Detecting Invasive Round Goby in Wadeable Streams: A Comparison of Gear Types

Abstract

Abstract The invasion of round goby Neogobius melanostomus into tributaries of the Laurentian Great Lakes poses concerns for the conservation of native fish communities and the functioning of stream ecosystems. In streams, where standard methods for detection are lacking, development of sensitive sampling methods to identify round goby-invaded sites is a prerequisite for the implementation of effective management strategies. We sampled 34 stream sites that spanned a range of goby densities with two active gears (electrofishing and seining) and one passive gear (minnow traps) to compare gear efficiency at detecting invasive round goby. Naive occupancy, defined as the number of sites where goby were detected with each gear divided by the total number of sites, was 0.79 (27/34 sites) for seining, 0.68 (23/34) for electrofishing, and 0.50 (17/34) for traps. The probability of detecting a single round goby in a single pass (determined with single-season, constant-probability models) was 0.75 ± 0.065 (mean ± SE...