assess changes in eutrophication and pollution in the periodically anoxic Flensburg Fjord since 1972. Low hydrodynamic activity together with sewage discharges and high primary production in the inner fjord promote the enrichment of present day surface sediments in organic matter and metals in contrast to the outer fjord. However, heavy metal contents in the fjord are typical for the western Baltic Sea, although they are higher than in the preindustrial period.Although the anthropogenic nutrient load has substantially decreased since the 1970s, sediments from the inner fjord contain more organic material in 2006 than in 1972 resulting from still high levels of primary production supported by internal nutrient loading. Of the heavy metals measured, a decrease in Pb content since the 1970s is distinct, which is explained by the banning on gasoline lead. Taken together, these results suggest that the amelioration of environmental conditions needs time but is indeed related to reduced anthropogenic inputs.     

Mussel farming as a nutrient reduction measure in the Baltic Sea: consideration of nutrient biogeochemical cycles

Nutrient loads from the land to the sea must be reduced to combat coastal eutrophication. It has been suggested that further mitigation efforts are needed in the brackish Baltic Sea to decrease nutrients, especially in eutrophic coastal areas. Mussel farming is a potential measure to remove nutrients directly from the sea. Mussels consume phytoplankton containing nitrogen (N) and phosphorus (P); when the mussels are harvested these nutrients are removed from the aquatic system. However, sedimentation of organic material in faeces and pseudo-faeces below a mussel farm consumes oxygen and can lead to hypoxic or even anoxic sediments causing an increased sediment release of ammonium and phosphate. Moreover, N losses from denitrification can be reduced due to low oxygen and reduced numbers of bioturbating organisms. To reveal if mussel farming is a cost-effective mitigation measure in the Baltic Sea the potential for enhanced sediment nutrient release must be assessed.     

Pollution history of the savannah river estuary and comparisons with Baltic Sea pollution history

The sediment record, as revealed in sediment cores, can be used to reconstruct the history of contaminant input into estuaries. The basic assumptions are that contaminant inputs equilibrate relatively rapidly with sediment inputs and that the sediment column represents a continuous sequence of sediment and associated contaminant accumulation. With radiochemical chronologies, it is possible to date sediments over a period corresponding to about five half-lives (100 years for ²¹⁰Pb). In our study we reconstruct the pollution history of the Savannah Estuary, which is a typical estuary in the South Atlantic Bight. A series of cores were taken in the estuary, followed by the analysis of the cores for a variety of organic and inorganic contaminants. Ages were assigned to different depth intervals by the use of two radiotracers, ²¹⁰Pb and ¹³⁷Cs. The major pesticides found were an isomer of DDT and dieldrin. The peak in their concentrations (1967) correlated with peak use of these pesticides before their use was banned. Between 1959 and 1962, there was more input of anthropogenic PAHs than before and after this period. The metals which showed significant changes in the cores include mercury, lead and chromium. Chromium reached a maximum during the late 1950s, followed by a decrease in the late 1960s. This chromium peak coincided with the initial operation of a titanium dioxide pigment plant in the Savannah Estuary. An interesting aspect of the study, which has been noted by many pollution history studies, was the decrease in the concentration of anthropogenic chemicals during the past two decades, suggesting that pollution controls have been effective, even while industrial and population growth was taking place.Similar studies have been carried out to reconstruct the historical record of contamination in the Baltic Sea. Concentrations of metals were found to increase after 1880 (industrial revolution in northern Europe). PCBs peaked in concentration in the late 1960s and the early 1970s, while DDT peaked in the 1960s. The Baltic experienced a major input of nutrients (N and P) after 1965 resulting from heavy use of fertilizers in this region.     

Environmental regulations of agriculture in the Baltic Sea catchment areas, with reference to the European Union and the North Sea

The environmental policies aimed at reducing nutrient emissions from the agricultural sectors in the Baltic states, Poland, Germany and Scandinavia are detailed. The emissions include leaching, run-off and erosion losses of nitrogen and phosphorus, volatile losses of ammonia, and farm waste discharges. Farm waste discharges and nitrate leaching from agricultural fields have received considerable attention during the last few decades, but more recently the remaining loss categories have also been recognized as substantial contributors of nutrients to the environment.

Environmental targets have been set in the Helsinki Commission (HELCOM) Ministerial Declaration of 15 February 1988, stating that a significant reduction (e.g. 50%) of the nutrient load to the Baltic Sea shall be reached before 1995. A similar target for the Oslo and Paris (OSPARCOM) Convention waters has been set by the North Sea ministers, while the EU Nitrate Directive expresses an environmental standard by setting an upper limit to nitrate concentrations in groundwater.

It is argued here that in most instances only marginal reductions in agricultural emissions will be achieved under the current policies before 1995 (or later). Exceptions are seen in transition economy countries where fertilizer consumption and livestock production have decreased significantly. As agriculture is a major source of nutrients to convention waters, the overall 50% reduction target will not be met. Furthermore, it is argued that there is scope for a considerable reduction of losses from agriculture and that the instruments to achieve the objectives are readily available. Measures should focus on the total input of nutrients to the agro-ecosystems and not so much attempt to regulate specific management practices. The more prominent instruments include the reduction or alteration of agricultural subsidies, market considerations and the use of environmental taxes (on fertilizers and nutrients in animal manure) combined with in-depth structural regulations. It is, however, necessary to generate further political willingness to ensure decisions and successful implementation of the various measures—a process which requires public attention.     

Heavy metals in Chukchi Sea sediments as compared to selected circum-arctic shelves

Surficial sediments from 31 stations on the northeastern Chukchi Sea, Alaskan Arctic were analysed by AAS and ICP-AES for Si, Al, Fe, Mn, Cu, Cr, Co, Zn, Ni and V. The metal concentrations are related to the sediment granulometry and show no correlations with organic carbon. Presumably all the heavy metals, except Cr and Co, are either adsorbed on clays and/or coprecipitated with ferrimanganic hydroxide. Cobalt is partitioned in an unknown mineral phase within the sand fraction.

Comparison of the heavy metal concentrations in muds of the Chukchi Sea with those of the high arctic shelves of Russia, East Greenland and the Beaufort Sea shows relatively lower levels of most metals in the Chukchi. Presumably these disparities are related to regional differences in sediment chemistries inherited from natural terrigenous sources rather than to any enhanced pollution in the non-Chukchi areas.

It is suggested that the concentrations and accumulation rates of the heavy metals reported here can serve as reliable baselines to monitor metal pollution in the Chukchi Sea.     

Hazardous Heavy Metal Distribution in Dahuofang Catchment,Fushun, Liaoning,an Important Industry City in China: A Case Study

Located in Liaoning Province, one of the traditional heavy industrial areas in China, Dahuofang Reservoir provides drinking water for nearly 30 000 000 citizens, as well as industrial and agricultural water for dozens of several cities and rural areas. The distribution of hazardous heavy metals is described in several types of soil, crops, and in different industrial or mining areas and main sewage irrigation areas. Five possible reasons that may cause the pollution are analyzed and listed. Also we provide some pragmatic suggestions for the remediation of heavy metals in contaminated soils.     

Ecological risk assessment of Cd and other heavy metals in soil-rice system in the karst areas with high geochemical background of Guangxi,China

Karst areas are widely distributed in China, and the soil derived in these areas is enriched with trace elements and has the typical characteristics of high geochemical background. Therefore, soil ecological risk has gradually attracted extensive attention. In this study, 1090 sets of rice grains and paired rhizosphere soils were collected as research objects from the outcropped karst areas of carbonate rocks in Guangxi, and the concentration characteristics and influencing factors of heavy metals, such as Cd and As, in rice grains and the corresponding soils were studied. According to the Chinese Soil Environmental Quality Standard(GB 15618-2018), the proportion of karstic soil samples in Guangxi with heavy metal(As, Cd, Cr, Cu, Hg, Ni,Pb and Zn) concentrations that exceed the standard risk screening values was generally greater than that of surface soils in China or non-karstic soils in Guangxi. Notably, Cd and As were the most prominently enriched heavy metals in soils. According to the Chinese Food Safety Standard(GB 2762-2017), Pb in rice grains from the studied area did not exceed the standard; the exceedance rates of Cr, Hg, and inorganic As were only about 1%; and the exceedance rate of Cd was 12.5%. Soil Cd concentration increased gradually whereas the concentration and exceedance rate of Cd in rice grains decreased gradually with the increase of soil pH. Specifically, the exceedance rate of Cd in rice grains was only 4% when soil pH6.5. The results indicated that the risk screening values of Cd element in the Chinese Soil Environmental Quality Standard are not satisfactorily applicable to the ecological risk assessment of Cd in karstic soils. Therefore, the recommended threshold values for the safe utilization and risk control of Cd in karstic soils was proposed so as to provide a basis for soil environmental quality hierarchization, pollution risk control and land safety zoning of agricultural land in karst areas in China.     

Some Environmental Consequences of Soil Dumping in the Black Sea as a Result of Dredging Operations in Kerch Strait

The results of monitoring performed by Southern Research Institute of Marine Fisheries and Oceanography (YugNIRO) in 1990–1998 in the course of dredging operations with dumping in the Black Sea of soils dredged in Kerch Strait are analyzed. The study covered the soil physical properties and particle size distribution; the extent of the soil pollution by heavy metals, oil products, and organochlorine compounds; the amounts of such pollutants delivered into the sea with these soils; the extent of pollution of water and bottom sediment in the zone of soil dumping offshore Kerch Strait. The amounts of pollutants entering the Black Sea as a result of soil dumping are compared with those entering the sea from other pollutant sources, and the extent of environmental pollution in the dumping zone is compared with the background level of the sea pollution. The admissible rates of soil dumping are estimated, and potential consequences of this process are predicted.     

Distribution and pollution assessment of heavy metals in surface sediments in the Yellow Sea

Heavy metal concentrations in surface sediments at 56 stations during two cruises in the Yellow Sea in summer and winter, 2011 were analyzed by inductively coupled plasma-mass spectrometry. The pollution status was assessed via the Geoaccumulation index and Hankanson potential ecological risk index. Higher concentrations of heavy metals (except for Mn) were found in the central Southern Yellow Sea and the western Northern Yellow Sea. The higher contents of Mn were much closer to Shandong Peninsula. Correlation analyses indicated that Pb, Cu, Fe, Ni, Zn and Co probably had the same origin and were controlled by grain size and total organic carbon. Pollution assessment showed that most areas of the Yellow Sea were not or lowly contaminated with the exception of the northwest and south parts of the Southern Yellow Sea showing Cd-contamination. The pollution status of the Yellow Sea in summer was worse than that in winter.     

Chronic pollution of freshwater bodies: Data on accumulation of pesticides,oil products,and other toxic substances in bottom deposits

The results of studies aimed to assess the information significance of the coefficients of bottom accumulation of hydrophobic organic substances and heavy metals as indicators of pollution of freshwater bodies are presented. It is shown that the same value of the coefficient of bottom accumulation may correspond to different situations in water bodies. Methods for the interpretation of data on the state of water bodies based on the coefficient of bottom accumulation and its components are proposed to reliably determine the level and character of pollution. Chronic pollution of a number of freshwater bodies of the Russian Federation is assessed by data on the accumulation of pesticides, oil products, polycyclic aromatic hydrocarbons, and heavy metals in bottom deposits.     

The exceptional Oder flood in summer 1997 — distribution patterns of the oder discharge in the Pomeranian Bight

The exceptional Oder flood in summer 1997 was a unique event in order to investigate the impacts on and the consequences for the ecosystem of the Baltic Sea of about 6.5 km³ additional water loaded with nutrients and contaminants and discharged within only 5 weeks. About 15 institutions participated in this investigation in both the Szczecin Lagoon and the Pomeranian Bight. The Baltic Sea Research Institute Warnemünde studied the water and nutrient inflow, the spreading of the Oder discharge, and the impact of the discharge on the ecosystem. The main topic of the presented investigations is a detailed study of the spatial and temporal spreading of the extreme river discharge in the Pomeranian Bight and the southern Baltic Sea by satellite data, ship observations and continuous buoy measurements as well as numerical modelling. The meteorological conditions were characterized by mainly easterly winds which guided the outflowing riverine water along the German coast into the Arkona Sea. The spatial and temporal development of the distribution patterns of the Oder discharge was monitored by about 80 Sea Surface Temperature (SST) images of NOAA satellites. Shipborne measurements showed that the vertical extent of the Oder plume ranged between 5 and 7 metres. The concentrations of inorganic nutrients, except higher silicate, were comparable to typical winter/early spring values (seasonal maximum) in this region. The high dilution effect of the flood water reduced the concentration of contaminants and thus, prevented a direct negative impact of trace metals and chlorinated organic compounds on the marine environment. Coupled physical-biochemical modelling in combination with SST-images demonstrated the temporal development and satellite data in the visible spectral range delivered the maximum extent of discharged river water into the southern Arkona Sea where a further western transport was limited by the upwelling region off Hiddensee. Thus, all detected effects of the Oder flood were confined to the Pomeranian Bight and the southern Arkona Sea, without long-term consequences for the ecosystem.     

Modelling the uptake and release of carbon dioxide in the Baltic Sea surface water

We present and analyse a fully coupled physical–biogeochemical model of the uptake and release of carbon dioxide in the Baltic Sea. The modelling includes the interaction between physical (stratification, temperature, salinity, penetration of solar radiation, and ice), chemical (total alkalinity, pH, dissolved inorganic carbon, oxygen, and nutrients), and biological processes (plankton and dissolved organic carbon (DOC)). These processes have been built into an advanced process-oriented coupled basin ocean model that has been extensively explored and validated for the Baltic Sea.