Last update:

Women “Soap Movement” against Freshwater Red Tide by Uroglena Americana in Lake Biwa, Shiga, Japan

A women-led movement against water pollution, red tides, eutrophication, moved administrators and companies while changing Japanese society.


Due to population growth and factories' settlements resulted from high growth, in the Shiga Prefecture, the water quality deterioration of Lake Biwa, the largest lake in Japan, had come to be regarded as a problem since late 1960[1].  Meanwhile, on 27 May 1977[2], a large scale freshwater red tide was generated by the golden alga Uroglena Americana[3] in the lake[4]. Red tides had occurred before locally[2]. However, at this time the impact was incomparable[2]. The red tide appeared on Lake North and Lake West, which were thought to be cleansed by the citizens of the prefecture[2].  

See more
Basic Data
Name of conflict:Women “Soap Movement” against Freshwater Red Tide by Uroglena Americana in Lake Biwa, Shiga, Japan
State or province:Shiga Prefecture
Location of conflict:Takashima-shi, Nagahama-shi, Hikone-shi, Ōtsu-shi, Oumihatiman-shi, Maibarashi, Yasu-shi, Kusatsu-shi, Moriyama-shi, Higashioumi-shi
Accuracy of locationMEDIUM (Regional level)
Source of Conflict
Type of conflict. 1st level:Industrial and Utilities conflicts
Type of conflict. 2nd level:Chemical industries
Aquaculture and fisheries
Water treatment and access to sanitation (access to sewage)
Specific commodities:Chemical products
Phosphorus, Nitrogen
Project Details and Actors
Project details

Population of the Shiga prefecture in 1977: 1,000,000 [9]

See more
Project area:67,000
Level of Investment for the conflictive projectn.a.
Type of populationSemi-urban
Affected Population:1,000,000 - 14,500,000
Start of the conflict:27/05/1977
End of the conflict:27/05/2008
Company names or state enterprises:Kao Corporation (Kao) from Japan - Release of phosphorus-free detergent "Just Powder" in March 1980 [17]
Lion Corporation (Lion) from Japan - Lion launched the industry's first non-phosphorus detergent “Seseragi” in the fall of 1973, and has continued to work on reducing phosphorus, and in 1977, completed the reduction of small concentrated phosphorus. [17]
Relevant government actors:Shiga prefecture
Environmental justice organizations (and other supporters) and their websites, if available:-Shiga Area Women's Groups' Association:
-Shiga Area Council Housewife Liaison Committee:
-Ōtsu Co-op:
Conflict & Mobilization
IntensityMEDIUM (street protests, visible mobilization)
Reaction stageIn REACTION to the implementation (during construction or operation)
Groups mobilizing:Local government/political parties
Social movements
Consumer groups, co-ops
Forms of mobilization:Community-based participative research (popular epidemiology studies, etc..)
Creation of alternative reports/knowledge
Development of a network/collective action
Development of alternative proposals
Involvement of national and international NGOs
Official complaint letters and petitions
Public campaigns
Shareholder/financial activism.
Street protest/marches
Boycotts of companies-products
Going around, Demonstration (education), On-site inspection
Environmental ImpactsVisible: Biodiversity loss (wildlife, agro-diversity), Loss of landscape/aesthetic degradation, Deforestation and loss of vegetation cover, Surface water pollution / Decreasing water (physico-chemical, biological) quality, Other Environmental impacts
Potential: Food insecurity (crop damage), Soil contamination, Groundwater pollution or depletion, Large-scale disturbance of hydro and geological systems
Other Environmental impactsOffensive odor
Socio-economical ImpactsVisible: Loss of landscape/sense of place
Project StatusIn operation
Conflict outcome / response:Environmental improvements, rehabilitation/restoration of area
Institutional changes
New legislation
Strengthening of participation
Technical solutions to improve resource supply/quality/distribution
Application of existing regulations
New Environmental Impact Assessment/Study
Withdrawal of company/investment
Do you consider this an environmental justice success? Was environmental justice served?:Yes
Briefly explain:The movement by local women forced the administration to the point of prohibiting the production and sale of the product that caused the red tides: the spread of this trend to the whole country has become significant for the lives of people.
Sources & Materials
Juridical relevant texts related to the conflict (laws, legislations, EIAs, etc)

Mother Lake 21 Project (accessed on 19-03-2019)
[click to view]

The regulations about prevention of eutrophication of Lake Biwa of Shiga Prefecture (accessed on 19-03-2019)
[click to view]

References to published books, academic articles, movies or published documentaries

[2] Chapter 2: Transition of the environment conservation movement in Shiga prefecture and soap movement (accessed on 25-03-2019)
[click to view]

[11] Muneta Y. (2 Jun. 2008). Eutrophication and Hypoxia of Lake Biwa. Institute for Chemical Research, Kyoto University. (accessed on25-03- 2019)
[click to view]

[12] Chapter 3: Water quality of Lake Biwa and Yodogawa water system (accessed on 25-03-2019)
[click to view]

[13] Chapter 4: What is Soap Movement? (accessed on 25-03-2019)
[click to view]

[14] Chapter 4: Social network analysis for Lake Biwa meeting (accessed on 25-03-2019)
[click to view]

[15] Kotani H., 1984, Water pollution control of Lake Biwa, Feature: Lake Biwa development and environmental protection technology, Vol. 13, No. 7 (accessed on 12-04-2019)
[click to view]

[17] Udou Y., Relationship between entry order and market share in the domestic laundry detergent market (accessed on 12-04-2019)
[click to view]

[1] Shiga water environment business promotion forum, Activities of citizens of the prefecture who protect Lake Biwa (accessed on 25-03-2019)
[click to view]

[2] Sekken Hyakka (accessed on 25-03-2019)
[click to view]

[3] Freshwater red tide (accessed on 30-03-2019)
[click to view]

[4] About present conditions and problem measures of environmental problems of Lake Biwa (accessed on 30-03-2019)
[click to view]

[5] Shiga prefecture, The 30th anniversary of the Day of Biwako (accessed on 25-03-2019)
[click to view]

[6] Kyoto Shinbun "The present soap movement", 17 May 2015 (accessed on 25-03-2019)
[click to view]

[7] Lake Biwa and human life, Lake Biwa Handbook revised edition (accessed on 25-03-2019)
[click to view]

[8] Eutrophication problem, Lake Biwa Handbook revised edition (accessed on 25-03-2019)
[click to view]

[9] Shiga prefecture, Population and number of households in Shiga prefecture (accessed on 25-03-2019)
[click to view]

[10] Nihon Keizai Shinbun "Stop the red tide by Public-Private relationship - Lake Biwa Environment Regeneration Path (1)”, 18 May 2015 (accessed on 25-03-2019)
[click to view]

[16] Kao (accessed on 12-04-2019)
[click to view]

[18] Lion (accessed on 12-04-2019)
[click to view]

Lake area (accessed on 25-03-2019)
[click to view]

About Prefecture liaison meeting of civic movement to promote the usage of powder soap to protect Lake Biwa, Paragraph 3 (accessed on 25-03-2019)
[click to view]

Shiga Prefecture, Overview of Lake Biwa (accessed on 25-03-2019)
[click to view]

Shiga water environment business promotion forum, System design, approach for water environmental preservation of Lake Biwa by administration (accessed on 25-03-2019)
[click to view]

Meta information
Contributor:EnvJustice, ICTA-UAB/Natsuka Kuroda,[email protected]
Last update18/08/2019
Conflict ID:4123
Legal notice / Aviso legal
We use cookies for statistical purposes and to improve our services. By clicking "Accept cookies" you consent to place cookies when visiting the website. For more information, and to find out how to change the configuration of cookies, please read our cookie policy. Utilizamos cookies para realizar el análisis de la navegación de los usuarios y mejorar nuestros servicios. Al pulsar "Accept cookies" consiente dichas cookies. Puede obtener más información, o bien conocer cómo cambiar la configuración, pulsando en más información.