Growth, Dispersal, Mortality, and Contribution of Largemouth Bass Stocked into Chickamauga Lake, Tennessee

Abstract

Marked fingerling largemouth bass Micropterus salmoides (both northern M. s. salmoides and Florida subspecies M. s. floridanus and their hybrid) were stocked into Chickamauga Lake, Tennessee, to enhance angling and introgress the Florida subspecies into the local gene pool. We evaluated mass marking and stocking success by sampling the stocked fish for 1 year poststocking. More than 128,000 fingerlings (35-64 mm total length) were immersed in a solution of 500 mg/L oxytetracycline (OTC) for 6 h and stocked into four embayments in the lake in spring 2002; two additional embayments served as controls and were not stocked (these embayments contained only wild, indigenous fish). In a blind test, 97% of sagittal otoliths were correctly scored as marked or unmarked. In a subsequent test, the OTC marks were clearly visible on every otolith removed from 240 OTC-treated bass held for 30 d. Age-0 largemouth bass were sampled with DC electrofishing gear at 7-19, 44-61, and 119-139 d after stocking, and sampling was conducted along 100-m transects within 1 km of the stocking sites in each embayment. Of all recaptures in the first sample, 31% occurred more than 600 m from the nearest stocking site, indicating rapid dispersal by some fish. Survival of stocked and wild age-0 largemouth bass was similar and low (4.5-6.9%) in two embayments; in the other two embayments, stocked fish survived at lower rates (0-4.3%) than wild fish (33.7-49.9%). Mean catches of all age-0 largemouth bass in the first sample were positively related to the number of fish stocked. By October 2002, the mean catch of all age-0 largemouth bass was similar among embayments. Contribution of stocked fish declined to approximately 2% (2 of 91 fish) the following spring. Cost per fingerling increased from US$0.35 at stocking to $12.00 at 140 d poststocking. Increasing the abundance of largemouth bass was not the primary objective of this stocking effort, but stocked fish will have to survive much better if managers hope to introgress Florida largemouth bass genes into the resident population

Stocking Contribution and Growth of Largemouth Bass Stocked at 50 and 100 mm into Backwaters of the Arkansas River

“…The percentage contributions of stocked fish to the year-class from this study are within the range of contributions previously reported for other systems (Terre et al 1995;Ryan et al 1998;Buynak et al 1999b;Janney 2001;Buckmeier and Betsill 2002;Heidinger and Brooks 2002;Hoxmeier and Wahl 2002;Jackson et al 2002;Porak et al 2002;Buckmeier et al 2003;Hoffman and Bettoli 2005;Heitman et al 2006). None of these studies directly compared different sizes of stocked fish in the same system during the same year.…”

“…There was little dispersal of stocked fish from a 500-ha embayment of a Texas reservoir (Buckmeier and Betsill 2002); during that study only one stocked fish was collected in unstocked coves bordering the mouth of the embayment. In contrast, Hoffman and Bettoli (2005) found that about 30% of stocked fingerling largemouth bass were captured more than 600 m from their stocking sites within 19 d post stocking. Stocking high numbers of largemouth bass at a single location within the study area might have caused some fish to disperse rapidly from the stocking site (Hoffman and Bettoli 2005).…”

“…In contrast, Hoffman and Bettoli (2005) found that about 30% of stocked fingerling largemouth bass were captured more than 600 m from their stocking sites within 19 d post stocking. Stocking high numbers of largemouth bass at a single location within the study area might have caused some fish to disperse rapidly from the stocking site (Hoffman and Bettoli 2005). In Pool 4 of the Arkansas River, a movement of 600 m would have placed most stocked fish outside of their respective stocked backwater area.…”

“…In previous studies, stocking densities ranged from 1 to 644 largemouth bass/ha and percentage contribution to the year-class of stocked fish ranged from 0% to 79% (Boxrucker 1986;Terre et al 1995;Ryan et al 1998;Buynak et al 1999b;Janney 2001;Buckmeier and Betsill 2002;Heidinger and Brooks 2002;Hoxmeier and Wahl 2002;Jackson et al 2002;Porak et al 2002;Buckmeier et al 2003;Hoffman and Bettoli 2005;Heitman et al 2006). Although it seems obvious that stocking more fish should lead to a higher proportion of stocked fish in the population, none of these references explicitly tested this hypothesis.…”

“…Largemouth bass have been supplementally stocked at sizes ranging from 43 mm TL (Hoffman and Bettoli 2005) to 315 mm TL (Buynak et al 1999b), but most have been stocked at sizes from 50 to 124 mm TL (Boxrucker 1986;Buynak and Mitchell 1999;Hoxmeier and Wahl 2002;Neal et al 2002;Porak et al 2002). Survival and contribution to the year-class can be higher when larger largemouth bass are stocked (Loska 1982).…”