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River area biopharmaceutical survey
Last Updated November 28, 2024
Overview of the survey
The Institute for Environmental Science evaluates the comprehensive water environment, including the water quality of the waters in the city's waters, and also shows changes in the biota to raise citizens' interest in rivers and the sea. For the purpose, almost every three years since 1973, we are investigating creatures that live in rivers and the sea in the city.
In the river area, the 16th survey was conducted in FY2022 and FY2023.
Over the past 50 years, some creatures have returned from the river in Yokohama once, such as Ayu, due to the improvement of water quality due to the spread of sewerage and the improvement of the river environment through the installation of fishways. While the types of fish, shrimp, and crabs that come and go through rivers and the sea are increasing, the number of alien species is also increasing, so it is necessary to pay attention to future trends.
Survey points
The survey points are 41 rivers in 6 water systems (2023 results) of rivers flowing through the city.
- Tsurumi River water system (12 points)
- Katabira River water system (4 points)
- Ookagawa water system (7 points)
- Miyakawa water system (2 points)
- Samurai River System (3 points)
- Sakaigawa water system (13 points: 1 point outside the city)
Details of the survey
We investigate fish, benthic animals, aquatic plants, adhering algae, and water quality, and evaluate river water quality from living creatures.
In recent years, we have been conducting surveys at each location once in summer and winter.
Examples of river organisms
Loach
Shrimp
Shrimpmo
A friend of squirrel
Survey reports, etc.
Rivers and sea creatures in Yokohama
Public information Yokohama River
Public information Yokohama river (PDF: 1,294KB)
Following the fact that the 16th survey conducted in FY2022 and FY2023 was the 50th anniversary of the start of the survey, we created a document "Public Relations Yokohama River" that summarizes the changes in the river in Yokohama for 50 years in an easy-to-understand manner.
The title is based on images taken during the survey.
Yo (aquatic plants): Mizukinbai, Himegama, Aoukikusa
This (fish): Abrahaya, Kawayoshinobori
(Adhesive algae): Bacillaria paradoxa, spore period of the family Asteraceae, Nitzschia frustulum, Stephanodiscus niagarae
Ma (benthic animals): Kawarinuma shrimp, Nuka shrimp, Nami Uzmushi, Hirama Kimizumai
River (river landscape): Hayafuchi River, Miyakawa River, Ookagawa River
(both in brush order)
River and sea creature survey point map
In the "River and Sea Creature Survey Point Map" of the Yokohama City Administrative Map Information Providing System (Yokohama Map), you can check familiar survey points.
Yokohama＞Local charm map＞River and sea creature survey point map
River and sea creature survey point map (introduction of survey points) (outside site)
Return to the page of biodiversity in Yokohama
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Inquiries to this page
Environmental Science Research Institute, Environmental Conservation Department, Green Environment Bureau
Telephone: 045-453-2550
Telephone: 045-453-2550
Fax: 045-453-2560
Email address: mk-kanken@city.yokohama.lg.jp
Page ID: 327-274-135
