Friday Mike, Haxton Tim
Biodiversity and Monitoring Section, Ministry of Northern Development, Mines, Natural Resources and Forestry, Rosslyn, Ontario, Canada.
Aquatic Research and Monitoring Section, Ministry of Northern Development, Mines, Natural Resources and Forestry, Peterborough, Ontario, Canada.
J Fish Biol. 2021 Dec;99(6):1940-1957. doi: 10.1111/jfb.14900. Epub 2021 Sep 27.
Lake sturgeon Acipenser fulvescens spawn at the base of Kakabeka Falls, a 39 m waterfall on the Kaministiquia River, a tributary to Lake Superior. Access to this historical spawning site can be restricted or delayed due to hydroelectric flow fluctuations that coincide with the A. fulvescens spawning season. The objectives of this study were to determine (a) the necessary flow conditions that facilitate spawning site access; (b) quantity and duration of flow required for successful spawning and dispersal of larvae; and (c) evaluate recruitment of juvenile A. fulvescens in relation to flow. A. fulvescens spawning migrations were tracked using a stationary telemetry receiver that logged the movements of 166 A. fulvescens fitted with radio-transmitters. Unrestricted access to the spawning site was facilitated when spawning flow was controlled at 23 m s in 2004 and 17 m s in 2006. Fluctuating (0.5-8.5 m s ) and delayed spawning flows resulted in restricted and delayed access to the spawning site. Flow duration for successful egg incubation, hatch and larval dispersal was determined by sampling larvae using drift nets and quantified using cumulative temperature units (CTU). Over 10 years, 10,083 larvae were captured between 31 May and 20 July with 97% of the drift occurring prior to 30 June. From the date of first spawning to the end of larval dispersal took an average of 38.6 days, and the mean CTU value was 398.6. In general, a minimum flow of approximately 14.5 m s from the date of initial spawning to the accumulation of c. 400 CTU ensured successful hatch and larval dispersal. During the timeframe of this study, recruitment was variable. This study described the complex and variable reproductive life history of A. fulvescens and defined spawning flow requirements ecologically, which can be used to develop operational provisions at hydropower facilities to ensure successful reproduction.
湖鲟（Acipenser fulvescens）在卡卡贝卡瀑布底部产卵，卡卡贝卡瀑布位于苏必利尔湖的支流卡米尼斯蒂夸河上，落差39米。由于水电流量波动与湖鲟的产卵季节重合，进入这个历史产卵地可能会受到限制或延迟。本研究的目的是确定：（a）有利于进入产卵地的必要水流条件；（b）成功产卵和幼体扩散所需的流量数量和持续时间；（c）评估湖鲟幼鱼补充数量与水流的关系。使用一个固定的遥测接收器跟踪湖鲟的产卵洄游，该接收器记录了166条装有无线电发射器的湖鲟的活动。2004年产卵流量控制在23米/秒、2006年控制在17米/秒时，有利于无限制地进入产卵地。波动的（0.5 - 8.5米/秒）和延迟的产卵流量导致进入产卵地受到限制和延迟。通过使用漂流网对幼体进行采样来确定成功进行卵孵化、幼体孵化和幼体扩散所需的水流持续时间，并使用累积温度单位（CTU）进行量化。在10多年的时间里，于5月31日至7月20日期间捕获了10083尾幼体，其中97%的漂流发生在6月30日之前。从首次产卵之日到幼体扩散结束平均需要38.6天，平均CTU值为398.6。一般来说，从初始产卵之日到积累约400个CTU期间，最小流量约为14.5米/秒可确保成功孵化和幼体扩散。在本研究期间，幼鱼补充数量各不相同。本研究描述了湖鲟复杂多变的繁殖生活史，并从生态学角度定义了产卵流量要求，可用于制定水电设施的运行规定以确保成功繁殖。
