Human-induced changes in the hydrological regimes of lotic waters such as hydropeaking have significant negative impacts on riverine life. However, the impacts of dynamic changes in water flow on adhesive fish eggs are not very well known. We focused on the effects of hydropeaking on the spawning ground of a rheophilic cyprinid fish, the asp (Leuciscus aspius). We tested whether a sudden increase in water velocity caused by hydropeaking may have negative effect on the adhesive eggs by the combination of field observations and laboratory experiments. The main objectives of the study were to (i) investigate abiotic characteristics of an asp spawning ground, (ii) monitor egg densities in relation to hydropeaking events and (iii) test detachment rates of the asp eggs in laboratory conditions in relation to water velocity. The asp spawning ground was associated with shallow water depths (0.2–0.4 m) and flowing water (0.1–0.4 m s⁻¹) during base flow. The water velocity that occurred on the spawning ground during the hydropeaking event was measured to be from 0.7–1.2 m s⁻¹. Asp eggs nearly disappeared from the spawning ground before their hatching time probably due to several hydropeaking events. The laboratory experiments showed the significant dependency of egg detachment rates on the water velocity and substrate type with a critical value of 0.7 m s⁻¹. Our data suggested that eggs may be negatively impacted by flow alterations. Avoiding hydropeaking or keeping water velocity below critical values is recommended for the management of rheophilous fish spawning grounds.

中文翻译：

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水峰对一种嗜流性鲤科鱼类附着卵的影响

人为引起的激流水域水文状况的变化，例如水峰，对河流生活产生了重大的负面影响。然而，水流的动态变化对粘附鱼卵的影响还不是很清楚。我们专注于水峰对嗜流性鲤科鱼类的产卵场的影响，asp ( Leuciscus aspius）。我们通过现场观察和实验室实验相结合，测试了由水峰引起的水流速度突然增加是否可能对粘附蛋产生负面影响。该研究的主要目标是 (i) 调查 asp 产卵场的非生物特征，(ii) 监测与水峰事件相关的卵密度，以及 (iii) 在实验室条件下测试与水速相关的 asp 卵的分离率. 在基流期间，asp 产卵场与浅水深（0.2-0.4 m）和流动的水（0.1-0.4 m s ^-1）有关。在水峰事件期间发生在产卵场的水速经测量为 0.7–1.2 m s ^-1. Asp 卵在孵化前几乎从产卵场消失，可能是由于几次水峰事件。实验室实验表明，卵脱离率对水速和基质类型有显着依赖性，临界值为 0.7 m s ^-1。我们的数据表明，流动变化可能会对鸡蛋产生负面影响。建议在流变性鱼类产卵场的管理中避免出现水峰或将水速保持在临界值以下。