Biomarkers of environmental contaminants in the coastal waters of Estonia (Baltic Sea): effects on eelpouts (Zoarces viviparus)

The eastern Baltic Sea near the Estonian coast is heavily navigated by numerous cargo ships and oil tankers. Hundreds of accidents and oil spills happen yearly in this area. Yet, there is a lack of data concerning the distribution and effects of the environmental contaminants, especially polycyclic aromatic hydrocarbons (PAHs). Different parts of the Baltic Sea have different levels of contamination; therefore a wide range of monitoring stations in coastal areas in the Gulf of Finland and Gulf of Riga were chosen. The aim of the present research was to document the responses of chosen biomarkers of environmental contaminants in different unstudied areas of the Estonian coastal sea. During 2009 and 2010 we measured PAH metabolites, EROD activities, geno- and cytotoxicity, histology, parasites and other biomarkers from the eelpout (Zoarces viviparus), a resident benthic fish species. The results showed that fish from the Gulf of Riga emitted lower levels of fluorescence in fixed wavelength analyses (representing equivalents of PAH metabolites in bile and urine), and consistently, showed less geno- and cytotoxicity and parasite infection, higher liver somatic index (LSI) and a higher condition factor (CF) than fish inhabiting areas close to the Baltic proper and in the Gulf of Finland. The results point to the effect of long-range contaminant transportation, whether atmospheric or hydrodynamic, and also to the intensive shipping activity in international routes. This study fills the gap of knowledge in this area that has persisted until now. Nevertheless, more studies in this area on the different groups of contaminants are necessary, to specify the factors that are responsible for observed biological effects.     

Comparison of trace metal bioavailabilities in European coastal waters using mussels from Mytilus edulis complex as biomonitors

Mussels from Mytilus edulis complex were used as biomonitors of the trace metals Fe, Mn, Pb, Zn, and Cu at 17 sampling sites to assess the relative bioavailability of metals in coastal waters around the European continent. Because accumulated metal concentrations in a given area can differ temporally, data were corrected for the effect of season before large-scale spatial comparisons were made. The highest concentration of Fe was noted in the North Sea and of Mn in the Baltic. Increased tissue concentrations of Pb were recorded in the mussels from the Bay of Biscay and the Baltic Sea. Low concentrations of metals were determined in the mussels from the Mediterranean Sea and the Northern Baltic. Relatively low geographic variations of Cu and Zn indicate that mussels are able to partially regulate accumulated body concentrations, which means Cu and Zn are, to some extent, independent of environmental concentrations.     

Estimation of riverine loads of nitrogen and phosphorus to the Baltic Sea, 1970–1993

This article presents the results of the first critical examination of time series of riverine nutrient-load data for the entire Baltic Sea drainage area. Water quality data collected by or for the different national environmental agencies were compiled and analysed statistically to identify and remove inconsistent or obviously incorrect observations. Moreover, sampling tours were undertaken to acquire additional information about the present nutrient concentrations in the largest rivers in the study area. Gaps in the time series of approved data were then filled in by employing statistical interpolation and extrapolation methods. Thereafter, the concentration and runoff data were combined to obtain estimates of monthly nutrient loads for the time period 1970–93. The results of the calculations showed that although there had been substantial changes in land use, atmospheric deposition and wastewater treatment in many parts of the study area, the total riverine loads of nitrogen (N) and phosphorus (P) to the Baltic Sea have been fairly constant since 1980, and most likely also since 1970. Moreover, the interannual variation was clearly correlated to the runoff. The mean annual loads for the time period 1980–93 were found to be about 825 000 tonnes N and 41 000 tonnes P, respectively. This implies that (i) several other investigators have strongly underestimated the riverine loads of nutrients, especially the nitrogen, and that (ii) the riverine loads by far exceed the input to the Baltic Sea from other sources, {i.e.} atmospheric deposition, direct emissions from cities and industries along the Baltic Sea coast and nitrogen fixation by marine algae.     

Scaling the trophic index (TRIX) in oligotrophic marine environments

The TRIX index used for the assessment of trophic status of coastal waters has been applied in many European seas (Adriatic, Tyrrhenian, Baltic, Black Sea, and North Sea). However, all these waters are characterized by high nutrient levels and phytoplankton biomass; index calibration based on systems that are principally eutrophic may introduce bias to the index scaling. In the present work the TRIX trophic index is evaluated using three standard sets of data characterizing oligotrophy, mesotrophy, and eutrophication in the Aegean (Eastern Mediterranean) marine environment. A natural eutrophication scale based on the TRIX index that is suitable to characterize trophic conditions in oligotrophic Mediterranean water bodies is proposed. This scale was developed into a five-grade water quality classification scheme describing different levels of eutrophication. It is questionable whether this index can form a universal index of eutrophication or the scaling of TRIX should be region specific.     

Optimum spatial analysis of monitoring data on temperature,salinity and nutrient concentrations in the Baltic Proper

In spite of the large number of monitoring data on hydrography and nutrients collected from the Baltic Sea, it is still difficult to describe large-scale distribution patterns of these variables. We therefore suggest a stochastic approach that allows the spatial reconstruction of the fields for the entire sea. The Baltic Sea monitoring data on temperature, salinity and nutrient concentrations from the years 1972–1991 are each divided into twenty data sets: five regions, times four seasons. The spatial regions are the Southern Baltic Proper, the Northern and Central Baltic Proper, both above and below halocline, and the region of the Gulf of Finland and the Gulf of Riga. The four seasons consist of three-month periods: January–March (winter), April–June (spring), July–September (summer) and October–December (fall). Each monthly subset of a regional and seasonal data set is modeled as a sample out of a monthly realization of a random field. The data sets are decomposed into mean and fluctuational components. The mean is determined as an average over the space cells with dimensions of standard sampling depth intervals vertically, 10 in meridional (south-north), 20 in zonal (west-east) directions and over five-year periods in time. The fluctuation fields are considered second-order stationary, homogeneous and horizontally isotropic. Estimated horizontal (surface) and vertical (depth) components of the spatial correlations are approximated by Gaussian functions. The correlation scales for the fields of the Baltic Proper are mostly larger than 100 nautical miles horizontally and 40 m vertically and their dependence on the sea region or season is relatively weak. The most probable noise-to-signal ratio values of the data lie in the interval 0.6 to 1.2. The estimated correlation functions and noise-to-signal ratios allow the optimum analysis technique to assess the correctness of each datum of a sample on the background of the field statistics. The outliers of each monthly sample are excluded from the analysis. The observed fluctuations are interpolated into locations with missing data by an optimum interpolation procedure. The discrete cell-and-five-year mean values are interpolated by a different, piece-wise linear technique. Since the data number for the mean interpolation considerably exceeds the data number for the fluctuation interpolation, the interpolation errors for the mean are assumed negligible compared to the interpolation errors for the fluctuation. The sums of the mean and fluctuation, interpolated into the withheld observation points, are compared to the actually observed values and to some other linear interpolation estimates. In all test cases the optimum interpolation procedure performs the best.     

New insight into defining the lakes of the southern Baltic coastal zone

There exist many classification systems of hydrographic entities such as lakes found along the coastlines of seas and oceans. Each system has its advantages and can be used with some success in the area of protection and management. This paper aims to evaluate whether the studied lakes are only coastal lakes or rather bodies of water of a completely different hydrological and hydrochemical nature. The attempt to create a new classification system of Polish coastal lakes is related to the incompleteness of lake information in existing classifications. Thus far, the most frequently used are classifications based solely on lake basin morphogenesis or hydrochemical properties. The classifications in this paper are based not only on the magnitude of lake water salinity or hydrochemical analysis but also on isolation from the Baltic Sea and other sources of water. The key element of the new classification system for coastal bodies of water is a departure from the existing system used to classify lakes in Poland and the introduction of ion-“tracking” methods designed to identify anion and cation distributions in each body of water of interest. As a result of the work, a new classification of lakes of the southern Baltic Sea coastal zone was created. Featured objects such as permanently brackish lakes, brackish lakes that may turn into freshwater lakes from time to time, freshwater lakes that may turn into brackish lakes from time to time, freshwater lakes that experience low levels of salinity due to specific incidents, and permanently freshwater lakes. The authors have adopted 200 mg Cl^? dm^?3 as a maximum value of lake water salinity. There are many conditions that determine the membership of a lake to a particular group, but the most important is the isolation lakes from the Baltic Sea. Changing a condition may change the classification of a lake.     

Atrazine and Alachlor Inputs to Surface and Ground Waters in Irrigated Corn Cultivation Areas of Castilla-Leon Region, Spain

The inputs of atrazine and alachlor herbicides to surface and ground waters from irrigated areas dedicated to corn cultivation in the Castilla-León (C-L) region (Spain) as related to the application of both herbicides were studied. Enzyme-linked immunosorbent assays (ELISA) were used for monitoring the atrazine and alachlor concentrations in 98 water samples taken from these areas. Seventy-nine of the samples were of ground waters and 19 were of surface waters. The concentration ranges of the herbicides detected in the study period (October 1997–October 1998) were 0.04–25.3 g L^–1 in the surface waters and 0.04–3.45 g L^–1 in the ground waters for atrazine, and 0.06–31.9 g L^–1 in the surface waters and 0.05–4.85 g L^–1 in the ground waters in the case of alachlor. The highly significant correlation observed between the concentrations of both herbicides in the surface waters (r = 0.89, p < 0.001) pointed to a parallel transport of atrazine and alachlor to these waters. A study was made of the temporal evolution of the concentrations of both herbicides, and it was found a maximum recharge of atrazine in the ground waters for April 1998 and of alachlor in October 1997 and October 1998. The temporal evolution of the concentrations of both herbicides in surface waters was parallel. The highly significant correlations observed between atrazine concentrations determined by ELISA and by HPLC (r = 0.92, p < 0.001) and between alachlor concentrations also determined by both methods (r = 0.96, p < 0.001) confirmed the usefulness of ELISA for monitoring both herbicides in an elevated number of samples. Using HPLC, the presence in some waters of the alachlor ethanesulfonate (ESA) metabolite was found at a concentration range of 0.52–4.01 g L^–1. However the interference of ESA in the determination of alachlor by ELISA was negligible. The inputs of atrazine and alachlor to waters found in this study, especially the inputs to ground waters, could pose a risk for human health considering that some waters, though sporadically, are even used for human consumption.     

Biological effects monitoring of the North Sea employing fish embryological data

Using the reproductive capacity of fish appears to be a suitable approach for risk assessment in the aquatic environment since fish are a typical representative thereof and in addition they are of considerable societal value. Generally the early embryonic stages are considered to be one of the most sensitive parts of a fish's life cycle. A method has been developed to use the state of health of live, naturally spawned fish embryos from plankton samples for biological effects monitoring. During the years 1985–1987 in the southern North Sea and in 1991–1992 in the whole of the North Sea fish eggs were sampled from surface waters and examined for developmental abnormalities. Elevated embryo malformation rates were detected in the plume of the major rivers Elbe and Rhine as well as along the eastern coast of England. Occurring malformations are thought to be pollution-related and may be used to define areas of environmental deterioration. The method is discussed in view of its suitability for biological effects monitoring using malformations in fish embryos as biomarkers.     

Dinoflagellate bloom in tropical fish ponds of coastal waters of the South China Sea

Red tide of dinoflagellate was observed in brackish water fish ponds of Terengganu along the coast of the South China Sea during the study period between January 1992 to December 1992. The nearby coastal moat water facing the South China Sea is the source of water for fish pond culture activities of sea bass during the study period. An examination of water quality in fish ponds during the study period indicated that both the organic nutrients were high during the pre-wet monsoon period. The source of the nutrients in coastal water was believed to be derived from the agro-based industrial effluents, fertilizers from paddy fields and untreated animal wastes. This coincided with the peak production of dinoflagellate in the water column in October 1992. The cell count ranges from 8.3 to 60.4×10.4×10⁴/l during the bloom peak period and the bloom species were compared entirely of non-toxic dinoflagellates with Protoperidinium quinquecorne occurring >90% of the total cell count. However, both cultured and indigenous fish species were seen to suffer from oxygen asphyxiation (suffocation due to lack of oxygen). The bloom lasted for a short period (4–5 days) with a massive cell collapse from subsurface to bottom water on the sixth day. The productivity values ranged from 5–25 C g/ l / h with a subsurface maximum value in October 1992. Two species of Ciliophora, Tintinnopsis and Favella, were observed to graze on these dinoflagellates at the end of the bloom period.     

Impact of emission from oil shale fueled power plants on the growth and foliar elemental concentrations of Scots pine in Estonia

To study the impact of air pollution on the growth and elemental composition of conifers, 5 sample plots wereestablished at different distances and directions from theEstonian Power Plant (Northeast Estonia) in 1999–2000. Theselected stands were 75–80(85)-yr-old parts (0.05 ha) of(Oxalis)-Myrtillus site type forest of 0.7–0.8density. The soils of all sample plots were Gleyic Podzols(Lkg) on sands. The several times higher Ca concentration inthe humus horizon of the sample plot NE from the Estonian PPis caused by the prevailing westerly and southerly winds whichcarry more pollutants NE from the power plant than to SSW. Toascertain the effect of power plants on the growth of Scotspine (Pinus sylvestris L.), the length growth of theneedles and shoots formed in 1997–2000, dry weight of 100needles, and density of needles on the shoots were measured.As compared to the control, the strongest inhibition of growthwas revealed in the sample plots situated 22 km north-east and17 km south-west from the Estonian Power Plant. As compared tocontrol, the needles of trees growing on sample plots closerto the power plant showed higher contents of Ca, S and Zn. Thecontent of Mg in needles increased with distance from thepollution source. Current year needles had higher contents ofCu and Zn than older needles. Today the amounts of fly ashemitted from Narva power plants are fallen. Long-term fly ashemission has caused changes in the measurements ofmorphological parameters and chemical composition of needles.     

Radioactivity, Physical and Chemical Parameters of Underground and Surface Waters in Qua Iboe River Estuary, Nigeria

Radioactivity, physical and chemical parameters of underground boreholes and surface waters in the region of Qua Iboe River Estuary involved in oil production activities were measured. The physical and chemical parameters measured included pH, temperature, turbidity, and concentrations of total dissolved and suspended solids, dissolved oxygen, chemical and biochemical oxygen demand, oils and grease, salinity, hardness (carbonates and bicarbonates), chlorine, sulphide, and metal ions. The work reveals that the radioactivity, physical and chemical parameters determined for both the underground and surface waters are safely below the international permissible limits except that of carbonate (68.6 mg/d – 228.7 mg/l) and bicarbonate (22.9 mg/l – 76.3mg/l) which renders both sources of water hard. The exceedingly high concentration range of hydrogen sulphide (40 mg/l–440 mg/l) in both sources is also beyond the international limit of 0.05mg/l. The ammonium ion concentration (1.40–2.80mg/l) was determined to be slightly higher in both the underground and surface waters than the international limit of 0.5mg/l.     

Methane in ocean waters: Concentration and carbon isotope variability at East Pacific Rise and in the Arabian Sea

Methane concentrations and stable carbon isotope ratios of water samples from the East Pacific Rise (EPR) at 21°S and the Arabian Sea (24°N, 65°E) have been determined. EPR surface water is in equilibrium (ca. 50 nl/L and –50<¹³CH₄<–46) with atmospheric methane. Deep background water has the signature of the remaining fraction of atmospheric methane partially oxidized in the water column by bacteria. Bottom near, hydrothermally influenced vent methane (>100nl/L and –30<¹³CH₄<–22) is detectable only close to the seep site. There is no input of hydrothermal methane into the atmosphere. EPR water is considered to be rather a sink than a source of atmospheric methane. Surface waters of the Arabian Sea are enriched in methane relative to the atmosphere (source for atmospheric methane). Carbon isotope ratios point to a bacterial origin of methane (¹³CH₄<–55) that is generated in the surface waters. Concentration changes and variations of carbon isotope ratios also suggest that methane seeping from the sea floor sediments of the Arabian Sea is oxidized by bacterial activity and does not reach the atmosphere.     

渤海环流对近岸海域无机氮分布特征的影响

基于2017年渤海近岸海域无机氮监测数据和HYCOM数值模拟结果,分析了渤海环流对无机氮污染分布特征的影响,结果表明渤海无机氮的空间分布特征与其环流结构密切相关:受渤海环流的影响,在春、夏、秋季,无机氮含量高值区呈现不同的强度和范围;在辽东湾,与春季相比,夏季环流结构与春季相反、速度大于春季,盘锦、营口近岸海域夏季无机氮污染范围缩小、含量降低,在锦州近岸海域亦出现高值;在渤海湾、莱州湾,与春季相比,夏季和秋季无机氮含量高值区范围缩小,无机氮含量等值线均随环流向高值中心扩展。     

A proposal for a long-term baseline phytobenthos monitoring programme for the Finnish Baltic coastal waters: monitoring submerged rocky shore vegetation

Several local surveys on the submerged vegetation have been conducted in past decades along the Finnish Baltic coastal areas. Surveys have been carried out by using various methods,which make the temporal comparisons of the results difficult.The need of a joint programme for coastal phytobenthic monitoringis emphasised by the Nordic Council of Ministers and HELCOM. TheFinnish coastal phytobenthic monitoring programme complements theBaltic HELCOM monitoring programme (COMBINE). It is primarily designed to reveal the effects of eutrophication. The programmeincludes general principles for selection of monitoring areas aswell as a proposal for monitored habitats, communities and species. The need of evaluated and tested field methods, datacollecting, interpretation and data storage are addressed in theQuality Assurance part. The cost-efficiency is secured by integrating the phytobenthos programme with the coastal water monitoring for obtaining the supporting data such like salinity,temperature and nutrients. In the design of the monitoring programme a special interest is paid on areas with high protection values such as Natura 2000 or HELCOM's BSPA (Baltic Sea Protected Areas) or on aspects that would support the implementation of the EU Water Framework Directive.     

Phytoplankton distribution across the southeast Adriatic continental and shelf slope to the west of Albania (spring aspect)

We present the first insight to the oceanography of the southeastern Adriatic Sea, where coastal water influenced by Albanian rivers comes into contact with the inflowing oligotrophic Eastern Adriatic Current (Ionian Surface Water and Levantine Intermediate Water). A distinct plankton distribution was observed on each side of the shelf break hydrographic boundary in May 2009, during gradual warming of the surface waters. The prochlorophytes accumulated along the nutricline above the shelf and continental slope. The phosphorus limited inshore waters were dominated by a small diatom Chaetoceros circinalis, dinoflagellates, cryptophytes, autotrophic picoplankton, and heterotrophic nanoplankton. The offshore surface layer was characterized by bigger nanoplankton (coccolithophorids, green flagellates). Low nutrient concentrations influence relatively low productivity not only above the Albanian shelf but also further to the north along the Montenegrine and Croatian coastal Adriatic Sea.     

近岸海域水质自动监测规范化研究

为规范近岸海域水质自动监测,基于近岸海域水质监测要求和质控要求、近岸海域水质自动监测系统特点和近岸海域水质自动监测运行的经验,开展了近岸海域水质自动监测规范化研究,编制了《近岸海域水质自动监测技术规范》(HJ 731—2014),规范了近岸海域水质自动监测系统建设、设备选择、系统验收、日常管理、维护和校准、质量保证和质量控制、数据有效性和上报、监测报告等方面的工作。有利于在标准方法基础上,使中国近岸海域水质自动监测系统的监测数据准确、可靠、可比,有利于近岸海域水质自动监测系统在日常监测中更好地发挥作用。     

Heavy Metal Monitoring Using Bivalved Shellfish from Zhejiang Coastal Waters, East China Sea

The interest of culturing bivalved shellfish (including mussels, clams, oysters etc.), has increased in recent years, but the consumption has been hampered both by high levels of heavy metals and toxic algae. The levels of heavy metals (Hg, Cd, Pb, Zn, Cu and As) were determined in soft tissues of different shellfish from Zhejiang coastal waters, East China Sea. The average concentrations of the heavy metals analyzed exhibited the following decreasing order: Zn > Cu > As > Cd > Pb > Hg. Comparison of heavy metals concentrations among species indicated that Bivalves clearly have significant potential as useful bioindicators; however, the results indicated that no one species is universally suitable, as is true of any organism used in these studies. The distribution of the metals was also investigated along the Zhejiang coast, which the results showed the mean concentration of Hg and Cd detected did not vary greatly and presented a similar spatial pattern at different sampling stations, the concentrations of Zn and Pb were highly variable at different sampling sites. The amounts of heavy metals in soft tissue of shellfish were also compared with those from the related species from other seas in China and world marine waters. The results suggested that the coastal area might be considered relatively unpolluted with heavy metals and the concentrations of metals in shellfish also below the seafood safety limits for human consumption.     

Biomass and number of fish impinged at a nuclear power plant by the Baltic Sea

The main aim of this study was to investigate the number and biomass of impinged fish at Forsmark Nuclear Power Plant in Sweden, located on the coast of the Baltic Sea. Of particular interest was the number of impinged individuals of the critically endangered European eel (Anguilla anguilla) which is regularly caught in the cooling system. Another aim was to determine the comparability of the results from Forsmark and results from impingement studies in other types of waters. Cross-systems studies make it possible to (1) estimate fish loss at plants where fish is not counted, and (2) to predict changes in fish loss from changes in electricity production or cooling water use. In 2010, 31,300,000 fish with a total biomass of 62,600 kg were impinged at Forsmark. In 2011, 27,300,000 fish weighing 38,500 kg were impinged. The maximum peak in total fish number and biomass occurred in spring. The most critical period for herring was in late summer and early autumn. Regarding eel, the largest impingement losses were recorded in November. The number of fish agreed with earlier established quantities of impinged fish in both freshwater and marine ecosystems. The study also estimated that 1,300 critically endangered eels could survive at Forsmark each year if a fish return system would be constructed to allow the passage of fish from the plant back to the Baltic Sea.     

Identification of Characteristic Regions and Representative Stations: A Study of Water Quality Variables in the Kattegat

Gradients in nutrient distributions and the effects of eutrophication are common features in most coastal marine areas. These structures occur in aquatic systems due to spatial differences in hydrography, nutrient loading and key biogeochemical processes. Two statistical methods, cluster analysis and probability mapping, have been used in the present study to determine characteristics and patterns in water quality variables. Combined, these two methods provide a useful tool to statistically determine spatial homogeneity and representativity of areas and stations. A case study is presented here in which water quality variables (salinity, dissolved inorganic nitrogen, dissolved inorganic phosphorus and chlorophyll) in surface waters of the Kattegat are analysed for the time period 1993-1997. It was found that morphology, the proximity to sources of nutrient loading from land, nutrient uptake and the infrequent water exchange between the Baltic Sea in the south and the Skagerrak in the north all contribute to create distinct regions of water quality. Regions with concentrations significantly different from the overall mean are identified. In addition to identification of regions with similar characteristics, representative stations (as well as not representative stations) for the respective regions were made. This type of information can be used to design new or revise old monitoring programs.     

Organochlorines and selenium in California night-heron and egret eggs

Exceptionally high concentrations of DDE were found in black-crowned night-heron (Nycticorax nycticorax) (geometric mean 8.62 g g^–1 wet wt.) and great egret (Casmerodius albus) (24.0 g g^–1) eggs collected from the Imperial Valley (Salton Sea), California in 1985. DDE concentrations in 14 of the 87 (16%) randomly selected night-heron eggs from six colonies (two in San Francisco Bay, three in the San Joaquin Valley, and one at Salton Sea) were higher than those associated with reduced reproductive success of night-herons (8 g g^–1). In addition, mean shell thickness of night-heron eggs collected from the San Joaquin Valley and from San Francisco Bay during 1982–1984 was significantly less than pre-DDT thickness and was negatively correlated (r=–0.50, n=75, P<0.0001) with DDE concentration. Mean selenium concentration in night-heron eggs from Salton Sea (1.10 g g^–1) was significantly higher than in eggs from three locations in the San Joaquin Valley, and in egret eggs from Salton Sea.