The Use of Hoop Nets Seeded with Mature Brook Trout to Capture Conspecifics

Abstract

The brook trout Salvelinus fontinalis, a native of eastern North America, is considered an invasive species in the western United States because it has been implicated in the decline of many native trout species there. Current methods for controlling brook trout are usually time-consuming and expensive and are sometimes harmful to nontarget species. We tested a passive method of control using hoop nets to capture fish during brook trout spawning in the fall. We seeded nets with four different combinations of brook trout (a single male, three males, a male–female pair, and a single female) as well as with no fish to determine whether hoop-net capture success was greater in nets seeded with conspecifics. Nets with a male–female pair captured 30% more brook trout than the next best treatment; the differences were significant, however, only in comparison with the catches resulting from the single- and multiple-male treatments. We also found that hoop nets captured five times as many mature male brook trout as mature females. Although we were unable to conclusively identify a treatment that increases hoop-net capture rates, hoop nets were successful in removing up to 34% of the estimated number of brook trout in the study stream, even though we did not attempt to maximize capture efficiencies. Hence, hoop netting may be helpful in reducing brook trout numbers if alternative methods of removal are undesirable.