A New App Can Measure Fish With a Smartphone, Can It Help Farmers?

Measuring fish size is important for understanding growth, stock structure and development. But doing this manually can take time, especially when researchers need measurements from many fish. ICAR-CMFRI has now developed MatsyaMetri, a smartphone application that can measure fish length and width without physically handling them.

The application uses the smartphone camera and augmented reality to estimate fish dimensions. Users place the fish within the camera view on a flat surface, while the app detects the surface and provides an on-screen measuring guide for recording its size.

The technology was developed by ICAR-CMFRI under a project focused on automated measurement of aquatic resources. The project aims to generate standardised length-frequency data used for fisheries stock assessment, population analysis and resource monitoring.

How does MatsyaMetri work?

The user first creates a sampling session and points an Android smartphone camera towards a flat surface. The fish is then placed within the camera’s view. The application detects the surface and uses image-based measurement to estimate the fish’s length and width.

The system can measure multiple individuals of the same species during one sampling session. It automatically records the measurements and photographs, then creates length-frequency distributions using suitable class intervals for further analysis.

Once the sampling session is completed, the measurements and photographs can be saved together. The recorded information can also be exported as a CSV file, allowing researchers to transfer the data for additional scientific analysis.

MatsyaMetri currently requires an Android smartphone that supports Google’s ARCore technology. Users must register and log in before creating a sampling session, according to ICAR-CMFRI’s description of the application.

Why does fish size matter?

Fish length provides important information about the population being studied. Researchers can examine the distribution of different size groups and use those patterns when assessing fish stocks, population structure and changes in aquatic resources.

Traditionally, collecting these measurements requires people to handle individual fish and record their dimensions manually. When hundreds or thousands of fish need to be assessed, that process can require considerable time and repeated measurements.

MatsyaMetri is designed to make this data collection faster and more systematic. ICAR-CMFRI says the application automatically records measurements and generates length-frequency datasets, reducing some of the manual work involved in field surveys.

The app also keeps photographs with the measurements. This creates a record that can be reviewed later and allows the data to remain connected with the specimens documented during a particular sampling session.

Can fish farmers use it?

For fish farmers, the technology could eventually have useful applications, but the current purpose needs to be understood. ICAR-CMFRI says MatsyaMetri is designed mainly for fisheries scientists, researchers and field survey teams conducting biological data collection.

A farmer could potentially use the measurements to document fish growth during sampling, but the available official information does not establish that the application has been tested as a farm-management tool.

This distinction matters because measuring fish with a smartphone does not by itself tell a farmer whether the stock is healthy, whether feed should be changed or when fish should be harvested.

Those decisions require additional information about species, age, feeding, water quality, disease, stocking density and market conditions. MatsyaMetri currently focuses on measurement and data generation rather than providing complete farm-management advice.

Where could the technology go next?

The biggest opportunity may come from combining automated measurements with larger fisheries datasets. When researchers collect standardised information from many locations, the resulting data can help build a clearer picture of fish populations and their size distribution.

For fish farmers, such information could become useful indirectly. Better stock assessments can support decisions about fisheries management, resource monitoring and sustainable use, although those broader benefits depend on how widely the technology is adopted.

The app is also relatively accessible because it uses a smartphone rather than requiring a dedicated measuring instrument. Still, users need compatible Android hardware and suitable conditions for placing the fish within the camera’s measurement area.

MatsyaMetri is therefore better understood as a digital measurement tool than a complete fisheries application. Its immediate value lies in making biological data collection easier, faster and more organised for people conducting fish surveys.

For farmers, the technology is worth watching rather than treating as a ready-made replacement for farm records. If future versions are tested for aquaculture use, smartphone-based measurement could become another way to track growth without repeatedly using manual measuring tools.

The larger lesson is that smartphones are becoming useful instruments for collecting agricultural and fisheries data. MatsyaMetri shows how a simple camera can be combined with software to turn an image into structured information that researchers can analyse.

For now, the strongest use case remains scientific fieldwork. But if the technology is adapted and validated for aquaculture farms, it could eventually help farmers record fish growth more quickly and create better records for production planning.