CMFRI Develops App That Measures Fish Size Without Handling Them

Measuring the size of a fish may soon require nothing more than a smartphone camera, thanks to a new mobile application developed by scientists at the ICAR-Central Marine Fisheries Research Institute (CMFRI).

The application, named MatsyaMetri, can estimate the length and width of a fish from an image captured using a smartphone camera, eliminating the need to physically handle and measure individual fish.

Once an image is captured, the app automatically records the measurements, potentially making biological data collection faster and more efficient for scientists and field survey teams.

Traditionally, researchers have had to measure fish manually, a process that can be laborious and time-consuming when large numbers of specimens are involved. MatsyaMetri is designed to simplify this process and can measure multiple fish of the same species during a single sampling session.

One of the key features of the application is its ability to generate length-frequency data. Such information is important in fisheries science because it helps researchers study the size distribution and population structure of fish in a particular area. The data can be used for stock assessment, population studies and monitoring the health of fishery resources.

The app also stores photographs along with the measurements collected during each sampling session. The information can subsequently be exported in CSV format, allowing researchers to analyse the data using other software.

Senior CMFRI scientist and ICAR-National Fellow Dr Eldho Varghese, who developed the application, said the objective was to simplify the collection of biological data and make fisheries-related information more systematic and accessible for scientific analysis.

The process of using MatsyaMetri is designed to be straightforward. A user first creates a sampling session and points the smartphone camera towards a flat surface. The fish is then positioned within the camera's field of view. The application detects the surface and displays an on-screen measuring guide before estimating the fish's length and width from the captured image.

MatsyaMetri has been developed for Android smartphones compatible with ARCore technology, Google's augmented reality platform. By using camera-based measurement and automated data recording, the application could significantly reduce the amount of manual work involved in large-scale fish sampling.

CMFRI Director Dr Grinson George said the application simplifies biological data collection by automatically recording measurements and generating datasets. The technology is primarily intended for scientists, researchers and field survey teams.

The application was developed under a project focused on the automated measurement of aquatic resources and the generation of standardised length-frequency data for fisheries stock assessment. The project is supported by the Indian Council of Agricultural Research (ICAR) under the Department of Agricultural Research and Education through the ICAR-National Fellow Project.

By combining smartphone imaging, augmented reality and automated measurement, MatsyaMetri could provide researchers with a faster and less intrusive way to collect large volumes of fisheries data, while reducing the need for repeated manual handling of fish.