Marine Biotas Survey

The Institute of Environmental Science comprehensively evaluates the water environment based on the water quality and biota of rivers and seas in the city, and aims to raise the interest of citizens. ), We have been investigating organisms that live in rivers and seas almost every three years.
In the waters, the 15th survey was conducted in fiscal 2020 and 2021 (FY2021 FY2023).
Since the start of the survey, the majority of the fish caught by the small bottom seine nets in the inner bay tended to be humid, Tenjikudai, Komochi Jaco, Shiroguchi (Ishimochi), and Makogare, which prefer mud. In recent years, Hatamochi Tenumeli, Ko Jaco Jaco, and Makogare have decreased. On the other hand, in this survey, many plankton-eating maji and Konoshiro, whose spring survey overlapped with the spawning season, were captured.
In this survey, three species of fish were first identified: Pigeon, Igodakahodeli, and Kutsuwa goby, all of which were rare species in Tokyo Bay, where the open ocean is the main distribution area. In addition to fish, a phenomenon in which the distribution area extends toward the back of the bay was observed in several organisms.

We investigate fish, coastal animals, benthic animals, seaweed and seaweed, plankton, and environmental factors (water quality, sediment), and conduct water quality evaluations based on biological indicators.
In fiscal 2021, the survey was conducted twice in spring and summer.