Quantification and attribution of the food web changes associated with the invasion of non-indigenous species in the marine realm often remain a challenge. One of the pelagic non-indigenous species of concern in the recent history of aquatic bioinvasions is the predatory cladoceran Cercopagis pengoi, which invaded the Baltic Sea in the early 1990s. While several studies have reported immediate declines in abundances of its potential prey, the long-term effects of C. pengoi on the food webs remain to be examined. Based on the long-term time series (1968–2018) in the Gulf of Riga (Baltic Sea), we found significant declines in abundance of the cladoceran Pleopis spp. and copepod Eurytemora affinis by 90 and 80%, respectively, are associated with the invasion of C. pengoi as well as significant alterations in seasonal abundance patterns of Pleopis spp., E. affinis and cladoceran Bosmina spp. The invasion of the non-indigenous predator has led to the changed prey abundance–temperature relationships. Special caution was taken in data preprocessing, to minimize the likelihood that observed changes in the zooplankton prey could be associated with factors other than the invasion of C. pengoi, such as temperature and storminess.

中文翻译：

---

通过比较入侵前和入侵后时间序列揭示特定分类群对中上层无脊椎动物捕食者入侵的反应

与入侵海洋领域的非土著物种有关的食物网变化的量化和归因经常仍然是一个挑战。在最近的水生生物入侵史中，令人关注的远洋非土著物种之一是捕食的笼形螯虾Cercopagis pengoi，它在1990年代初入侵波罗的海。尽管有几项研究报告了其潜在猎物的数量立即减少，但仍需检查槟榔果对食物网的长期影响。基于里加湾（波罗的海）的长期时间序列（1968年至2018年），我们发现锁骨角le Pleopis spp的丰度显着下降。和co足类Eurytemora affinis由90和80％，分别与入侵相关联C. pengoi以及在季节性丰度模式显著改变Pleopis属，E. AFFINIS和枝角类象鼻属。非本土捕食者的入侵导致猎物的丰度与温度的关系发生了变化。在数据预处理中要特别谨慎，以最大程度地减少浮游动物猎物中观察到的变化可能与除企鹅衣原体入侵之外的其他因素（例如温度和暴风雨）相关联的可能性。