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.

鱼卵的漂流行为对于鱼类早期资源评估、产卵场识别以及河流管理均具有关键意义。为进一步阐明鱼卵在纵向、垂向与横向的运动规律，研究团队在搭载粒子追踪系统（PTV）的28米长水槽中开展实验，探究了鱼卵与减速水流的跟随特性。实验结果显示：鱼卵的纵向流速约为平均水流流速的0.83倍，而其垂向流速与水流流速无显著相关性。在漂流过程中，鱼卵几乎沿主流中轴线向两侧均匀扩散。本研究结果可为鱼类早期资源保护以及急流河流的生态调度提供有效参考。不过，仍需开展更多研究以明确高流速是否有利于漂流鱼卵的存活。