Brown Trout Redd Locations in the Northernmost Section of Spearfish Creek in Spearfish, South Dakota, USA

Abstract

Salmonid fish are known to reproduce throughout the Black Hills in South Dakota, however, it is not known when or where they are spawning or how successful their spawning is. This study documented for the first-time brown trout (Salmo trutta) redd locations and redd construction timing in a 1.6 km reach of Spearfish Creek, within the northern most part of the city of Spearfish, South Dakota, USA in 2020. Redds were first observed on October 13, 2020, with observations continuing until November 17 when no new redds were spotted. Redd construction peaked during the first week of November, with 52 observed. A total of 146 redds was recorded over the course of the study, resulting in a density of 91 redds/km. This is the first study to document redds in this section of Spearfish Creek. These observations will allow for comparisons to future spawning activity which may be impacted by the increased urbanization likely along this section of the creek. Hopefully, This study can also guide future research and habitat projects throughout this section of Spearfish Creek, and potentially throughout this region.