Evaluation of Generalized Habitat Criteria for Assessing Impacts of Altered Flow Regimes on Warmwater Fishes

Abstract

Assessing potential effects of flow regulation on southeastern warmwater fish assemblages is problematic because of high species richness and poor knowledge of habitat requirements for most species. Our study investigated relationships between availability and temporal persistence of key habitats and fish assemblage structure at regulated and unregulated sites in the Tallapoosa River system. Fish assemblage characteristics at seven sites were quantified based on 1,400 electrofishing samples collected during 1994 and 1995. Physical Habitat Simulation (PHABSIM) programs were used to model availability and persistence of key habitats at regulated and unregulated sites. Associations between fish assemblages and availability or persistence of key habitats were identified via regression and analysis of variance. We found that hydropeaking dam operation reduced the average length of time that shallow‐water habitats persisted and also reduced year‐to‐year variation in the persistence of shallow‐water habitats compared with unregulated sites. Across sites and years, proportional representation of catostomids was positively correlated with persistence of shallow and slow‐water habitats during spring. Proportion of individuals as cyprinids was positively correlated with median availability of deep–fast habitat whereas proportion of percids was inversely related to median availability of deep–fast habitat. Mean fish density was positively correlated with the persistence of shallow and slow‐water habitats. Comparisons of key‐habitat measures and fish abundances between 1994 and 1995 at each site indicated that higher abundances of percids, catostomids, and cyprinids were associated with increased availability and persistence of shallow and slow‐water habitats in 1995. These findings demonstrate that the temporal and spatial availability of key habitats could serve as useful measures of the potential effects of flow alteration on lotic fish assemblages and suggest that both short‐term persistence of key habitats as well as annual variation in key‐habitat availability are important for maintaining diverse fish assemblages.

Macroinvertebrate instream flow studies after 20 years: a role in stream management and restoration

“…As discussed earlier in this paper, there are concerns about applying IFIM to assess the effect of flow modifications on southeastern streams of the United States, because of the high richness of fish species and limited knowledge of habitat requirements. Bowen et al (1998) investigated the use of generalized habitat metrics, rather than species specific, as one potential approach to this dilemma. Parameters for five key habitat types were selected and IFIM site models were developed at seven locations along the Tallapoosa River in Alabama.…”

“…The analysis of persistence (in hours) and availability of key habitat conditions may also make this approach especially useful in evaluating the effects of rapidly fluctuating flows downstream of peaking hydroelectric projects. The application of the approach described by Bowen et al (1998) could also be explored for its applicability to benthic macroinvertebrates. In fact, employing the low gradient or high gradient benthic community diversity suitability curves we have developed may approximate the use of generalized habitat metrics.…”

“…In fact, employing the low gradient or high gradient benthic community diversity suitability curves we have developed may approximate the use of generalized habitat metrics. Bowen et al (1998) focused on spring and summer months as those critical for fish spawning. Benthos should be evaluated over the entire year because of their general lack of mobility, compared with fish.…”

Simulation of Change in Physical Habitat of Fish Using the Mobile Bed Model in a Downstream River of Dam

“…하지 만 기존에 수행된 연구들은 댐 건설로 인하여 변화된 유황이 서식처에 미치는 단기적인 영향을 주로 연구 하였다 (Bowen et al 1988, Valentin et al 1996, Yi et al 2010a ( ) ( ) Habitat suitability curves for Zacco platypus used in this study (Kim 1997, Sung et al 2005.…”

Impacts of flow regulation on slackwaters in river channels

“…[23] While slackwaters are internationally recognized [e.g., Schiemer et al, 2001;Bowen et al, 2003;Nielsen et al, 2010] and represent a key habitat [sensu Bowen et al, 1998], there is no definitive criteria for defining slackwaters in ecological studies. Hydraulic criteria are commonly species specific and life stage dependent [Hancock and Bunn, 1999;Schiemer et al, 2001]; however, low velocities are clearly an important consideration with respect to mechanisms such as swimming ability of fishes [Koehn et al, 1994;Bowen et al, 1998;Price, 2007] and hydraulic residence time for invertebrates [Schiemer et al, 2001; King and Crook, 2002] and phytoplankton [Hein et al, 2004].…”