Midwest Fish & Wildlife Conference 2017

AUTHORS: Tony J Barada, Jeff Jackson, Aaron Blank, Jordan Katt - Nebraska Game and Parks Commission

ABSTRACT: Gizzard shad in small water bodies are known to compete with sportfish, often limiting growth potential and size structure of fishes commonly sought by anglers.  However, gizzard shad populations are dynamic in nature and can be difficult to manage.  Previous research has shown that gizzard shad have a low lethal tolerance to rotenone, and applying very low doses (approx. 5% of normal renovation applications) targeting gizzard shad may be a valuable tool for improving a fishery without having to conduct a complete renovation. 
Low-dose rotenone applications were conducted at two waterbodies in southeast Nebraska during the fall of 2013.  One application was conducted on an 18-acre sand pit lake, while a large-scale application was conducted at a 740-acre flood control reservoir.  Fish communities differed between the two water bodies, however the goal of improving each recreational fishery was similar. 
Multiple years of standard surveys (trap netting, gill netting, electrofishing) were conducted pre- and post-application at each waterbody.  Surveys indicated gizzard shad were successfully eradicated from both water bodies one year after application.  However, gizzard shad were detected in the flood control reservoir in year two.  Common fisheries demographics (relative abundance, size structure, condition, growth) of sportfish will be compared and presented to demonstrate the utility of low-dose rotenone applications as a fisheries management tool.