北欧湖泊鱼类状况调查:酸化、富营养化和放养活动对现有鱼类品种组成的影响

1995～1997年间对挪威、瑞典和芬兰的3821个湖泊的鱼类种群状况做了评估.采用分层随机抽样从芬诺斯堪的亚(芬兰、挪威、瑞典、丹麦的总称)所有面积≥0.04km2的126482个湖泊中选择调查湖泊.分析了湖泊的水化学,湖内鱼类状况则从邮件调查问卷中获得.鱼类种群损失发生最为频繁的地区在挪威南部酸化最严重的地区,而在芬诺斯堪的亚东部最少.根据调查问卷,鳟(Salmotrutta)、拟鲤(Rutilus rutilus)、北极红点鲑(Salvelinus alpinus)和鲈鱼(Percafluviatilis)鱼群损失的数量估计超过10000条.这些品种的鱼群潜在地受低碱性湖水影响的数量超过11000条.大约有3300个湖泊显示出总磷高于25μg/L,品种以鲤科鱼为主,这在芬诺斯堪的亚东部、芬兰西南最为明显.这次调查并未显示出鱼类品种由于富营养化而灭绝.1/3的湖泊人工放养了至少一个新的鱼类品种,最常放养的品种有鳟、白鲑(Coregonus lavaretus s.1.)、北极红点鲑、虹鳟(Oncorhynchusmykiss)、梭鲈(Stizostedion lucioperca)、茴鱼(Thymallus thymallus)、狗鱼(Esox lucius)、欧鳊(Abramis brama)、丁 (Tinca tinca)和欧 (Phoxinus phoxinus).在芬诺斯堪的亚湖泊,这些品种的人工放养量估计超过52000群.因此,北欧湖泊现有鱼类品种的数量最近受放养的影响超过了因环境变化如酸化等而损失造成的影响.     

Changes in the heavy metal and nutrient contents of dried feather mosses during long-term storage

This study measured heavy metal and nutrient concentrations of two feather mosses during the periods of dry storage. Samples (Hylocomium splendens, Pleurozium schreberi) were collected in the nationwide moss surveys carried out on the permanent sample plots of the 8th Finnish National Forest Inventory in 1985–86, 1990, 1995 and 2000. A small amount of each moss sample was analyzed soon after collection, and the remainder was dried and stored at the Paljakka environmental specimen bank (ESB). The 108 stored samples from 27 plots were reanalyzed in 2008. Concentrations of heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, Zn) and nutrients (Ca, K, Mg, P) were determined and compared for each survey year. Overall, Fe, Pb and Cr concentrations decreased, and Cu concentrations increased significantly during storage. The greatest decrease was observed in samples from plots where their initial concentrations were the highest. Changes in the concentrations of Cd, Ni and Zn were less pronounced. The loss of heavy metals is likely due to drying when cell membranes rupture and some of the surface material is lost. K, P and, to some extent, Mg concentrations increased during storage, whereas Ca did not change significantly. Nutrient increase is probably due to their movement from older to younger growths during the initial phase of drying. Ca is mostly bound to cell walls and is not easily released. Results emphasize the importance of establishing the intended use of a stored moss prior to sampling, in order to select and optimize an appropriate storage technique.     

Identification of structural breaks in the forest product markets: how sensitive are to changes in the Nordic region?

Forests play a fundamental role in the global carbon cycle and can be managed to mitigate greenhouse gas emissions and conserve or sequester carbon. Global policy and environmental changes can affect regional consumption of forest products, as well as inter-regional trade of forest goods and services. This study analyzes global and regional change impacts on the production, consumption and trade of forest products in two Nordic countries, Finland and Sweden. Annual data on removal and trade (1964–2012) for roundwood and sawnwood is used to identify structural breaks based on Chow tests. According to the analysis, the time period is divided into two periods: t1 (1964–1980) and t2 (1981–2012). In the first period, breaks occurred in 1975 and 1976 in the Finnish model and no break is found in the Swedish model. In the second period, we identify breaks in 1991 and 1992 for the Finnish model and in 2004, 2005 and 2006 for the Swedish model. Although our findings have broad empirical support, we do not identify any specific incident as a direct cause of the changes in the consumption and trade patterns of the two types of wood in these countries. The models and analysis presented here can serve as methodological tools for policymakers to better understand the effects of structural changes in the production of forest goods and services in the Nordic region and globally.     

A decision framework for possible remediation of contaminated sediments in the River Kymijoki, Finland

Background, aim, and scope  The paper describes the spatial contamination of the River Kymijoki, South-Eastern Finland, and the coastal region of the Gulf of Finland with PCDD/Fs and mercury. The findings of ecotoxicologial and human health studies are also reported, including environmental and human risk assessments. Sediments from the River Kymijoki, draining into the Gulf of Finland, have been heavily polluted by the pulp and paper industry and by chemical industries. A wood preservative, known as Ky-5, was manufactured in the upper reaches of the river between 1940 and 1984 causing severe pollution of river sediments with polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF). Moreover, the sediments have been polluted with mercury (Hg) from chlor-alkali production and the use of Hg as a slimicide in pulp and paper manufacturing. Materials and methods  An extensive sediment survey was conducted as well as sediment transport modeling, toxicity screening of sediment invertebrates, and a survey of contaminant bioaccumulation in invertebrates and fish. Studies on human exposure to PCDD/Fs and the possible effects on hypermineralization of teeth as well as an epidemiological study to reveal increased cancer risk were also conducted. An assessment of the ecological and human health risks with a null hypothesis (no remediation) was undertaken. Results  The sediment survey revealed severe contamination of river and coastal sediments with PCDD/Fs and Hg. The total volume of contaminated sediments was estimated to reach 5 × 10⁶ m³ and hot spots with extremely high concentrations (max 292,000 ng g⁻¹ or 1,060 ng I-TEQ g⁻¹ d.w.) were located immediately downstream from the pollution source (approximately 90,000 m³). Sediment contamination was accompanied by changes in benthic assemblages, but direct effects were masked by many factors. The fish showed only slightly elevated PCDD/F levels in muscle, but orders of magnitude higher in the liver compared with reference freshwater sites and the Baltic Sea. The concentrations in human fat did not reveal high human exposure in the Kymijoki area in general and was lower than in sea fishermen. The relative risk for total cancer among farmers was marginally higher (RR = 1.13) among those living close to the river, compared with farmers living further away, and the possibility of increased cancer risk cannot be ruled out. A conservative risk assessment revealed that the present probability of exceeding the WHO upper exposure limit of 4 pg WHO-TEQ kg⁻¹ d⁻¹ for PCDD/Fs and DL-PCBs was 6%. The probability of exceeding the WHO limit value of 0.23 μg kg⁻¹ d⁻¹ for methyl mercury was estimated to be notably higher at 62%. Based on these studies and the estimated risks connected with different remediation techniques a general remediation plan with cost benefit analysis was generated for several sub-regions in the river. Dredging, on-site treatment, and a close disposal of the most contaminated sediments (90,000 m³) was suggested as the first phase of the remediation. The decision regarding the start of remediation will be made during autumn 2008. Conclusions  The sediments in the River Kymijoki are heavily polluted with PCDD/Fs and mercury from earlier chlorophenol, chlor-alkali, and pulp and paper manufacturing. A continuous transport of contaminants is taking place to the Gulf of Finland in the Baltic Sea. The highly increased PCDD/F and Hg levels in river sediments pose an ecotoxicological risk to benthic fauna, to fish-eating predators and probably to human health. The risks posed by mercury exceed those from PCDD/Fs and need to be evaluated for (former) chlor-alkali sites and other mercury releasing industries as one basis for remediation decision making. Recommendations and perspectives  The studies form the basis of a risk management strategy and a plan for possible remediation of contaminated sediments currently under consideration in the Southeast Finland Regional Environment Centre. It is recommended that a detailed restoration plan for the most seriously contaminated areas should be undertaken. Based on current knowledge, the restoration of the whole river is not feasible, considering the current risk caused by the contaminated sediment in the river and the costs of an extensive restoration project. The experiences gained in the present case should be utilized in the evaluation of PCDD/F- and mercury-contaminated sites in other countries. The case demonstrates that the historic reservoirs are of contemporary relevance and should be addressed, e.g., in the national implementation plans of the Stockholm Convention. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Does control of soil erosion inhibit aquatic eutrophication?

Much of the phosphorus (P) from erosive soils is transported to water bodies together with eroded soil. Studies clarifying the impact of soil erosion on eutrophication have sought largely to quantify the reserves of P in soil particles that can be desorbed in different types of receiving waters. Aquatic microbiology has revealed that the cycling of P is coupled to the availability of common electron acceptors, Fe oxides and SO?, through anaerobic mineralization in sediments. Eroded soil is also rich in Fe oxides, and their effect on the coupled cycling of C, Fe, S, and P has been neglected in eutrophication research. Soil erosion, and its control, should therefore be studied by considering not only the processes occurring in the water phase but also those taking place after the soil particles have settled to the bottom. We propose that in SO?-rich systems, Fe oxides transported by eroded soil may promote Fe cycling, inhibit microbial SO? reduction and maintain the ability of sediment to retain P. We discuss the mechanisms through which eroded soil may affect benthic mineralization processes and the manner in which soil erosion may contribute to or counteract eutrophication.     

Livelihoods, vulnerability and adaptation to climate change in Morogoro, Tanzania

This article examines farmers’ livelihood responses and vulnerability to climate variability and other stressors in Morogoro, Tanzania, to understand their implications for adaptation to climate change by agricultural households in developing world more generally. In Morogoro, agricultural households have extended cultivation, intensified agriculture, diversified livelihoods and migrated to gain access to land, markets and employment as a response to climatic and other stressors. Some of these responses have depleted and degraded natural resources such as forest, soil and water resources, which will complicate their living with climate change in the future. This will be particularly problematic to vulnerable groups such as women, children and pastoralists who have limited access to employment, markets and public services. In this light, fair adaptation to climate change by agricultural households in Morogoro and elsewhere in developing countries requires several complementary responses. Adaptation efforts should involve effective governance of natural resources because they function as safety nets to vulnerable groups. In addition, strengthening of national markets by infrastructure investments and institutional reforms is needed to give incentives to intensification and diversification in agriculture. Market participation also demands enhancement of human capital by public programs on health, education and wellbeing.     

Residential indoor,outdoor, and workplace concentrations of carbonyl compounds: relationships with personal exposure concentrations and correlation with sources

Personal 48-hr exposures of 15 randomly selected participants as well as microenvironment concentrations in each participant's residence and workplace were measured for 16 carbonyl compounds during summer-fall 1997 as a part of the Air Pollution Exposure Distributions within Adult Urban Populations in Europe (EXPOLIS) study in Helsinki, Finland. When formaldehyde and acetaldehyde were excluded, geometric mean ambient air concentrations outside each participant's residence were less than 1 ppb for all target compounds. Geometric mean residential indoor concentrations of carbonyls were systematically higher than geometric mean personal exposures and indoor workplace concentrations. Additionally, residential indoor/outdoor ratios indicated substantial indoor sources for most target compounds. Carbonyls in residential indoor air correlated significantly, suggesting similar mechanisms of entry into indoor environments. Overall, this study demonstrated the important role of non-traffic-related emissions in the personal exposures of participants in Helsinki and that comprehensive apportionment of population risk to air toxics should include exposure concentrations derived from product emissions and chemical formation in indoor air.     

Industrial ecology flows of agriculture and food industry in Finland: utilizing by-products and wastes

Although half of the administrative units in China are said to have implemented their local Agenda 21, the promotion of sustainable communities is not pervasive. In this paper, we adopted a relatively untried mode of analysis and a socio-economic context to illustrate the potentials and failures of China's grassroots local government bodies in achieving sustainable waste management. Our study shows that, among the three main functions of sustainable waste management (ensuring environmental hygiene, provision of recycling logistics and changing the consumption pattern of the local community) for local governments, grassroots local government bodies in mainland China are only able to do the minimum, i.e. ensuring environmental hygiene and handling complaints. One of the reasons for the failure is that, despite the emphasis on capacity building in China's Agenda 21, the reality is that no action is taken to empower grassroots local government. Despite the high profile accorded by the Chinese central government to motivating local governments to formulate their own Agenda 21, local sustainability and waste management performance have little relevance to the appraisal systems of these government agents.     

Dioxin concentrations in sediments of the Baltic Sea--a survey of existing data

Recent survey results for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, dioxins) in Baltic Sea sediments from Finland, Sweden and Denmark were merged with previously published Baltic Sea data. Regional distribution of concentration levels, differences in congener patterns, and temporal changes in sediment profiles were examined. One of the main objectives was to study if any major point sources for different PCDD/F congeners could be identified on a regional scale, based on sediment records. The survey confirmed the impact of chlorophenol production derived highly chlorinated PCDF-congeners on the total toxicity in sediments in the Gulf of Finland near the Kymijoki river estuary. Signatures of other point sources or combined point sources pertinent to specific industry branches or particular production processes (such as pulp bleaching, vinyl chloride production, thermal processes) may be discerned. However, the findings did not support any of the known point sources significantly influencing those congeners that are most abundant in Baltic herring and salmon. Instead, regional distributions in the Baltic Sea indicate that atmospheric deposition may act as a major source for those congeners and especially for 2,3,4,7,8-PeCDF. There were clear indications of declines in levels in sediment in some areas, but generally the levels of highly chlorinated PCDD/Fs on the northern coast of the Gulf of Finland were still high when compared with other areas of the Baltic Sea. Major areas with data gaps cover the south-eastern and eastern coastal regions of the Baltic Proper and the southern Gulf of Finland.