moving patterns of drifting fish eggs

The drifting behavior of fish eggs is crucial for early-stage fish resources estimation, fish spawning ground identification and river management. To further clarify move patterns of drifting fish eggs in longitudinal, vertical, and lateral directions, their followability with the decelerating flow was studied in a 28 m flume equipped with particle tracing system (PTV). The results showed that the longitudinal velocity of fish eggs was 0.83 times of the mean flow velocity, while the vertical velocity of fish eggs was not significantly related to the flow velocity. During drifting, fish eggs spread almost uniformly to both sides along the central axis of the main current. The results are useful for early-stage fish resource conservation and ecological scheduling of the rivers with rapid flows. However, more studies are needed to confirm whether high flow velocity is beneficial to the survival of drifting fish eggs.