River biotaste survey

The Institute of Environmental Science aims to raise citizens' interest in rivers and the sea by evaluating the comprehensive water environment, including the river water quality in the city's waters, and showing changes in the biota. For the purpose, we have been investigating creatures that live in rivers and seas in the city almost every three years since 1973.
In the river area, the 15th survey was conducted in FY2018 and FY2019.
Over the past 40 years, some creatures have returned to Yokohama rivers, even though they have disappeared once, such as Ayu, due to improvements in water quality due to the spread of sewerage systems and improvement of river environment by setting up fishways. While the number of fish, shrimp, and crabs coming and going through rivers and seas has increased, the number of exotic species is also increasing, so it is necessary to pay attention to future trends.

We investigate fish, benthic animals, aquatic plants, adhering algae, and water quality, and evaluate the water quality of rivers from creatures.
In recent years, surveys have been conducted at each site once a summer and winter.