TY - JOUR
T1 - Aerial insect responses to non-native Chinook salmon spawning in a Great Lakes tributary
AU - Collins, Scott F.
AU - Marshall, B.
AU - Moerke, A.
N1 - Funding Information:
We would like to thank Lake Superior State University's School of Biological Sciences and Aquatic Research Laboratory, as well as R. Espinoza of the Michigan DNR Thompson Fish Hatchery for logistical and field support. This research was made possible by funding from the LSSU Undergraduate Research Committee , the Great Lakes Fishery Trust , and the Great Lakes Council of the Federation of Fly Fishers . Additionally, we thank J. Muehlbauer and three anonymous reviewers for comments and insights that improved this manuscript. The authors have no conflict of interest to declare.
Publisher Copyright:
© 2016 International Association for Great Lakes Research.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2016/6/1
Y1 - 2016/6/1
N2 - We investigated whether spawning by non-native Chinook salmon influenced aerial insect abundance in the riparian zone of Thompson Creek, a tributary of Lake Michigan, located in Michigan, USA. Specifically, we evaluated whether decades of salmon disturbance affected patterns of aquatic insect emergence, and how both live salmon and salmon carcasses influenced the abundance of terrestrial carrion flies. Retaining wall timbers from a low-head dam on Thompson Creek were removed, providing a unique opportunity to compare stream reaches that were exposed to the immediate ecological impacts of salmon (i.e., disturbance, subsidy effects) with reaches experiencing decades of spawning activity. Using sticky traps to collect aerial insects, we observed fewer adult aquatic insects in downstream reaches conditioned to decades of salmon disturbance in comparison to naïve upstream reaches. Reduced abundance in downstream reaches was primarily driven by taxa more susceptible to disturbance in the larval life stage (e.g., Diptera: Simuliidae, Ephemeroptera). A greater abundance of adult Chironomidae midges were detected in upstream reaches with higher numbers of spawning salmon and carcasses. Though abundance of adults differed between upstream and downstream reaches, we observed no evidence of early emergence. In addition, carrion fly abundance was greatest at reaches with more live and dead salmon. Evidence from our study suggests that non-native salmon have the potential to influence patterns of aerial insect abundance in riparian zones. Our findings suggest that non-native Chinook salmon can affect aerial insect assemblages; however, the propagating effects of these changes through riparian food webs warrant further investigation.
AB - We investigated whether spawning by non-native Chinook salmon influenced aerial insect abundance in the riparian zone of Thompson Creek, a tributary of Lake Michigan, located in Michigan, USA. Specifically, we evaluated whether decades of salmon disturbance affected patterns of aquatic insect emergence, and how both live salmon and salmon carcasses influenced the abundance of terrestrial carrion flies. Retaining wall timbers from a low-head dam on Thompson Creek were removed, providing a unique opportunity to compare stream reaches that were exposed to the immediate ecological impacts of salmon (i.e., disturbance, subsidy effects) with reaches experiencing decades of spawning activity. Using sticky traps to collect aerial insects, we observed fewer adult aquatic insects in downstream reaches conditioned to decades of salmon disturbance in comparison to naïve upstream reaches. Reduced abundance in downstream reaches was primarily driven by taxa more susceptible to disturbance in the larval life stage (e.g., Diptera: Simuliidae, Ephemeroptera). A greater abundance of adult Chironomidae midges were detected in upstream reaches with higher numbers of spawning salmon and carcasses. Though abundance of adults differed between upstream and downstream reaches, we observed no evidence of early emergence. In addition, carrion fly abundance was greatest at reaches with more live and dead salmon. Evidence from our study suggests that non-native salmon have the potential to influence patterns of aerial insect abundance in riparian zones. Our findings suggest that non-native Chinook salmon can affect aerial insect assemblages; however, the propagating effects of these changes through riparian food webs warrant further investigation.
KW - INHS
KW - Low-head dam
KW - Chinook salmon
KW - Disturbance
KW - Insect emergence
KW - Dam removal
KW - Non-native
UR - http://www.scopus.com/inward/record.url?scp=84977851714&partnerID=8YFLogxK
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U2 - 10.1016/j.jglr.2016.02.010
DO - 10.1016/j.jglr.2016.02.010
M3 - Article
VL - 42
SP - 630
EP - 636
JO - Journal of Great Lakes Research
JF - Journal of Great Lakes Research
IS - 3
ER -