Habitat Associations of Three Black Bass Species in a Reservoir System

Abstract

The habitat associations of three species of black bass Micropterus spp. were examined in six habitat types (i.e., sediment, gravel, rock, riprap, brush, and aquatic plants) along a cascade of 10 reservoirs in the Tennessee River. We tested whether habitat selection differed among the three species and whether species' co-occurrence depended on habitat type. We found that some species occurred in some habitats in proportion to habitat availability (some at higher frequencies and some at frequencies lower than availability) and that juveniles and adults exhibited similar occurrence patterns. Our habitat selection results largely corroborate previous descriptions of black bass habitat associations and generally track preference for lithic habitats, as reported in native streams. We expected the different black bass species to show negative co-occurrence to avoid competitive interactions. Nevertheless, we found that with few exceptions, adults co-occurred in habitats mostly as expected by chance and juveniles co-occurred more often than was expected by chance. Our findings imply that environmental filtering, rather than competitive interactions that dominate in natural environments, may be the dominant mechanism shaping black bass assemblages in reservoirs of the Tennessee River. The observed patterns of habitat selection and co-occurrence further suggest that the conservation and management of black bass assemblages in reservoirs can be supported through habitat management activities. Protecting and enhancing the remaining lithic habitat in the reservoirs as well as recovering habitat that is blanketed by sediment could provide desirable environments for all black bass species.

Fisheries Volume 48 Number 1 January 2023

“…For black bass in the study reservoirs, I speculate that the interaction between niche differences across taxa imposed by a combination of habitat preferences and habitat requirements, and by the underlying availability of habitats in these artifi cial environments, forces the observed taxa divergences in abundance-occupancy patterns. In the study reservoirs, Largemouth Bass are generalists relative to habitat selection (jack-of-all-trades), whereas Spotted Bass and Smallmouth Bass tend to have keener affi nities for rocky habitats (Miranda et al 2021a ). As jacks-of-all-trades, Largemouth Bass in the study reservoirs may not need to be highly abundant at any one location, because they can occupy more places across the reservoirs.…”

“…Negative effects of habitat degradation and climate change may be countered by habitat recovery, protection, enhancement, and development activities (Sass et al 2017 ;Miranda et al 2020 ). Habitat conservation activities can target all or selected black basses (Long et al 2015 ;Miranda et al 2021a ). Considering the abundance-occupancy patterns observed, small improvements in occupancy stimulated by habitat enhancement could pay dividends by disproportionately increasing abundance.…”

“…The system includes 44 reservoirs >100 ha, of which nine impound the mainstem Tennessee River over a stretch of 1,025 km (Figure 1 ) and were part of this study. All nine of these reservoirs are joined by locks and have relatively similar fi sh assemblages (Miranda et al 2021b ) and habitats (Miranda et al 2021a ), differing mostly in size. The nine study reservoirs, constructed during 1913-1944, range in length from 26 to 296 km and in surface area from 63 to 650 km 2 .…”

“…Generalist congeners, because of their similar life history strategies, often coexist in reservoirs in North America, including species of black bass Micropterus spp. The black basses are sympatric over a large portion of their native ranges (Lee et al 1980 ), frequently cooccur (Miranda et al 2021a ), and occupy the top trophic levels in aquatic systems (Tringali et al 2015 ). Coexistence of these closely related sympatric species is fostered by specialization, including habitat associations that reduce competitive interactions (Schoener 1974 ).…”

Abundance–Occupancy Patterns Of Black Bass In An Impounded River

“…The patterns did not differ among reservoirs but differed among species. Fish habitat in these nine contiguous impoundments varies little (Miranda et al 2021a) as the cascade of reservoirs stretches over 1,025 km but only drops 140 m in elevation. Reservoir operation in terms of water level fluctuations and releases is similar among the nine reservoirs.…”