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Biology, Spawning, and Movements of Cycleptus meridionalis in the Lower Alabama River, Alabama
Maurice F. Mettee, Thomas E. Shepard, Patrick E. O’Neil, and Stuart W. McGregor

Southeastern Naturalist, Volume 14, Issue 1 (2015): 147–172

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Southeastern Naturalist 147 M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 22001155 SOUTHEASTERN NATURALIST 1V4o(1l.) :1144,7 N–1o7. 21 Biology, Spawning, and Movements of Cycleptus meridionalis in the Lower Alabama River, Alabama Maurice F. Mettee1,*, Thomas E. Shepard1, Patrick E. O’Neil1, and Stuart W. McGregor1 Abstract - The goals of this study were to describe the biology, spawning season, and movements of Cycleptus meridionalis (Southeastern Blue Sucker) in the lower Alabama River, and evaluate possible spawning-site fidelity to Millers Ferry Lock and Dam. We also present fisheries, river discharge, and lock-use data in support of our recommendation to implement fish-passage operations at Claiborne and Millers Ferry locks and dams. We collected a total of 1094 Southeastern Blue Suckers—704 males, 355 females, and 35 sexundetermined individuals—below Millers Ferry and Claiborne locks and dams from 1995 to 2005. Females were significantly longer and heavier per given total length than males. Spawning season lasted from March through April. Peak spawning occurred in mid-March when the water temperature was 15–20 °C. Age estimates ranged from 4 to 34 years for males and females. We recaptured 20% (206) of 1049 anchor-tagged fish multiple times (range = 1–10) at intervals between captures of 1–3618 d, and recaptures occurred 1–99 km downstream after release. We detected 75% (111) of 149 sonic-tagged fish 1–19 times at intervals between detections of 1–1288 d at distances of 4–250 km downstream after release. Spawning-site fidelity was confirmed by the recapture of 57 anchor-tagged fish and the detection of 15 sonic-tagged fish in or near Millers Ferry tailwater. Daily fish-passage operations completed at Claiborne and Millers Ferry locks and dams from January through April should increase upstream fish-migration success into the upper Alabama and Cahaba rivers without adversely affecting navigation, hydroelectric generation schedules, and industrial water needs along the river. Introduction The genus Cycleptus contains 2 described and 1 undescribed species. Cycleptus elongatus (Lesueur) (Blue Sucker) inhabits the main channel and primary tributaries of the Mississippi River basin from Louisiana north into Ohio and the Dakotas (Gilbert 1978, Page and Burr 2011). Cycleptus meridionalis (Burr and Mayden) (Southeastern Blue Sucker ) is restricted to main channels of the Pearl and Pascagoula rivers, MS, and the Alabama, Cahaba, Coosa, Tallapoosa, and lower Tombigbee rivers, AL (Boschung and Mayden 2004, Mettee et al. 1996). Bessert (2006) suggested Blue Sucker and Southeastern Blue Sucker were not reciprocally monophyletic when he concluded that these species probably diverged in the early Pleistocene and remained reproductively isolated thereafter. A third undescribed species was recognized in the Rio Grande River by Burr and Mayden (1999) and Bessert (2006). 1Geological Survey of Alabama, PO Box 869999, Tuscaloosa, AL 35486. *Corresponding author - fishman7@bellsouth.net. Manuscript Editor: Andrew Rypel Southeastern Naturalist M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 148 The distributions of Blue Sucker and Southeastern Blue Sucker are reasonably well known, but their biology, life history, and movements have not been well documented, in part because these fishes inhabit large rivers that are difficult to sample effectively (Burr and Warren 1986). State and federal agencies and conservation groups have recommended endangered, rare, or special concern listing for both taxa because their ranges have been diminished or adversely affected by reservoir construction, habitat degredation, increased sedimentation, and pollution (Boschung 1992, Eitzmann et al. 2005, Elstad and Werdon 1993, Etnier 1997, Etnier and Starnes 1993, Guillory et al. 1978, Moss et al. 1983, Pflieger 1975, Robinson and Buchanan 1988, Swift et al. 1986, Warren et al. 2000, Williams et al. 1989). Peterson and Nicholson (1997) suggested Southeastern Blue Sucker populations were stable in Mississippi based on earlier collections of 323 individuals and their collection of 559 specimens in the Pearl and Pascagoula rivers. Ross (2001) noted the species was widespread in Mississippi but future distribution and abundance could be adversely affected by reservoir construction. Less than 40 specimens had been collected in Alabama prior to this study (Mettee et al. 1996). The goals of our study were to describe the biology, spawning season, and movements of Southeastern Blue Sucker in the Alabama River; evaluate possible spawning-site fidelity to the Millers Ferry tailwater area; and present fisheries, river discharge, and lock-use data in support of our recommendation to implement fishpassage operations at Claiborne and Millers Ferry locks and dam s. Field Site Description The Alabama River begins at the junction of the Coosa and Tallapoosa rivers in east-central AL (Fig. 1). It flows ~465 km southwest and joins the lower Tombigbee River, which receives discharge from the upper Tombigbee and Black Warrior rivers, to form the Mobile River. The Cahaba River, the major tributary of the Alabama River, contains one of the richest fish faunas in the US for its size (Pierson et al. 1989). The Mobile River flows ~10 km before splitting into the Mobile and Tensaw rivers. The Mobile River continues ~48 km downstream before entering the northwest section of Mobile Bay. The Tensaw River subsequently divides to form the Apalachee, Blakely, Middle, and Tensaw rivers, all of which flow into the middle section and northeast corner of Mobile Bay (Mettee et al. 1996). The Mobile office of the US Army Corps of Engineers (USCOE) constructed 3 locks and dams on the Alabama River in the 1960s and 1970s to link the port of Mobile with shipping facilities on the Alabama, Coosa, and Tallapoosa (ACT) rivers. Commercial use of the ACT Waterway never developed as expected; nevertheless, the USCOE continued channel maintenance along the 481-km-long waterway until 2008, when dredging operations were reduced to include only the lower 118 km of the river and lock approaches at each dam. In 2012, recreational boat passage through the lock chambers was eliminated and commercial lockage required a 3-day scheduling notice. Southeastern Naturalist 149 M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 Figure 1. Physiographic sections, hydroelectric dams (H), and navigation locks and dams (N) in the Mobile River basin. Southeastern Naturalist M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 150 Two Alabama River locks and dams were located in the study area. Claiborne Lock and Dam at Alabama River kilometer (ARkm) 118 has a 154-m-wide by 10.1-m-high crested spillway, a gated spillway containing six 18.5-m-wide gates, and a 25.9-m-wide by 184.6-m-long operating lock chamber (Fig. 2). Millers Ferry Figure 2. Top: downstream to upstream photographs of the crested spillway (left), gated spillway (center), and lock chamber (right) at Claiborne Lock and Dam. Bottom: the gated spillway (left) and lock chamber (right) at Millers Ferry Lock and Dam. Southeastern Naturalist 151 M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 Lock and Dam at ARkm 214 has a gated spillway containing seventeen 15.4-m-wide gates and a 25.9-m-wide by 184.6-m-long operating lock chamber. A hydroelectric generating facility is situated on the east bank of the river about 0.3 km downstream of the lock chamber. The spill gates at Millers Ferry are closed most of the year to conserve reservoir water for hydroelectric generation. The only exceptions are from January through April when the gates at both dams are temporarily opened for upstream flood control. Crested spillway height at Claiborne during normal flow and hydraulic turbulence through the spill gates at both dams during floods probably restrict upstream movement of most Alabama River fishes during these periods. Methods We collected gill-net samples in the generator-discharge area below Millers Ferry hydroelectric dam (Fig. 3) in March and April from 1995–2005. Generation discharge was discontinued on each sample day from 0900–1200. We deployed five to eight 61.5-m-long monofilament and multifilament nets with a 6.4- to 8.9-cm bar-mesh, foamcore float, and leadcore bottom lines in the immediate generatoroutflow area, fished for approximately 60 min, and retrieved samples. We placed all Southeastern Blue Suckers in a large, aerated holding tank for later processing. All other species were identified, tallied, and then immediately released. We also collected Southeastern Blue Suckers from the Claiborne tailwater on 2 consecutive nights in November 2000 using the same gill nets and and an outboard-powered, aluminum boat equipped with a Smith-Root GPP 5.0 electrofishing gear. We completed processing and tagging operations downstream of each netting area. For all Southeastern Blue Suckers collected, we measured total length (TL) and standard length (SL) in millimeters (mm), and total wet weight (TW) in grams (g). We determined fish sex by visual inspection and application of light abdominal pressure. If gametes failed to appear, we recorded the fish as sex undetermined. We implanted a 14-month sonic tag in each of 29 fishes collected from 1996 through 1998, and a 48-month tag in each of 120 fishes collected from late 1999 through 2003. Each Betadine-soaked tag was inserted into the abdominal cavity through a 3.0–4.0-cm-long incision made near the ventral midline and midway between the vent and pelvic fin base. We sutured the incision and cleaned the surgical area with Betadine. We placed each fish that received a sonic tag in a live well and monitored it for several minutes to insure proper tag function and upright swimming behavior before release. We implanted a Betadine-soaked, numbered, internal anchor tag in each Southeastern Blue Sucker by inserting through a separate 0.5- to 1.0-cm-long vertical incision made through the left side of the body near the end of the depressed pectoral fin. Uncoated tags were implanted in 237 fish collected from 1995–1996, and clear-coated tags were implanted in 812 fish collected from 1997–2005. Several uncoated tags were illegible at the time of recapture because the tag numbers had either worn away or they were covered with dense, persistent growth. Rather than surgically remove the tag disk from these fish, we implanted a coated tag in the same general area. We immediately released all fish that received only anchor tags. Southeastern Naturalist M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 152 We used linear regressions to describe the relationships between TL and SL and between Log10(TW) and Log10(SL), and then assessed sexual differences in TL–SL and Log10(TW)–Log10(SL) relationships using analysis of covariance (ANCOVA). Spawning-population size was estimated using Jolly (Jolly 1965) and Jolly-Seber (Seber 1982) population-estimate models. We calculated the Jolly Figure 3. The sample-collection area in the generator-outflow area below Millers Ferry powerhouse. Southeastern Naturalist 153 M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 estimates by hand using 1997–2000 recapture data. The Jolly-Seber estimate and 95% confidence intervals were calculated by analyzing 1995–2003 capture and recapture data with Mark computer software (White and Burnham 1999). We estimated the ages of Alabama River fishes using the following age and growth formulas developed by Peterson and Nicholson (1997): age = (TL - 402.705 ÷ 8.706) (r2 = 0.466, P < 0.001, n = 40) for males, and age = (TL - 411.308 ÷ 9.695) (r2 = 0.696, P < 0.001, n = 32) for females. The approximate hatching year of the oldest male and female Southeastern Blue Suckers were calculated by subtracting the estimated age of each individual from the date of its last recapture year. We made annual listening trips from March through October to monitor the preand post-spawning movements of sonic-tagged fish and locate their downstream summer habitats. We detected sonic-tagged fish with a sonic receiver (USR-5W, Sontronics, Tuscon, AZ) and directional hydrophone (DH-2, Sonotronics). During each tracking trip, we stopped the boat at ~400–600-m intervals, lowered the hydrophone into the water, and completed two or three 360º-sweeps to detect signals in the 69–83 kHz tag-range. When we detected a sonic-tagged fish, we repositioned the boat several times to precisely locate the fish. When the sonic signal was equally audible in all directions, we recorded the date, time, river km, depth, and GPS coordinates on paper field sheets; location coordinates were saved on a GPS-enabled depth finder. We used detection data and location coordinates to construct movement maps for selected individuals. All collection, tagging, capture/recapture, and sonic-detection data were cataloged into the Geological Survey of Alabama (GSA) fish-collection files in Tuscaloosa, AL. Continued sonic-detection success expanded the original 96-km search area between Millers Ferry and Claiborne locks and dams to include 214 km of the lower Alabama River, 82 km of the lower Tombigbee River, 16 km of the Mobile River, and ~104 km in the Mobile, Tensaw, and Middle river sections of the Mobile–Tensaw River Delta (MTRD). Results Population and biological data We captured a total of 1094 Southeastern Blue Suckers, including 704 males (64%), 355 females (33%), and 35 individuals of undetermined sex (3%), below Claiborne and Millers Ferry locks and dams from 1995–2005 (Table 1). We collected a low of 32 specimens in 2001 and a high of 200 in 2003. Catch per hour (CPH) ranged from 0.6 (1998) to 6.7 (2003). Males outnumbered females during the years 1995–1997, 1999, 2001–2003, and 2005; females outnumbered males in 1998, 2000, and 2004. We collected 29 (17 males and 12 females) of the 1094 individuals in Claiborne tailwater in November 2000 (Table 1). Alabama River females were generally longer and heavier per TL than males (Table 2). Total-length range = 446–742 mm for females and 438–702 mm for males, and SL range = 379–608 mm for females and 338–575 mm for males. Totalweight range = 813–6000 g for females and 800–3824 g for males. Year-to-year Southeastern Naturalist M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 154 variations in female TW were probably influenced by collection date, reproductive readiness, river discharge, and water temperature. We compared the relationship of TL to SL for 722 males and 329 females collected in 1995–2003 (Mettee et al. 2003). The equations for this relationship were: SL = 7.75 + 0.81 (TL) (r = 0.944) for males and SL = -7.97 + 0.845 (TL) (r = 0.945) for females (Fig. 4). Slopes of TL–SL regressions were significantly different by sex (P < 0.01) as determined using ANCOVA. We also examined the relationship of TW to SL for 670 males and 308 females collected during the same period (Fig. 4). Equations for this relationship were: log10TW = -5.4433 + 3.2615 (log10SL) (r = 0.923) for males and log10TW = -6.6070 + 3.7214 (log10SL) (r = 0.954) for females. These slopes were also significantly different by sex (P < 0.01) as determined with ANCOVA. Table 1. Summary data for Southeastern Blue Suckers collected in the Alabama River from 1995– 2005. TNH = total net hours, CPH = catch per hour. Undetermined Year Sample period TNH Males Females sex Total CPH 1995 March 23–May 3 40 60 54 13 127 3.2 1996 March 27–April 30 55 88 20 2 110 2.0 1997 March 17–April 15 56 63 49 0 112 2.0 1998 March 23–May 5 72 20 22 2 44 0.6 1999 March 8–April5 46 108 33 1 142 3.1 2000 March 6–29 35 24 36 0 60 1.7 November 7–8A 14 17 12 0 29 2.1 2001 April 4–17 24 21 5 6 32 1.3 2002 March 12–April 16 30 73 28 2 103 3.4 2003 March 26–April 16 30 121 78 1 200 6.7 2004 March 15–April 8 40 18 20 6 44 1.1 2005 March 7–21 25 72 17 2 91 3.6 Totals 467 704 355 35 1094 2.3 ATotal from 2 night-sampling efforts completed below Claiborne Lock and Dam. Table 2. Total length (TL; mm), standard length (SL; mm), and total weight (TW; g) of male and female Southeastern Blue Suckers collected in the Alabama River from 1995–2005. NA = electronic scale not functioning. Males Females Year TL SL TW TL SL TW 1995 438–668 362–555 888–4108 446–718 379–600 813–5276 1996 458–656 338–555 800–3038 534–722 442–605 1542–4254 1997 458–702 394–575 987–3450 551–710 460–590 1555–5670 1998 480–634 385–525 1025–3132 540–639 450–512 1902–3975 1999 462–693 391–570 805–3915 520–690 432–570 1372–4815 2000 440–630 372–510 910–2905 502–706 400–572 1595–4385 2001 472–615 390–510 957–2045 510–680 430–574 1390–4765 2002 453–642 383–526 987–3005 535–690 427–583 1737–4218 2003 471–700 379–546 980–3705 501–742 412–608 1360–6000 2004 478–655 395–532 1025–3824 558–695 465–541 2585–4421 2005 458–698 427–555 NA 538–698 420–563 NA Southeastern Naturalist 155 M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 Spawning season We compiled the following spawning information for Southeastern Blue Sucker from notes collected during 418 hours of gill-net sampling in the Miller Ferry generator-outflow area in March and April. Individuals collected from early to Figure 4. Total length versus standard length (top) and standard length versus total weight (bottom) for male and female Southeastern Blue Suckers collected below Millers Ferry powerhouse from 1995–2003. Southeastern Naturalist M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 156 mid-March were in pre-spawning condition. Males were moderate to dark blue with numerous small white tubercles on the head, body, and fins. Females were light blue to medium gray with fewer, less-developed white tubercles on the body and fins. Light to moderate abdominal pressure produced limited numbers of gametes from both sexes. Water temperatures during this period ranged from 10 ºC to 15 ºC, depending on discharge velocity, air temperature, time of day, and cloud cover. Peak spawning occurred from mid- to late-March when the water temperature ranged from 15 ºC to 20 ºC. Many fishes removed from the nets during this time were in small clusters containing a gravid female and several males. The head, body, and fins were medium to dark blue on males and light blue to gray on females. Spawning colors lightened somewhat after we placed individuals in the live well. Most males had 1–5 prominent white tubercles on their scales, and their heads were covered with irregularly spaced tubercles (Fig. 5). Dense concentrations of tubercles were present on the opercle, the head just above the eye, and near the posterior angle of the mouth. Most fin rays were outlined with a line of small tubercles, and there were fewer scattered on fin membranes. Gravid females were more deep-bodied than males, and fewer, smaller tubercles were present on the body, fins, and head (Fig. 5). Males and females extruded large quantities of gametes as they were removed from the net, measured, weighed, and tagged. Several individuals were bleeding where scales had been recently lost; some fish had fresh scratches on their heads and the vertical fins on few others were freshly split. Age and growth Southeastern Blue Sucker males from the Alabama River ranged in estimated age from 4 (438 mm TL) to 34 y (702 mm TL) (Table 3). Eighteen percent (124) of males ranged from age 4 to 13 y, 65% (459) ranged from age 14 to 23 y, and 17% (121) ranged from age 24 to 34 y. The estimated ages of Alabama River females ranged from 4 (446 mm TL) to 34 y (742 mm TL) (Table 4). Eleven percent (40) of females ranged from age 4 to 13 y, 73% (260) ranged from age14 to 24 y, and 16% (55) ranged from age 24 to 34 y. We collected a total of 124 juvenile (13 y and less) males compared to 40 juvenile (13 y and less) females. Feeding behavior We did not quantify diet in our study, but field notes from the collection of 3 Southeastern Blue Suckers downstream of Claiborne Lock and Dam with boatelectrofishing gear confirmed these fishes fed primarily on tricopteran larvae. We also observed large numbers of trichopteran larvae on tree limbs suspended in the water column throughout the immediate sampling area. Anchor tagging Numbered anchor tags were implanted in 704 males, 355 females and 35 Southeastern Blue Suckers of undetermined sex. The number of fish tagged per year ranged from 32 (2001) to 200 (2003) (Table 5). We recaptured a total of 206 fishes—160 males, 37 females, and 9 of undetermined sex—244 times from 1995 through 2005. Individuals recaptured per year ranged from 1 (2001, 2007) to 45 Southeastern Naturalist 157 M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 Figure 5. Top: a 625-mm-TL tuberculate male Southeastern Blue Sucker collected below Millers Ferry powerhouse on 15 March 2004. Bottom: a 645-mm-TL gravid female collected in the same area on 27 March 2003. A recently implanted yellow anchor-tag is visible between pelvic and pectoral fins on the tuberculate male. Southeastern Naturalist M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 158 (2003). Total individuals recaptured from a single tagging-class ranged from 2 (2001) to 50 (1995). The last fish recaptured in 2007 was anchor-tagged and released in the generator-outflow area in 2003. Southeastern Blue Suckers released in the generator-outflow area during the periods 1995–1997 and 1999–2004 were last recaptured at the same location in 2005 (Table 6). One fish released in the same area in 1998 was last recaptured in 2004. Total recapture time for these individuals ranged from 366 days (2004) to 3816 d (1995). Forty-one individuals were recaptured 2–42 d following initial release, 113 were recaptured once in 315–3263 d, 43 were recaptured twice in 351–2914 d, and 5 individuals were recaptured 3 times in 1078–3290 d. One fish was recaptured 4 times in 2913 d, one was recaptured 5 times in 2195 d, and one was recaptured 6 times in 2179 d. Table 3. Estimated ages of 704 male Southeastern Blue Suckers collected in the Alabama River from 1995 to 2005. Capture/recapture year Age 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Totals 34 1 1 1 3 33 2 2 32 2 2 31 1 1 3 5 30 1 3 1 2 7 29 1 1 1 1 1 1 6 28 1 1 2 3 2 9 27 3 1 1 1 5 1 3 15 26 3 1 4 5 2 5 20 25 1 3 1 4 8 2 5 24 24 2 4 3 1 4 10 1 3 28 23 1 2 2 2 8 4 1 7 12 1 3 43 22 1 2 2 4 4 7 11 1 9 41 21 2 3 4 3 1 11 9 4 37 20 5 9 1 12 3 12 4 1 3 50 19 2 4 7 2 9 6 5 13 2 6 56 18 1 6 7 1 9 3 5 2 7 3 42 17 4 15 5 3 8 2 1 3 7 3 51 16 5 10 10 13 6 1 3 4 52 15 8 9 6 4 5 4 2 2 4 1 2 47 14 10 8 2 1 5 6 2 2 3 1 40 13 8 9 1 2 1 2 3 1 27 12 4 2 2 2 1 2 1 4 2 3 23 11 7 2 4 4 2 1 2 1 23 10 1 1 1 1 1 1 2 3 1 1 1 14 9 3 2 1 2 3 1 1 1 14 8 1 2 2 3 1 2 11 7 1 1 1 2 5 6 1 1 1 1 4 5 1 1 4 1 1 2 Totals 60 88 63 20 108 60 21 73 121 18 72 704 Southeastern Naturalist 159 M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 The longest recapture record (3815 d) was for a male fish released in the generator- outflow area in 1995 and recaptured in the same area 8 times, including once in 1997, 2000, 2003, 2004, and 2005, and 3 times in 2002. Two of the 2002 recaptures were in the generator-outflow area; the third was from Claiborne Lock and Dam tailwater. This fish measured 500 mm TL when released on 4 April 1995 and 553 mm TL when recaptured on 14 March 2005. The Jolly model (1965) estimated a Southeastern Blue Sucker spawningpopulation size of 775–1034 individuals in the lower Alabama River (Mettee et al. 2003). The Jolly-Seber model (Seber 1982) produced a slightly higher estimate of 733–1275 individuals. Population estimates from both methods were conservative given that we collected 1094 individuals from 1995 to 2005, and several of the last samples collected contained more untagged than tagged individuals. Table 4. Estimated ages of 355 female Southeastern Blue Suckers collected in the Alabama River from 1995 to 2005. Capture/recapture year Age 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Totals 34 1 1 33 1 1 32 1 1 2 31 2 2 30 1 2 3 29 2 3 1 1 1 8 28 2 1 1 1 1 6 27 1 1 1 2 1 6 26 2 1 1 1 4 1 3 13 25 1 2 2 1 5 1 1 13 24 2 2 2 7 1 4 18 23 4 2 2 1 2 4 4 1 20 22 1 2 7 1 2 5 8 1 1 28 21 1 2 2 4 1 3 6 1 3 23 20 4 2 5 2 6 10 3 1 33 19 3 3 3 6 1 5 1 22 18 2 9 4 3 6 7 31 17 2 5 5 4 7 1 5 3 32 16 2 4 3 2 2 4 17 15 7 3 4 1 2 1 1 1 4 1 25 14 7 1 1 1 1 11 13 12 2 2 2 1 1 2 1 23 12 3 2 5 11 4 1 1 6 10 1 1 2 9 1 1 1 3 8 7 6 5 4 1 1 Total 55 20 49 22 33 29 5 28 78 19 17 355 Southeastern Naturalist M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 160 Five anchor-tagged fish released in the generator-outflow area moved downstream past Claiborne Lock and Dam. Two of the individuals moved back upstream past Claiborne and were recaptured in the generator-outflow area in a subsequent year. The first fish was released below Millers Ferry in 1999, recaptured below Claiborne Lock and Dam in 2000, and recaptured below Millers Ferry in 2002. The second fish was released in 1995, recaptured 8 times in the generator-outflow area, and once below Claiborne Lock and Dam. The third fish released in 1997 was recaptured below Claiborne Lock and Dam in 2000. The fourth fish released in 1997 was recaptured in the same area in 1999 and below Claiborne Lock and Dam in 2000. The last fish was released in April 2003 and recaptured below Claiborne Lock and Dam in 2007. Eighty-three (37%) of 227 fish fitted with uncoated tags and 161 (19%) of 867 fish fitted with clear-coated tags were recaptured during the study (Table 5). Tag numbers on clear-coated tags were still visible 2–2905 d after initial release. Table 5 Number of Southeastern Blue Suckers anchor-tagged and recaptured in the Alabama River from 1995 to 2005. 1995–1996: uncoated were used; 1997–2005: coated tags were used. Recapture year Tag Number 1990s 2000s Number year tagged 95 96 97 98 99 00 01 02 03 04 05 06 07 recaptured 1995 127 3 15 11 0 9 2 0 4 3 2 1 50 1996 110 1 15 3 8 1 0 3 2 33 1997 112 2 11 3 0 3 6 2 27 1998 44 3 3 2 0 2 1 1 12 1999 142 5 9 0 5 9 1 29 2000 89 1 1 3 5 2001 32 2 2 2002 103 14 14 4 5 37 2003 200 10 1 14 25 2004 44 2 14 16 2005 91 7 1 8 Total 1094 3 16 26 8 36 18 1 36 45 10 44 0 1 244 Table 6. Longest recapture periods for Southeastern Blue Sucker anchor-tagged in the Alabama River from 1995–2005. Year First day tagged Last day recapture Total days tagged 1995 4/19/95 3/14/05 3816 1996 4/9/96 3/15/05 3263 1997 3/14/97 3/15/05 2924 1998 4/20/98 4/6/04 2197 1999 3/30/99 4/8/05 2202 2000 3/27/00 3/31/05 1831 2001 4/3/01 3/9/05 1437 2002 3/12/02 3/15/05 1100 2003 3/26/03 3/15/05 721 2004 3/15/04 3/15/05 366 Southeastern Naturalist 161 M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 Sonic tagging and tracking Signals from the four sonic-tagged fish released in 1996 were not detected between Millers Ferry and Claiborne locks and dams, so tracking efforts were moved downstream of Claiborne dam. The first signal detected came from a fish positioned in a partially submerged treetop lying along the right bank of the river about 20 km downstream of the dam. When the signal remained stationary during 3 subsequent site visits, we boat-electrofished the immediate detection area to determine if the fish was alive or dead. As soon as we began electrofishing, the fish immediately moved to the opposite bank and continued swimming upstream for about 200 m. It moved back to its original habitat several days later. Boat electrofishing was a useful tool to confirm whether sonic-tagged fishes survived the tagging process, successfully moved downstream, and occupied restricted summer habitats. Some of these fishes moved back upstream past Claiborne, and we detected them either downstream of the Millers Ferry spillway or in the generator-outflow area in a subsequent year. This same fish was recaptured in healthy condition in the generator-outflow area in March 1998 and sacrificed to determine if the tagging process produced any unexpected internal damage; the recapture occurred several months past the tag’s advertised 14-month life. When we examined the fish, we observed that all sutures were completely healed and the surgical scar was covered with regenerated abdominal scales. The tag was encased in adipose tissue near its original placement location. The lack of internal bruising and organ damage suggested the tagging experience and 2 years of tag operation produced no long-term adverse effects. The fish, dissection notes, and sonic tag were deposited into the GSA Fish Collection in Tuscaloosa, AL. Seventy-five percent (111) of 149 sonic-tagged fish were detected from 1 to 19 times, 1–1288 d following release, from 4 to 250 km downstream in the Alabama, Middle, Mobile, Tensaw, and Tombigbee rivers. The number of fish sonic-tagged in a single year ranged from 4 (1996) to 36 (2002) (Table 7). Total fish detected per tracking year ranged from 3 (1996) to 40 (2000). Total fishes detected from a single tagging class ranged from 4 (1996) to 24 (2002). Table 7. Number of Southeastern Blue Suckers sonic-tagged and detected in the Alabama, Tombigbee, Middle, Mobile, and Tensaw rivers from 1996 to 2005. Fish Detection year Fish detected Tag year tagged 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 (% per tag class) 1996 4 3 2 4 (100) 1997 13 8 3 8 (62) 1998 12 12 7 1 12 (100) 1999 21 18 16 4 1 19 (91) 2000 28 23 9 5 23 (82) 2001 15 9 6 10 (67) 2002 36 24 14 3 24 (67) 2003 20 8 9 1 11 (55) Totals 149 3 10 15 25 40 22 36 22 12 1 111 (75) Southeastern Naturalist M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 162 Detection success was highest from June to December when river discharge and turbidity levels were lowest, and lowest from January through May when river discharge and turbidity were highest and water depths exceeded 7–8 m. Sonictagging operations were suspended in 2003, but continued tracking efforts detected fourteen 2002 fish and eight 2003 fish in 2003, three 2002 fish and nine 2003 fish in 2004, and one 2003 fish in 2005 (T able 7). We never detected 38 sonic-tagged fish even though we checked the pinging sequence for each tag before the fish was released. Some individuals may have died from surgical injury or natural causes. In a few instances, a properly functioning tag stopped pinging for no apparent reason. After reviewing our tagging and detection procedures in the field, the tag producer concluded that some batteries expired prematurely when tag codes contained four numbers or tags were programmed to ping at a faster rather than a slower interval. Thirty-eight sonic-tagged fish remained between Millers Ferry and Claiborne locks and dams after release, and 73 fish moved downstream past Claiborne Lock and Dam (Fig. 6). We detected 61 tags from Claiborne Lock and Dam downstream to the junction of the Alabama and Tombigbee rivers. One was located in the lower Tombigbee River about 5 km upstream of its junction with the Alabama River, and 11 fish were discovered in the Mobile, Middle, and Tensaw rivers. Eleven lower Alabama River sonic-tagged fish moved back upstream past Claiborne Lock and Dam 1–2 years after initial release (Fig. 6). We detected 3 fish between Claiborne and Millers Ferry locks and dams. Eight were detected or collected in or near the generator-outflow area below Millers Ferry powerhouse. We detected 1 fish released in 2002 in the generator-outflow area at 15 sites upstream and downstream of Claiborne Lock and Dam from 2002 to 2004. The 759-day tracking record for this fish confirmed it moved ~570 km between detection locations. The longest combined recapture and sonic detection record for any Southeastern Blue Sucker was from a 460-mm TL male anchor-tagged and released in the generator outflow in April 1996. When recaptured in the same area 3 y later (March 1999), the fish received a second anchor tag and a new 48-month sonic tag. Later the same year, we detected the sonic signal 5 times downstream of Claiborne Lock and Dam and 159 km downstream of Millers Ferry. The fish was assumed dead when we detected no sonic signal in 2000 and 2001. That assumption was proved incorrect when the signal was detected near Millers Ferry tailwater in August and September 2002. The combined 1292-d recapture and sonic detection record confirmed this fish moved upstream and downstream past Claiborne Lock and Dam t wice. Fish passage Southeastern Blue Suckers can move upstream past Claiborne Lock and Dam in one of 2 ways: by going through the lock chamber with a vessel, or by crossing over the crested and gated spillways when they are inundated by floods. Movement through the lock chamber has become less likely because only 15 vessels continued upstream past Claiborne in 2004 and 19 locked through in 2005 and 2006 combined (M. Eubanks, USCOE, Mobile District, Mobile, AL). Southeastern Naturalist 163 M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 Figure 6. Summer habitat locations of 111 Southeas tern Blue Suckers sonic- tagged and released below Millers Ferry powerhouse and summer locations of 11 fish that moved back upstream past Claiborne Lock and Dam in a s u b s e q u e n t year. Southeastern Naturalist M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 164 Upstream movement over the spillway is restricted to a few days each year when this structure is inundated by winter flooding. No movement occurred when the spillway remained dry all year. With 3 exceptions, Claiborne spillway was inundated <41 d per year during 1985–2005 (Table 8). It was inundated for 76 d in 1990, 53 d in 1996, and 70 d in 1998. The number of days the spillway was inundated in a single year ranged from 9 (1988 and 2000) to 76 (1990). The spillway was inundated for an average 3.1 d in December, 5.5 d in January, 8.2 d in February, 11.4 d in March, and 4.6 d in April. It remained completely dry in December, January, February, March, and April for 12, 9, 3, 3, and 8 consecutive years, respectively. Millers Ferry Lock and Dam is an effective barrier to almost all fish migration upstream. Most upstream barge traffic ended several years ago, and the gated spillway is closed most of the year to conserve water for hydroelectric generation. The gates are periodically opened from January through April to reduce the effects of upstream flooding, but these events are usually short-lived and extreme hydraulic turbulence near the dam prohibits most, if not all, fishes from going through the spill gates. Average monthly discharge of the Alabama River at Millers Ferry Lock and Dam ranged from 280 to 2619 m3/s in January (mean = 1301 m3/s), 361–3861 m3/s in February (mean =1572 m3/s), 467–3821 m3/s in March (mean = 1786 m3/s), and 235–3842 m3/s in April (mean = 1381 m3/s) from 1985 to 2006 (Fig. 7). Peak hydroelectric generation at Millers Ferry Lock and Dam requires around 708 m3/s Table 8. Estimated number of days Claiborne spillway was inundated by winter floods from December through April 1985–2005. Year December January February March April Total 1985 0 0 12 0 0 12 1986 4 0 0 8 0 12 1987 0 12 8 16 1 37 1988 0 6 3 0 0 9 1989 3 7 0 17 14 41 1990 0 17 28 26 5 76 1991 0 0 9 11 5 25 1992 15 6 12 5 0 38 1993 0 22 1 8 7 38 1994 5 0 10 12 12 39 1995 7 0 11 18 0 36 1996 2 5 16 24 6 53 1997 6 7 10 15 1 39 1998 0 22 23 20 5 70 1999 0 1 8 4 0 13 2000 0 0 0 2 7 9 2001 0 0 2 29 8 39 2002 13 6 2 1 0 22 2003 0 4 6 20 10 40 2004 11 0 11 0 0 22 2005 0 0 1 4 15 20 Total days inundated 66 115 173 240 96 690 Average days 3.1 5.5 8.2 11.4 4.6 32.9 Southeastern Naturalist 165 M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 (M. Eubanks, pers. comm.), thus, discharge levels exceeding this quantity should be available to operate the lock chambers for fish passage. Discussion This study and studies by Peterson and Nicholson (1997) and Peterson et al. (1999, 2000) have greatly expanded our knowledge on the biology, life history, spawning season, and movements of the Southeastern Blue Sucker. Populations in all 3 drainages where the taxon has been documented are more widespread, abundant, and stable than previously believed. As such, the species does not require state or federal protection at this time. More than 944 Southeastern Blue Suckers have been collected in Mississippi (Peterson and Nicholson 1997). The largest known population in Alabama, estimated at ~1500 individuals, inhabits the lower Alabama River. This estimate should increase pending future sampling between Millers Ferry and Henry locks and dams. Our sampling efforts below Coffeeville and Demopolis locks and dams suggested the lower Tombigbee River is inhabited by the second-largest spawning population of Southeastern Blue Suckers documented thus far. The status of this Figure 7. Average monthly discharge (m3/s) of the Alabama River at Millers Ferry Lock and Dam, 1985–2006. Bars are arranged in increasing order. The 708 m3/s line is the required discharge for maximum hydroelectric generation at Millers Ferry powerhouse. Southeastern Naturalist M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 166 population should be confirmed by future sampling in the main channel between these dams. The Cahaba River contains a small but healthy population, as do the lower Coosa and Tallapoosa rivers. Lack of recent collection success suggests that a small population discovered in the upper Coosa River by Scott (1951) has likely disappeared. Limited numbers of Southeastern Blue Suckers were collected in the upper Tombigbee River prior to construction of the Tennessee-Tombigbee Waterway. This population was severely reduced or eliminated after the original riverine environment was replaced by a human-made navigation channel (Boschung 1989). The male:female sex ratio was 2:1 for Alabama River fish and 1:1 for Pearl and Pascagoula fish. Females were longer and heavier than males per unit TL in Alabama and Mississippi. The TL range was similar for females collected in the Alabama River (446–742 mm) and Pearl and Pascagoula rivers (452–702 mm) (Peterson et al. 1997), but greater for males collected in the Alabama River (438–702 mm) compared to those collected in the Pearl and Pascagoula rivers (327–593 mm). Female TW ranged from 800 to 6000 g in the Alabama River and from 1200 to 5300 g in the Pearl and Pascagoula rivers. Male TW ranged from 800 to 3800 g in the Alabama River and from 900 to 2200 g in the Pearl and Pascagoula rivers. Differences in sex ratio, TL, and TW between drainages were probably influenced by differences in collection methods and study duration. Most of our samples were collected weekly below Miller Ferry powerhouse with large gill nets in March–April from 1995 to 2005. Peterson and Nicholson (1997) collected samples weekly or monthly in randomly selected specific reaches of the Pearl and Pascagoula rivers with boat-electrofishing gear from late February 1996 to January 1997. Relationships of TL to SL and SL to TW were significantly different for Alabama River males and females. Females collected in the Pearl and Pascagoula rivers were significantly heavier than males per unit TL (Peterson et al. 1999, Peterson and Nicholson 1997). Similar slope differences occurred for Blue Suckers collected in the Neosho River (Moss et al. 1983). No significant difference in log10WW and log10TL slopes was observed for Blue Suckers collected in pool 20 in the Mississippi River (Rupprecht and Jahn 1980). Kansas River fish ranged from 242 mm to 782 mm TL and weighed from 86 g to 5443 g (Eitzmann et al. 2005). The spawning season for Southeastern Blue Suckers in the Alabama River extended from March through April. Peak spawning occurred from mid- to late- March. Intense spawning colors, free-flowing gametes, and the presence of fresh wounds suggested some fishes were actively spawning over a debris-strewn (tree limbs, pieces of treated lumber, boat anchors, fishing gear, and various pieces of metal scrap) rocky bottom when collected. Adults left the Millers Ferry spawning area by early May. Spawning occurred from late February into early March in the Pearl and Pascagoula rivers (Peterson et al. 1999). Spawning times for Southeastern Blue Suckers there were consistent with those in the Current River, MO, (Pflieger 1975), but slightly earlier than spawning in pool 20 in the upper Mississippi River (Rupprecht and Jahn 1980), the Neosho River (Moss et al. 1983), and pool 9 of the Mississippi River (McInerny and Held 1988). Southeastern Naturalist 167 M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 Three factors probably contributed to lower sampling success in the Alabama River. Generation schedules limited gill-netting activity to 2 h per week. Longer sampling periods would likely have produced larger catches. Some collection efforts were postponed when continuous generation was needed to fulfill increased local electrical demand. Other collections were postponed when prolonged drought conditions prevented fish from moving upstream past Claiborne Lock and Dam. We collected only 44 fish in 72 samples in 1988 when extreme flooding delayed sampling efforts until after the peak spawning season had ended. We collected only 32 fish in 24 samples in 2001 because the crested spillway at Claiborne Lock and Dam was never inundated by winter floods in 2000–2001. Netting success rebounded in 1999, 2002, and 2003 when we collected 142, 103, and 200 fish, respectively. Color and reproductive data suggested that most spawning activity was completed by 13–24-year-old males and females. Spawning activity probably diminished in 27–31-year-old males and females. The oldest individuals collected were 32–34-year-old males and females. Nineteen 30–34-year-old males and nine 30–34-year-old females probably hatched prior to or while Millers Ferry and Claiborne locks and dams were under construction. Assuming these estimates are correct, 33–34-year-old males and females may have participated in some of the first upstream spawning migrations past Claiborne Lock and Dam. More study is needed to develop new procedures for calculating consistent age estimates for Southeastern Blue Suckers and Blue Suckers. Opercle ring-counts indicated the estimated age of Pearl and Pascagoula river males ranged from 4 to 33 y; the estimated age for females ranged from 6 to 31 y (Peterson and Nicholson 1997, Peterson et al. 1999). Using the age and growth formulas of Peterson and Nicholson (1997) and Peterson et al. (1999), we estimated the ages of Alabama River males and females were 4–34 y. Robert E. Jenkins (Roanoke College, Salem, VA) used opercle ring-counts to estimate that the age of a 460-mm-TL fish collected in the Cahaba River was 22 years. All 3 studies support the >30-year life-span for Southeastern Blue Sucker proposed by Peterson and Nicholson (1997), Burr and Mayden (1999), and Peterson et al. (1999). Growth-ring counts on scales and gill filaments produced much younger age estimates for Blue Sucker. The life span of fishes collected in pool 20 of the Mississippi River was 10 y (Rupprecht and Jahn 1980). The average age of Blue Suckers collected in the Neosho River was 9 y for females and 7 y for males (Moss et al. 1983). The age of fishes in the Kansas River ranged from 1 to 16 y (n = 99); the most abundant age was 9 y (Eitzmann et al. 2005). Vokoun et al. (2003) indicated Grand River fishes attained 22 years of age. Our attempts to locate, remove, and examine otoliths from several Alabama River specimens were completely unsuccessful. We were unable to locate any reports that utilized these small delicate structures for age and growth studies. The presence of freshly calloused areas along the median pelvic-fin margins of 3 Southeastern Blue Suckers boat-electrofished downstream of Claiborne Lock and Dam suggested these fishes used their pelvic fins to grasp small tree limbs while feeding on tricopteran and other readily available insect larvae. Utilizing food Southeastern Naturalist M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 168 sources suspended in the water column would be a more efficient foraging behavior than scavenging for food attached to silt-covered trees and rocks on the river bottom. We did not find any previous observations of this type of feeding behavior for Southeastern Blue Sucker or Blue Sucker. Nemotodes and tricopteran, coleopteran, and chironomid larvae were the dominant food items for 206 male and female Southeastern Blue Suckers collected in the Pearl and Pascagoula rivers (Peterson and Nicholson 1997, Peterson et al. 1999). The recapture of anchor-tagged fish was especially useful in confirming the identity of several sonic-tagged Southeastern Blue Suckers whose tag batteries had expired. We likely would not have identified these individuals as recaptures because suture lines were healed and covered by regenerated abdominal scales. Southeastern Blue Suckers retained anchor tags longer than Poyldon spathula (Wahlbaum) (Paddlefish), Ictalurus punctatus (Rafinesque) (Channel Catfish), and I. furcatus (Lesueur) (Blue Catfish) tagged in Energy Lake, KY (Timmons and Howell 1995) and Paddlefish tagged in the Alabama River (Mettee et al. 2009). Sonic-tracking data confirmed Southeastern Blue Suckers completed long spawning runs, moved upstream and downstream past Claiborne Lock and Dam, and occupied fairly restricted summer habitats in the lower Alabama, lower Tombigbee, Middle, Mobile, and Tensaw rivers. The detection of 11 fish in the MTRD suggested fish survived in low salinity as the salt water wedge moved upstream during summer months. Failure to collect any individuals in Mobile Bay suggested a 575-mm adult collected at a boat slip at Dauphin Island (Swingle (1971) probably originated from the MTRD. Sonic-tagged fish staged below Claiborne Lock and Dam during the fall and winter months moved upstream past the dam when the spillways were inundated by floods, and spawned in the tailwater and generator-outflow areas below Millers Ferry Lock and Dam. Most Southeastern Blue Suckers left the generator area by early May. Individuals that failed to move past Claiborne spawned below the dam and near rock jetties in lower sections of river. Spawning-site fidelity was confirmed by the recapture of 57 anchor-tagged fish and the detection of 15 sonic-tagged fish in or near Millers Ferry tailwater during a subsequent spawning season. The most disappointing aspect of this study was our failure to collect any smaller Southeastern Blue Suckers or locate any nursery areas for the species in the Alabama River. Peterson et al. (1997) reported similar results in the Pearl and Pascagoula rivers. Studies are needed in all 3 drainages to locate younger age classes and nursery habitats for the species. The Alabama River is an ideal environment for implementing fish-passage operations. The river channel is inhabited by >150 freshwater and marine fish species (Mettee et al. 1996), a diversity equal to or greater than is found in many states. Several species, including Acipenser oxyrinchus desotoi (Mitchill) (Gulf Sturgeon), Scaphirhynchus suttkusi Williams & Clemmer (Alabama Sturgeon), Paddlefish, Atractosteus spatula (Lacepède) (Alligator Gar), Anguilla rostrata (Lesueur) (American Eel), Alosa alabamae Jordan and Evermann (Alabama Shad), Ictiobus bubalus Rafinesque (Smallmouth Buffalo), Southeastern Blue Sucker, Moxostoma Southeastern Naturalist 169 M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 carinatum Cope (River Redhorse), Blue Catfish, Channel Catfish, Strongylura marina (Walbaum) (Atlantic Needlefish), and Mugil cephalus L. (Striped Mullet), are known to complete long spawning migrations into the lower Alabama River. Paddlefish, an important commercial species, spawns below Millers Ferry and Claiborne locks and dams in April, spends the summer months in the lower Alabama River and MTRD, feeds in northern sections of Mobile Bay during the winter months, and returns to the Alabama River to spawn the following spring (Mettee et al. 2009). Flow-attraction studies in 2004 demonstrated that large numbers of fish move into Claiborne and Millers Ferry locks and dams during their upstream spawning runs (Mettee et al. 2006). One sonic-tagged fish released downstream of Millers Ferry in early 2004 moved upstream through Millers Ferry lock chamber with a USCOE snagboat and was detected at several locations in Bill Dannelly Reservoir in 2004–2005 (Mettee et al. 2006). Four sonic-tagged fish released in Mobile Bay in March 2006 moved upstream into the Alabama River and were detected upstream and downstream of Claiborne Lock and Dam in 2007. All 4 fish returned to the MTRD after the spawning season ended (Mettee et al. 2009 ). Sampling data collected from 1995–2005 suggested several large-river species spawned below Claiborne and Millers Ferry locks and dams at slightly different times of the year. Hiodon tergisus Lesueur (Mooneye) and Moxostoma poecilurum Jordan (Blacktail Redhorse) spawn from late January into February. The Lepisosteus osseus (L.) (Longnose Gar), Smallmouth Buffalo, Southeastern Blue Sucker, and M. carinatum (Cope) (River Redhorse) spawn in March. Paddlefish spawn from late March through April, and Aplodinotus grunniens Rafinesque (Freshwater Drum) spawns in May. The lower Alabama River supports one of the richest fish faunas in North America for rivers of its size (Pierson et al. 1989) and daily fish-passage operations at Claiborne and Millers Ferry locks and dams from January through April should improve upstream migration success of these and other fish species into the upper Alabama and Cahaba rivers, thus increasing diversity in those systems. All of these activities could be accomplished without adversely affecting navigation, hydroelectric generation schedules, and industrial water needs and quality along the river. Acknowledgments We thank several individuals and agencies for their contributions to the success of this project. Bill Reeves contributed to the initial project design, donated large gill-nets, and participated in sample collection during the early years of the project. Fred Harders and Steve Rider of the Wildlife and Freshwater Fisheries Division (WFFD) of the Alabama Department of Conservation and Natural Resources secured subsequent funding, supplied pontoon boats and personnel, participated in sample collection, and served as project advisors and coordinators through the remaining study years. Tom Groce, Mike Eubanks, and Ed Varner of the USCOE (Mobile District Office) coordinated all lock and dam operations with Bobby Phelps and his staff at Claiborne and Millers Ferry locks and dams. Ed Tybergein from Alabama Power Company shared results from his unpublished sonic-tracking studies in the Mobile River. Jerry Moss, Phillip Kilpatrick, and Ken Weathers from WFFD and Philip Henderson, Southeastern Naturalist M.F. Mettee, T.E. Shepard, P.E. O’Neil, and S.W. McGregor 2015 Vol. 14, No. 1 170 Arthur McLin, and Neil Moss from the Alabama Geological Survey participated in numerous collecting and sonic-tracking trips during the study. 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