Understanding dreissenid mussel population dynamics and their impacts on lake ecosystems requires quantifying individual growth across a range of habitats. Most dreissenid mussel growth rates have been estimated in nutrient rich or nearshore environments, but mussels have continued to expand into deep, cold, low-nutrient habitats of the Great Lakes. We measured annual quagga mussel (Dreissena rostriformis bugensis) growth at 15 m, 45 m, and 90 m in Lake Ontario using caged mussels near Oswego, New York, USA from June 2018 to May 2019. Quagga mussel growth (starting size 12 mm) was greatest at 15 m (mean shell length increase = 10.2 mm), and was lower at 45 m (5.9 mm) and 90 m (0.7 mm). Caged mussels were obtained from near the 90-m site and those reared at 15 and 45 m developed thicker shells than those that were caged at 90 m. We observed relatively high colonization by quagga and, to a lesser degree, zebra mussels (Dreissena polymorpha) at 15 m, very few colonizers at 45 m, and none at 90 m. Higher growth potential, but low natural mussel densities observed at 15 m and 45 m suggest factors other than growth limit dreissenid abundance at these depths. The relatively slow dreissenid growth rates observed in offshore habitats are consistent with the gradual abundance increases documented in these zones across the Great Lakes and suggest new mussels that become established in these habitats may contribute to ecosystem effects for decades.

了解德莱森贻贝种群动态及其对湖泊生态系统的影响需要量化一系列栖息地的个体生长。大多数德莱森贻贝的生长速度是在营养丰富或近岸环境中估计的，但贻贝继续向五大湖深处、寒冷、低营养的栖息地扩张。我们测量了一年一度的斑驴贻贝 ( Dreissena rostriformis bugensis)2018 年 6 月至 2019 年 5 月，在美国纽约州奥斯威戈附近使用笼养贻贝，在安大略湖 15 m、45 m 和 90 m 处生长。斑驴贻贝生长（起始大小 12 mm）在 15 m 处最大（平均壳长增加= 10.2 mm)，在 45 m (5.9 mm) 和 90 m (0.7 mm) 处较低。笼养贻贝是从 90 米附近的地点获得的，在 15 米和 45 米养殖的贻贝比在 90 米笼养的贻贝壳厚。我们观察到斑马贻贝的定植率相对较高，斑马贻贝（Dreissena polymorpha) 在 15 m 处，在 45 m 处很少有殖民者，在 90 m 处没有。在 15 m 和 45 m 处观察到较高的生长潜力，但自然贻贝密度较低，这表明除了生长之外的因素限制了这些深度的德莱森鱼丰度。在近海栖息地观察到的相对缓慢的德莱森鱼生长速度与五大湖这些区域记录的丰度逐渐增加一致，并表明在这些栖息地中建立的新贻贝可能有助于数十年来的生态系统效应。