The variability of the zooplankton community over a spatial and a tidal scale, the relationship between physico-chemical variables, and the abundance of zooplankton were studied in the temperate and turbid Bahía Blanca Estuary (Southwestern Atlantic, Argentina). Samples were taken by pumps during 12-h tidal cycles, at 3-h intervals, from two depths and three sites across the main channel in the inner and middle estuary zones. The zooplankton was dominated by the copepods Acartia tonsa and Euterpina acutifrons, and larvae of the invasive Pacific oyster Crassostrea gigas. The physico-chemical variables that most influenced the zooplankton community were salinity, temperature, suspended particulate matter, and chlorophyll a Most taxa showed higher abundances in the inner estuary, which corresponds to a turbid and shallow area. The abundance of A. tonsa was higher in the inner estuary while that of E. acutifrons was higher in the middle estuary. This spatial distribution is consistent with the tidal distribution of these species as in the inner estuary the abundance of A. tonsa peaked at ebb tide and that of E. acutifrons peaked at flood tide. Significant differences in the zooplankton community structure both across the channel and between depths were detected by multivariate analyses, but no clear patterns were found in the abundance of each taxon by a species-level analysis. The results provide insight into the patterns of zooplankton distribution and abundance in a temperate, turbid, and human-impacted coastal ecosystem, considering different spatial and short-term scales. These results will be useful to design efficient sampling programmes in highly dynamic environments.

在温带和浑浊的巴伊亚布兰卡河口（阿根廷西南大西洋），研究了浮游动物群落在空间和潮汐尺度上的变异性，理化变量之间的关系以及浮游动物的丰度。在潮汐周期的12小时内，以3小时的间隔，通过泵从内河口和中河口区域主通道的两个深度和三个位置采集样品。浮游动物以pe足纲car螨（Acartiatona）和赤E（Euterpina acutifrons）以及入侵太平洋牡蛎Crassostrea gigas的幼虫为主。影响浮游动物群落的理化变量是盐度，温度，悬浮颗粒物和叶绿素a。大多数的分类单元在内河口有较高的丰度，这对应于浑浊而浅的区域。内河口A.tonsa的丰度较高，中河口E. acutifrons的丰度较高。这种空间分布与这些物种的潮汐分布是一致的，因为在河口内，在退潮时A.tonsa和E.acutifrons的丰度达到峰值。在洪水潮达到顶峰。通过多变量分析发现了跨通道和不同深度之间浮游动物群落结构的显着差异，但是通过物种水平分析，在每个分类单元的丰度中均未发现清晰的模式。研究结果提供了对不同温度和短期尺度下温带，浑浊和人类影响的沿海生态系统中浮游动物分布和丰度模式的了解。这些结果对于在高度动态的环境中设计有效的采样程序很有用。