The distribution, density, biomass and size-structure of the zebra mussel (Dreissena polymorpha) population in Lake Winnipeg were examined between 2017 and 2019. Zebra mussels have colonized most of the available hard substrate in the south basin and Narrows region, but colonization of the north basin remains low at present, even on suitable substrate. Numerical densities and shell free biomass peaked at 5530 ± 953 m⁻² and 64.7 ± 57.9 g shell free dry mass m⁻² respectively. The distribution appeared to be strongly limited by substrate type and availability, with further limitations on the distribution imposed by physical disturbance in shallow waters and unsuitable substrate in deeper areas of the lake. Zebra mussels <1 year old dominated the populations, and individuals >18 mm were exceedingly rare. Poor recruitment was observed at sites along the eastern side of the south basin compared to elsewhere in the lake. The proximate causes of these differences in colonization success and recruitment are not clear, but may be in part due to heterogeneous patterns of key physico-chemical environmental conditions such as calcium concentrations required for successful development of juvenile mussels and colder water temperatures in the north basin. This study provides a baseline of information on which to track further expansion of zebra mussels in Lake Winnipeg and assist efforts to develop an understanding of how zebra mussels may affect the ecology of Lake Winnipeg.

2017 年至 2019 年期间，对温尼伯湖斑马贻贝 ( Dreissena polymorpha ) 种群的分布、密度、生物量和大小结构进行了研究。斑马贻贝已在南部盆地和纳罗斯地区的大部分可用硬质基质中定殖，但即使在合适的基质上，北部盆地目前仍处于低位。数值密度和无壳生物量在 5530 ± 953 m ^-2和 64.7 ± 57.9 g 无壳干重 m ^-2处达到峰值分别。分布似乎受到基质类型和可用性的强烈限制，浅水区的物理干扰和湖深区域不合适的基质进一步限制了分布。<1 岁的斑马贻贝在种群中占主导地位，> 18 毫米的个体极为罕见。与湖中的其他地方相比，在南盆地东侧的地点观察到补充不良。这些定植成功和补充差异的近因尚不清楚，但部分原因可能是关键物理化学环境条件的异质模式，例如成功发育幼体贻贝所需的钙浓度和北部盆地较冷的水温.