Survey of fishery resources is automatically effected by providing an identification element (i.e. IC tag) to each fishing gear, locating a plurality of such fishing gears under the sea to catch fishery resources, thereafter, using a reading device (e.g. tag reader) to read all the identification elements to obtain an identification data for each of the fishing gears, while obtaining an operating position in this survey by GPS device, and then counting number of fish catches for each of the fishing gears. All the data thus obtained are processed by a computer, so that a data of fishery resources distribution under the sea can be obtained automatically, without requiring much labor and expenses in conducting the survey. A device for effecting such method is also provided.