Mekong at the Crossroads

The Mekong region is undergoing rapid transitions, socially, economically, and environmentally. Economies are stabilizing after the political turbulence of the last several decades, and development pressures as well as ambitions are vast. Water is related to these social, economic, and environmental changes in many ways and in a very profound manner. This article summarizes the approach and major conclusions of the research project title "Integrated Water Resources Management (IWRM) on the Mekong River." The concept of IWRM is elaborated in the setting of these major transitions, and the roles of academic research and education are highlighted.     

The “Seili-index” for the Prediction of Chlorophyll-α Levels in the Archipelago Sea of the northern Baltic Sea,southwest Finland

Environmental Modeling & Assessment - To build a forecasting tool for the state of eutrophication in the Archipelago Sea, we fitted a Generalized Additive Mixed Model (GAMM) to marine...     

Using Global Datasets to Create Environmental Profiles for Data-Poor Regions: A Case from the Irrawaddy and Salween River Basins

The increasing availability of spatial data inspires the exploration of previously less-studied, yet regionally and nationally important areas, such as the Irrawaddy and Salween River Basins in Southeast Asia. This article documents our experience using global datasets to create environmental basin profiles in these two basins. Our approach draws on the concepts of freshwater vulnerability assessments that guided the selection of indicators. Data on land use, population distribution and fertilizer load were used. The unit of analysis was chosen to distinguish areas with similar bio-geographical characteristics, such as the critical delta areas. Results were further discussed for sub-areas that experience relatively the most pressure in terms of examined indicators within the studied area. The river mouths of both rivers had the most intensive land use and high population density. They are also home to important ecosystems and are sensitive to changes in upstream areas. Our study presents a concise and spatially distributed view of the environmental basin profiles of the Irrawaddy and Salween River Basins. The analysis also provides some interesting methodological insights about the potential of public macro-scale datasets for environmental assessment. The spatial approach allowed the analysis of different indicators, providing a platform for data integration as well as a visually powerful overview of the study area. Yet, the use of macro-scale datasets entails challenges. Despite improvements, the assessment process tends to be driven by the availability and quality of data, rather than by the actual research and management needs. The greatest utility of macro-scale datasets lies—at least in data-poor areas—in larger scale comparative analyses between the basins and their different sub-areas.     

Integrated water management of the Brahmaputra basin: Perspectives and hope for regional development

Water is strongly linked with the overall development framework of the Brahmaputra basin. However, the absence of integrated management of Brahmaputra water resources and lack of coordination among the riparian states constitutes an ongoing threat to future development plans within the basin. Brahmaputra's abundant hydropower potential can help give riparian countries a safer energy future that is the key driving force behind the prospect of potential cooperation. This paper analyses the current status of Brahmaputra water resources and identifies the perspectives of riparian countries regarding the development of the Brahmaputra basin. It also identifies the opportunities for cooperation and regional development through integrated water development and management of the Brahmaputra basin. It is essential to develop an integrated water resources management approach involving all riparians to foster regional development and overcome the prospect of severe water conflict along the Brahmaputra basin.     

Production and sedimentation of peptide toxins nodularin-R and microcystin-LR in the northern Baltic Sea

This seven-year survey was primarily targeted to quantification of production of nodularin-R (NOD-R), a cyclic pentapeptide hepatotoxin, in Baltic Sea cyanobacteria waterblooms. Additionally, NOD-R and microcystin-LR (MC-LR; a cyclic heptapeptide toxin) sedimentation rates and NOD-R sediment storage were estimated. NOD-R production (70-2450 μg m⁻³; ∼1 kg km⁻² per season) and sedimentation rates (particles; 0.03-5.7 μg m⁻² d⁻¹; ∼0.3 kg km⁻² per season) were highly variable over space and time. Cell numbers of Nodularia spumigena did not correlate with NOD-R quantities. Dissolved NOD-R comprised 57-100% of total NOD-R in the predominantly senescent, low-intensity phytoplankton blooms and seston. Unprecedentedly intensive MC-LR sedimentation (0.56 μg m⁻² d⁻¹) occurred in 2004. Hepatotoxin sedimentation rates highly exceeded those of anthropogenic xenobiotics. NOD-R storage in surficial sediments was 0.4-20 μg kg⁻¹ (∼0.1 kg km⁻²). Loss of NOD-R within the chain consisting of phytoplankton, seston and soft sediments seemed very effective.     

Contamination of River Kymijoki sediments with polychlorinated dibenzo-p-dioxins, dibenzofurans and mercury and their transport to the Gulf of Finland in the Baltic Sea

Kymijoki, the fourth largest river in Finland, has been heavily polluted by pulp mill effluents as well as the chemical industry. Up to 24,000 ton of wood preservative, chlorophenol known as Ky-5, was manufactured in the upper reaches of the river, an unknown amount of which was discharged into the river between 1940 and 1984. Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) occurred as impurities in the final Ky-5 product. The PCDD/F concentrations and burden in the river sediments were studied and the transport of PCDD/Fs from contaminated sites downstream and into the Gulf of Finland in the Baltic Sea was estimated. More than 190 sediment cores were sampled to estimate the volume of contaminated sediments and the total PCDD/F burden. The transport of PCDD/Fs was estimated using sediment traps placed at several sites. The survey revealed that sediments in the river were heavily polluted by PCDD/Fs, the main toxic congener being 1,2,3,4,6,7,8-heptachlorodibenzofuran, a major contaminant in the Ky-5 product. The mean total concentration at the most polluted river site downstream from the main source was 42000 microg kg(-1) d.w. (106 microg I-TEQ kg(-1)). The elevated concentrations in the coastal region and the present estimated transport from the River Kymijoki confirm earlier assessments that the river is a major source of PCDD/F for the Gulf of Finland.     

Large net forest loss in Cambodia’s Tonle Sap Lake protected areas during 1992–2019

Historical land-use practices have caused forest loss in Cambodia’s Tonle Sap Lake area (TSLA), the largest freshwater lake in Southeast Asia. However, it remains unclear if this deforestation trend had continued since 2001 when the land was designated as protected areas. Using satellite imagery, we investigated forest conversion flows and fragmentation patterns in the TSLA for 1992–2001, 2001–2010, and 2010–2019, respectively. Results show substantial forest losses and fragmentations occurring at the lower floodplain where the protected areas are located until 2010, with some forest regain during 2010–2019. The land conversions indicated that forest clearing and agricultural farming were the primary causes for observed extensive forest loss during 1992–2010. Hence, despite the creating of protected areas in 2001, our findings reveal the persistence of alarming forest loss in the TSLA until 2010. On the other hand, while net forest loss has stopped after 2010, forest regain during 2010–2019 is way too small to restore the region’s total forest area to even the level when the protected areas were established. Thus, more effective planning and implementations of forest management and restoration policies are needed for the TSLA.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-022-01704-4.