Occurrence of perfluorinated organic acids in the North and Baltic Seas. Part 2: distribution in sediments

Purpose  

The distribution of polar perfluorinated compounds (PFCs) in sea water of the North and Baltic Seas has been described in part 1 of this study. In part 2, their occurrence in sediments is described in order to further investigate their distribution routes and possible sinks.     

Framing Environmental Risks in the Baltic Sea: A News Media Analysis

Scientific complexity and uncertainty is a key challenge for environmental risk governance and to understand how risks are framed and communicated is of utmost importance. The Baltic Sea ecosystem is stressed and exposed to different risks like eutrophication, overfishing, and hazardous chemicals. Based on an analysis of the Swedish newspaper Dagens Nyheter, this study discusses media representations of these risks. The results show that the reporting on the Baltic Sea has been fairly stable since the beginning of the 1990s. Many articles acknowledge several risks, but eutrophication receives the most attention and is also considered the biggest threat. Authorities, experts, organizations, and politicians are the dominating actors, while citizens and industry representatives are more or less invisible. Eutrophication is not framed in terms of uncertainty concerning the risk and consequences, but rather in terms of main causes.     

Environmental contaminants in four eider species from Alaska and arctic Russia

Population declines in four species of eider; common (Somateria mollissima), king (Somateria spectabilis), spectacled (Somateria fischeri) and Steller's (Polysticta stelleri), have raised concerns about exposure to contaminants. Livers and kidney tissues were collected from eiders in Alaska and Russia for organic and elemental analyses. Results showed that organochlorine and many elemental levels were below toxic thresholds; however, in many cases, cadmium, copper, lead and serenium appeared high relative to other waterfowl and may warrant concern. With the exception of lead, local anthropogenic sources for these elements are not known. Although adverse physiological responses have not been documented in eiders, these four elements cannot be ruled out as contaminants of potential concern for some eider species.     

The Potential of Current- and Wind-Driven Transport for Environmental Management of the Baltic Sea

The ever increasing impact of the marine industry and transport on vulnerable sea areas puts the marine environment under exceptional pressure and calls for inspired methods for mitigating the impact of the related risks. We describe a method for preventive reduction of remote environmental risks caused by the shipping and maritime industry that are transported by surface currents and wind impact to the coasts. This method is based on characterizing systematically the damaging potential of the offshore areas in terms of potential transport to vulnerable regions of an oil spill or other pollution that has occurred in a particular area. The resulting maps of probabilities of pollution to be transported to the nearshore and the time it takes for the pollution to reach the nearshore are used to design environmentally optimized fairways for the Gulf of Finland, Baltic Proper, and south-western Baltic Sea.     

The Baltic haline conveyor belt or the overturning circulation and mixing in the Baltic

A study of the water-mass circulation of the Baltic has been undertaken by making use of a three dimensional Baltic Sea model simulation. The saline water from the North Atlantic is traced through the Danish Sounds into the Baltic where it upwells and mixes with the fresh water inflow from the rivers forming a Baltic haline conveyor belt. The mixing of the saline water from the Great Belt and Oresund with the fresh water is investigated making use of overturning stream functions and Lagrangian trajectories. The overturning stream function was calculated as a function of four different vertical coordinates (depth, salinity, temperature and density) in order to understand the path of the water and where it upwells and mixes. Evidence of a fictive depth overturning cell similar to the Deacon Cell in the Southern Ocean was found in the Baltic proper corresponding to the gyre circulation around Gotland, which vanishes when the overturning stream function is projected on density layers. A Lagrangian trajectory study was performed to obtain a better view of the circulation and mixing of the saline and fresh waters. The residence time of the water masses in the Baltic is calculated to be 26-29 years and the Lagrangian dispersion reaches basin saturation after 5 years.     

Environmental problems of Canakkale City and solutions

Environmental problems are getting more serious in almost every region of Turkey. They occur for many reasons and take many forms. Canakkale City has potential for both domestic and international tourism, because of its rich historical past and natural and cultural resources. However, in common with other parts of the country, Canakkale faces environmental problems such as air pollution, water pollution, soil pollution, solid wastes, noise pollution, and negative effects on flora and fauna. The maintenance of historical and architectural texture, and the establishment of new settlement areas in suitable parts of the city, are not taken into consideration sufficiently when investments are made in both transportation and industrial areas. This research was conducted under three main headings: analysis, evaluation and synthesis. The aim was to make some recommendations dealing with the domestic problems, such as the improvement of the city as a contemporary settlement, the development of urban settlements and industrialisation, and the improvement of the lifestyle of the city residents.     

Estuarine circulation in the Taranto Seas

The Taranto basin is a shallow water marine system in the South of Italy characterized by the presence of a lagoon environment together with a semi-enclosed bay connected to the Ionian Sea. This marine system experienced over the last few decades strong biochemical pollution and environmental degradation, and it is considered a hotspot study site for economic, ecological and scientific reasons. The aim of this study was to examine, on an annual temporal scale and with high spatial resolution, the main hydrodynamical processes and transport scales of the system by means of a 3D finite element numerical model application, adopting the most realistic forcing available. The model allowed us to assess the role played by baroclinic terms in the basin circulation, describing its estuarine nature. In particular, the main features of water circulation, salinity and temperature distribution, water renewal time and bottom stress were investigated. Our results allowed us to equate this system dynamic to that of a weakly stratified estuary, identifying the main driving sources of this mechanism. The vertical stratification over the whole year was proved to be stable, leading to a dual circulation flowing out on the surface, mainly through Porta Napoli channel, and inflowing on the bottom mainly through Navigabile channel. This process was responsible also for the renewal time faster on the bottom of the Mar Piccolo basin than the surface. Due to the great importance of the Taranto basin for what concerns sediment pollution, also the effect of currents in terms of bottom stress was investigated, leading to the conclusion that only in the inlets area the values of bottom stress can be high enough to cause erosion.     

The Costs of Meeting the Environmental Objectives for the Baltic Sea: A Review of the Literature

The environmental targets of the recently agreed Baltic Sea Action Plan (BSAP) targets are likely associated with a considerable cost, which motivates a search for low-cost policies. The following review shows there is a substantial literature on cost-efficient nutrient reduction strategies, including suggestions regarding low-cost abatement, but actual policies at international and national scale tend to be considerably more expensive due to lack of instruments that ensure a cost-efficient allocation of abatement across countries and sectors. Economic research on the costs of reducing hazardous substances and oil spill damages in the Baltic Sea is not available, but lessons from the international literature suggest that resources could be used more efficiently if appropriate analysis is undertaken. Common to these pollution problems is the need to ensure that all countries in the region are provided with positive incentives to implement international agreements.     

Simulated distributions of Baltic Sea-ice in warming climate and consequences for the winter habitat of the Baltic ringed seal

Sea-ice in the Baltic Sea in present and future climates is investigated. The Rossby Centre Regional Atmosphere-Ocean model was used to perform a set of 30-year-long time slice experiments. For each of the two driving global models HadAM3H and ECHAM4/OPYC3, one control run (1961-1990) and two scenario runs (2071-2100) based upon the SRES A2 and B2 emission scenarios were conducted. The future sea-ice volume in the Baltic Sea is reduced by 83% on average. The Bothnian Sea, large areas of the Gulf of Finland and Gulf of Riga, and the outer parts of the southwestern archipelago of Finland will become ice-free in the mean. The presented scenarios are used to study the impact of climate change on the Baltic ringed seal (Phoca hispida botnica). Climate change seems to be a major threat to all southern populations. The only fairly good winter sea-ice habitat is found to be confined to the Bay of Bothnia.     

Reduction of Baltic Sea Nutrient Inputs and Allocation of Abatement Costs Within the Baltic Sea Catchment

The Baltic Sea Action Plan (BSAP) requires tools to simulate effects and costs of various nutrient abatement strategies. Hierarchically connected databases and models of the entire catchment have been created to allow decision makers to view scenarios via the decision support system NEST. Increased intensity in agriculture in transient countries would result in increased nutrient loads to the Baltic Sea, particularly from Poland, the Baltic States, and Russia. Nutrient retentions are high, which means that the nutrient reduction goals of 135 000 tons N and 15 000 tons P, as formulated in the BSAP from 2007, correspond to a reduction in nutrient loadings to watersheds by 675 000 tons N and 158 000 tons P. A cost-minimization model was used to allocate nutrient reductions to measures and countries where the costs for reducing loads are low. The minimum annual cost to meet BSAP basin targets is estimated to 4.7 billion €.     

Climate Warming and Pikeperch Year-Class Catches in the Baltic Sea

Climate change scenarios concerning the Baltic Sea predict increase in surface water temperatures. Pikeperch (Sander lucioperca (L.)) inhabits the coastal areas of the northern Baltic Sea and is an important fish species for the Finnish fisheries. The year-class strength of pikeperch varies strongly between years and significantly depends on water temperature. We aimed to study the effects of changing temperature conditions on pikeperch fisheries and distribution based on commercial catch data from the period 1980–2008 in the Finnish coastal areas of the Baltic Sea. The results indicated that warmer summers will produce stronger pikeperch year-classes that consequently contribute significantly to the future catches. The average temperature in June–July explained 40% of the variation in the year-class catches in the Gulf of Finland and 73% in July–August in the Archipelago Sea. During the study period, the distribution of pikeperch catches expanded toward north along the coasts of the Bothnian Sea.     

Arsenic in sediments from the southeastern Baltic Sea

Arsenic occurs as a persistent constituent in many of the chemical weapons dumped into the Baltic Sea; it can be used as an indicator of leakage and dispersal of released munitions to the marine environment. Total arsenic was analysed in sediment samples taken from the Lithuanian economic zone in the Baltic Sea, which included samples from the chemical munitions dumpsite in the Gotland Basin and national monitoring stations in the southeastern Baltic Sea. Arsenic concentrations in sediments ranged from 1.1 to 19.0 mg kg(-1), with an average of 3.4 mg kg(-1). Although there was evidence of slightly elevated arsenic content in sediments near the weapons dumpsite, arsenic concentrations were nevertheless quite low relative to other investigations in the Baltic and North Seas.     

Heavy metals in zooplankton from the Southern Baltic

Samples of zooplankton and suspended matter were collected using a Bongo net (0.33/0.50 mm mesh net), and Nucleopore filters, respectively, from the Southern Baltic off Poland. Major classes of zooplankton, and selected heavy metals (Fe, Co, Ni, Mn, Pb, Cd, Cu, Zn, Cr) were determined in the collected samples. Concentrations of heavy metals in zooplankton were corrected for metals contributed by particulate matter adhering to zooplankton organisms. Heavy metals levels measured in nearshore samples (Bay of Gdańsk, Pomeranian Bay) were higher than those in the samples from the open sea. The only exception was cadmium exhibiting larger concentrations in the offshore as compared to the nearshore samples (0.8 vs. 1.3 microg/g d.w.). This was attributed to decreased concentrations, of both dissolved and particulate cadmium, caused by algal bloom. Larger concentrations of heavy metals in the Bay of Gdańsk in comparison with the Pomeranian Bay (e.g. Cd-1.3 vs. 0.8 microg/g, Cu-20.5 vs. 8.3 microg/g, Pb-12.9 vs. 1.2 microg/g, Cr-12.4 vs. 1.4 microg/g) were attributed to the direct discharge of the Vistula river to the Bay of Gdańsk, while the Pomeranian Bay receives the Odra river runoff indirectly, via the Szczecin Lagoon. The nonlinear estimation of the data set was used to evaluate concentrations of heavy metals in Copepoda and Cladocera. Copepoda proved to be enriched with heavy metals in comparison with Cladocera.     

Denitrification in the river estuaries of the northern Baltic Sea

Estuaries have been suggested to have an important role in reducing the nitrogen load transported to the sea. We measured denitrification rates in six estuaries of the northern Baltic Sea. Four of them were river mouths in the Bothnian Bay (northern Gulf of Bothnia), and two were estuary bays, one in the Archipelago Sea (southern Gulf of Bothnia) and the other in the Gulf of Finland. Denitrification rates in the four river mouths varied between 330 and 905 micromol N m(-2) d(-1). The estuary bays at the Archipelago Sea and the Gulf of Bothnia had denitrification rates from 90 micromol N m(-2) d(-1) to 910 micromol N m(-2) d(-1) and from 230 micromol N m(-2) d(-1) to 320 micromol N m(-2) d(-1), respectively. Denitrification removed 3.6-9.0% of the total nitrogen loading in the river mouths and in the estuary bay in the Gulf of Finland, where the residence times were short. In the estuary bay with a long residence time, in the Archipelago Sea, up to 4.5% of nitrate loading and 19% of nitrogen loading were removed before entering the sea. According to our results, the sediments of the fast-flowing rivers and the estuary areas with short residence times have a limited capacity to reduce the nitrogen load to the Baltic Sea.     

Factors regulating the coastal nutrient filter in the Baltic Sea

Ambio - The coastal zone of the Baltic Sea is diverse with strong regional differences in the physico-chemical setting. This diversity is also reflected in the importance of different...     

Ecosystem consequences of cyanobacteria in the northern Baltic Sea

Cyanobacteria of the Baltic Sea have multiple effects on organisms that influence the food chain dynamics on several trophic levels. Cyanobacteria contain several bioactive compounds, such as alkaloids, peptides, and lipopolysaccharides. A group of nonribosomally produced oligopeptides, namely microcystins and nodularin, are tumor promoters and cause oxidative stress in the affected cells. Zooplankton graze on cyanobacteria, and when ingested, the hepatotoxins (nodularin) decrease the egg production of, for example, copepods. However, the observed effects are very variable, because many crustaceans are tolerant to nodularin and because cyanobacteria may complement the diet of grazers in small amounts. Cyanobacterial toxins are transferred through the food web from one trophic level to another. The transfer rate is relatively low in the pelagic food web, but reduced feeding and growth rates of fish larvae have been observed. In the benthic food web, especially in blue mussels, nodularin concentrations are high, and benthic feeding juvenile flounders have been observed to disappear from bloom areas. In the littoral ecosystem, gammarids have shown increased mortality and weakening of reproductive success under cyanobacterial exposure. In contrast, mysid shrimps seem to be tolerant to cyanobacterial exposure. In fish larvae, detoxication of nodularin poses a metabolic cost that is reflected as decreased growth and condition, which may increase their susceptibility to predation. Cyanobacterial filaments and aggregates also interfere with both hydromechanical and visual feeding of planktivores. The feeding appendages of mysid shrimps may clog, and the filaments interfere with prey detection of pike larvae. On the other hand, a cyanobacterial bloom may provide a refuge for both zooplankton and small fish. As the decaying bloom also provides an ample source of organic carbon and nutrients for the organisms of the microbial loop, the zooplankton species capable of selective feeding may thrive in bloom conditions. Cyanobacteria also compete for nutrients with other primary producers and change the nitrogen (N): phosphorus (P) balance of their environment by their N-fixation. Further, the bioactive compounds of cyanobacteria directly influence other primary producers, favoring cyanobacteria, chlorophytes, dinoflagellates, and nanoflagellates and inhibiting cryptophytes. As the selective grazers also shift the grazing pressure on other species than cyanobacteria, changes in the structure and functioning of the Baltic Sea communities and ecosystems are likely to occur during the cyanobacterial bloom season.     

Cyclic volatile methylsiloxanes in fish from the Baltic Sea

Laboratory studies suggest that the cyclic volatile methylsiloxanes (cVMS) octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) will persist in the aquatic environment and bioaccumulate in fish. Here these cVMS were measured in herring collected in the Swedish waters of the Baltic Sea and the North Sea and in grey seals from the Baltic Proper. D4, D5, and D6 were present in herring muscle at concentrations around 10, 200, and 40 ng g⁻¹ lipid weight, respectively. The ratio of these concentrations was similar to the relative magnitude of estimated emissions to water, suggesting that the efficiency of overall transfer through the environment and food web was similar (within a factor 2–3) for the three chemicals. The concentrations of D5 and D6 were similar in herring caught in the highly populated Baltic Proper and in the less populated Bothnian Sea and Bothnian Bay. The D4 concentrations were lower at the most remote northern station, suggesting that D4 is less persistent than D5 and D6. Herring from the North Sea had lower levels of all three chemicals. The concentrations of D4, D5 and D6 in grey seal blubber were lower than the lipid normalized concentrations in herring, indicating that they do not biomagnify in grey seals.     

The relationship between metal concentrations and phenotypes in the Baltic clam Macoma balthica (L.) from the Gulf of Gdansk, southern Baltic

Soft tissue accumulated concentrations of nine metals (V, As, Se, Ag, Cd, Pb, Mn, Cu and Zn) were studied in two main phenotypes (1) according to external shell colour (white and pink), and (2) according to shell shape (shell with a rounded posterior end--"regular" and with an elongate posterior end and a notable flexure--"irregular") of the Baltic clam Macoma balthica from southern Baltic Sea off Poland. No differences in metal concentrations were observed between colour-based phenotypes. By contrast, "irregular" clams exhibited generally higher concentrations of all elements in their tissues than "regular" bivalves. This finding provides the first reference on a potential linkage of shell deformation with tissue metal concentrations within one entire population of clams living in the same habitat. Different ability of metal handling in the shape-based phenotypes is presumably related to different physiological capacity of the bivalves induced by the selection effect of specific environmental conditions. It is suggested that unfavourable conditions in deep waters of the Gulf of Gdansk (e.g. hypoxia/anoxia, hydrogen sulphide, elevated bioavailability of metals) induces, in a certain part of the population, morphological deformation of shell (thereby leading to irregular shape) and in parallel physiological adaptations which result in greater sensitivity to trace metals of "irregular" clams. This hypothesis however, requires further investigation with special focus on genetic divergences between phenotypes because till now we cannot exclude the co-occurrence of two types (semi-species) of clams in the Gulf: an Atlantic type and a Baltic type. Genetic analysis with a use of DALP technique revealed strong intrapopulational polymorphism but no fingerprints or intraspecific polymorphism characterising any of the phenotypes considered (both colour- and shape-based). Since eight polymorphic loci were clearly identified further studies of population genetic structure hold optimistic promise.     

PCDD/Fs and PCBs in Baltic herring during the 1990s

Baltic herring samples caught from the Baltic Sea during the spring periods of 1993-1994 and 1999 were analysed for polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), and polychlorinated biphenyls (PCB). For analyses, 1570 individual herring were combined to 120 pools. Correlations between concentrations of congeners 1,2,3,7,8-PeCDD, 1,2,3,7,8-PeCDF, 2,3,4,7,8-PeCDF, and 2,3,4,6,7,8-HxCDF, and age of herring were the strongest (r>0.8) followed by correlations between PCB congeners PCB 105, 118, 126, 156, 169 and 180 (r>0.7), and age of herring. Due to higher fat percentage in herring in the Gulf of Bothnia the concentrations of PCDD/Fs and PCBs on fresh weight (fw) basis were higher than in herring in the Gulf of Finland. The concentrations of WHO(PCDD/F)-TEQs ranged from 1 to 27 pg/g fw, depending on the age and catchment area of herring, and concentrations of WHO(PCB)-TEQs reached 32 pg/g fw. Between the two studied time points no clear downward trend in concentrations was observed.     

Sorption and predicted mobility of herbicides in Baltic soils

This study was undertaken to determine sorption coefficients of eight herbicides (alachlor, amitrole, atrazine, simazine, dicamba, imazamox, imazethapyr, and pendimethalin) to seven agricultural soils from sites throughout Lithuania. The measured sorption coefficients were used to predict the susceptibility of these herbicides to leach to groundwater. Soil-water partitioning coefficients were measured in batch equilibrium studies using radiolabeled herbicides. In most soils, sorption followed the general trend pendimethalin > alachlor > atrazine～ amitrole～ simazine > imazethapyr > imazamox > dicamba, consistent with the trends in hydrophobicity (log K_ow) except in the case of amitrole. For several herbicides, sorption coefficients and calculated retardation factors were lowest (predicted to be most susceptible to leaching) in a soil of intermediate organic carbon content and sand content. Calculated herbicide retardation factors were high for soils with high organic carbon contents. Estimated leaching times under saturated conditions, assuming no herbicide degradation and no preferential water flow, were more strongly affected by soil textural effects on predicted water flow than by herbicide sorption effects. All herbicides were predicted to be slowest to leach in soils with high clay and low sand contents, and fastest to leach in soils with high sand content and low organic matter content. Herbicide management is important to the continued increase in agricultural production and profitability in the Baltic region, and these results will be useful in identifying critical areas requiring improved management practices to reduce water contamination by pesticides.