Column on Biodiversity

Biodiversity is the Color of Life: Biological Diversity and Cultural Diversity of Lake Biwa, an Ancient Lake

Yukiko Kada
President of Biwako Seikei Sport College, Ex-Governor of Shiga Prefecture, Ex-President of Japanese Association for Environmental Sociology

Rice Paddies are Reservoirs for Capturing Fish

“In a night, the rice paddies turned into reservoirs for capturing nigoro-buna. That was a gift of the rain. Quick-eyed kids never missed such an attractive playground. Curious boys started to fight over capturing nigoro-buna before going to school.”  (Mitsuhiko Imamori, 15 June 2015)

Mr. Mitsuhiko Imamori, born in Otsu City located in the southwest shore of Lake Biwa, described in his column published in the MIDORI Press his happy memories and how he became a satoyama photographer.  In the mid-1950s, fish living in Lake Biwa swam in the canals and came into the rice paddies for spawning after the rain.  He said that he was drawn to the lure of satoyama by the excitement of chasing the fish.

Mr. Imamori grew up in Obanagawa-cho in the west part of Otsu City.  Now there are many buildings and the Otsu-kyo train station in the area.  Rice paddies around Lake Biwa were started to develop about 2300 years ago, and fish spawning in rice paddies around Lake Biwa was commonly observed until recently.  The below photograph shows a site in Satsukawa-cho, Moriyama City close to the 'Biwako Ohashi' toll bridges in the mid-1950s.  Older people living around the area speak nostalgically of the lost landscapes.  “After the rain, carp and crucian carp (nigoro-buna (Carassius auratus glandoculis)), were swimming from Lake Biwa into rice paddies for spawning.  We called such places “uojima.”  We caught them and made funazushi (a specialty of Shiga Prefecture, salted and fermented crucian carp in rice).”


The below-right photograph shows the same site in 1997.  The Lake Biwa Comprehensive Development Plan was also considered to be a water resource development making use of Lake Biwa as a multi-purpose dam.  Dikes and water gates were constructed between Lake Biwa and the rice paddies in order to artificially manipulate the water level of the lake, and the fishways were interrupted.  In addition, rice paddies were consolidated, and their water use was divided into agricultural use and drainage.  In Satsukawa-cho, irrigation canals were buried underground and the water was supplied by bulbs like a waterworks system.  There was drainage, but the environment for fish to swim into rice paddies was totally damaged.

Cultural Diversity Born from Biological Diversity

Lake Biwa is an ancient lake with four million years of history, and has maintained rich ecosystems with abundant endemic species and so is like an “exhibition site of evolution.”  It is noteworthy that endemic fish species in Lake Biwa do not (cannot) spawn offshore, and have spawning habitats in coastal areas such as reed belts, rice paddies and rocky beach areas.  Even large fish like Lake Biwa catfish (Silurus biwaensis) spawn in rocky coastal areas around May to June.  As well as kids like Mr. Imamori in his former days, adults also enjoyed catching fish including crucian carp in rice paddies and reed belts, and secured food for the year.  These fish were also offered to regional shrines for yearly festivals, and were considered to be irreplaceable from religious and cultural perspectives.


“Who owns nature?” This topic has been discussed in the field of environmental sociology and several studies have been conducted.  Especially, “The Tragedy of the Commons” published by an American biologist in the late 1960s was a milestone.  He insisted that “Nature should also be owned by individuals because common ownership of nature such as pastures enhances selfish use and leads to the depletion of nature.”  His article triggered arguments about the ownership of nature. 

When I studied in the United States in the 1970s, I focused on the “ownership and utilization of nature,” and after I came back to Japan, I started conducting research on traditional knowledge about the utilization of land, water and living things around Lake Biwa.  According to this ownership research the land is owned by individuals, but the water is commonly owned and managed by the respective communities.  This ownership and management have been traditionally undertaken.  The research also revealed that fish in rice paddies do not belong to owners of the rice paddies but to people who catch them; this means that fish are considered to be “unlimited common resources” in many regions.  Here we can see “care for and co-existence with the weak” based on “diverse ecosystems” in order to meet everybody’s need for food regardless of land ownership.  In other words, land, water and living things have been “used and managed in a multi-layered way.”  Inedible living things such as killifish or fireflies also had an important significance as objects for kids to play with.  Such cultural use of water and fish in Japanese villages was maintained as village communities and linked to religious faiths for tutelary gods.  Cultural diversity was maintained by biological diversity.

Land consolidation of rice paddies was conducted with the purpose of modernizing agriculture.  Large quantities of pesticides and agricultural chemicals were dosed liberally in rice paddies in order to improve rice productivity.  “Rice monoculture” was promoted, and fish in rice paddies were considered to be a nuisance.  Fish also could not live in rice paddies rich in agricultural chemicals, and living things including the fish gradually disappeared from the rice paddies and canals. 


Suggestion for Integrating Cultural Diversity into the National Biodiversity Strategy

The concept of biodiversity was an internationally emerging issue at the Rio Earth Summit in 1992.  In 1995, Japan ratified the Convention on Biological Diversity and the first National Biodiversity Strategy (Ministry of the Environment, Japan) was presented.  However, I had a serious feeling of detachment when I read it.  The strategy was mainly focused on American conservatism, and as seen in the below figure, it was based on a “conflicting social model” as exemplified by “human society and culture versus nature.”  Based on my in-depth research about villages around Lake Biwa, it was obvious that “biological diversity underpins cultural diversity.”  So I strongly insisted on my opinions at the congresses at Japan’s Ministry of the Environment and Agency for Cultural Affairs, and appealed the necessity of national strategies based on the “duplicated social model” shown below.  In addition to my research, a lot of research in diverse fields including anthropology, ethnology and environmental sociology was also published, and the revised national strategy presented in 2002 expressly showed that Japanese cultural diversity has been maintained and developed by biodiversity, and the co-existing inter-relationship between the two is the essence of the Japanese nature view.  The reed belts of Nishinoko Lake, an inner lake of Lake Biwa, designated as the first “Important Cultural Landscape” is considered by the Agency for Cultural Affairs to be a “duplicated social model”.


“Fish Nursery Paddy Fields” Project to Retrieve Fish in Paddy Fields

After preparations from the end of the 1980s, the Lake Biwa Museum was opened in 1996 as a general facility for research and exhibition about “interaction between Lake Biwa and humans.”  Just after its opening, I launched and initiated “integrated research on rice paddies.”  This research not only focused on history, culture, societies, and ecological characteristics of rice paddies but also the restoration of multi-functional aspects of rice paddies such as “uojima” spawning places.  My project team suggested to the Agricultural Division of the local government of Shiga Prefecture that this idea would contribute to the population recovery of endemic species.  At that time, the endemic species of Lake Biwa had already decreased to about one twentieth of what they had been, and especially, the depletion of crucian carp for making funazushi was serious.  However, there was great resistance.  The Agricultural Division promoted modernized agriculture and the officers in charge had a strong sectional opinion that “rice paddies are for cultivating crops and fish are a nuisance.  Fish is a matter handled by Fisheries Division.”  There was a high wall to achieving the goal to raise fish in rice paddies.  But this wall was transcended by the research results presented by a researcher at the Lake Biwa Museum.  The research indicated that tens of thousands of larval fish were born from several crucian carp released in rice paddies, and swam into Lake Biwa.  When this paper was published, a young officer in charge of agriculture started to construct fishways in rice paddies in cooperation with the people of the regional land improvement authority around 2003.  At that time, our slogan was not “maintenance of biodiversity” but a gourmand strategy with the slogan of “let’s enjoy funazushi.”  This strategy was disseminated gradually, and especially after 2006, I focused on it as the governor, and promoted it as a key agricultural and environmental policy. 

In order to promote the “Fish Nursery Paddy Fields” Project, an understanding of regional communities and their land improvement authority was essential.  Older people who knew “uojima” in the past made moves, and now more than 50 regions are participating in this project.  The idea of “Satisfaction among all parties concerned with the fish nursery paddy fields” was naturally born from the areas proactively joining the project.  “Fish Nursery Paddy Fields” is good for wildlife and Lake Biwa.  In addition, “children play with fish in rice paddies,” and “communities are activated.”  The rice crop cultivated at “Fish Nursery Paddy Fields” is sold at expensive prices as brand rice since it is grown in a safe environment where fish can live.



Lake Biwa and its Waterfront Landscapes Were Designated as a Japan Heritage in 2015

After my inauguration as Governor in 2006, I deployed staff in the Division of Cultural Property Protection in order to discover “Treasures of Water” related to Lake Biwa. Then, 100 treasures were designated over several years and the policy that enabled them to have respective stories.  As a result of this series of efforts, Lake Biwa and its waterfront landscapes were designated as a Japan Heritage in 2015.  Traditional food culture represented by funazushi was nurtured through these efforts.  As a result, “water treasures” became a source of peoples’ pride and were situated as a tourism resource.  In 2017, a “Grutto Water Cultural Fair” will be held around Lake Biwa.  The environmental co-existence model duplicating nature and humans is expected to be focused on by overseas people as well as Japanese people.


 Profile of Yukiko Kada


Dr. Kada was born in Saitama Prefecture in 1950.  She was drawn in by the lure of agriculture and nature under the influence of her peasantist mother.  Being impressed during junior-high and high school trips to Mt. Hiei and Lake Biwa, she moved to the Kansai Region, in the west part of Japan. When she was a student at Kyoto University, she became to have interest in the co-existence of water and humans on a global scale through exploration in Africa questing for the origin of mankind.  After studying at the graduate school of The University of Wisconsin-Madison, she started her career as a researcher at the Lake Biwa Research Institute, and launched environmental sociological research in rice paddies and villages around Lake Biwa.  In the 1980s, she advocated “life environmentalism” with sociologists and anthropologists.  She was awarded her Ph.D. degree in agriculture from Kyoto University in 1985.  In the 1990s, she proposed the establishment of the Lake Biwa Museum, and had been involved in its establishment, design and operation.  After she served as Professor at Kyoto Seika University, she challenged in the 2006 gubernatorial election to make the best use of her academic achievements in politics, and was elected as the 5th woman Governor in Japan.  She developed new key policies including “Lake Biwa Environmental Policies,” “Child-raising and Women Participation,” “Regional Employment and Activation,” the “Graduation from Dams – Watershed Management Policy” and the “Graduation from Nuclear Power Plants Policy.”  She received an honorable retirement from the position of Governor of Shiga Prefecture in July 2014.  Now she serves as President of Biwako Seikei Sport College, and has been engaged in nurturing youth and establishing a society where multigenerational people live happily together through regenerating water culture and the environment in Shiga Prefecture.


Her major books include: “Inochi ni kodawaru seiji wo shiyo!” (in Japanese, Politics Valuing Lives)(Fubaisya, 2013), “Chiji wa nani ga dekirunoka – Nihon-byo no chiryo wa chiiki kara” (in Japanese, What the Governor Can Do – Recovery from Japan Disease by Local Efforts)(Fubaisya, 2012),  “Seikatsu-kankyo-shugi de iko! – Biwako ni koishita chiji” (in Japanese, Go Along with Life Environmentalism – The Governor Who Fell in Love with Lake Biwa)(Iwanami Junior Book, 2008), “Mizu wo meguru hito to shizen” (in Japanese, Humans and Nature Around Water – from Field Sited of Japan and Abroad)(Yuhikaku, 2003), “Kankyo-shakaigaku” (in Japanese, Environmental Sociology)(Iwanami Shoten, 2002), “Mizubegurashi no kankyogaku, Biwako to sekai no mizuumi kara” (in Japanese, Lifestyle Environmentology of Waterfronts – from Lake Biwa and World Lakes)(Showa-do, 2001).