The common carp, Cyprinus carpio, is a large, long-lived, fecund and mobile cyprinid, which evolved in complex inter-braided Ponto-Caspian rivers that experience both springtime flooding and freezing winters. Studies suggest adults often move to productive, shallow lakes and floodplains to spawn because they often lack egg predators and then return to deeper normoxic waters to overwinter. Whether these movements involve individuals consistently selecting, or homing to, the same spawning and refuge lakes as part of a strategy benefiting their reproductive success is unknown. To address this question, we examined the movements of 67 radio-tagged adult carp for 3 years in a watershed with 11 interconnected lakes. Carp were tagged and released into a centrally located, normoxic deep lake in spring and fall. Each spring over 95% of its adults left via a single stream and swam into one of 5 shallow lakes, with most individuals (84%) selecting the same lake(s) in which to spawn each year (median Bhattacharyya affinity coefficient of similarity of 0.82). Young were later found in those lakes without egg predators, which cannot survive winter anoxia. After spawning, carp spent summers moving between productive lakes in an individualistic fashion, presumably foraging, with most (89%) eventually returning to the same deep lake to overwinter (median Bhattacharyya affinity of 1.0). These movements appear to reveal a life-history tactic involving seasonal homing migration, first to a spawning location and later to winter refuges, that is well adapted to productive but highly heterogeneous and interconnected freshwater environments.
Bibliographical noteFunding Information:
This study was funded by the National Science Foundation (Grant No. #IIS 1111638). Nate Banet performed the study, analysed the data, wrote initial drafts and edited presubmission drafts. John Fieberg assisted with data analysis and edited the manuscript. Peter Sorensen conceived of the project, funded it, assisted with data collection and analysis, revised, and then edited the manuscript. In addition, Przemek Bajer kindly helped with tagging and fish tracking as did Mary Headrick, Reid Swanson, Justine Dauphinais, Nathan Berg, Justin Howard, Peter Leonard and Catherine Nester. Matt Kocian from Rice Creek Watershed District assisted with data collection, sharing lake data and watershed district maps. We thank several homeowners for allowing us to use their property for remote tracking stations including Tannie and Walter Eshenaur. Jon Adsem helped with the remote receivers. Volkan Isler was instrumental in procuring NSF funding and extremely patient in waiting for this publication. Benjamin Banet and Rachel Edwards assisted with the figures. John Fieberg and Peter Sorensen received partial salary support from the Minnesota Agricultural Experimental Station. We thank our reviewers and editor for their many helpful comments.
© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
- invasive species