Lake whitefish (Coregonus clupeaformis) within the waters of Green Bay, Lake Michigan have recently shown a substantial increase in abundance. Furthermore, after over 100 years of extirpation, adult lake whitefish are found spawning within major Wisconsin tributaries to Green Bay. Many knowledge gaps still exist with respect to the chronology of adult river migrations, including the physical characteristics of upstream habitats selected for reproduction and the extent of larval production by these riverine ecotypes. Here, we use hydroacoustic imaging along with egg and larval surveys to evaluate this novel riverine spawning in 2017 and 2018. Highest abundance of adults was observed in the month of November as temperatures declined below 8 °C. Spawning areas consisted of cobble substrates, and site-specific fish densities were primarily correlated with river flows between 0.3 and 1.0 m/s, with specific values varying by tributary and year. Locations of egg deposition mirrored areas of high observed fish densities. Larval production was documented on each tributary using active trawl ichthyoplankton sampling, and larvae were observed outmigrating to open water environments. We estimated tributaries produced 452,000 larvae in 2017 and 721,000 larvae in 2018. To our knowledge, this represents the first documentation of successful lake whitefish larval production from Green Bay tributaries and suggests tributary spawning populations contribute to the greater abundance of lake whitefish observed in recent years.

怀特菲什湖（Coregonus clupeaformis）在绿湾水域内，密歇根湖最近显示出大量的增加。此外，在经过100多年的灭绝之后，发现在威斯康星州主要支流至绿湾的地方产卵了成年白鲑。关于成年河流迁移的时间顺序，仍然存在许多知识鸿沟，包括为繁殖而选择的上游生境的物理特征以及这些河流生态型的幼体产量范围。在这里，我们使用水声成像以及鸡蛋和幼虫调查来评估2017年和2018年这种新颖的河流产卵。由于温度下降到8°C以下，因此在11月份观察到了成年成虫的最高数量。产卵区域由卵石基质组成，特定地点的鱼类密度主要与0.3-1之间的河流流量相关。0 m / s，具体值因支流和年份而异。卵的沉积位置反映了高鱼群密度的区域。使用主动拖网鱼浮游生物采样记录了每个支流上的幼体产量，观察到幼体向开放水域环境迁移。我们估计，支流在2017年产生了452,000幼虫，而在2018年产生了721,000幼虫。据我们所知，这是绿湾支流成功生产湖泊白鲑幼体的第一份文件，并暗示了支流产卵种群对近年来观察到的湖泊白鲑的丰度做出了较大贡献。 。使用主动拖网鱼浮游生物采样记录了每个支流上的幼体产量，观察到幼体向开放水域环境迁移。我们估计，支流在2017年产生了452,000幼虫，而在2018年产生了721,000幼虫。据我们所知，这是绿湾支流成功生产湖泊白鲑幼体的第一份文献，并暗示了支流产卵种群对近年来观察到的湖泊白鲑丰富性做出了贡献。 。使用主动拖网鱼浮游生物采样记录了每个支流上的幼体产量，观察到幼体向开放水域环境迁移。我们估计，支流在2017年产生了452,000幼虫，而在2018年产生了721,000幼虫。据我们所知，这是绿湾支流成功生产湖泊白鲑幼体的第一份文献，并暗示了支流产卵种群对近年来观察到的湖泊白鲑丰富性做出了贡献。 。