Midwest Fish & Wildlife Conference 2018

AUTHORS. Nick Kramer, Kansas Department Wildlife, Parks, and Tourism

ABSTRACT. Gill nets are one of the most popular gears implemented to assess fish populations in North America (Gabelhouse et al. 1992). Ease of construction and low maintenance has led to their success and widespread implementation in the field of fisheries management (Bonar et al. 2009; Miranda and Boxrucker 2009; Hubert et al. 2012). The characteristics of a gill net, along with the size and shape of the fish affect how capture occurs (i.e., wedging, gilling, tangling, or a combination). Many studies have been completed on selectivity of various sizes of mesh (Reddin 1986; Holst et al. 1996; Miranda and Boxrucker 2009; Hubert et al. 2012). Despite the importance of mesh size, the shape of the mesh can also be altered by modifying the hanging ratio which in turn will affect the catchability of fishes with differing body shapes. Additional studies have demonstrated the effectiveness of hobbling or tying down gill nets. This creates more of a “baggy” net which studies have shown to capture a wider size range of fish (Scholten and Bettoli 2007) and may increase catches of species that could easily become tangled due to external protrusions (e.g., Channel Catfish; Smith et al. 2017, or Paddlefish; Hoffnagle and Timmons 1989). In recent years, Kansas Department of Wildlife, Parks, and Tourism biologists have become interested in managing Blue and Flathead Catfish and have placed an increased priority on sampling these species; however, the biologists currently have little insight into fully representative population parameters due to standardized sampling gear that does not capture larger individuals (Buckmeier and Schlechte 2009). Thus, the objective of this study is to evaluate the effectiveness of various gill net designs to sample fish populations in Kansas impoundments with special consideration given to species of interest for biologists (e.g., Blue Catfish, Flathead Catfish).