We present the first comprehensive analysis of the Pacific Northwest estuaries (PNWE) zooplankton time series, which encompasses 38 estuaries distributed across more than 1000 km of the North American Pacific Coast. With observations spanning more than 20 yr, we here examine biogeographic trends among zooplankton communities, patterns of biological invasion across the region, and environmental correlates with dominant native and invasive taxa. Our results show that some estuaries across the region are invaded by multiple zooplankton species and that the geographic extent of invasion is far greater than previously reported for at least five species of copepods: Pseudodiaptomus inopinus, Pseudodiaptomus forbesi, Oithona davisae, Limnoithona sinensis, Sinocalanus doerrii, and the cladoceran Bosmina coregoni. Some of these species appear to be rapidly spreading across the region, while others have occupied a relatively static geographic range for decades. The copepod, P. inopinus, is by far the most abundant and geographically widespread of these invaders, comprising more than 90% of all zooplankton abundance at some sites. We propose that the geographic distribution of these invaders is strongly constrained by geomorphic characteristics that define the salinity and mixing regimes in these estuaries, reflecting the strong role that physical forces play in structuring estuarine zooplankton communities.

中文翻译：

---

浮游动物的大规模入侵：来自东北太平洋38个河口的20年时间序列的见解

我们对太平洋西北河口（PNWE）浮游生物时间序列进行了首次综合分析，其中包括分布在北美太平洋海岸1000多公里中的38个河口。通过对20多年的观测，我们在这里检查了浮游动物群落之间的生物地理趋势，该地区的生物入侵模式以及与主要原生和入侵类群相关的环境。我们的研究结果表明，该地区的一些河口由多种浮游动物和入侵的地域范围远远大于以前至少五种桡足类的报道入侵：Pseudodiaptomus inopinus，Pseudodiaptomus forbesi，长腹剑水蚤davisae，Limnoithona冬虫夏草，细巧doerrii和枝角类象鼻coregoni。这些物种中的某些似乎在整个地区迅速扩散，而其他物种则几十年来一直占据相对静止的地理范围。co足类迄今是这些入侵者中最丰富和地理分布最广的地区，占某些地点所有浮游动物数量的90％以上。我们建议这些入侵者的地理分布受到地貌特征的强烈限制，这些特征定义了这些河口的盐度和混合状态，反映了物理力在构造河口浮游动物群落中的强大作用。