Benthic invertebrates are important trophic links in aquatic food webs and serve as useful bioindicators of environmental conditions because their responses integrate the effects of both water and sediment qualities. However, long-term data sets for benthic invertebrate assemblages across broad geographic areas are rare and, even if collected, historic data sets are often not readily accessible. This data set provides densities of benthic macroinvertebrates for all taxa collected during lake-wide surveys in Lake Ontario, a Laurentian Great Lake, from 1964 to 2018. This information resulted from surveys funded by the governments of the United States and Canada to investigate the status and changes of Lake Ontario benthic community. Of the 13 lake-wide benthic surveys conducted in Lake Ontario over the course of 54 yr, we were able to acquire taxonomic data to the species level for 11 of the surveys and data to the group level for the other two surveys. Density data are provided for taxa representing the Annelida, Arthropoda, Mollusca, Cnidaria, Nemertea, and Platyhelminthes phyla. Univariate and multivariate analyses revealed that the compositional structure of Lake Ontario invertebrate assemblages differed markedly by depth and were also significantly altered by the Dreissena spp. invasion in early 1990s. The introduction of invasive dreissenids has changed the community historically dominated by Diporeia, Oligochaeta, and Sphaeriidae, to a community dominated by quagga mussels and Oligochaeta. Considering the rarity of long-term benthic data of high taxonomic resolution in lake ecosystems, this data set could be useful to explore broader aspects of ecological theory, including effects of different environmental factors and invasive species on community organization, functional and phylogenetic diversity, and spatial scale of variation in community structure. The data set could also be useful for studies on individual species including abundance and distribution, species co-occurrence, and how the patterns of dominance and rarity change over space and time. Use of this data set for academic or educational purposes is encouraged as long as the data source is properly cited using the title of this Data Paper, the names of the authors, the year of publication, the journal name, and the article number.

中文翻译：

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1964 年至 2018 年安大略湖底栖无脊椎动物组合的密度数据

底栖无脊椎动物是水生食物网中重要的营养环节，可作为环境条件的有用生物指标，因为它们的反应综合了水和沉积物质量的影响。然而，跨越广泛地理区域的底栖无脊椎动物组合的长期数据集很少见，即使收集了历史数据集，也往往不容易获得。该数据集提供了 1964 年至 2018 年在劳伦森大湖安大略湖的全湖调查期间收集的所有类群的底栖大型无脊椎动物的密度。此信息来自美国和加拿大政府资助的调查，以调查现状和安大略湖底栖群落的变化。在过去 54 年间在安大略湖进行的 13 次全湖底栖调查中，我们能够获得 11 项调查的物种级别的分类数据，以及其他两项调查的组级别数据。提供了代表环节动物、节肢动物、软体动物、刺胞动物、线虫和扁形动物门的分类群的密度数据。单变量和多变量分析表明安大略湖无脊椎动物组合的组成结构因深度而显着不同，并且也因德雷塞纳属 1990 年代初入侵。入侵性德莱森的引入改变了历史上由Diporeia主导的社区、Oligochaeta 和 Sphaeriidae，到一个以斑斑贻贝和 Oligochaeta 为主的社区。考虑到湖泊生态系统中高分类分辨率的长期底栖数据的稀有性，该数据集可用于探索生态理论的更广泛方面，包括不同环境因素和入侵物种对群落组织、功能和系统发育多样性的影响，以及群落结构变异的空间尺度。该数据集还可用于研究单个物种，包括丰度和分布、物种共存以及优势和稀有性模式如何随空间和时间变化。鼓励将此数据集用于学术或教育目的，只要使用本数据论文的标题、作者姓名、