Gibson-Reinemer Daniel K, Solomon Levi E, Pendleton Richard M, Chick John H, Casper Andrew F
Illinois Natural History Survey, Illinois River Biological Station, Prairie Research Institute, University of Illinois, Havana, IL, United States of America.
Department of Natural Resources, Cornell University, Ithaca, NY, United States of America.
PeerJ. 2017 Sep 14;5:e3641. doi: 10.7717/peerj.3641. eCollection 2017.
In the Mississippi River Basin of North America, invasive bigheaded carp (silver carp and bighead carp , also referred to as Asian carp) have spread rapidly over the past several decades. In the Illinois River, an important tributary of the Upper Mississippi River, reproduction appears to be sporadic and frequently unsuccessful, yet bigheaded carp densities in this river are among the highest recorded on the continent. Understanding the causative factors behind erratic recruitment in this commercially-harvested invasive species is important for both limiting their spread and managing their harvest. We analyzed weekly catch records from 15 years of a standardized monitoring program to document the emergence of age-0 bigheaded carp in relation to environmental conditions. The appearance of age-0 fish was generally linked to hydrographic attributes, which probably serve as a cue for spawning. However, we found profound differences in the number of age-0 fish among years, which varied by as much as five orders of magnitude in successive years. The strong link between summer flooding and age-0 fish production we observed emphasizes the importance of understanding the hydrologic context in which sustained invasions occur. Despite evidence of sporadic recruitment, bigheaded carp populations in the Illinois River appear to be consistent or increasing because of particularly strong, episodic year classes.
在北美洲的密西西比河流域，入侵性的大头鲤（鲢鱼和鳙鱼，也被称为亚洲鲤鱼）在过去几十年中迅速扩散。在密西西比河上游的一条重要支流伊利诺伊河中，繁殖似乎是零星发生的，而且常常不成功，但这条河中的大头鲤密度却是该大陆有记录以来最高的。了解这种商业捕捞的入侵物种繁殖不稳定背后的成因，对于限制它们的扩散和管理其捕捞量都很重要。我们分析了一个标准化监测项目15年的每周捕捞记录，以记录0龄大头鲤的出现与环境条件的关系。0龄鱼的出现通常与水文特征有关，这些特征可能是产卵的信号。然而，我们发现不同年份0龄鱼的数量存在显著差异，连续几年的差异高达五个数量级。我们观察到夏季洪水与0龄鱼产量之间的紧密联系，强调了了解持续入侵发生的水文背景的重要性。尽管有零星繁殖的证据，但由于特别强大的偶发鱼群，伊利诺伊河中的大头鲤种群似乎保持稳定或在增加。
