Smallmouth Bass Summer Habitat Use, Movement, and Survival in Response to Low Flow in the Illinois Bayou, Arkansas

Abstract

The southwestern edge of the natural range of smallmouth bass Micropterus dolomieu contains streams that become disconnected pools during summer primarily owing to hydrogeologic conditions, including high evapotranspiration rates. These conditions may complicate fisheries management by affecting fish behavior or mortality rates. The objectives of this study were to characterize summer habitat use by smallmouth bass, estimate the changes in the extent of available habitat, describe summer movement patterns, and estimate summer survival rates. Radio transmitters were implanted into 60 smallmouth bass during May 2006, and the fish were tracked until October in the forks of the Illinois Bayou, which drains a portion of the Ozark National Forest. Habitat characteristics were measured as the summer progressed, and during this time most riffle–run habitat dried completely, resulting in a series of disconnected pools. The decreases in wetted area exceeded 55% in certain 2‐km study reaches; however, smallmouth bass were consistently found at a median depth of 0.80 m. Boulder habitat was preferred when it was available; however, cobble, gravel, and bedrock substrates were also used. By July, velocity was below detection levels and water temperature occasionally exceeded 30°C. The average distance moved by smallmouth bass was 270 m in May, decreasing to 54 m by July. The distances moved were greater on average but more variable in streams with larger losses of wetted area, as fish moved away from drying areas. The survival rate was lowest in the stream most accessible to anglers. Dryness appeared to increase mortality, as survival estimates were lower than expected from published studies of streams with continuous summer flow. The effective management of fisheries under such hydrologic conditions may require preserving continuous surface flow and the quality of remnant pools as well as implementing more restrictive harvest regulations in summer.

Behavioural thermoregulation and bioenergetics of riverine smallmouth bass associated with ambient cold‐period thermal refuge

“…The longest movement we observed was 42.5 km, which was greater than the maximum 7.5 km movement of smallmouth bass previously documented in this stream (Todd & Rabeni ), and our maximum and average movement distances were greater than observed for most smallmouth bass populations, but within the range documented for smallmouth bass (Lyons & Kanehl ; Hafs et al. ). The longest documented migration by smallmouth bass was 109 km in a Wisconsin stream during autumn when water temperatures fell below 16 °C and in conjunction with a rain event (Langhurst & Schoenike ).…”

Evaluating Two Observational Sampling Techniques for Determining the Distribution and Detection Probability of Age‐0 Smallmouth Bass in Clear, Warmwater Streams

“…Accurate sampling of age-0 smallmouth bass is problematic because these fish are thought to use a variety of habitats (see Pert et al 2002 for a review), whereas adults are generally associated with deepwater habitats (Munther 1970;Probst et al 1984;Todd and Rabeni 1989;Brewer et al 2007;Dauwalter and Fisher 2008;Hafs et al 2010). Species that use a variety of habitat types in a stream are particularly difficult to sample accurately because commonly used sampling methods have biases related to habitat conditions, particularly depth, current velocity, and cover (Peterson and Paukert 2009).…”

Channel Unit Use by Smallmouth Bass: Do Land‐Use Constraints or Quantity of Habitat Matter?

“…The physical factors related to the patterns observed in this study are unclear, though the physical and chemical consequences of urbanization have been well documented and include altered hydrology (Arnold et al 1982;Paul and Meyer 2001;Walsh et al 2005) and temperature (Paul and Meyer 2001). Extreme discharges during critical periods increase Smallmouth Bass mortality and reduce recruitment success (Peterson and Kwak 1999;Smith et al 2005;Hafs et al 2010) and high water temperatures restrict growth and reduce Smallmouth Bass densities (Sowa and Rabeni 1995;Zweifel et al 1999). The influence of pasture agriculture on aquatic fauna may be less pronounced than that found under well-studied, more intensive agriculture practices (e.g., row crop) (Meador and Goldstein 2003;Strayer et al 2003).…”

“…Secondary production by several crayfish species (a primary food source of Smallmouth Bass: Rabeni 1992; Roell and Orth 1993;Roell and DiStefano 2010) was higher in nonpool channel units even though they represented only a small fraction of total stream area in Ozark streams (Brewer et al 2009). Additionally, Hafs et al (2010) indicated survival of Smallmouth Bass was lower than expected when moving-water channel units dried during summer. Collectively, these studies suggest channel units that are rarely, if ever, used by Smallmouth Bass are still very important to the overall fitness of this species.…”