On 21 April 2021, Osaka, Japan-based Yanmar Marine Systems began accepting orders within Japan for a new automated fish counting system. The system is designed for tuna farming and utilizes image recognition technology to count the number of fish.
In fish farming, it is essential to know the number of fish inside each net in order to control production volume and the amount of feed used. Furthermore, in recent years as part of a drive towards more sustainable resource management, fishing vessels are required to accurately report the number of young pacific bluefin tuna caught in the wild, which end up being used for breeding at fish farms. Current methods are laborious and time-intensive requiring manual counting of the total number of fish caught and visually counting underwater images when moving the fish to aquaculture nets.
To tackle this problem and support the aquaculture industry, YMS has developed the Automated Fish Counting System which significantly reduces the time needed to count fish. Yanmar’s Research & Development Center developed image recognition and processing technology and an integrated system including hardware, such as a specially designed underwater camera and image processing computer, to realize real-time automated counting. Under optimal conditions, the system has succeeded in automatically counting tuna with an accuracy of more than 98%. In the future, YMS aims to contribute to greater efficiency and development of the fishing and aquaculture industry by reducing feed costs, cutting work time, and facilitating the accurate reporting of catches.
Product overview
Currently only available to the Japanese market, the standard configuration includes an underwater camera (including video cable), onboard monitor, image processing computer and dedicated software.
Diagram of the automated fish counting system

The counting system enables users to analyze and check results during or immediately after video capture. The viewing angle of the underwater camera can be adjusted by remote control even after the camera is installed underwater, reducing the time required to install and adjust the camera.
The viewing angle and brightness can be adjusted to reduce image disturbances and reduce their impact on automated analysis. The screen display and correction functionality enable easy manual counting and correction after automated analysis even for images affected by environmental disturbances.
Video of the automated fish counting system – The movie on YouTube: https://youtu.be/hr-CO8hJ_SE
The automated fish counting system is being developed in collaboration with the aquaculture division of Maruha Nichiro. In preparation for mass production, Maruha Nichiro arranged several sites for Yanmar to conduct trials under various environmental conditions to evaluate the product’s performance.