IWHR’s Research Center for Sustainable Hydropower Development has jointly carried out model fish egg drifting and recapturing test in the middle reaches of the Yangtze River with Yangtze River Fisheries Research Institute of China Academy of Fishery Science.

Based on previous experiments, properties of the model eggs have been improved in this test, and unmanned boat used to accurately measure the terrain and flow field of the test section for the first time. A total of more than 30 million fish eggs were released, more than 10 thousand fish eggs were successfully recaptured, the farthest distance of the river section for the recapture was more than 15 kilometers, and model fish eggs were successfully recaptured in all of the more than 10 sampling points in the downstream of the release point, which indicates an important progress.

The study is an important basis for accurately locating fish spawning grounds and scientifically estimating the amount of early fish resources, and is an effective method to quantitatively study the pattern of fish egg drifting.

Releasing model fish eggs

Recapturing the model fish eggs

The unmanned boat measuring underwater terrain and flow field