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.     

Accidental release: Fuzzy selection of adequate formal model

Risk assessment of a chemical process plant requires the application of a variety of consequence models in order to estimate the potential physical effects of accidental releases. The types of models required vary depending upon the substance under consideration and the circumstances of a release. The objective of this study was the development and application of a system based upon ‘fuzzy logic’, for the selection of a computer model to be used in consequence analysis in specific situations where only certain types of consequence models can be used. The collection of data for modelling purposes from different kinds of computer model and application of fuzzy methods were also important aims of the study.     

Use of decision analysis interviews to support the sustainable use of the forests in Finnish Upper Lapland

Controversy between alternative uses of forests in Finnish Upper Lapland has been going on for decades, and in recent years it has been escalated to a serious conflict. The core of the conflict is the adverse impacts of forestry on old forests which are important grazing areas for reindeer and which are regarded as intact nature and wilderness areas. This paper describes the experiences of applying multi-criteria decision analysis interview approach on this conflict. The approach provides tools for structuring the problem and preferences of the stakeholders as well as for analyzing the effects of different alternatives in a common framework. We focus on the practical experiences gained from the application of this approach in this context. Multi-criteria decision analysis was found to be a useful approach to evaluate the economic, ecological and cultural aspects of this intense conflict. The obtained experiences also support the view that the approach works best when tightly integrated into the planning process.     

Study of Miller timing on exhaust emissions of a hydrotreated vegetable oil (HVO)-fueled diesel engine

The effect of intake valve closure (IVC) timing by utilizing Miller cycle and start of injection (SOI) on particulate matter (PM), particle number, and nitrogen oxide (NO_x) emissions was studied with a hydrotreated vegetable oil (HVO)-fueled nonroad diesel engine. HVO-fueled engine emissions, including aldehyde and polyaromatic hydrocarbon (PAH) emissions, were also compared with those emitted with fossil EN590 diesel fuel. At the engine standard settings, particle number and NO_x emissions decreased at all the studied load points (50%, 75%, and 100%) when the fuel was changed from EN590 to HVO. Adjusting IVC timing enabled a substantial decrease in NO_x emission and combined with SOI timing adjustment somewhat smaller decrease in both NO_x and particle emissions at IVC??50 and??70 °CA points. The HVO fuel decreased PAH emissions mainly due to the absence of aromatics. Aldehyde emissions were lower with the HVO fuel with medium (50%) load. At higher loads (75% and 100%), aldehyde emissions were slightly higher with the HVO fuel. However, the aldehyde emission levels were quite low, so no clear conclusions on the effect of fuel can be made. Overall, the study indicates that paraffinic HVO fuels are suitable for emission reduction with valve and injection timing adjustment and thus provide possibilities for engine manufacturers to meet the strictening emission limits.

Implications: NO_x and particle emissions are dominant emissions of diesel engines and vehicles. New, biobased paraffinic fuels and modern engine technologies have been reported to lower both of these emissions. In this study, even further reductions were achieved with engine valve adjustment combined with novel hydrotreated vegetable oil (HVO) diesel fuel. This study shows that new paraffinic fuels offer further possibilities to reduce engine exhaust emissions to meet the future emission limits.

Supplementary Materials: Supplementary materials are available for this paper. Go to the publisher's online edition of the Journal of the Air & Waste Management Association for a complete list of analysed PAH compounds.     

Water quality monitoring using remote sensing in support of the EU water framework directive (WFD): A case study in the Gulf of Finland

Water quality monitoring using remote sensing has been studied in Finland for many years. But there are still few discussions on water quality monitoring using remote sensing technology in support of water policy and legislation in Finland under the WFD. In this study, we present water quality monitoring using remote sensing in the Gulf of Finland, and focus on the spatial distribution of water quality information from satellite-based observations in support of water policy by a case study of nitrate concentrations in surface waters. In addition, we briefly describe instruments using a system of river basin districts (RBD), highlighting the importance of integrated water resources and river-basin management in the WFD, and discuss the role of water quality monitoring using remote sensing in the implementation of water policy in Finland under the WFD.     

Recent trends of biocides in pikes of the Lake Päijänne

Pikes were sampled in May 1980 from three areas of the Lake Päijänne, Finland and analyzed for their contents of total mercury, methyl mercury, hexachlorobenzene (HCB), DDE, PCB and chlorophenolic residues. An improved method for methyl mercury determination was applied and 82–84 % methylation of mercury in pikes regardless of area or biological variation was observed. Statistical analysis with previous results from the same areas gave a very significant decreasing trend of mercury levels at all three areas from 1970 to 1980. Future levels of mercury in fish to be consumed as food could be estimated from the trend regression. The very low levels of DDE and PCB showed some increasing trend when the influence of fat contents was eliminated by covariance analysis. General appearance of HCB at sub-ppb level was observed. Also pentachlorophenol occured at 10–70 ppb (fresh weight) levels at all areas, but the other chlorophenols were abundant only at Tiirinselkä which is most contaminated by pulp bleaching effluents.     

Organochlorine concentrations in diseased vs. healthy gull chicks from the northern Baltic

The population decline of the nominate lesser black-backed gull Larus fuscus fuscus in the Gulf of Finland (northern Baltic) is caused by an exceedingly high chick mortality due to diseases. The chick diseases include degeneration in various internal organs (primarily liver), inflammations (mainly intestinal), and sepsis, the final cause of death. The hypothesis of starvation causing intestinal inflammations (leading to sepsis) was tested by attempting to reproduce lesions in apparently healthy herring gull L. argentatus chicks in captivity. The herring gull chicks were provided a similar low food-intake frequency as observed for the diseased chicks in the wild. However, empty alimentary tract per se did not induce the intestinal inflammations and therefore, inflammations seem to be innate or caused by other environmental factors in the diseased lesser black-backed chicks. They had very high concentrations of PCB in their liver; but the concentrations were not significantly higher than those of the healthy herring gull chicks, indicating a common exposure area for both species (i.e. the Baltic Sea). When compared to NOEL and LOEL values for TEQs in bird eggs our TEQ levels clearly exceed most or all of the values associated with effects. Compared with published data on fish-eating waterbirds, the DDE concentrations in the diseased lesser black-backed chicks were well above the levels previously correlated with decreased reproduction, while the residues in apparently healthy herring gulls were below those levels. The DDE/PCB ratio in lesser black-backs was significantly elevated, indicating an increased exposure to DDTs as compared with most other Baltic and circumpolar seabirds. The possible exposure areas of DDT in relation to differential migration habits of the two gull species are discussed.     

Soil Acidity Parameters and Defoliation Degree in Six Norway Spruce Stands in Finland

Soil acidity parameters (pH, basesaturation, exchangeable Al) in the organic and mineralsoil layers and in soil water (pH, dissolved organiccarbon, total Al, Al³⁺ and molar Ca/Al ratios) insix Norway spruce stands in different parts of Finlandwere compared. An attempt was also made to relate thedegree of defoliation in the tree stand to N and Sdeposition and soil parameters. No relationship was foundbetween soil acidity parameters and defoliation in thesix stands. Defoliation was positively correlated withstand age and the C/N ratio of the organic layer, andnegatively with the cation exchange capacity. The plotlocated on a so-called sulphate soil on the west coast ofFinland had very low soil pH values, and extremely highAl and SO₄ ^2- concentrations and molar Ca/Alratios of well below 1.0 in soil water. Despite the highnatural acidity in the soil on this plot, defoliation inthe spruce stand was the lowest (mean 8.6%) of all sixplots. The results of this study indicate that soilacidity is not a major factor affecting stand conditionin these spruce stands, and that the variation in soilacidity parameters is closely related to climatic factorsand natural soil formation processes.     

Effect of liming on the behaviour of (90)Sr and (137)Cs in a lake ecosystem

Liming of lakes is considered one possible remedial action to reduce the accumulation of radionuclides into fish in the case of a radiological accident. These responses were tested in field conditions in a small acidified lake that was divided into two parts: one limed with CaCO₃ and the other half left as an unlimed control. The transfer of ⁹⁰Sr from water into fish decreased on average by 50% during the first year after liming. However, at the same time the ⁹⁰Sr concentration in water increased, reaching a maximum within 6 months after liming. Approximately 50% more ⁹⁰Sr was detected in water in the limed part of the lake than on control side during the first year. ⁹⁰Sr was most probably released from the sediment as the Ca concentration and pH of the water increased. As a result of these two processes, which counterbalanced each other (increased release of ⁹⁰Sr into water from sediment and decreased transfer of ⁹⁰Sr from water into fish), the ⁹⁰Sr concentration in fish did not notably differ between the limed and control sides of the lake. Liming may only be suitable as a remedial action if carried out immediately after a radiological accident, before significant amounts of radionuclides have been deposited in lake sediments. In the case of ¹³⁷Cs, the effect of liming was less pronounced. ¹³⁷Cs activity concentration in water increased in the first year by 20% and uptake by fish decreased by 20%.     

Extensive tree health monitoring networks are useful in revealing the impacts of widespread biotic damage in boreal forests

We surveyed the regional distribution of conifer defoliation in Finland with an extensive monitoring network during 1995–2006 (EU Forest Focus Level I). The average defoliation in the whole Finland was 10.3% in pine and 19.9% in spruce. The sharp changes were often related to abiotic and biotic factors. The mean age of the stand explained more than one half of the between-plot variance in defoliation. In a variance component analysis, the main effect of years was negligible, while most of the random variation was due to plot main effect and plot × year interaction. About one fifth of the defoliation could be attributed to abiotic or biotic damage, and there were strong local correlations, e.g., between the changes in defoliation and degree of pine sawfly (Diprionidae) damage. There were clear temporal and spatial patterns in the incidence of the most important causes [Scots pine: Scleroderris canker (Gremmeniella abietina), pine shoot beetles (Tomicus sp.), and pine sawflies (Diprion pini, Neodiprion sertifer); Norway spruce: rust fungi (primarily Chrysomyxa ledi)]. Our results suggest that extensive monitoring networks can reveal useful information about the widespread outbreaks of pest organisms (insects and fungi) already in their increase phases, giving some time for management decisions. In a changing climate, large-scale, regular monitoring of tree health, including abiotic and biotic causes, is more important than ever before.