Research List

Research on the impacts of climate change on the water quality and ecosystems of Lake Biwa and its adaptation measures (Policy-oriented Research 1)

　Our previous research has revealed that the frequent occurrence of massive blooms of large phytoplankton and the impacts of climate change may be disrupting the smooth functioning of the biogeochemical cycle, including the food chain. Therefore, we will focus on organic matter produced in the surface layer and its sedimentation to the deep bottom layer, oxygen consumption due to organic matter decomposition, and the distribution of oxygen depletion and benthic organisms in the deep bottom layer. We will evaluate the complex impacts of climate change on the water quality and ecosystems of the north basin of Lake Biwa and propose directions for climate change adaptation measures.

More details in Japanese (PDF: 757KB)

Research on the functions of various green infrastructure in river basins and their conservation and restoration (Policy-oriented Research 2)

　We will clarify the green infrastructure functions of river basin ecosystems to conserve them and mitigate disasters in the basins. Furthermore, we will propose methods to conserve and restore ecosystems to maximize their functions. To achieve this goal, we will develop technology to monitor the functions of green infrastructure in river basin ecosystems and use this information to help evaluate these functions. Furthermore, we will propose methods for conserving and restoring ecosystems and organize information on key points for maintaining and continuing them.

More details in Japanese(PDF: 428KB)

Research on mathematical modeling for sustainable forest management (Policy-oriented Research 3)

　This project aims to develop a mathematical model that illustrates the relationship between final felling and the fulfillment of a forest's multiple functions in areas designated for continuous timber production. The goal is to identify management methods that ensure the sustainable provision of these functions, such as carbon sequestration and water conservation.We are developing methods to build a foundational data infrastructure—including information on forest species composition and resource volume—to promote region-specific forest development. This project is specifically for forests where multifunctional roles are maintained through natural cycles, without human intervention.

More details in Japanese(PDF: 434KB)

Research on the balance and sources of plastic waste in the Lake Biwa basin and the science outreach (Policy-oriented Research 4)

　The increasing environmental burden of plastic waste has become a major global issue. To understand the dynamics of plastics in the Lake Biwa basin, this study aims to clarify the overall balance of plastic waste and identify its main sources by investigating its components. Furthermore, the study explores important considerations for effectively communicating the scientific findings to the public.

More details in Japanese(PDF: 371KB)

Ecological restoration and current status of coastal ecosystems in Lake Biwa (Investigation and Analytical Studies 1)

　Various nature restoration and conservation activities have been conducted along the coastal areas of Lake Biwa. However, as these efforts have continued over a long period, challenges have emerged in securing sustainable human resources, funding, and monitoring systems. To promote effective and efficient ecosystem management, this study applies appropriate technologies and frameworks to address key issues such as the excessive proliferation of aquatic plants, the management of invasive alien species, and the improvement of habitats for bivalves and other aquatic organisms. The aim of this study is to assess the current ecological conditions and identify critical challenges toward the substantial and practical restoration of biodiversity.

More details in Japanese(PDF: 499KB)

Plankton monitoring in Lake Biwa and the Seta River, and current status assessment of phytoplankton succession (Investigation and Analytical Studies 2)

　To conserve and restore the aquatic environment, we will conduct continuous plankton monitoring in Lake Biwa and the Seta River. This project will allow us to promptly detect changes in plankton community structure in the lake and river. We will publish the preliminary results on the plankton community in the Seta River. Using the long-term datasets from Lake Biwa, we will analyze relationships among phytoplankton, water quality, and meteorological conditions. Based on the plankton data, we will evaluate the lake's current condition and identify potential future problems. In addition, we will investigate the density of blue-green algae in Lake Nishinoko. Measures to suppress algal growth and improve water quality in the lake will also be examined.

More details in Japanese(PDF: 358KB)

Monitoring of Lake Biwa and other water environments (Monitoring and Assessment 1)

　We monitor the water quality of public water bodies, including Lake Biwa, considering both environmental and water-use perspectives. Specifically, we investigate whether water quality meets environmental standards and examine the plankton communities that cause algal blooms. Furthermore, we integrate these results with long-term monitoring data to evaluate the current status and temporal changes in the aquatic environment of Lake Biwa and other water bodies.。

More details in Japanese(PDF: 487KB)

[Collaborative research with Lake Biwa Branch, National Institute for Environmental Studies, Japan] Research on comprehensive lake environmental assessment and improvement methods for the conservation of a healthy aquatic environment in Lake Biwa

　Lake Biwa Branch Office of National Institute for Environmental Studies (NIES) was established in April 2017 at Lake Biwa Environmental Research Institute (LBERI). The Lake Biwa Branch promotes collaborative research aimed at the conservation and restoration of the Lake Biwa watershed ecosystem, based on NIES' pioneering research achievements and expertise in analyzing and assessing lake sediment environments and ecosystems.

Study on water quality and lake-bottom environment for the protection of the soundness of the water environment

　To conserve, manage, and restore the environment of Lake Biwa, a detailed understanding of both the water and the benthic environments, which are the controlling factors of the lake ecosystem, is essential. This study applies innovative environmental analysis methods developed at NIES to research the water and benthic environments of Lake Biwa.

More details in Japanese(PDF: 425KB)

Research on the distribution and ecology of the native fishes of Lake Biwa

　Focusing on native fish as representative organisms of the Lake Biwa ecosystem, this study aims to propose appropriate methods for their conservation, management, and restoration. Furthermore, to enhance the efficiency of ecosystem assessment as a foundation for research, we will explore monitoring techniques that incorporate the latest technologies.

More details in Japanese(PDF: 347KB)

Investigation of factors behind concentration fluctuations of photochemical oxidants in Shiga Prefecture (Investigation and Analytical Studies 3)

　To clarify the factors behind fluctuations in photochemical oxidants that fail to meet environmental standards, this study collaborates with surrounding municipalities and conducts monitoring and analyses of precursors, including volatile organic compounds (VOCs) and other substances, as well as analyses of high-concentration cases using data from continuous air monitoring systems. The aim is to provide fundamental information for developing measures to reduce photochemical oxidant levels.

More details in Japanese(PDF: 401KB)

Application of methods for chemical investigation in aquatic emergency incidents (Investigation and Analytical Studies 4)

　To support official responses to water pollution incidents, we are systematically updating instrumental analysis methods in collaboration with other municipalities. In addition, by integrating instrumental analysis with bioassay-based screening, we aim to identify pollution sources and support prompt countermeasures.

More details in Japanese (PDF: 368KB)

Air quality monitoring (Monitoring and Assessment 2)

　In accordance with the Air Pollution Control Act, we 1) continuously conduct constant monitoring with automatic air monitoring stations and surveys of hazardous air pollutants, etc., 2) issue warnings as necessary and compile monitoring results such as compliance with environmental standards and trends in environmental concentrations, and 3) monitor compliance with emission standards of facilities generating soot or smoke.

More details in Japanese (PDF: 352KB)

Source monitoring of water and soil environments (Monitoring and Assessment 3)

　To protect the water environment in the Lake Biwa basin, we conduct environmental monitoring as part of our responsibilities under the Water Pollution Control Act and other related laws. Our monitoring program has three key functions. We regularly inspect regulated facilities to ensure their wastewater meets discharge standards. When environmental emergencies occur, such as pollution accidents or groundwater contamination incidents, we perform water quality analyses to evaluate the extent of contamination and provide essential information for cleanup efforts. We also conduct water-quality analyses to continuously monitor the levels of chemical substances released into the environment.

More details in Japanese (PDF: 353KB)

Research on regional development for utilizing natural capital to achieve a Net-Zero society (Policy-oriented Research 5)

　This study aims to develop a mathematical model to evaluate the relationship between natural capital and socio-economic systems quantitatively, and to analyze the impact of climate change on this relationship. From a socio-economic perspective, we will conduct scenario analyses that incorporate information on residents' awareness and the social acceptability of required behavioral changes. In addition, we will examine multi-stakeholder communication processes involving government, residents, businesses, and other actors in the formulation of policies for achieving a net-zero society. Through these efforts, the study will propose approaches for the sustainable and effective use of local resources, concrete methods to encourage residents' participation, and measures to build consensus. These findings will help reduce CO₂ emissions and foster a vibrant community led by prefectural residents.

More details in Japanese (PDF: 475KB)

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[Research by the Environmental Research Promotion Organization] Research to restore fishery resources by utilizing abundant native fish and shellfish

　The decline of native fish and shellfish in the Lake Biwa basin is an urgent issue. To address this issue, in 2014, prefectural administrative departments and prefectural testing and research institutions came together to establish an organization to promote environmental research on Lake Biwa. It is called the "Lake Biwa Environmental Research Promotion Organization." The Lake Biwa Environmental Research Promotion Organization facilitates collaboration between organizations and conducts realistic research and studies to clarify the causes of the decline of native fish and shellfish in Lake Biwa. The results will be used to propose policies to restore the lake's rich fishing resources through native fish and shellfish.

More details in Japanese(PDF: 219KB)

*This project consists of Policy-oriented Research 1 to 3

Research on the examination and implementation of coastal environmental improvement methods using bivalves as evaluation indicators (Policy-oriented Research 1)

　Based on the results of the coastal environmental assessment and improvement using bivalves as an indicator, we will compile a "Technical Document on Coastal Environment Improvement (tentative name)" that summarizes the methods used. In accordance with the "Technical Document," we will assess and analyze the current situation at several locations around Lake Biwa and propose goals and measures for improving the coastal environment. We will also establish and implement methods for building sustainable and effective activities by residents.

More details in Japanese(PDF: 440KB)

Research on restoring connectivity in water systems to promote the migration of native fish and protect their habitats (Policy-oriented Research 2)

　To conserve native fish such as Ayu, Char, and Biwa trout, we will research to restore connections among forests, rivers, and lakes. First, we will study sediment movement, including sediment runoff patterns and the state of the sediment environment in the river basin. Next, we will develop methods to monitor changes in the river environment to conserve and restore native fish. Finally, we will clarify the requirements and challenges for native fish conservation and restoration activities through collaboration between various stakeholders. We will use the results of our research to make policy recommendations grounded in scientific evidence.

More details in Japanese (PDF: 189KB)

Research on the factors and indicators for efficient material cycling in lakes (Policy-oriented Research 3)

　It is increasingly recognized that, in addition to reducing the amount of substances within lakes by controlling inflow loads, it is also important to enhance the efficient material cycling that supports aquatic organisms such as fish and shellfish. Therefore, this study focuses on identifying factors that promote efficient material cycling in lakes by examining nutrient dynamics and the production and consumption of organic matter, and on developing indicators to assess the efficiency of this cycling.

More details in Japanese (PDF: 259KB)

Research on biodiversity conservation and restoration (Policy-oriented Research 4)

　As there are currently no established methods for scientifically evaluating the outcomes of biodiversity conservation activities, this study aims to develop assessment approaches that enhance the sense of impact and lead to practical improvements. In addition, we will address the urgent threats to biodiversity in Shiga Prefecture (invasive alien species, climate change, etc.), and promote research into methods and frameworks for incorporating scientific knowledge into evaluations from a long-term perspective.

More details in Japanese(PDF: 405KB)

Research on forests for the conservation of the environment of Lake Biwa and its surroundings (Policy-oriented Research 5)

　To conserve the environment of Lake Biwa and its surroundings, we will broadly extract the multifunctional and diverse values of forests and systematically organize and analyze them. We will attempt zoning that considers both the preservation of forests' multifunctional benefits and the utilization of forest resources. We will examine forest management to ensure the next generation inherits healthy forests in Shiga Prefecture.

More details in Japanese(PDF: 398KB)

Research on the benthic environment and its impact on the ecosystem of the South basin (Policy-oriented Research 6)

　To promote the restoration of the ecosystem in the South basin, we will elucidate the mechanisms of hypoxic water mass formation in the bottom layer of Lake Biwa's South basin through field surveys and three-dimensional numerical modeling.
In addition, we will investigate macrophyte distribution, bottom-layer dissolved oxygen (DO), biological communities around macrophytes and filamentous algae, and evaluate the impacts of changes in macrophyte and filamentous algae abundance on organisms and the ecosystem.

More details in Japanese (PDF: 339KB)

Development of a monitoring plan for new indicators (bottom-water DO) and specific consideration of the evaluation (Investigation and Analytical Studies 1)

　To address bottom-water dissolved oxygen (DO), which has been adopted as an environmental standard, we will measure DO concentrations in the bottom layers of Lake Biwa and accurately capture their spatial distribution and temporal fluctuations. We will also analyze the factors influencing variations in sediment oxygen demand (SOD), a major contributor to bottom-water DO depletion in the northern basin of the lake. Based on these findings, we will propose monitoring methods to evaluate bottom-water DO and support the implementation of a statutory measurement plan.

More details in Japanese (PDF: 345KB)

Plankton monitoring and evaluation of forecasting approaches for plankton dynamics in Lake Biwa and the Seta River (Investigation and Analytical Studies 2)

　We will conduct plankton monitoring in Lake Biwa. In addition, to address the risk of water-use problems caused by odorous phytoplankton bloom, we will examine short-term forecasting methods for these phytoplankton in the Seta River.

More details in Japanese(PDF: 396KB)

Monitoring of Lake Biwa and other water environments (Monitoring and Assessment 1)

　We monitor the water quality of public water bodies, including Lake Biwa, considering both environmental and water-use perspectives. Specifically, we investigate whether water quality meets environmental standards, and examine the plankton communities that cause algal blooms. Furthermore, we integrate these results with long-term monitoring data to evaluate the current status and temporal changes in the aquatic environment of Lake Biwa and other water bodies.

More details in Japanese (PDF: 147KB)

[Collaborative research with the National Institute for Environmental Studies, Lake Biwa Branch] Research on comprehensive lake environmental assessment and improvement methods for the conservation of a healthy aquatic environment in Lake Biwa

 　Lake Biwa Branch Office of National Institute for Environmental Studies (NIES) was established in April 2017 at Lake Biwa Environmental Research Institute (LBERI). The Lake Biwa Branch promotes collaborative research aimed at the conservation and restoration of the Lake Biwa watershed ecosystem, based on NIES' pioneering research achievements and expertise in the analysis and assessment of lake sediment environments and ecosystems.

Study on water quality and lake-bottom environment for the protection of the soundness of the water environment

　To support the conservation, management, and restoration of a healthy water environment in Lake Biwa, this study uses total organic carbon (TOC) as a quantitative water-quality indicator and conducts a comprehensive analysis of the lake's organic-matter budget. In addition, the research is conducted on the sediment environment, which is considered to exert substantial influence on both water quality and the lake's ecosystem.

More details in Japanese (PDF: 222KB)

Studies on conservation and ecosystem management of Lake Biwa

　Focusing on native fish as representative organisms of the Lake Biwa ecosystem, we will attempt to elucidate the environmental factors necessary for the recovery of each species in order to propose appropriate conservation, management, and restoration methods for each species. In addition, we will examine monitoring methods that apply the advanced technologies to improve the accuracy of ecosystem assessments, which form the basis of our research.

More details in Japanese (PDF: 205KB)

Investigation of factors behind concentration fluctuations of photochemical oxidant and other air pollutants in Shiga Prefecture (Investigation and Analytical Studies 3)

　This study investigates photochemical oxidants (Ox) and fine particulate matter (PM2.5) along with their precursors, such as volatile organic compounds (VOCs), through monitoring and analysis. The aim is to clarify the factors driving variations in their concentrations in Shiga Prefecture and to obtain insights that can contribute to the development of effective concentration-reduction measures.

More details in Japanese (PDF: 445KB)

Development of methods for chemical investigation in aquatic emergency incidents (Investigation and Analytical Studies 4)

　To establish investigation methods for identifying the causes and impacts of chemical spills, we are developing approaches using gas chromatography–mass spectrometry (GC/MS), liquid chromatography–mass spectrometry (LC/MS), and bioassay-based acute toxicity tests using fish as a simple technique.

More details in Japanese (PDF: 251KB)

Air quality monitoring (Monitoring and Assessment 2)

　Regarding the air environment in Shiga Prefecture, in accordance with the Air Pollution Control Act, we 1) continuously conduct constant monitoring with automatic air monitoring stations and surveys of hazardous air pollutants, etc., 2) compile monitoring results such as compliance with environmental standards, and 3) monitor compliance with emission standards of facilities generating soot or smoke.

More details in Japanese (PDF: 132KB)

Source monitoring of water and soil environments (Monitoring and Assessment 3)

　To protect the water environment in the Lake Biwa basin, we conduct environmental monitoring as part of our responsibilities under the Water Pollution Control Act and other related laws. Our monitoring program has three key functions. We regularly inspect regulated facilities to ensure their wastewater meets discharge standards. When environmental emergencies occur, such as pollution accidents or groundwater contamination incidents, we perform water quality analyses to evaluate the extent of contamination and provide essential information for cleanup efforts. We also conduct water-quality analyses to continuously monitor the levels of chemical substances released into the environment.

More details in Japanese (PDF: 153KB)

Research on strategic scenarios for a sustainable society in response to climate change (Policy-oriented Research 7)

　This study focuses on climate change and explores vulnerability assessment methods that reflect regional characteristics and climate impacts. Building on these assessments, we will develop scenarios for a decarbonized society with virtually zero CO₂ emissions by 2050, as well as long-term visions for a society resilient to climate change. Furthermore, we will establish an information infrastructure to support the social implementation of climate change countermeasures, including both mitigation and adaptation measures. Through this platform, we will provide clear, accessible information and support evidence-based policy.

More details in Japanese (PDF: 481KB)

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[Research by the Environmental Research Promotion Organization] Research toward revitalizing the bounty of native fish and shellfish

　In response to the urgent issue of the decline in native fish and shellfish, we will elucidate the causes of the decline and propose policies to restore native fish and shellfish from a comprehensive perspective, including the connections between water systems and feeding environments. In our research, we will collaborate with prefectural testing and research institutions.

More details in Japanese(PDF: 322KB)

*This project consists of Policy-oriented Research 1 to 3

Research on the restoration of the shallow bottom environment and organisms in the coastal areas of Lake Biwa (Policy-oriented Research 1)

　As one of the measures to improve ecosystems in coastal areas, in order to obtain the knowledge necessary for the design of restoring shallow sandy areas, we will evaluate the factors that form the habitat and feeding environment using bivalves and other benthic macroinvertebrates as evaluation indicators, and by evaluating the impact of beach nourishment on the bottom sediment and living organisms, we will present design methods for restoring and conserving coastal environments that are thriving with bivalves and benthic macroinvertebrates, tailored to the environmental characteristics of the area.

More details in Japanese(PDF: 324KB)

Research on restoring connectivity in waterways to conserve native fish (Policy-oriented Research 2)

　To conserve native fish, we aim to elucidate the sediment movement mechanism in the "forest-river-estuary" area, focusing on sediment movement, which affects the formation of fish and shellfish habitats and spawning environments. Furthermore, by verifying the continuity of nature restoration activities by local people, we will identify key points for sediment management methods to conserve fish spawning environments. Finally, we will present key points for continuing nature restoration activities in the region.

More details in Japanese(PDF: 303KB)

Research on material cycling for ecosystem conservation (Policy-oriented Research 3)

　There is a growing need to improve water quality and sustain fishery resources by enhancing efficient material cycling that supports aquatic organisms such as fish and shellfish. This study aims to understand the structure of the lake's food chain and to analyze the relationship between water quality and fishery resources using simulation models. Based on these analyses, we will explore desirable material cycling from the perspective of ecosystem conservation and propose management strategies to mitigate stagnation in the cycling process.

More details in Japanese(PDF: 361KB)

Research on strategy for biodiversity conservation and restoration (Policy-oriented Research 4)

　This study aims to strategically advance the long-term and comprehensive conservation and restoration of biodiversity in Shiga Prefecture. We will examine measures to promote the incorporation of biodiversity into socio-economic activities, analyze the factors driving biodiversity loss, and present ideal measures to address rare, endemic, and invasive species.

More details in Japanese(PDF: 630KB)

Research on forest management for the conservation of the environment of Lake Biwa and its surroundings (Policy-oriented Research 5)

　To sustainably utilize the multifunctional forests, we will examine labor-saving forest regeneration techniques for cut-over areas in artificial forests and techniques to prevent soil erosion caused by deer feeding, and present findings that will contribute to appropriate forest management.

More details in Japanese(PDF: 219KB)

Research on ecosystem restoration through the management of aquatic plants (Policy-oriented Research 6)

　To appropriately manage the abundant submerged aquatic plants in the south basin of Lake Biwa, we use modeling to clarify the mass balance in the lake and predict potential aquatic plant growth based on nutrient levels in the sediment. We also aim to evaluate the ecological impacts of previous aquatic plant removal on organisms and ecosystems by analyzing the relationships between biological communities and environmental factors.

More details in Japanese(PDF: 285KB)

Water quality monitoring by depth and development of monitoring and evaluation methods for a new indicator (bottom-water DO) (Investigation and Analytical Studies 1)

　To understand long-term trends in water quality and their relationship to changes in the aquatic environment of Lake Biwa, we will conduct water-quality monitoring across different depths. In light of the recent establishment of a national environmental standard for bottom-water dissolved oxygen (DO), this study also aims to develop efficient monitoring and evaluation methods that reflect the current status of bottom-water DO and its key driving factors.

More details in Japanese (PDF: 235KB)

Plankton monitoring in Lake Biwa and the Seta River, and evaluation of plankton succession (Investigation and Analytical Studies 2)

　Continuous plankton monitoring in Lake Biwa will enable the prompt detection of changes in the plankton community. The monitoring data will be analyzed to assess plankton succession in the Seta River. Furthermore, the interactions between zooplankton and phytoplankton will be evaluated.

More details in Japanese (PDF: 232KB)

Monitoring of Lake Biwa and other water environments (Monitoring and Assessment 1)

　We monitor the water quality of public water bodies, including Lake Biwa, considering both environmental and water-use perspectives. Specifically, we investigate whether water quality meets environmental standards, and examine the plankton communities that cause algal blooms. Furthermore, we integrate these results with long-term monitoring data to evaluate the current status and temporal changes in the aquatic environment of Lake Biwa and other water bodies.

More details in Japanese(PDF: 214KB)

[Regional revitalization joint research] Research on comprehensive lake environment assessment and improvement methods for the conservation of a healthy aquatic environment in Lake Biwa

　Lake Biwa Branch Office of National Institute for Environmental Studies (NIES) was established in April 2017 at Lake Biwa Environmental Research Institute (LBERI). Based on NIES's pioneering achievements and expertise in the analysis and assessment of lake sediment environments and ecosystems, the Lake Biwa Branch and LBERI jointly promote collaborative research aimed at conserving and restoring the Lake Biwa watershed ecosystem.

Study on water quality and lake-bottom environment for the protection of the soundness of the water environment

　To support the conservation, management, and restoration of a healthy water environment in Lake Biwa, this study uses total organic carbon (TOC) as a quantitative water-quality indicator and conducts a comprehensive analysis of the lake's organic-matter budget. In addition, the research is conducted on the sediment environment, which is considered to exert substantial influence on both the lake's water quality and ecosystems.

More details in Japanese(PDF: 273KB)

Studies on conservation and ecosystem management of Lake Biwa

　Focusing on native fish as representative organisms of the Lake Biwa ecosystem, we will attempt to elucidate the environmental factors necessary for the recovery of each species in order to propose appropriate conservation, management, and restoration methods for each species. In addition, we will examine monitoring methods that apply the advanced technologies to improve the accuracy of ecosystem assessments, which form the basis of our research.

More details in Japanese(PDF: 261KB)

Investigation of concentration fluctuations of air pollutants such as PM2.5 (Investigation and Analytical Studies 3)

　This study investigates PM2.5, which is advected from domestic and international sources, including transboundary pollution from the Eurasian continent, and analyzes the factors behind the difference in PM2.5 concentrations within the prefecture. In addition, the study examines the relationships among PM2.5, yellow dust, other air pollutants, and atmospheric deposition to provide accurate and relevant information on air quality to residents of the prefecture.

More details in Japanese(PDF: 249KB)

Investigation of the impacts of chemical substances and establishing emergency response procedures for water pollution accidents (Investigation and Analytical Studies 4)

　To obtain information on the toxicity and related properties of unregulated chemicals, for which data remain insufficient in the Lake Biwa watershed, we are developing comprehensive instrumental analysis methods for groups of related substances, thereby improving the efficiency of environmental chemical analyses. Using these methods, we conduct monitoring to assess potential risks in Lake Biwa. In addition, we are developing bioassay-based methods to evaluate the total and ecological risks of chemical substances that are difficult to assess using instrumental analysis of individual chemicals. Furthermore, we aim to establish emergency response procedures for water pollution accidents, thereby strengthening crisis management.

More details in Japanese (PDF: 347KB)

Air quality monitoring (Monitoring and Assessment 2)

　To ensure the safety and security of the air environment in Shiga Prefecture, we continuously monitor photochemical oxidant concentrations using automatic air monitoring stations, conduct surveys of hazardous air pollutants, and analyze the results, including evaluating compliance with environmental standards. In addition, we conduct monitoring of facilities that generate soot or smoke in accordance with the law and provide information necessary to reduce emissions of air pollutants from factories, etc.

More details in Japanese(PDF: 179KB)

Source monitoring of water and soil environments (Monitoring and Assessment 3)

　To protect the water environment in the Lake Biwa basin, we conduct environmental monitoring as part of our responsibilities under the Water Pollution Control Act and other related laws. Our monitoring program has three key functions. We regularly inspect regulated facilities to ensure their wastewater meets discharge standards. When environmental emergencies occur, such as pollution accidents or groundwater contamination incidents, we perform water quality analyses to evaluate the extent of contamination and provide essential information for cleanup efforts. We also conduct water-quality analyses to continuously monitor the levels of chemical substances released into the environment.

More details in Japanese(PDF: 225KB)

Research on the future vision of a sustainable Shiga that fosters a sense of well-being and support for its social implementation (Policy-oriented Research 7)

　To realize a sustainable society, we will develop a database of key climate change mitigation and adaptation measures, identify barriers to their introduction, and clarify both the requirements for implementation and the interrelationships among measures.
Recognizing that the sense of "well-being" among prefectural residents is a crucial factor in advancing these measures, we will identify their key components and formulate a Shiga Social Vision that quantifies well-being and evaluates the effects of these measures.

　In addition, we will propose progress management methods—comprising systems and indicators—that promote the sharing of this future vision, support the implementation of measures, and enable flexible reviews in response to external factors. Through these efforts, we aim to facilitate the social implementation of the envisioned sustainable society.

More details in Japanese(PDF: 555KB)

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Research into the restoration of connections between water systems and living organisms Research toward revitalizing the bounty of native fish and shellfish  [Priority research project]

　In response to the urgent issue of the decline of native fish and shellfish in the Lake Biwa basin, we will take a comprehensive perspective, including the relationship between water systems and feeding environments, to elucidate the causes of the decline and propose policies to restore native fish and shellfish. We will conduct research in collaboration with prefectural research institutions.

More details in Japanese (PDF: 3,100KB) 

*This project consists of Policy-oriented Research 1 to 3

Research on the evaluation of bottom sediment environments in coastal areas (Policy-oriented Research 1)

　To conserve and restore coastal ecosystems, including the south basin of Lake Biwa, we will focus on the bottom sediment environment, which serves as the habitat for native fish and shellfish. We will identify the bottom sediment conditions that are desirable for sustaining rich biodiversity. By evaluating the impact of the artificial shoreline, which accounts for approximately 70% of the south basin of Lake Biwa's shoreline, on the ecological functions of the coastal area, we will present a method for coastal area management aimed at restoring habitats.

More details in Japanese (PDF: 2,933KB)

Research on river basin management for the conservation and restoration of native fish (Policy-oriented Research 2) 

　We will clarify the impacts of various environmental factors on the conservation and restoration of native fish. Furthermore, we will focus on the "aquatic system connections" from forests to lakes that affect the distribution and movement of native fish, and visualize the influencing factors using maps. Finally, based on the results, we will propose optimal methods for managing river basins that consider the habitats of native fish and other species and aim to implement these methods in conservation activities in collaboration with various stakeholders.

More details in Japanese (PDF: 2,672KB)

Research on evaluation of food resources for native planktivorous fish (Policy-oriented Research 3)

　To evaluate the desirable food resources for native planktivorous fish (such as ayu and honmoroko), we will investigate the occurrence of plankton. Focusing on the 'trophic linkage' from nutrients to plankton and fish, we will organize their interrelationships to understand the current status of food resources. In addition, through this assessment, we will examine the factors affecting native planktivorous fish from the perspective of the food resources.

More details in Japanese (PDF: 2,077KB)

Research on the conservation of biodiversity and the promotion of its sustainable use (Policy-oriented Research 4)

　To promote biodiversity conservation and ensure its blessings are passed on to future generations, we assess the current state of biodiversity in Shiga Prefecture and propose effective measures to conserve it. We also suggest ways to integrate biodiversity conservation into various government and business policies and initiatives.

More details in Japanese (PDF: 2,275KB)

Research on managing forests as a headwater for Lake Biwa (Policy-oriented Research 5)

　Forests in Shiga Prefecture serve a variety of important functions, such as acting as a headwater for Lake Biwa. This research aims to identify effective methods for managing these forests to sustain their multifunctional roles. We first investigate the potential for natural regeneration in clear-cut areas of mature artificial forests. Next, we examine forest management techniques for restoring natural forests near villages called "satoyama".

More details in Japanese (PDF: 2,748KB)

Research on the vision of a sustainable society for Lake Biwa and Shiga Prefecture and methods for its realization (Policy-oriented Research 6)

　To realize a sustainable society—one that maximizes people's well-being within environmental constraints, primarily CO2 emissions—it is necessary to quantify people's well-being and evaluate the effectiveness of various policies in terms of well-being. To achieve this goal, through a prefecture-wide survey, we will identify the elements that constitute people's sense of well-being, such as "connection with nature," "revitalization of the local economy," and "safety and security," and construct indicators to represent well-being.

　Additionally, as key elements supporting the well-being indicators in Shiga Prefecture, we will focus particularly on "Lake Biwa" and "energy." Regarding Lake Biwa, we will evaluate its ecological health by examining the relationships between material cycles (such as nitrogen and phosphorus) and ecological systems. Regarding energy, we will assess the feasibility of introducing renewable energy based on wood biomass, with a focus on effectively utilizing regional resources in Shiga Prefecture. Based on these evaluation results, we will identify the relationship between these two elements and the well-being indicators.

　Furthermore, we will utilize the constructed well-being indicators to envision the future society that the region should aim for, with participation from diverse stakeholders, and support the creation of action plans for each stakeholder to achieve this vision.

More details in Japanese (PDF: 1,251KB)

Research on predicting the behavior of radioactive materials to support the formulation of a monitoring plan (Policy-oriented Research 7)

　To support the development of a monitoring plan for a nuclear power plant accident in the near prefecture, this study uses an advection-diffusion model to simulate the behavior of radioactive materials in the atmosphere, on the surface, in water, and in bottom sediments under various conditions. It also examines the potential impacts on ecosystems based on these predictions and provides insights into monitoring strategies tailored to different diffusion scenarios.

More details in Japanese (PDF: 2,502KB)

Comprehensive assessment of the hypolimnion and benthic environment in the North basin (Investigation and Analytical Studies 1)

 　To understand the trend of hypoxia in the hypolimnion of the North Basin and its impacts on water quality and the ecosystem, we continuously monitor hypolimnetic conditions and investigate the effects of hypoxic periods on the benthic ecosystem.Furthermore, by using models and other approaches, we elucidate the mechanisms underlying hypoxia formation and comprehensively analyze the findings to integratively and quantitatively evaluate the factors driving hypoxia and its impacts on water quality and the ecosystem.

More details in Japanese (PDF: 2,333KB)

Investigation of advection effects on air pollutants such as PM2.5 (Investigation and Analytical Studies 2)

　To understand the current status of air pollutants such as PM2.5, which are advected from domestic and international sources, including transboundary pollution from the Eurasian continent, this study analyzes advection patterns during the periods of high PM2.5 concentration and identifies meteorological factors contributing to these elevated levels. In addition, this study aims to clarify the impacts of air pollutants on the Lake Biwa watershed and its ecosystem by analyzing the temporal variations and contributing factors of nitrogen deposition from the atmosphere to the Lake Biwa basin.

More details in Japanese(PDF: 2,898KB)

Investigation of the impacts of chemical substances and developing methods for total chemical risk assessment (Investigation and Analytical Studies 3)

 　To obtain information on the toxicity and related properties of unregulated chemicals, for which data remain insufficient in the Lake Biwa watershed, we develop comprehensive instrumental analysis methods for groups of related substances, thereby improving the efficiency of environmental chemical analyses. Using these methods, we conduct monitoring to assess potential risks in Lake Biwa. In addition, we are developing bioassay-based methods to evaluate the total and ecological risks of chemical substances that are difficult to assess using instrumental analysis of individual chemicals.

More details in Japanese(PDF: 2,384KB)

Monitoring of Lake Biwa and other water environments (Monitoring and Assessment 1)

　We monitor the water quality of public water bodies, including Lake Biwa, considering both environmental and water-use perspectives. Specifically, we investigate whether water quality meets environmental standards, and examine the plankton communities that cause algal blooms. Furthermore, we integrate these results with long-term monitoring data to evaluate the current status and temporal changes in the aquatic environment of Lake Biwa and other water bodies.

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Air quality monitoring (Monitoring and Assessment 2)

　To monitor the air environment in Shiga Prefecture, we conduct surveys on compliance with environmental standards and on regulated facilities and hazardous air pollutants, and evaluate the current state based on continuous monitoring.

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Source monitoring of water and soil environments (Monitoring and Assessment 3)

　To protect the water environment in the Lake Biwa basin, we conduct environmental monitoring as part of our responsibilities under the Water Pollution Control Act and other related laws. Our monitoring program has three key functions. We regularly inspect regulated facilities to ensure their wastewater meets discharge standards. When environmental emergencies occur, such as pollution accidents or groundwater contamination incidents, we perform water quality analyses to evaluate the extent of contamination and provide essential information for cleanup efforts. We also conduct water-quality analyses to continuously monitor the levels of chemical substances released into the environment.

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Research on sustainable society systems (Policy-oriented Research 1）

　To realize a sustainable society, we have reached the stage of developing a roadmap of measures and policies necessary to reduce greenhouse gas emissions. Moving forward, it will be essential to understand how these measures impact real life, including the regional economy and quality of life. Based on this understanding, we will need to develop specific initiatives and policies that foster a shift toward a community-rooted society where people can experience well-being. 

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Research on restoring the "connections" between water, living things, and life in the Lake Biwa basin (Policy-oriented Research 2)  

　A sustainable society is not just about being "low carbon" and "recycling," but also about "coexistence with nature." In particular, the themes of "restoring the relationship between life and the lake" and "preserving and restoring the Lake Biwa basin ecosystem" are considered key to the future of Lake Biwa's comprehensive conservation. Therefore, from these two key perspectives, we will organize issues according to the characteristics of the region, from the watershed to the lakeside area and within the lake itself. Ultimately, we hope to show the direction for water system management, leading to the promotion of concrete initiatives. 

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Research on new water quality management indicators for Lake Biwa (Policy-oriented Research 3)

　Although reductions in inflow loadings to Lake Biwa have been progressing, the chemical oxygen demand (COD) has not shown a decreasing trend. In addition, the concentration ratio of total nitrogen to total phosphorus (N/P ratio) is on the rise due to different trends in the increases and decreases of total nitrogen and total phosphorus. By elucidating these emerging phenomena, this research aims to support future water quality management, including the assessment of necessary countermeasures and the setting of management targets, thereby contributing to the restoration and maintenance of good water quality and balanced nutrient conditions.

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Research on adaptive management methods for the ecosystem in the South basin of Lake Biwa (Policy-oriented Research 4)

　Issues facing the south basin of Lake Biwa include changes in habitat due to reduced natural lake shores, the expansion of the distribution range of invasive alien species, and the massive overgrowth of submerged macrophytes. Given the characteristics of the south basin of Lake Biwa, which requires multifaceted solutions, including the conservation and restoration of water quality and the ecosystem, as well as the preservation of the landscape and the promotion of fisheries and tourism, it is necessary to promote appropriate ecosystem conservation measures from a comprehensive perspective by indicating the direction of management methods, including institutional aspects, on the premise that future predictions involve uncertainty. 

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Assessment of the hypolimnion and benthic environment in the North basin (Investigation and Analytical Studies 1)

　In the hypolimnion of the North basin, hypoxia frequency is expected to increase in the future. In particular, given ongoing concerns about global warming, it is essential to obtain detailed knowledge of the impacts on water quality and the ecosystem, and to build these findings into a scientific knowledge base. Such efforts will provide the foundation for examining and evaluating the necessity and validity of hypoxia countermeasures based on scientific evidence. 

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Examination of water quality assessment methods using seasonal succession of plankton (Investigation and Analytical Studies 2)

　In Lake Biwa, both the abundance and diversity of phytoplankton, which affect water quality, have been declining. Therefore, it is necessary to investigate the occurrence of phytoplankton. In addition, based on data on phytoplankton abundance and diversity, it is essential to examine methods for assessing water quality. 

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Analysis and evaluation of atmospheric deposition (Investigation and Analytical Studies 3)

　Monitoring results show that concentrations of photochemical oxidants are increasing, and fine particulate matter has been added as a new environmental monitoring standard. By studying the dynamics of transboundary air pollutants, we aim to understand how much atmospheric load reaches the Lake Biwa catchment. We also aim to clarify the mechanisms of photochemical oxidant formation, which still exceed environmental standards, and to evaluate their impacts on the water quality of Lake Biwa and on the surrounding vegetation.

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Investigation of the impacts of chemical substances and developing analytical methods (Investigation and Analytical Studies 4)

　Information on the toxicity, exposure pathways, and environmental persistence of many chemical substances remains insufficient, and advancing scientific environmental risk assessment has become a nationwide challenge. To investigate chemical exposure and prepare effective countermeasures in the near future for Lake Biwa and its inflowing rivers, we are accumulating relevant data by developing reliable analytical methods and detecting chemicals in the environment. 

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Monitoring of Lake Biwa and other water environments (Monitoring and Assessment 1)

　To ensure the safety and security of Lake Biwa and the water and soil environments in Shiga, we conduct water quality monitoring in accordance with relevant laws and regulations. Specifically, we have been monitoring water quality in Lake Biwa and the Seta River (since 1972), conducting wastewater surveys of factories and business establishments, and performing water quality surveys in specific areas, such as swimming beaches and Lake Nishinoko. 

Biological environment monitoring (Monitoring and Assessment 2)

　To ensure a safe and secure aquatic environment in Lake Biwa, we will investigate the occurrence of plankton communities that cause algal blooms (aoko) in the lake. In addition, we will examine compliance with environmental standards related to coliform bacteria in Lake Biwa and the Seta River. 

Air quality monitoring (Monitoring and Assessment 3)

　To maintain the safety and security of the air environment in Shiga Prefecture, in accordance with the Air Pollution Control Act, we conduct surveys of compliance with environmental standards for photochemical oxidants and related pollutants using automatic air monitoring stations and monitoring each emission source. 

Source monitoring of water and soil environments (Monitoring and Assessment 4)

　To ensure the safety and security of Lake Biwa and Shiga's water environment, we conduct comprehensive monitoring of chemical substances increasingly released by modern lifestyles and conveniences. We track the sources of these substances, assess their actual concentrations in the Lake Biwa and Seta River water environments, and monitor compliance with water quality standards. 

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Research on the Lake Biwa basin management system (Policy-oriented Research 1)  

　The "Lake Biwa Basin Integrated Management Model," originally developed between 2005 and 2007 to simulate the future of Lake Biwa, was further enhanced and refined in this study. Using the updated model, we illustrated future scenarios for Lake Biwa, accounting for its diverse values—such as water quality, landscape, and ecosystems—and proposed policy measures to realize those futures. 

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Research on mitigation of non-point source loads (Policy-oriented Research 2)

　To conserve water quality in Lake Biwa, it is necessary to implement measures not only against "point" source pollution from domestic and industrial wastewater, but also against "non-point" source pollution from agricultural land and urban areas. In this study, we examined the impacts of non-point source loads on Lake Biwa, which have not yet been fully understood, and proposed possible directions for measures. In addition, we evaluated the effectiveness of the measures implemented so far.

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Research on the mechanisms of water pollution (Policy-oriented Research 3)

　Organic pollution entering Lake Biwa has been estimated to decrease due to the development of sewage systems and other wastewater treatment facilities. However, the chemical oxygen demand (COD), an indicator of organic matter in the lake that represents the amount of oxygen required to oxidize organic matter chemically, has not shown a corresponding decline. In contrast, the biochemical oxygen demand (BOD), which indicates the amount of oxygen consumed by microorganisms during the decomposition of organic matter, has decreased. These trends suggest that organic matter less readily degraded by biological processes (refractory organic matter) may be increasing. This study aimed to elucidate the underlying mechanism of such water pollution. 

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Research on water quality fluctuations driven by internal loading and water quality management for ecosystem conservation (Policy-oriented Research 4)

　Although the water quality of Lake Biwa has improved due to reductions in external loadings, environmental standards have not been met for many water quality parameters, except for phosphorus and dissolved oxygen in the northern basin. In this study, we collected long-term water-quality monitoring data from Lake Biwa, conducted research on appropriate nutrient balance, and proposed measures to improve and conserve water quality. 

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Research on lakeshore ecosystem conservation, restoration, and management (Policy-oriented Research 5)

　To halt biodiversity loss in Shiga Prefecture, conserving the habitats of Lake Biwa and its littoral zones is an urgent priority. This study presents scientific insights and management guidelines for biodiversity conservation in the lakeshore ecosystem, based on analyses of shoreline geomorphological and land use changes, as well as current biological surveys.

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Research on sustainable society systems (Policy-oriented Research 6)

　In 2007, Shiga Prefecture developed the "Sustainable Shiga Society Vision" to achieve a sustainable society by 2030. Moving forward, we must examine policy measures such as economic and legal systems to realize this vision. Collaboration between the prefecture and local regions is essential in this process. Using a systematic modeling approach, we investigated the institutional and economic support measures the prefecture can provide to implement this vision at the regional level, as well as the challenges that arise.

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Monitoring and analysis of hypoxia and its impacts on the ecosystem in the North Basin of Lake Biwa (Monitoring and Assessment 1) 

　Hypoxia has been observed near the lake bottom in the North Basin of Lake Biwa, raising concerns about water quality deterioration and ecological impacts. This study aimed to elucidate the extent and mechanisms of hypoxia, and to assess its impacts on the ecosystem, thereby contributing to the conservation of the aquatic and natural environments.

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Analytical monitoring for optimizing water quality monitoring in Lake Biwa (Monitoring and Assessment 2)

　Currently, water quality monitoring is conducted once a month at 47 fixed locations in Lake Biwa. However, several challenges remain, including uncertainty about whether these sites provide a comprehensive understanding of the lake's overall water quality. In this study, we utilized the "Lake Biwa Basin Hydrological and Material Cycle Simulation Model" to evaluate and identify more effective and efficient monitoring sites and periods. 

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Monitoring and analysis of long-term succession of plankton in Lake Biwa (Monitoring and Assessment 3) 

　We have been investigating plankton in Lake Biwa for nearly 30 years. Based on these data, we examined changes in plankton and their effects on lake water quality. In addition, we established survey methods for plankton in Lake Biwa and prepared a monitoring manual.  

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Analytical monitoring for assessing the current state of the atmospheric environment (Monitoring and Assessment 4)

　Since 1972, monitoring stations have been established to measure air quality within the prefecture. However, with the recent population increase and the growing number of areas where photochemical smog warnings are issued, it has become necessary to review the monitoring system. In this study, simulations were used to understand the current state of the air and to establish an appropriate and efficient monitoring method.

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Research on the realization of a sustainable society in Shiga Prefecture

　We need to create a "sustainable society" that successfully balances environmental protection, social well-being, and economic growth. However, what would such a society actually look like? Moreover, is it truly achievable? To address these fundamental questions, we developed a quantitative model that describes how society functions and used it to explore potential pathways toward sustainability.

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Research on the development of an analytical system for integrated watershed management of Lake Biwa

　To ensure the comprehensive conservation of Lake Biwa, it is essential to evaluate its multiple values—including water quality, ecosystems, and landscape—and to implement effective management measures. In this study, we developed a set of simulation models to predict future conditions in the Lake Biwa basin and to support the formulation of appropriate policies.

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Understanding the impact of non-point source loads on the water quality in Lake Biwa

　To conserve water quality in Lake Biwa, it is necessary to implement measures not only against "point" source pollution from domestic and industrial wastewater, but also against "non-point" source pollution from agricultural land and urban areas. In this study, we investigated the non-point source loads from rivers under different rainfall and seasonal conditions, and their impacts on the water quality in Lake Biwa.

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Developing methods for conserving and assessing biodiversity based on the regional characteristics of watersheds

　Shiga Prefecture's biodiversity is being lost. There is a need to conserve native species, including endemic species. So, what should be the goals and what should be taken into consideration when working on conservation and restoration in each region? This study presented methods for conserving and assessing biodiversity through surveys in representative regions.

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Research on the development of an environmental information system involving prefectural residents

　Local water quality surveys are being conducted to improve the aquatic environment. By sharing the collected environmental information and organizing it in a clear, visual format, the data can be effectively utilized in community activities.As part of this research, we have developed the Lake Biwa Environmental Map, an online platform that is freely accessible to all residents and stakeholders.

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Research on the impacts of water quality in Shiozu Bay on the ecosystem of the North basin of Lake Biwa

　In Shiozu Bay, located in the northern part of Lake Biwa, deterioration of water quality and eutrophication are progressing, raising concerns about their impacts on the North basin.