Why the Stall? Using Metabolomics to Define the Lack of Upstream Movement of Invasive Bigheaded Carp in the Illinois River

Bigheaded Carp have spread throughout the Mississippi River basin since the 1970s. Little has stopped the spread as carp have the ability to pass through locks and dams, and they are currently approaching the Great Lakes. However, the location of the leading edge in the Illinois River has stalled for over a decade, even though there is no barrier preventing further advancement towards the Great Lakes. Defining why carp are not moving towards the Great Lakes is important for predicting why they might advance in the future. The aim of this study was to test the hypothesis that anthropogenic contaminants in the Illinois River may be playing a role in preventing further upstream movement of Bigheaded Carp. Ninety-three livers were collected from carp at several locations between May and October of 2018. Liver samples were analyzed using gas chromatography-mass spectrometry in a targeted metabolite profiling approach. Livers from carp at the leading edge had differences in energy use and metabolism, and suppression of protective mechanisms relative to downstream fish; differences were consistent across time. This body of work provides evidence that water quality is linked to carp movement in the Illinois River. As water quality in this region continues to improve, consideration of this impact on carp spread is essential to protect the Great Lakes. The data shared here contains the raw data from the fish collection.

自20世纪70年代以来，大头鱼（Bigheaded Carp）已遍布密西西比河流域。由于大头鱼能够穿过水闸和大坝，其扩散几乎未受阻碍，目前正逼近五大湖。然而，尽管不存在阻碍其进一步向五大湖推进的屏障，伊利诺伊河中的扩散前沿位置已停滞十余年。明确大头鱼未向五大湖移动的原因，对于预测其未来可能扩散的驱动因素至关重要。本研究旨在验证以下假设：伊利诺伊河中的人为污染物可能在阻止大头鱼进一步向上游移动方面发挥作用。2018年5月至10月期间，研究人员在多个地点采集了93份大头鱼肝脏样本。采用靶向代谢组学分析方法，通过气相色谱-质谱联用技术（gas chromatography-mass spectrometry）对肝脏样本进行了分析。与下游区域的大头鱼相比，扩散前沿的大头鱼肝脏在能量利用和代谢方面存在差异，且其保护机制受到抑制；这些差异在时间上具有一致性。本研究为伊利诺伊河水质与大头鱼移动之间存在关联提供了证据。随着该区域水质持续改善，考虑这种影响对大头鱼扩散的作用对于保护五大湖至关重要。此处共享的数据包含鱼类采集的原始数据。