<%BANNER%>

Distribution and Habitat Selection of Largemouth Bass in a Florida Limerock Pit


PAGE 1

DISTRIBUTION AND HABITAT SELECTION OF LARGEMOUTH BASS IN A FLORIDA LIMEROCK PIT By TROY M. THOMPSON, JR. A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2003

PAGE 2

ACKNOWLEDGMENTS I thank the members of my committee, Drs. Chuck Cichra, Daniel E. Canfield, Jr., and William Lindberg, for the advice and critical review that were so crucial to completion of this thesis. I thank David Watson (Florida LAKEWATCH) for his help with the location map for Kirkpatrick Lake. I appreciate Dr. Allen Riggs (College of Veterinary Medicine, University of Florida) expertise and help with transmitter implantation. Jason Hale was an invaluable aid in loading the habitat map into ArcInfo and an excellent source of GIS wisdom. Wes Porak (Florida Fish and Wildlife Conservation Commission) was helpful with his advice and introducing me to Lorraine Fries (Texas Parks and Wildlife Department) who was gracious enough to oversee the subspecies identification of the largemouth bass from Kirkpatrick Lake. I thank Margaret Glenn of Dr. Bill Hallers (Department of Agronomy, University of Florida) lab for use of their ATS receiver and antenna. I also appreciate the labs of Drs. Micheal Allen, Daniel E. Canfield, Jr., and Thomas K. Frazer (Department of Fisheries and Aquatic Sciences, University of Florida) for use of various equipment necessary to complete this study. I greatly appreciate the late Senator George G. Kirkpatrick, Jr., for whom the lake was named, for allowing me to use his lake to study the largemouth bass he loved so much. ii

PAGE 3

I thank Dr. Jimmy Cheek, Dean of the College of Agricultural and Life Sciences, and Dr. Chris Waddell, Dean of the Florida Cooperative Extension Service, for providing my graduate assistantship, without which I would not have been able to pursue my graduate degree. Last but not least, thanks go out to all the folks who helped me in the field: Rob Burns, Jason Childress, Chuck Cichra, Sharon Fitz-Coy, Jeff Hill, Natalie Love, Jeff Sowards, and Will Strong. iii

PAGE 4

TABLE OF CONTENTS page ACKNOWLEDGMENTS..................................................................................................ii LIST OF TABLES.............................................................................................................vi LIST OF FIGURES..........................................................................................................vii ABSTRACT.....................................................................................................................viii INTRODUCTION...............................................................................................................1 STUDY SITE DESCRIPTION............................................................................................3 METHODS..........................................................................................................................6 Transmitter Implantation..............................................................................................6 Radio-Tracking.............................................................................................................7 Dissolved Oxygen/Temperature Sampling...................................................................8 Habitat Mapping...........................................................................................................8 Home Ranges and Habitat Selection..........................................................................11 Diel Sampling.............................................................................................................12 Fish Attracting Device Study......................................................................................12 RESULTS..........................................................................................................................14 General........................................................................................................................14 Habitat Selection.........................................................................................................16 Home Range...............................................................................................................19 Diel Sampling.............................................................................................................19 Fish Attracting Device Utilization..............................................................................20 DISCUSSION....................................................................................................................22 General........................................................................................................................22 Genetics......................................................................................................................25 Transmitters................................................................................................................25 Management Implications..........................................................................................26 iv

PAGE 5

LIST OF REFERENCES...................................................................................................28 BIOGRAPHICAL SKETCH.............................................................................................32 v

PAGE 6

LIST OF TABLES Table page 1 Size distribution and tagging information for largemouth bass in Kirkpatrick Lake, Florida............................................................................................................15 2 Percent habitat use by largemouth bass and percent habitat available in Kirkpatrick Lake, Florida, between 1 May 2002 and 1 May 2003..........................16 3 Values of the linear selection index L for littoral habitat use by largemouth bass in Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003. Positive values indicate preference; negative values indicate avoidance..........................................17 4 Values of the linear selection index L for pelagic habitat use by largemouth bass in Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003. Positive values indicate preference; negative values indicate avoidance..........................................18 5 Mean values of the linear selection index L for habitat use by largemouth bass in Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003..................................18 6 Number of observations and home range (ha) for largemouth bass in Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003......................................................20 7 Seasonal home ranges for largemouth bass in Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003.........................................................................................20 8 Number and percent of follow-up largemouth bass locations that were in a different sub-basin during two diel sampling dates in Kirkpatrick Lake, Florida, on 22 August 2002 and 17 April 2003.....................................................................21 vi

PAGE 7

LIST OF FIGURES Figure page 1 Kirkpatrick Lake location and bathymetric map (from Florida LAKEWATCH). Depth contours and distances are in feet....................................................................5 2 Pelagic and littoral zones in Kirkpatrick Lake, Florida. The littoral zone extended to the 3.5-m depth contour, May 2002 to May 2003..................................................9 3 Distribution of habitats and fish attracting device installation sites for Kirkpatrick Lake, Florida, May 2002 to May 2003.....................................................................10 vii

PAGE 8

Abstract of Thesis presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science DISTRIBUTION AND HABITAT SELECTION OF LARGEMOUTH BASS IN A FLORIDA LIMEROCK PIT By Troy M. Thompson, Jr. Chairperson: Dr. Charles E. Cichra Major Department: Fisheries and Aquatic Sciences Radio telemetry was used to determine the distribution and habitat selection of largemouth bass (Micropterus salmoides) in a north-central Florida lake from 18 April 2002 to 1 May 2003 so that management recommendations that would increase angler catch rates could be made. The study site (Kirkpatrick Lake, Alachua County, Florida) is a steep-sided, 7-ha flooded limerock quarry, and is composed of six conjoined sub-basins. Twelve largemouth bass were internally implanted with radio transmitters (of no more than 18% of the total length of the fish) and tracked. Over the course of the study, the number of fish tracked was reduced to five as transmitters failed or ceased movement. Pelagic areas were selected over littoral areas during the summer and fall/winter periods (p = 0.022). Only one fish utilized littoral areas more than pelagic areas during this period. In the spring (February through April), habitat use switched; littoral areas seemed to be selected over pelagic areas for four of five fish based on the preference values. However, no significance was found because of the low number of replicates viii

PAGE 9

(n = 5). Sunken trees were the only structural habitat significantly utilized by largemouth bass (p < 0.001). Other structural habitats had generally neutral preference values. Areas within 5 m of the shoreline were strongly avoided (p < 0.001). Home range was correlated with days sampled (n = 12, r = 0.69, p = 0.01), but not total length and weight of fish (n = 5, r = 0.57, p = 0.31; n = 5, r = 0.52, p = 0.36, respectively). Home range varied from 0.56 to 4.84 ha with means of 3.04 ha for all fish, and 4.09 ha for the five fish that were tracked over the entire study. No seasonal trends were evident in home range size. One fish established a separate home range from 9 January to 18 February 2003; after which it returned to its previous range. Largemouth bass locations, observed during two diel tracking sessions, were consistent with weekly daytime data collected over the full term of the study. Fish exhibited constant movement during diel sampling periods, often moving between sub-basins. No day/night or spring/summer differences in movement or habitat preference were detected. There was no evidence of any diel on-shore/off-shore movement patterns. Twenty mushroom-hat fish attracting devices (FADs) were suspended vertically into the lake at four sites on October 4, 2002. Although four of the five remaining largemouth bass utilized these FADs at least once, the neutral preference values indicate that the FADs were not a significant habitat for the largemouth bass. Due to the selection of pelagic areas, except during the spawning season, it is speculated that the largemouth bass fed primarily on open water prey. Increasing structural habitat may not measurably increase angler catch rates for largemouth bass in lakes where open water prey are the principal forage. Therefore, fisheries managers should focus their efforts on angler education in such lakes. ix

PAGE 10

INTRODUCTION Habitat selection by largemouth bass (Micropterus salmoides) is an important consideration in fisheries management. Knowledge of selected habitats can aid biologists in making management decisions. As ambush predators, largemouth bass typically utilize structural littoral habitat such as vegetation and woody debris, though they are sometimes found off-shore in deeper, open water. Aquatic vegetation is the principal habitat available for the Florida largemouth bass (M. s. floridanus), which evolved in the shallow, highly vegetated waters of Florida and seems to prefer shallow water (Chew 1975). Colle et al. (1989) found that the Florida largemouth bass utilized open water areas after all submerged aquatic vegetation was removed from Lake Baldwin, a shallow Florida lake. Quarry lakes are fairly common in Florida and throughout the United States and are often utilized by anglers. There is a lack of research on habitat selection by largemouth bass in steep-sided systems that have a narrow littoral zone. The home range of largemouth bass has been quantified by various authors (Warden and Lorio 1975; Fish and Savitz 1983), the size of which varies with fish size (Chappell 1974), length of time sampled, and water body size and morphometry. Largemouth bass have activity centers within their home range where they spend the majority of their time (Winter 1977; Doerzbacher 1980; Betsill et al. 1986; Boyer 1994). Other researchers noted that subsets of the population exhibit random movement and do not have activity centers (Ball 1947; Moody 1960). It has therefore been hypothesized that there are mobile and sedentary segments of some largemouth bass populations 1

PAGE 11

2 (Fetterolf 1952; Funk 1957; Moody 1960; Poddubnyi et al. 1974; Miller 1975). Factors leading to a transient lifestyle may include differential prey selection or lack of suitable habitat. One response by fisheries managers to a perceived lack of natural habitat is to supplement it with artificial habitat or structure, which has been shown to attract and concentrate prey and sport fish (Hazzard 1937; Rodeheffer 1939, 1940, 1945; Manges 1959; Anderson 1964; La Roche 1972; Prince et al. 1975). This often results in higher catch rates for anglers (Prince et al. 1975; Wilbur 1978), which is often a goal of sportfishery managers. If largemouth bass have a mobile lifestyle due to a lack of attractive habitat, then offering habitat may allow them to assume a more sedentary habit. This would allow the fish to be more accessible to anglers, who of ten fish near structural habitat. The purpose of this study was to determine the distribution and habitat selection of largemouth bass in a deep, steep-sided Florida lake and to assess changes in distribution after installation of artificial structure.

PAGE 12

STUDY SITE DESCRIPTION Kirkpatrick Lake is located in Alachua County, Florida, west of Gainesville (Figure 1). It is a flooded limerock quarry consisting of six conjoined sub-basins with a total surface area of approximately 7 ha. Much of the perimeter of the lake is comprised of 10 to 30-m vertical walls. This steep-sided lake has a mean depth of 6.5 m and a maximum depth of 11m. Giant bulrush (Scirpus californicus), alligator weed (Alternanthera philoxeroides), and cattails (Typha latifolia) are present but limited in abundance due to the lack of suitable shallow substrate. Southern naiad (Najas guadalupensis) is common in the littoral zone and grows to an average height of 0.3 m. The littoral zone extends to a mean depth of 3.5 m. Littoral zone width averages 10 m but ranges from 0 to 45 m. Six large trees have been submerged in the lake as structural habitat. The lake was naturally oligotrophic based on water clarity (Forsburg and Ryding 1980), having secchi disk depths up to 6 m (Christy Horsburgh, Department of Fisheries and Aquatic Sciences, University of Florida, unpublished data). The lake is currently fertilized during the warm months to increase algal production and enhance fish production. Fish are also fed pelleted food. Secchi disk depths now range from less than 1m when the lake is fertilized (February to November) to over 3 m when the lake is not fertilized and water temperatures are lower. Sport fish in the lake include largemouth bass, hybrid striped bass (Morone chrysops x Morone saxatilis), bluegill (Lepomis macrochirus), warmouth (Lepomis gulosus), and redear sunfish (Lepomis microlophus). Prey species include golden shiner (Notemigonous chrysoleucas), threadfin shad 3

PAGE 13

4 (Dorosoma petenense), gizzard shad (Dorosoma cepedianum), lake chubsucker (Erimyzon sucetta), eastern mosquitofish (Gambusia holbrooki), blue tilapia (Oreochromis aureus), and brown bullhead (Ictalurus nebulosus). Fishing pressure is light (2-3 fishing parties per week) because it is a private water body that has controlled access and a catch and release only fishing policy. Although large adult largemouth bass (> 406 mm TL) are often stocked into the lake, but are not routinely caught by anglers.

PAGE 14

5 02505007501000 Figure 1. Kirkpatrick Lake location and bathymetric map (from Florida LAKEWATCH). Depth contours and distances are in feet.

PAGE 15

METHODS Transmitter Implantation Eleven largemouth bass, weighing from 1.0 to 3.0 kg, were collected from the lake by electrofishing (300 V, 7A, DC pulse) on 16 April 2002 and implanted with Advanced Telemetry Systems (ATS) Model f1235 temperature-sensing radio transmitters (75 mm x 18 mm, 24 g). These transmitters had radio frequencies ranging from 48.411 to 48.825 MHz. One transmitter did not operate properly and had to be replaced. A twelfth fish was implanted on 7 May 2002 after the new transmitter arrived. We attempted to capture fish over a broad size range so that transmitter weights would be no more than two percent of the body weight (Mesing and Wicker 1986). Fish handling procedures were recommended by Dr. Allen Riggs, College of Veterinary Medicine, University of Florida. Surgical tools and transmitters were disinfected with 95% ethyl alcohol before use. Each fish was individually anesthetized in a 51-L aerated cooler containing 150-mg/L MS-222 solution. After a fish lost equilibrium, total length (TL) and weight were measured before moving the fish for surgery to a 95-L aerated cooler containing 100-mg/L MS-222 solution. Both solutions were buffered at a rate of two parts sodium bicarbonate to one part MS-222. While in the second cooler, the fish was placed into a wooden trough such that its head was submerged while the area of operation was out of the water. A 20 to 25-mm vertical incision was made 25 to 30 mm anterior of the anus. The transmitter was inserted into the body cavity and the incision was closed with a single row of four to five stitches through both the peritoneum and integument using size 6

PAGE 16

7 3-0 reverse cutting needles and monofilament suture material (Fluorofil, Schering-Plough, Union, New Jersey). Antibiotic topical ointment (Panalog) was rubbed onto the incision to help prevent infection. Two Floy T-bar internal anchor tags were inserted into the dorsal pterigiophores and a small piece of the right pelvic fin was clipped from each fish. The fish was then placed into a cooler of fresh water for recovery before being released at the site of its capture. Total handling time for each fish was 20 to 30 minutes. Two signs were placed near the boat ramp and picnic area of this private lake advising anglers to immediately release tagged fish unharmed at the site of capture. At least one tagged fish was caught and released back into the lake by a an angler during this study. Fin samples were sent to the A. E. Woods Fish Hatchery (Texas Parks and Wildlife Department) in San Marcos, Texas for DNA analysis. Radio-Tracking Each fish was located weekly from 1 May 2002 to 1 May 2003 (unless the transmitter failed or ceased movement) with an ATS Model R2000 receiver and a loop antenna. Radio-tracking was performed using a 3-m johnboat propelled by an electric trolling motor to minimize disturbance to the fish. Sampling times were randomly varied between 0700 and 2100 hrs to reduce bias associated with time of day. Fish located near vertical walls were triangulated parallel and perpendicular to the wall to eliminate false locations due to signal reflection. A GPS reading was taken directly above the location of the fish along with the time of day. Because GPS readings could not always be taken due to the steepness of the rock walls, all locations were also marked on a detailed bathymetric map developed by Florida LAKEWATCH (Department of Fisheries and Aquatic Sciences, University of Florida, Gainesville, FL) in November 2000. Prevailing weather conditions (% clouds, precipitation, and wind) were recorded to note any

PAGE 17

8 behavioral changes due to weather. Pulse rate (seconds/100 pulses) was measured for each transmitter with a stopwatch. Dissolved Oxygen/Temperature Sampling Dissolved oxygen/temperature profiles were recorded, with a Yellow Springs Instruments Model 58 dissolved oxygen/temperature meter, in every sub-basin in which a radio-tagged fish was located. The recorded pulse rate of each transmitter was then compared with the calibration curve, supplied with each transmitter, to obtain the temperature of each fish. This temperature was then compared with the temperature profile of the sub-basin to approximate the depth of each fish. Habitat Mapping The bathymetric map of Kirkpatrick Lake was copied into ArcView GIS 3.2 as a base-map for habitat and location mapping. ArcView was used to measure habitat areas, count locations per habitat, and generate digital maps of the lake and its habitats. The littoral zone was defined as the area from the shoreline out to the 3.5 m depth contour, the mean maximum depth of rooted aquatic vegetation (Figure 2). Littoral areas included clean shoreline, brushy shoreline (shoreline that had terrestrial bushes growing out into the water), humps, boulders, small brush-piles (such as single Christmas trees submerged into the lake), shallows (relatively flat areas that were less than 2 m deep), saddles (littoral areas between sub-basins), and other non-structural areas (Figure 3). Pelagic areas (> 3.5 m depth) included open water, fish feeders, aerators, large sunken trees, and

PAGE 18

9 Figure 2. Pelagic and littoral zones in Kirkpatrick Lake, Florida. The littoral zone extended to the 3.5-m depth contour, May 2002 to May 2003.

PAGE 19

10 Figure 3. Distribution of habitats and fish attracting device installation sites for Kirkpatrick Lake, Florida, May 2002 to May 2003.

PAGE 20

11 fish attracting devices (FADs). These habitats were visually marked in the winter, when water clarity was high, and drawn onto the bathymetric map. These habitats were then redrawn onto the base-map using ArcView. A 5-m buffer was placed around structural habitats (humps, boulders, brushpiles, trees, aerators, feeders, and FADs). A fish was considered to be utilizing a particular habitat when it was within 5 m of the habitat. Maps showing the location fixes for each fish were then overlaid onto the habitat map to count the number of locations per habitat. Home Ranges and Habitat Selection Annual and seasonal home ranges were calculated with ArcView using the smallest convex-polygon method (Winter 1977). Outliers were removed from the individual home range estimates if they occurred as single locations in a sub-basin and were not along travel routes. The sampling year was broken up into three seasons. The summer season included all sampling dates from May 2002 through October 2002. Fall/winter sampling dates were from November 2002, when the lake started to destratify, through January 2003. Spring sampling dates were from February 2003 through May 2003 (the typical spawning period for largemouth bass in north Florida). Annual and seasonal habitat selection were determined from a modification of Strauss (1979) linear index of food selectivity, L = r i p i ; where r i is the percent use of habitat i and p i is the percent availability of habitat i (Mesing and Wicker 1986). Habitat preference values can range from (avoidance) to +1 (preference). The Wilcoxon signed rank test (Hollander and Wolfe 1973) was used to determine if mean L values were significantly different from zero ((2) = 0.05).

PAGE 21

12 Diel Sampling Diel sampling was conducted on 22 August 2002 and 17 April 2003 to determine if habitat use and movements were equivalent between day and night. Sampling began at 0700 hrs and ended at approximately 0300 hrs. Each fish was tracked every four hours during diel sampling and its location marked on the bathymetric map. GPS readings were not taken during diel sampling because of potential effects on fish movements. For each time period, pulse rate was recorded for each fish and a dissolved oxygen/temperature profile was recorded for each sub-basin in which a fish was located. Fish Attracting Device Study Twenty mushroom-hat FADs were suspended vertically into the lake at four sites (Figure 3) on 4 October 2002. They were constructed using 150-L plastic trash cans. After the bottom was cut out, the remaining cylinder was cut vertically to make two arc-shaped pieces. These pieces along with the lid were used to construct one four-tiered structure. Holes were drilled in the center of these pieces and 10-mm diameter nylon rope threaded through the holes (with three 0.6-m segments of 38-mm diameter PVC pipe placed in between as spacers). The top and bottom pieces were secured with several knots in the rope. Each FAD was anchored with a 20x20x40-cm concrete block. Five dense 15x20-cm Styrofoam floats were used to float each structure. Each FAD was 2-m long from the lowest piece to the top of the floats. Depth was adjusted on site so that the bottom of each FAD was no deeper than 3 m below the water surface (the shallowest observed depth that the water became anoxic). This meant that the top of each FAD was 1 m underwater and thus less visible to anglers. FADs were placed in open water near funnels of recorded fish travel. Each site consisted of five FADs placed approximately 2 m apart in a pentagon formation. Radio-tagged fish were located three times each week

PAGE 22

13 for two weeks prior to FAD placement and three times each week for four weeks thereafter to quantify any changes in habitat use. Afterwards, normal weekly sampling was resumed for the remainder of the study.

PAGE 23

RESULTS General At first, all 12 radio-tagged largemouth bass were identified to be the Florida subspecies based on the analysis of microsatellite DNA loci Lma 0012, Mdo 0006, and Mdo 0004 (Texas Parks and Wildlife Department, unpublished data) Preliminary data from the Texas Parks and Wildlife Department suggested that these loci were diagnostic between northern and Florida largemouth bass. Subsequent analysis by the Texas Parks and Wildlife Department found that these loci were not diagnostic. Further analysis was performed on seven intrapseudogenic loci, which preliminary data show to be completely fixed for either northern or Florida largemouth bass. Results from this analysis indicate that eleven of the fish sampled were intergrades and one (Fish 704) was pure Florida strain (Texas Parks and Wildlife Department, unpublished data). No DNA could be extracted from the twelfth fish. Because of these conflicting results, largemouth bass were not designated to subspecies for this study. Tagged largemouth bass were successfully located, on average, over 99% of the time. Five fish (471, 684, 725, 764, and 825) most likely died, or possibly shed their transmitters, when their movements ceased during the course of the study (Table 1). It is unlikely that the transmitters were shed since the first cessation of movement came 3.5 months after transmitter implantation (Allen Riggs, personal communication). Efforts to instigate movement, if the fish was alive but inactive, were unsuccessful. Further efforts to recover the transmitters or fish carcasses were also unsuccessful. Transmitters in four 14

PAGE 24

15 of the five fish ceased movement in August and early September. During this time period, one to two dead, untagged largemouth bass, greater than 375 mm TL, were observed per week in Kirkpatrick Lake. This pattern of finding a few larger dead largemouth bass over an extended period during the hotter months is consistent with largemouth bass virus (Wes Porak, Florida Fish and Wildlife Conservation Commission, personal communication) and, speculatively, may be the cause of these deaths. Two fish (561 and 704) either experienced transmitter failure or were removed from the lake by poachers. Another transmitter (Fish 744) stopped pulsing on 17 April 2003, so depth could no longer be calculated. However, the transmitter continued to emit a tone and the fish could be located for the duration of the study. Dissolved oxygen concentrations were less than 2 mg/L, at water depths below 4.2 m, from the start of radio-tracking until the lake destratified on 14 November 2002. Observed oxygen concentrations did not drop below 2 mg/L (at depths up to 5.5 m) for the remainder of the study. Table 1. Size distribution and tagging information for largemouth bass in Kirkpatrick Lake, Florida. Fish Total Weight Tagging Last Number of Number of Location number length (mm) (g) date observation 1 observations attempts rate (%) 411 556 2950 16-Apr-02 1-May-03 66 66 100.00 471 446 1265 16-Apr-02 22-Aug-02 16 16 100.00 501 422 979 16-Apr-02 1-May-03 65 66 98.48 561 448 1248 16-Apr-02 30-Aug-02 21 21 100.00 684 459 1267 16-Apr-02 26-Oct-02 37 38 97.37 704 483 1409 16-Apr-02 18-Sep-02 24 24 100.00 725 512 2193 16-Apr-02 7-Aug-02 14 14 100.0 744 475 1322 16-Apr-02 1-May-03 65 66 98.48 764 523 2203 7-May-02 22-Aug-02 13 13 100.00 784 455 1357 16-Apr-02 21-Apr-03 65 66 98.48 804 444 1161 16-Apr-02 1-May-03 66 67 98.51 825 466 1358 16-Apr-02 6-Sep-02 22 22 100.00 Overall rate (%): 99.28 1 First observation was 1 May 2002 for all fish except 764 which was 18 May 2002.

PAGE 25

16 Habitat Selection Pelagic areas were utilized more than twice as often as littoral areas (from the shoreline to the 3.5 m depth contour) by the largemouth bass (Table 2). Other utilized habitats included sunken trees while shoreline areas were avoided. Table 2. Percent habitat use by largemouth bass and percent habitat available in Kirkpatrick Lake, Florida, between 1 May 2002 and 1 May 2003. Habitat type % Use % Available Pelagic zone 68.4 60.2 Littoral zone 31.6 39.8 Pelagic habitats Sunken trees 11.5 3.4 Aerators/feeders 2.8 2.2 Fish attracting devices 5.5 2.5 Open water 48.6 52.1 Littoral habitats Brushpiles 0.5 3.0 Humps/boulders 1.6 1.3 Shallows/saddles 7.4 15.4 Non-structural 22.1 20.1 Shoreline Brushy 0.2 9.5 Clean 6.5 90.5 Structural habitats were not heavily utilized by largemouth bass in Kirkpatrick Lake (Tables 3 and 4). Sunken trees were the only structural habitat significantly utilized by largemouth bass (p < 0.001, Table 5). Other structural habitats had generally neutral L-values. Areas within 5 m of the shoreline were strongly avoided (p < 0.001). Pelagic areas were selected over littoral areas during the summer and fall/winter periods (p = 0.022). Only one fish (784) utilized littoral areas more than pelagic areas during this period. During the fall/winter period, the lake destratified and the dissolved

PAGE 26

17 oxygen and temperature readings became uniform. Positive L-values for open water were higher than in the summer, indicating increased use of open water areas. Littoral areas seemed to be selected over pelagic areas in the spring. L-values were positive for four of the five remaining fish but no significance was found because of the low number of replicates (n=5). Fish 411, the largest fish in the study and possibly a female, seemed to utilize open water areas most of the time. Table 3. Values of the linear selection index L for littoral habitat use by largemouth bass in Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003. Positive values indicate preference; negative values indicate avoidance. Fish Littoral Brushy Clean Brush Humps/ Shallows/ number zone shore shore piles boulders saddles Summer 411 -0.16 -0.10 -0.90 -0.03 0.04 -0.10 471 -0.20 -0.10 -0.90 -0.03 -0.01 -0.15 501 -0.21 -0.10 -0.88 -0.03 -0.01 -0.15 561 0.00 -0.10 -0.90 -0.03 -0.01 -0.15 684 -0.26 -0.10 -0.82 -0.03 0.04 -0.04 704 -0.14 -0.05 -0.82 0.01 -0.01 -0.11 725 -0.09 -0.10 -0.83 -0.03 -0.01 -0.15 744 0.00 -0.10 -0.77 -0.03 -0.01 -0.15 764 -0.01 -0.10 -0.83 -0.03 -0.01 -0.08 784 0.13 -0.10 -0.88 -0.03 0.01 -0.05 804 -0.02 -0.10 -0.82 -0.03 -0.01 -0.10 825 -0.07 -0.10 -0.76 -0.03 0.04 -0.01 Fall/Winter 411 -0.31 -0.10 -0.81 -0.03 0.17 -0.15 501 -0.30 -0.10 -0.90 -0.03 -0.01 -0.15 744 -0.22 -0.10 -0.81 -0.03 -0.01 -0.15 784 0.33 -0.10 -0.90 -0.03 -0.01 0.12 804 -0.22 -0.10 -0.90 -0.03 -0.01 -0.15 Spring 411 -0.21 -0.10 -0.85 -0.03 0.05 0.03 501 0.04 -0.10 -0.73 -0.03 -0.01 0.03 744 0.33 -0.10 -0.72 0.04 -0.01 0.11 784 0.40 -0.10 -0.84 -0.03 -0.01 0.38 804 0.13 -0.10 -0.85 -0.03 -0.01 -0.10

PAGE 27

18 Table 4. Values of the linear selection index L for pelagic habitat use by largemouth bass in Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003. Positive values indicate preference; negative values indicate avoidance. Fish Pelagic Sunken Aerators/ Fish attracting number zone trees feeders devices 1 Summer 411 0.16 0.02 -0.02 0.07 471 0.20 0.23 0.05 ----501 0.21 0.28 0.06 -0.03 561 0.00 0.07 -0.02 ----684 0.26 -0.01 0.01 -0.03 704 0.14 0.23 -0.02 ----725 0.09 -0.03 -0.02 ----744 0.00 0.10 0.00 -0.03 764 0.01 0.04 -0.02 ----784 -0.13 -0.01 0.03 -0.03 804 0.02 0.05 0.03 -0.03 825 0.07 0.01 -0.02 ----Fall/Winter 411 0.31 0.06 0.25 -0.03 501 0.30 -0.03 0.08 0.07 744 0.22 0.15 -0.02 0.16 784 -0.33 -0.03 -0.02 -0.03 804 0.22 0.15 0.07 -0.03 Spring 411 0.21 0.03 0.10 0.11 501 -0.04 0.09 0.04 -0.03 744 -0.33 0.03 -0.02 -0.03 784 -0.40 0.03 -0.02 -0.03 804 -0.13 0.08 -0.02 0.10 1 Fish without an L-value were no longer being located when the fish attracting devices were deployed. Table 5. Mean values of the linear selection index L for habitat use by largemouth bass in Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003. Positive values indicate preference; negative values indicate avoidance. Values with asterisks (*) are significantly different (p < 0.05) from zero. Littoral Brushy Clean Brush Shallows/ Season zone shore shore piles saddles Summer/Winter -0.10* -0.09* -0.85* -0.03* -0.10* Spring 0.14 -0.10 -0.80 -0.02 0.09 Pelagic Sunken Aerators/ Fish attracting Humps/ Season zone trees feeders devices boulders Summer/Winter 0.10* 0.07* 0.02 0.01 0.01 Spring -0.14 0.05 0.02 0.03 0.00

PAGE 28

19 Home Range For this study, home range was defined as the area through which a fish traveled during the study period (Burt 1943). One outlier was removed from each of the home range estimates of Fish 471, 501, and 684. Home range estimates varied from 0.56 to 4.84 ha with a mean of 3.04 ha (Table 6). Home range was correlated with days sampled (n = 12; r = 0.69; p = 0.01). After equalizing the number of observations by removing the fish that were not located for the duration of the study, total length and weight were not correlated with home range (n = 5, r = 0.57, p = 0.31; n = 5, r = 0.52, p = 0.36, respectively), and mean home range increased to 4.09 ha. Seasonal home ranges were calculated for the five fish that were located for the duration of the study (Table 7). Mean home range was 2.82, 2.23, and 2.72 ha for the summer, fall/winter, and spring periods, repectively. No seasonal trends were evident in home range size. Fish 804 established a separate winter home range primarily in the southernmost sub-basin from 9 January 2003 to 18 February 2003, after which, it returned to its spring/summer range in the three northern sub-basins of the lake. Diel Sampling Largemouth bass locations, observed during both diel tracking sessions, were consistent with weekly daytime data collected during the course of the study. No day/night or spring/summer differences in movement or habitat preference were detected. Fish exhibited constant movement during diel sampling periods. No fish was found in the same location more than two consecutive times. Movement between sub-basins was common for both the spring and summer sampling dates (Table 8). There was no evidence of any diel on-shore/off-shore movement patterns among the fish.

PAGE 29

20 Table 6. Number of observations and home range (ha) for largemouth bass in Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003. Fish Number of Home number observations range (ha) 411 66 4.57 471 16 0.56 501 65 3.49 561 21 2.64 684 37 1.82 704 24 2.42 725 14 2.08 744 65 4.30 764 13 3.79 784 65 4.84 804 66 3.27 825 22 2.74 mean 3.04 Table 7. Seasonal home ranges for largemouth bass in Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003. Summer Winter Spring Fish home home home number range (ha) range (ha) range (ha) 411 3.59 1.38 2.74 501 1.11 1.99 3.47 744 2.85 3.36 2.84 784 4.53 3.07 2.28 804 2.01 1.38 2.25 mean 2.82 2.23 2.72 Fish Attracting Device Utilization After FAD deployment, four of the five remaining fish utilized a FAD at least once (8 out of 146 observations). However, preference values were generally neutral and the FADs were not a significant habitat for the largemouth bass. Largemouth bass selected sunken trees over FADs, based on the preference values.

PAGE 30

21 Table 8. Number and percent of follow-up largemouth bass locations that were in a different sub-basin during two diel sampling dates in Kirkpatrick Lake, Florida, on 22 August 2002 and 17 April 2003. Fish were located every four hours. Four observations per fish per sampling date. Fish 22/23 August 2002 17/18 April 2003 1 Total % of total 411 0 1 1 12.5 501 0 2 2 25.0 561 2 ---2 25.0 684 2 ---2 25.0 704 3 ---3 37.5 744 2 2 4 50.0 784 2 3 5 62.5 804 3 0 3 37.5 825 0 ---0 0.0 1 Fish without a value were no longer being located when the second diel sampling was performed.

PAGE 31

DISCUSSION General Several studies have documented seasonal use of off-shore areas by largemouth bass in the winter after lake destratification (Warden and Lorio 1975; Prince and Maughan 1979; Betsill 1986; Woodward and Noble 1997). Most of these locations were oriented to structural habitat. Pelagic areas were utilized night and day, and year-round, except during the spawning season, in Kirkpatrick Lake. The majority of these locations were in the open water limnetic zone not associated with any structural habitat. Mesing and Wicker (1986), Wanjala (1986), and Colle et al. (1989) also found utilization of the open water limnetic zone by largemouth bass. It is a common perception that only mid-size largemouth bass utilize the open water limnetic zone with any regularity. Wanjala (1986) concluded that largemouth bass longer than 380 mm TL in an Arizona lake could not forage effectively in open water because of their bulky body shape. However, fish up to 556 mm TL utilized open water regions of Kirkpatrick Lake. Mesing and Wicker (1986) and Colle et al. (1989) radio-tracked largemouth bass up to 615 mm and 499 mm TL, respectively, that utilized open water most of the time. This indicates that big largemouth bass are capable of feeding efficiently in open water when it is energetically productive to do so. The mean home range of 3.04 ha for the largemouth bass in Kirkpatrick Lake is larger than means reported for largemouth bass in larger systems ( [1.06 ha] Winter 1977; [< 0.5 ha] Nieman and Clady 1980; [1.0 and 1.4 ha] Mesing and Wicker 1986; [1.37 and 22

PAGE 32

23 1.73 ha] Boyer 1994; [2.11 ha] Woodward and Noble 1997). The larger home range size in Kirkpatrick Lake probably reflects the more mobile lifestyle of open water fish. Colle et al. (1989) found a larger mean of 21 ha in the off-shore component of largemouth bass in 80-ha Lake Baldwin, Florida. This may be because the fish had to range further to forage effectively based on the larger size and simpler morphometry of Lake Baldwin. Fish 804 established a separate winter home range and then returned to its prior home range before spawning season. This agrees with Woodward and Nobles (1997) findings for Jordan Lake, North Carolina, where four of eleven adult largemouth bass established separate winter home ranges and returned to prior home ranges in early spring. This had only been observed previously in sub-adult largemouth bass (Woodward 1996). There was considerable overlap in largemouth bass home ranges in Kirkpatrick Lake. One fish was located in the same spot as another fish on several occasions. This indicates possible shoaling activity. Large shoals of mobile largemouth bass were observed on three different occasions. These shoals contained 20 to 30 fish that ranged in size from an estimated 300 to 425 mm TL. Shoaling behavior in predatory fish is commonly associated with foraging activity for open water prey. Betsill (1983) and Wildhaber (1985) found a lack of overlap in individual home ranges of largemouth bass in two small Texas impoundments. This indicates the largemouth bass normally did not occupy the same areas and possibly defended territories. There were no pelagic prey species present in these impoundments; sunfish were the primary forage (Betsill 1983; Wildhaber 1985). Habitat may be a more important component of the life history of largemouth bass when the primary forage are littoral species such as sunfish.

PAGE 33

24 Structural habitat was not utilized extensively by largemouth bass in Kirkpatrick Lake based on the preference values. Largemouth bass were often observed in open water chasing shad to the surface. Angling efforts verified that these fish were largemouth bass. Therefore, pelagic clupeids are most likely the primary forage for largemouth bass in the lake. Diet studies should confirm this. Increasing structural habitat may not measurably increase angler catch rates for largemouth bass in lakes where open water prey are the principal forage. Sunfish may not be utilized in Kirkpatrick Lake to the extent they are in most other systems for two reasons. Based on observation, there seems to be a lack of suitable spawning substrate for sunfish; this would reduce overall production of adequately-sized prey. The fish in the lake are also fed with floating fish food and many of the sunfish present are too large to be consumed by most largemouth bass. If production of young sunfish were increased, largemouth bass would likely utilize littoral areas more often. Although FADs were offered as habitat to attract largemouth bass and possibly alter their habits from actively hunting in open water to ambush predation, this did not occur in any of the five fish radio-tracked after FAD deployment. The odds of detecting a change in habit depend on what mechanisms are driving the largemouth bass to utilize open water. If largemouth bass utilize open water because structural habitat is limited, adding habitat could allow some fish to revert to ambush predation, assuming a source of forage is available near the habitat. If the fish utilize open water as a means of procuring pelagic prey, however, increasing structural habitat probably will not alter the food base and therefore will be less likely to elicit a response in the behavior of the largemouth bass. Although it potentially only takes one fish to illustrate a shift in habit, the odds of

PAGE 34

25 detecting a change in a natural system are low. Therefore, behavioral questions such as this may best be answered in an experimental setting, where environmental variables can be better controlled. Genetics Adult largemouth bass from area lakes have been stocked into Kirkpatrick Lake for the last several years (Dr. Dan Canfield, Jr., Department of Fisheries and Aquatic Sciences, University of Florida). It is unknown where the fish first stocked into the lake originated. These fish would likely have the most input on the genetics of the current population. Kirkpatrick Lake lies between the Suwannee River, Florida, and Orange Lake, Florida. The percentage of the Florida largemouth bass subspecies genome was estimated to be 96.25% for the Suwannee River population and 97.5% for the Orange Lake population (Phillip et al. 1983). This indicates that while largemouth bass populations in this region are intergraded, the percentage of northern subspecific input is low. Because of the conflicting results from microsatellite genetic analysis, further genetic testing is necessary to determine the percentage of Florida subspecific input on largemouth bass in Kirkpatrick Lake. Although no direct comparisons between the northern and Florida largemouth bass subspecies were made in this study, subspecific information may be useful to future researchers as more and more largemouth bass studies are performed at the subspecies level. Transmitters Transmitter size was more important than weight during implantation of largemouth bass in Kirkpatrick Lake. Although Ross and McCormick (1981) recommend transmitters weigh less than 2% of the weight of the fish, it has been shown that fish quickly adapt to transmitter weights of 2.4 to 4.3% of body weight (Crumpton 1982;

PAGE 35

26 Connors 2002). The transmitter was 2.5% of the body weight and 17.8% of the total length for the smallest fish in this study. Although a smaller fish could have been used based on the percent transmitter weight, we found insertion and suturing difficult when the transmitter was greater than 20% of the total length of the fish (using practice specimens prior to initiating this study) because of the physical constraints of the abdominal cavity. Since most internal radio transmitters are cylindrical, transmitter length can be used to estimate the minimum size fish needed for implantation. Also, length of a fish does not fluctuate seasonally like weight. Based on our experience, transmitter length should be no more than 18% of the total length of the fish. Temperature data from the transmitters were often inconsistent with the data from the temperature profiles. Thirty percent of the temperature calculations from the transmitter calibration curves were higher than the surface water temperatures. This could have been due to changes in the transmitters. Since depth was not an important part of this study, the data were only used to illustrate general trends. In retrospect, the money used to purchase the temperature-sensing feature would have been better spent buying extra transmitters as insurance against transmitter loss or failure. Management Implications Although much time and effort has been spent planting bulrush and putting brushpiles, trees, and FADs into Kirkpatrick Lake, the results from this study indicate that most of these habitats were not significantly utilized by largemouth bass. Thus, increasing structural habitat may not measurably increase angler catch rates, by attracting/concentrating adult largemouth bass, in lakes where open water prey are the principal forage.

PAGE 36

27 Fisheries managers should consider the behavioral ecology of the largemouth bass as well as the human dimensions of the anglers before implementing habitat enhancement strategies. The shoreline was the most often fished area by anglers in Kirkpatrick Lake (Daniel E. Canfield, Jr., personal communication) while the largemouth bass were found mostly in open water areas. In order to increase catch rates, it is necessary that either the anglers fish open water areas more often or the largemouth bass utilize littoral areas more often. Littoral habitat use by largemouth bass may be increased if production of littoral prey, such as sunfish, is increased. In addition to liming/fertilization programs, fish production in quarry lakes may possibly be increased with habitat manipulations that create more shallow, flat areas for spawning. Marked FADs placed into open water may have an indirect positive effect on angler catch rates by attracting anglers to under fished open water areas. Since habitat manipulations may not be cost-effective (based on utilization by largemouth bass) in lakes where open water prey are the principal forage, fisheries managers should focus their efforts on angler education.

PAGE 37

LIST OF REFERENCES Anderson, J. K. 1964. Preand post-impoundment limnological studies and lake investigations. State of Kentucky Dingell Johnson Project F-19. Progress Report: Fish Attractors. 3pp. Ball, R. C. 1947. A tagging experiment on the fish population on Third Sister Lake, Michigan. Trans. Am. Fish. Soc. 74:360-369. Betsill, R. K., R. L. Noble, and W. H. Neill. 1986. Distribution and habitat selection of telemetered northern and Florida largemouth bass in 2 small Texas impoundments. Proc. Annu. Conf. Southeast. Assoc. Fish and Wildl. Agencies 40:275-286. Burt, W. H. 1943. Territoriality and home range concepts as applied to mammals. Journal of Mammology. 24:346-352. Boyer, M. G. 1994. Effect of 2,4-D amine on the movement and feeding behavior of largemouth bass. Masters Thesis. University of Florida, Gainesville, Florida. 133pp. Chappell, J. A. 1974. Response of largemouth bass to thermal effluent from Oconee Nuclear Power Plant. Masters Thesis. Clemson University, Clemson, South Carolina. Chew, R. L. 1975. The Florida largemouth bass. Pages 450-458 in R. H. Stroud and H. Clepper, eds. Black bass biology and management. Sport Fishing Institute, Washington, D.C. 534 pp. Colle, D. E., R. L. Calteux, and J. V. Shireman, 1989. Distribution of Florida largemouth bass in a lake after elimination of all submersed aquatic vegetation. N. Amer. J. Fish. Manage. 9:213-218. Connors, K. B., D. Scruton, J. A. Brown, and R. S. McKinley. 2002. The effects of surgically-implanted dummy radio transmitters on the behavior of wild Atlantic salmon smolts. Hydrobiologia 483:231-237. Crumpton, J. E. 1982. Effects of dummy radio transmitters on the behavior of largemouth bass. Proc. Annu. Conf. Southeast. Assoc. Fish and Wildl. Agencies 36:351-357. 28

PAGE 38

29 Doerzbacher, J. F. 1980. Movements and home range of largemouth bass (Micropterus salmoides) in relation to water quality of the Atchafayala river basin, Louisiana. Masters Thesis. Louisiana State University, Baton Rouge, Louisiana. Fetterolf, Carlos de la Mesa. 1952. A population study of the fishes of Wintergreen Lake, Kalamazoo County, Michigan: with notes on movement and effect of netting on condition. Masters Thesis. Michigan State University, East Lansing, Michigan. 127pp. Fish, P. A., and J. Savitz. 1983. Variations in home range of largemouth bass, yellow perch, bluegill, and pumpkinseeds in an Illinois lake. Trans. Am. Fish. Soc. 112:147-153. Forsburg, C., and S.O. Ryding, 1980. Eutrophication parameters and trophic state indices In 30 Swedish waste-receiving lakes. Archiv fur Hydrobiologie 88:189-207. Funk, J. L. 1957. Movement of stream fishes in Missouri. Trans. Am. Fish. Soc. 85:3957. Hazzard, A. S. 1937. Results of stream and lake improvement in Michigan. Trans. 2 nd North Am. Wildl. Nat. Resour. Conf. 1937:620-624. Hollander, M., and D. A. Wolfe. 1973. Nonparametric statistical methods. John Wiley and Sons, Inc. New York. 503pp. La Roche, S. 1972. Statewide lake and stream investigation. State of Maine. Dingell Johnson Project F-8. Final Job Report: Fish haven study. 6pp. Manges, D. E. 1959. Large impoundment investigations. State of Tennessee. Dingell Johnson Project F-12. Final Job Report: Study of the construction and value of brush shelters. 27pp. Mesing, C. L., and A. M. Wicker. 1986. Home range, spawning migrations, and homing of radio-tagged Florida largemouth bass in two central Florida lakes. Trans. Am. Fish. Soc. 115: 286-295. Miller, R. J. 1975. Comparitive behavior of centrarchid basses. Pages 85-94 in R. H. Stroud and H. Clepper, eds. Black bass biology and management. Sport Fishing Institute, Washington, D.C. 534 pp. Moody, H. L. 1960. Recaptures of adult largemouth bass from the St. Johns River, Florida. Trans. Am. Fish. Soc. 89:295-300. Nieman, D. A., and M.D. Clady. 1980. Winter movement of Florida and northern largemouth bass near a heated effluent. Proc. Annu. Conf. Southeast Assoc. Fish and Wildl. Agencies 34:11-18.

PAGE 39

30 Odum, E. P., and E. J. Kuenzler. 1955. Measurement of territory and home range size in birds. Auk 72:128-137. Phillip, D. P., W. F. Childers, and G. S. Whitt. 1983. A biochemical genetic evaluation of the northern and Florida subspecies of largemouth bass. Trans. Am. Fish. Soc. 112:1-20. Poddubnyi, A. G., N. A. Gordeev, and I. E. Permitin. 1974. Migration pattern of the feeding fish populations in relation to e nvironmental factors (translated from Russian). Pages 278-349 in B. S. Kuzin, ed. Biologi cal and hydrological factors of local movements of fish in reservoirs U.S. Bur. Sport Fish. and Wildl. And Nat. Sci. Found., Washington, D.C. Prince, E. D., and O. E. Maughan. 1979. Telemetric observations of largemouth bass near underwater structures in Smith Mountain Lake, Virginia. Pages 26-32 in D. L. Johnson and R. A. Stein, eds., Response of fish to habitat structure in standing water. North Cent. Div. Am. Fish. Soc. Spec. Publ. 6. Prince, E. D., R. F. Raleigh, and R. V. Corning. 1975. Artificial structures and centrarchid basses. Pages 498-505 in R. H. Stroud and H. Clepper, eds. Black bass biology and management. Sport Fishing Institute, Washington, D. C. 534 pp. Rodeheffer, I. A. 1939. Experiments in the use of brush shelters by fish in Michigan lakes. Pap. Mich. Acad. Sci. Arts Lett. 24(1938):183-193. Rodeheffer, I. A. 1940. The use of brush shelte rs by fish in Douglas Lake, Michigan. Pap. Mich. Acad. Sci. Arts Lett. 25(1939):357-366. Rodeheffer, I. A. 1945. Fish populations in a nd around brush shelters of different sizes placed at varying depths and distances apart in Douglas Lake, Michigan. Pap. Mich. Acad. Sci. Arts Lett. 30(1944):321-345. Ross. M. J., and J. H. McCormick. 1981. Effects of external radio transmitters on fish. Prog. Fish Cult. 43:67-72. Smith, S. M., and D. J. Orth. 1990. Distributions of largemouth bass in relation to aquatic vegetation in Flat Top Lake, West Virginia. Proc. Annu. Conf. Southeast Assoc. Fish. And Wildl. Agencies 44:36-44. Strauss. R. E. 1979. Reliability of estimates for Ivlevs electivity index, the forage ratio, and a proposed linear index of food selection. Trans. Am. Fish. Soc. 108:344-352. Wanjala, B. S., J. C. Tash, W. J. Matter, and C. D. Ziebell. 1986. Food and habitat use by different sizes of largemouth bass ( Micropterus salmoides ) in Alamo Lake, Arizona. J. Freshwater Ecol. 3:359-369.

PAGE 40

31 Warden, R. L., and W. J. Lorio. 1975. Movements of largemouth bass (Micropterus salmoides) in impounded waters as determined by underwater telemetry. Trans. Am. Fish. Soc. 104:696-702. Wilbur, R. L. 1978. Two types of fish attractors compared in Lake Tohopekaliga, Florida. Trans. Am. Fish. Soc. 107:689-695. Wildhaber, M. L. 1985. Activity and distribution of northern and Florida largemouth bass (Micropterus salmoides salmoides and M. s. floridanus) relative to environmental features of a small impoundment in central Texas. Masters Thesis. Texas A&M University, College Station, Texas. 99 pp. Winter, J. D. 1977. Summer home range movements and habitat use by four largemouth bass in Mary Lake, Minnesota. Trans. Am. Fish. Soc. 106:323-330. Woodward, K. O. 1996. Reservoir movements of sub-adult largemouth bass (Micropterus salmoides). M.S. Thesis, North Carolina State University, Raleigh, North Carolina. 47pp. Woodward, K. O., and R. L. Noble. 1997. Over-winter movements of adult largemouth bass in a North Carolina reservoir. Proc. Annu. Conf. Southeast Assoc. Fish. And Wildl. Agencies 51:113-122.

PAGE 41

BIOGRAPHICAL SKETCH Troy McDaniel Thompson, Jr. was born in Martinsville, Virginia, on 2 June 1975. He spent most of his spare time hunting and fishing in a three-county area of Virginia known as the moonshine capital of the world. In 1993, he graduated from Fieldale-Collinsville High School knowing that he wanted a career in fisheries or wildlife management. After two years of classes at Patrick Henry Community College, Troy transferred to the Virginia Polytechnical Institute and State University in 1995. After being told that there were twice as many wildlife graduates as fisheries graduates, but the same number of jobs available for each, he did the math and decided on a career in fisheries. In May 1998, he graduated cum laude with a Bachelor of Science in Forestry and Wildlife with a concentration in fisheries. In July 1998, he began working as a technician for the Virginia Department of Game and Inland Fisheries in Forest, VA. It took him three short years to realize that working time with no benefits was not the career apex he had in mind when he left Virginia Tech. In August 2001, Troy enrolled as a graduate student under Dr. Chuck Cichra in the Department of Fisheries and Aquatic Sciences at the University of Florida to pursue a graduate degree. He will receive his Master of Science degree in December 2003. With increased knowledge, skills, and abilities, Troy hopes to pursue a research/management position as an agency biologist. 32


Permanent Link: http://ufdc.ufl.edu/UFE0001444/00001

Material Information

Title: Distribution and Habitat Selection of Largemouth Bass in a Florida Limerock Pit
Physical Description: Mixed Material
Copyright Date: 2008

Record Information

Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
System ID: UFE0001444:00001

Permanent Link: http://ufdc.ufl.edu/UFE0001444/00001

Material Information

Title: Distribution and Habitat Selection of Largemouth Bass in a Florida Limerock Pit
Physical Description: Mixed Material
Copyright Date: 2008

Record Information

Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
System ID: UFE0001444:00001


This item has the following downloads:


Full Text












DISTRIBUTION AND HABITAT SELECTION OF LARGEMOUTH BASS IN A
FLORIDA LIMEROCK PIT














By

TROY M. THOMPSON, JR.


A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF
FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE
DEGREE OF MASTER OF SCIENCE


UNIVERSITY OF FLORIDA


2003















ACKNOWLEDGMENTS

I thank the members of my committee, Drs. Chuck Cichra, Daniel E. Canfield, Jr.,

and William Lindberg, for the advice and critical review that were so crucial to

completion of this thesis.

I thank David Watson (Florida LAKEWATCH) for his help with the location map

for Kirkpatrick Lake. I appreciate Dr. Allen Riggs' (College of Veterinary Medicine,

University of Florida) expertise and help with transmitter implantation. Jason Hale was

an invaluable aid in loading the habitat map into ArcInfo and an excellent source of GIS

wisdom. Wes Porak (Florida Fish and Wildlife Conservation Commission) was helpful

with his advice and introducing me to Lorraine Fries (Texas Parks and Wildlife

Department) who was gracious enough to oversee the subspecies identification of the

largemouth bass from Kirkpatrick Lake.

I thank Margaret Glenn of Dr. Bill Haller's (Department of Agronomy, University

of Florida) lab for use of their ATS receiver and antenna. I also appreciate the labs of

Drs. Micheal Allen, Daniel E. Canfield, Jr., and Thomas K. Frazer (Department of

Fisheries and Aquatic Sciences, University of Florida) for use of various equipment

necessary to complete this study.

I greatly appreciate the late Senator George G. Kirkpatrick, Jr., for whom the lake

was named, for allowing me to use his lake to study the largemouth bass he loved so

much.









I thank Dr. Jimmy Cheek, Dean of the College of Agricultural and Life Sciences,

and Dr. Chris Waddell, Dean of the Florida Cooperative Extension Service, for providing

my graduate assistantship, without which I would not have been able to pursue my

graduate degree.

Last but not least, thanks go out to all the folks who helped me in the field: Rob

Burns, Jason Childress, Chuck Cichra, Sharon Fitz-Coy, Jeff Hill, Natalie Love, Jeff

Sowards, and Will Strong.
















TABLE OF CONTENTS
page

A C K N O W L E D G M E N T S .................................................................................................. ii

LIST OF TABLES ............ ......................................... .... .......... .. ............. vi

L IST O F F IG U R E S .... ......................................................... .. .......... .............. vii

A B S T R A C T .......................................... .................................................. v iii

INTRODUCTION ............................... .................... ...............

STUDY SITE DESCRIPTION......................................... .................................. 3

M E T H O D S .......................................................................... . 6

T ransm hitter Im plantation ........................................... .................................6
Radio-Tracking ..................................................................... ...............
Dissolved Oxygen/Temperature Sampling ............ .........................................8
H habitat M apping ................................................................... ................................ 8
Home Ranges and Habitat Selection ................................... ................................11
D ie l S a m p lin g ................................................................................................12
Fish Attracting Device Study.............................................................. .............12

R E S U L T S ................................................................................14

G e n e ra l ........................................................................................................ 1 4
H ab itat S ele ctio n ................................................................................................... 16
H o m e R a n g e ............................................................................................................... 1 9
D ie l S a m p lin g ....................................................................................................... 1 9
Fish Attracting Device Utilization............................. ................... 20

D IS C U S S IO N ........................................................................................2 2

G e n e ra l ......................................................................................................2 2
G e n e tic s ..............................................................................2 5
T ransm hitters ............................................................................................... ....... 25
Management Implications .............................................. ...............26










L IST O F R E F E R E N C E S ........................................................................ ..................... 28

B IO G R A PH IC A L SK E T C H ...................................................................... ..................32


























































v















LIST OF TABLES


Table pge

1 Size distribution and tagging information for largemouth bass in Kirkpatrick
L ak e, F lorida. ...................................................... ................. 15

2 Percent habitat use by largemouth bass and percent habitat available in
Kirkpatrick Lake, Florida, between 1 May 2002 and 1 May 2003..........................16

3 Values of the linear selection index L for littoral habitat use by largemouth bass
in Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003. Positive values
indicate preference; negative values indicate avoidance............... ..................17

4 Values of the linear selection index L for pelagic habitat use by largemouth bass
in Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003. Positive values
indicate preference; negative values indicate avoidance............... ..................18

5 Mean values of the linear selection index L for habitat use by largemouth bass in
Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003 .............................18

6 Number of observations and home range (ha) for largemouth bass in Kirkpatrick
Lake, Florida, from 1 M ay 2002 to 1 M ay 2003................................................ 20

7 Seasonal home ranges for largemouth bass in Kirkpatrick Lake, Florida, from 1
M ay 2002 to 1 M ay 2003 ................................................................ .....................20

8 Number and percent of follow-up largemouth bass locations that were in a
different sub-basin during two diel sampling dates in Kirkpatrick Lake, Florida,
on 22 August 2002 and 17 April 2003 ...................................... ............... .21















LIST OF FIGURES


Figure pge

1 Kirkpatrick Lake location and bathymetric map (from Florida LAKEWATCH).
Depth contours and distances are in feet ....................................... ............... 5

2 Pelagic and littoral zones in Kirkpatrick Lake, Florida. The littoral zone extended
to the 3.5-m depth contour, May 2002 to May 2003................................ ............... 9

3 Distribution of habitats and fish attracting device installation sites for Kirkpatrick
Lake, Florida, M ay 2002 to M ay 2003.................................... ............. .. 10















Abstract of Thesis presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Master of Science

DISTRIBUTION AND HABITAT SELECTION OF LARGEMOUTH BASS IN A
FLORIDA LIMEROCK PIT

By

Troy M. Thompson, Jr.

Chairperson: Dr. Charles E. Cichra
Major Department: Fisheries and Aquatic Sciences

Radio telemetry was used to determine the distribution and habitat selection of

largemouth bass (Micropterus salmoides) in a north-central Florida lake from 18 April

2002 to 1 May 2003 so that management recommendations that would increase angler

catch rates could be made. The study site (Kirkpatrick Lake, Alachua County, Florida) is

a steep-sided, 7-ha flooded limerock quarry, and is composed of six conjoined sub-

basins. Twelve largemouth bass were internally implanted with radio transmitters (of no

more than 18% of the total length of the fish) and tracked. Over the course of the study,

the number of fish tracked was reduced to five as transmitters failed or ceased movement.

Pelagic areas were selected over littoral areas during the summer and fall/winter

periods (p = 0.022). Only one fish utilized littoral areas more than pelagic areas during

this period. In the spring (February through April), habitat use switched; littoral areas

seemed to be selected over pelagic areas for four of five fish based on the preference

values. However, no significance was found because of the low number of replicates









(n = 5). Sunken trees were the only structural habitat significantly utilized by largemouth

bass (p < 0.001). Other structural habitats had generally neutral preference values. Areas

within 5 m of the shoreline were strongly avoided (p < 0.001).

Home range was correlated with days sampled (n = 12, r = 0.69, p = 0.01), but not

total length and weight offish (n = 5, r = 0.57, p = 0.31; n = 5, r = 0.52, p = 0.36,

respectively). Home range varied from 0.56 to 4.84 ha with means of 3.04 ha for all fish,

and 4.09 ha for the five fish that were tracked over the entire study. No seasonal trends

were evident in home range size. One fish established a separate home range from 9

January to 18 February 2003; after which it returned to its previous range.

Largemouth bass locations, observed during two diel tracking sessions, were

consistent with weekly daytime data collected over the full term of the study. Fish

exhibited constant movement during diel sampling periods, often moving between sub-

basins. No day/night or spring/summer differences in movement or habitat preference

were detected. There was no evidence of any diel on-shore/off-shore movement patterns.

Twenty mushroom-hat fish attracting devices (FADs) were suspended vertically

into the lake at four sites on October 4, 2002. Although four of the five remaining

largemouth bass utilized these FADs at least once, the neutral preference values indicate

that the FADs were not a significant habitat for the largemouth bass.

Due to the selection of pelagic areas, except during the spawning season, it is

speculated that the largemouth bass fed primarily on open water prey. Increasing

structural habitat may not measurably increase angler catch rates for largemouth bass in

lakes where open water prey are the principal forage. Therefore, fisheries managers

should focus their efforts on angler education in such lakes.















INTRODUCTION

Habitat selection by largemouth bass (Micropterus salmoides) is an important

consideration in fisheries management. Knowledge of selected habitats can aid biologists

in making management decisions. As ambush predators, largemouth bass typically utilize

structural littoral habitat such as vegetation and woody debris, though they are sometimes

found off-shore in deeper, open water. Aquatic vegetation is the principal habitat

available for the Florida largemouth bass (M. s. floridanus), which evolved in the

shallow, highly vegetated waters of Florida and seems to prefer shallow water (Chew

1975). Colle et al. (1989) found that the Florida largemouth bass utilized open water

areas after all submerged aquatic vegetation was removed from Lake Baldwin, a shallow

Florida lake. Quarry lakes are fairly common in Florida and throughout the United States

and are often utilized by anglers. There is a lack of research on habitat selection by

largemouth bass in steep-sided systems that have a narrow littoral zone.

The home range of largemouth bass has been quantified by various authors

(Warden and Lorio 1975; Fish and Savitz 1983), the size of which varies with fish size

(Chappell 1974), length of time sampled, and water body size and morphometry.

Largemouth bass have "activity centers" within their home range where they spend the

majority of their time (Winter 1977; Doerzbacher 1980; Betsill et al. 1986; Boyer 1994).

Other researchers noted that subsets of the population exhibit random movement and do

not have activity centers (Ball 1947; Moody 1960). It has therefore been hypothesized

that there are mobile and sedentary segments of some largemouth bass populations









(Fetterolf 1952; Funk 1957; Moody 1960; Poddubnyi et al. 1974; Miller 1975). Factors

leading to a transient lifestyle may include differential prey selection or lack of suitable

habitat.

One response by fisheries managers to a perceived lack of natural habitat is to

supplement it with artificial habitat or structure, which has been shown to attract and

concentrate prey and sport fish (Hazzard 1937; Rodeheffer 1939, 1940, 1945; Manges

1959; Anderson 1964; La Roche 1972; Prince et al. 1975). This often results in higher

catch rates for anglers (Prince et al. 1975; Wilbur 1978), which is often a goal of sport-

fishery managers.

If largemouth bass have a mobile lifestyle due to a lack of attractive habitat, then

offering habitat may allow them to assume a more sedentary habit. This would allow the

fish to be more accessible to anglers, who often fish near structural habitat. The purpose

of this study was to determine the distribution and habitat selection of largemouth bass in

a deep, steep-sided Florida lake and to assess changes in distribution after installation of

artificial structure.















STUDY SITE DESCRIPTION

Kirkpatrick Lake is located in Alachua County, Florida, west of Gainesville

(Figure 1). It is a flooded limerock quarry consisting of six conjoined sub-basins with a

total surface area of approximately 7 ha. Much of the perimeter of the lake is comprised

of 10 to 30-m vertical walls. This steep-sided lake has a mean depth of 6.5 m and a

maximum depth of 11m. Giant bulrush (Scirpus californicus), alligator weed

(Alternantheraphiloxeroides), and cattails (Typha latifolia) are present but limited in

abundance due to the lack of suitable shallow substrate. Southern naiad (Najas

guadalupensis) is common in the littoral zone and grows to an average height of 0.3 m.

The littoral zone extends to a mean depth of 3.5 m. Littoral zone width averages 10 m but

ranges from 0 to 45 m. Six large trees have been submerged in the lake as structural

habitat. The lake was naturally oligotrophic based on water clarity (Forsburg and Ryding

1980), having secchi disk depths up to 6 m (Christy Horsburgh, Department of Fisheries

and Aquatic Sciences, University of Florida, unpublished data). The lake is currently

fertilized during the warm months to increase algal production and enhance fish

production. Fish are also fed pelleted food. Secchi disk depths now range from less than

Im when the lake is fertilized (February to November) to over 3 m when the lake is not

fertilized and water temperatures are lower. Sport fish in the lake include largemouth

bass, hybrid striped bass (Morone chrysops xMorone saxatilis), bluegill (Lepomis

macrochirus), warmouth (Lepomis gulosus), and redear sunfish (Lepomis microlophus).

Prey species include golden shiner (Notemigonous chrysoleucas), threadfin shad






4


(Dorosomapetenense), gizzard shad (Dorosoma cepedianum), lake chubsucker

(Erimyzon sucetta), eastern mosquitofish (Gambusia holbrooki), blue tilapia

(Oreochromis aureus), and brown bullhead (Ictalurus nebulosus). Fishing pressure is

light (2-3 fishing parties per week) because it is a private water body that has controlled

access and a catch and release only fishing policy. Although large adult largemouth bass

(> 406 mm TL) are often stocked into the lake, but are not routinely caught by anglers.


































,22

'1
O 4 jiz 2
26

F2 2 ,,2


2 22
"8


10


14
C14


22
jg '

2I,~rT^^ 5


6 2


6 o


0B (I
-oi jo q

i~ 6
.P


26 S9
\/B
l~ Tc 28>


180 250 500 750 1000
0 250 500 750 1000


Figure 1. Kirkpatrick Lake location and bathymetric map (from Florida LAKEWATCH).
Depth contours and distances are in feet.


10
14


26

6_


17`















METHODS

Transmitter Implantation

Eleven largemouth bass, weighing from 1.0 to 3.0 kg, were collected from the

lake by electrofishing (300 V, 7A, DC pulse) on 16 April 2002 and implanted with

Advanced Telemetry Systems (ATS) Model f1235 temperature-sensing radio transmitters

(75 mm x 18 mm, 24 g). These transmitters had radio frequencies ranging from 48.411 to

48.825 MHz. One transmitter did not operate properly and had to be replaced. A twelfth

fish was implanted on 7 May 2002 after the new transmitter arrived. We attempted to

capture fish over a broad size range so that transmitter weights would be no more than

two percent of the body weight (Mesing and Wicker 1986). Fish handling procedures

were recommended by Dr. Allen Riggs, College of Veterinary Medicine, University of

Florida. Surgical tools and transmitters were disinfected with 95% ethyl alcohol before

use. Each fish was individually anesthetized in a 51-L aerated cooler containing 150-

mg/L MS-222 solution. After a fish lost equilibrium, total length (TL) and weight were

measured before moving the fish for surgery to a 95-L aerated cooler containing 100-

mg/L MS-222 solution. Both solutions were buffered at a rate of two parts sodium

bicarbonate to one part MS-222. While in the second cooler, the fish was placed into a

wooden trough such that its head was submerged while the area of operation was out of

the water. A 20 to 25-mm vertical incision was made 25 to 30 mm anterior of the anus.

The transmitter was inserted into the body cavity and the incision was closed with a

single row of four to five stitches through both the peritoneum and integument using size









3-0 reverse cutting needles and monofilament suture material (Fluorofil, Schering-

Plough, Union, New Jersey). Antibiotic topical ointment (Panalog) was rubbed onto the

incision to help prevent infection. Two Floy T-bar internal anchor tags were inserted into

the dorsal pterigiophores and a small piece of the right pelvic fin was clipped from each

fish. The fish was then placed into a cooler of fresh water for recovery before being

released at the site of its capture. Total handling time for each fish was 20 to 30 minutes.

Two signs were placed near the boat ramp and picnic area of this private lake advising

anglers to immediately release tagged fish unharmed at the site of capture. At least one

tagged fish was caught and released back into the lake by a an angler during this study.

Fin samples were sent to the A. E. Woods Fish Hatchery (Texas Parks and Wildlife

Department) in San Marcos, Texas for DNA analysis.

Radio-Tracking

Each fish was located weekly from 1 May 2002 to 1 May 2003 (unless the

transmitter failed or ceased movement) with an ATS Model R2000 receiver and a loop

antenna. Radio-tracking was performed using a 3-m johnboat propelled by an electric

trolling motor to minimize disturbance to the fish. Sampling times were randomly varied

between 0700 and 2100 hrs to reduce bias associated with time of day. Fish located near

vertical walls were triangulated parallel and perpendicular to the wall to eliminate false

locations due to signal reflection. A GPS reading was taken directly above the location of

the fish along with the time of day. Because GPS readings could not always be taken due

to the steepness of the rock walls, all locations were also marked on a detailed

bathymetric map developed by Florida LAKEWATCH (Department of Fisheries and

Aquatic Sciences, University of Florida, Gainesville, FL) in November 2000. Prevailing

weather conditions (% clouds, precipitation, and wind) were recorded to note any









behavioral changes due to weather. Pulse rate (seconds/100 pulses) was measured for

each transmitter with a stopwatch.

Dissolved Oxygen/Temperature Sampling

Dissolved oxygen/temperature profiles were recorded, with a Yellow Springs

Instruments Model 58 dissolved oxygen/temperature meter, in every sub-basin in which a

radio-tagged fish was located. The recorded pulse rate of each transmitter was then

compared with the calibration curve, supplied with each transmitter, to obtain the

temperature of each fish. This temperature was then compared with the temperature

profile of the sub-basin to approximate the depth of each fish.

Habitat Mapping

The bathymetric map of Kirkpatrick Lake was copied into ArcView GIS 3.2 as a

base-map for habitat and location mapping. ArcView was used to measure habitat areas,

count locations per habitat, and generate digital maps of the lake and its habitats. The

littoral zone was defined as the area from the shoreline out to the 3.5 m depth contour, the

mean maximum depth of rooted aquatic vegetation (Figure 2). Littoral areas included

clean shoreline, brushy shoreline (shoreline that had terrestrial bushes growing out into

the water), humps, boulders, small brush-piles (such as single Christmas trees submerged

into the lake), shallows (relatively flat areas that were less than 2 m deep), saddles

(littoral areas between sub-basins), and other non-structural areas (Figure 3). Pelagic

areas (> 3.5 m depth) included open water, fish feeders, aerators, large sunken trees, and












F S-


U'


N
Pelagic zone
Littoral zone w E
S

Figure 2. Pelagic and littoral zones in Kirkpatrick Lake, Florida. The littoral zone
extended to the 3.5-m depth contour, May 2002 to May 2003.


P4









































M Aerators and feeders
I Fish attracting devices N
SBrushpiles
Humps and boulders
Shallows and saddles W E
SSunken trees
Brushy shoreline
Clean shoreline S



Figure 3. Distribution of habitats and fish attracting device installation sites for
Kirkpatrick Lake, Florida, May 2002 to May 2003.










fish attracting devices (FADs). These habitats were visually marked in the winter, when

water clarity was high, and drawn onto the bathymetric map. These habitats were then

redrawn onto the base-map using ArcView. A 5-m buffer was placed around structural

habitats (humps, boulders, brushpiles, trees, aerators, feeders, and FADs). A fish was

considered to be utilizing a particular habitat when it was within 5 m of the habitat. Maps

showing the location fixes for each fish were then overlaid onto the habitat map to count

the number of locations per habitat.

Home Ranges and Habitat Selection

Annual and seasonal home ranges were calculated with ArcView using the

smallest convex-polygon method (Winter 1977). Outliers were removed from the

individual home range estimates if they occurred as single locations in a sub-basin and

were not along travel routes. The sampling year was broken up into three seasons. The

summer season included all sampling dates from May 2002 through October 2002.

Fall/winter sampling dates were from November 2002, when the lake started to destratify,

through January 2003. Spring sampling dates were from February 2003 through May

2003 (the typical spawning period for largemouth bass in north Florida). Annual and

seasonal habitat selection were determined from a modification of Strauss' (1979) linear

index of food selectivity, L = ri pi; where ri is the percent use of habitat i and pi is the

percent availability of habitat i (Mesing and Wicker 1986). Habitat preference values can

range from -1 (avoidance) to +1 (preference). The Wilcoxon signed rank test (Hollander

and Wolfe 1973) was used to determine if mean L values were significantly different

from zero (ac(2) = 0.05).









Diel Sampling

Diel sampling was conducted on 22 August 2002 and 17 April 2003 to determine

if habitat use and movements were equivalent between day and night. Sampling began at

0700 hrs and ended at approximately 0300 hrs. Each fish was tracked every four hours

during diel sampling and its location marked on the bathymetric map. GPS readings were

not taken during diel sampling because of potential effects on fish movements. For each

time period, pulse rate was recorded for each fish and a dissolved oxygen/temperature

profile was recorded for each sub-basin in which a fish was located.

Fish Attracting Device Study

Twenty mushroom-hat FADs were suspended vertically into the lake at four sites

(Figure 3) on 4 October 2002. They were constructed using 150-L plastic trash cans.

After the bottom was cut out, the remaining cylinder was cut vertically to make two arc-

shaped pieces. These pieces along with the lid were used to construct one four-tiered

structure. Holes were drilled in the center of these pieces and 10-mm diameter nylon rope

threaded through the holes (with three 0.6-m segments of 38-mm diameter PVC pipe

placed in between as spacers). The top and bottom pieces were secured with several knots

in the rope. Each FAD was anchored with a 20x20x40-cm concrete block. Five dense

15x20-cm Styrofoam floats were used to float each structure. Each FAD was 2-m long

from the lowest piece to the top of the floats. Depth was adjusted on site so that the

bottom of each FAD was no deeper than 3 m below the water surface (the shallowest

observed depth that the water became anoxic). This meant that the top of each FAD was

1 m underwater and thus less visible to anglers. FADs were placed in open water near

funnels of recorded fish travel. Each site consisted of five FADs placed approximately 2

m apart in a pentagon formation. Radio-tagged fish were located three times each week






13


for two weeks prior to FAD placement and three times each week for four weeks

thereafter to quantify any changes in habitat use. Afterwards, normal weekly sampling

was resumed for the remainder of the study.















RESULTS

General

At first, all 12 radio-tagged largemouth bass were identified to be the Florida

subspecies based on the analysis of microsatellite DNA loci Lma 0012, Mdo 0006, and

Mdo 0004 (Texas Parks and Wildlife Department, unpublished data) Preliminary data

from the Texas Parks and Wildlife Department suggested that these loci were diagnostic

between northern and Florida largemouth bass. Subsequent analysis by the Texas Parks

and Wildlife Department found that these loci were not diagnostic. Further analysis was

performed on seven intrapseudogenic loci, which preliminary data show to be completely

fixed for either northern or Florida largemouth bass. Results from this analysis indicate

that eleven of the fish sampled were intergrades and one (Fish 704) was pure Florida

strain (Texas Parks and Wildlife Department, unpublished data). No DNA could be

extracted from the twelfth fish. Because of these conflicting results, largemouth bass

were not designated to subspecies for this study.

Tagged largemouth bass were successfully located, on average, over 99% of the

time. Five fish (471, 684, 725, 764, and 825) most likely died, or possibly shed their

transmitters, when their movements ceased during the course of the study (Table 1). It is

unlikely that the transmitters were shed since the first cessation of movement came 3.5

months after transmitter implantation (Allen Riggs, personal communication). Efforts to

instigate movement, if the fish was alive but inactive, were unsuccessful. Further efforts

to recover the transmitters or fish carcasses were also unsuccessful. Transmitters in four









of the five fish ceased movement in August and early September. During this time period,

one to two dead, untagged largemouth bass, greater than 375 mm TL, were observed per

week in Kirkpatrick Lake. This pattern of finding a few larger dead largemouth bass over

an extended period during the hotter months is consistent with largemouth bass virus

(Wes Porak, Florida Fish and Wildlife Conservation Commission, personal

communication) and, speculatively, may be the cause of these deaths. Two fish (561 and

704) either experienced transmitter failure or were removed from the lake by poachers.

Another transmitter (Fish 744) stopped pulsing on 17 April 2003, so depth could no

longer be calculated. However, the transmitter continued to emit a tone and the fish could

be located for the duration of the study.

Dissolved oxygen concentrations were less than 2 mg/L, at water depths below

4.2 m, from the start of radio-tracking until the lake destratified on 14 November 2002.

Observed oxygen concentrations did not drop below 2 mg/L (at depths up to 5.5 m) for

the remainder of the study.

Table 1. Size distribution and tagging information for largemouth bass in Kirkpatrick
Lake, Florida.

Fish Total Weight Tagging Last Number of Number of Location
number length (mm) (g) date observation1 observations attempts rate (%)
411 556 2950 16-Apr-02 1-May-03 66 66 100.00
471 446 1265 16-Apr-02 22-Aug-02 16 16 100.00
501 422 979 16-Apr-02 1-May-03 65 66 98.48
561 448 1248 16-Apr-02 30-Aug-02 21 21 100.00
684 459 1267 16-Apr-02 26-Oct-02 37 38 97.37
704 483 1409 16-Apr-02 18-Sep-02 24 24 100.00
725 512 2193 16-Apr-02 7-Aug-02 14 14 100.0
744 475 1322 16-Apr-02 1-May-03 65 66 98.48
764 523 2203 7-May-02 22-Aug-02 13 13 100.00
784 455 1357 16-Apr-02 21-Apr-03 65 66 98.48
804 444 1161 16-Apr-02 1-May-03 66 67 98.51
825 466 1358 16-Apr-02 6-Sep-02 22 22 100.00
Overall rate (%): 99.28
1First observation was 1 May 2002 for all fish except 764 which was 18 May 2002.










Habitat Selection

Pelagic areas were utilized more than twice as often as littoral areas (from the

shoreline to the 3.5 m depth contour) by the largemouth bass (Table 2). Other utilized

habitats included sunken trees while shoreline areas were avoided.


Table 2. Percent habitat use by largemouth bass and percent habitat available in
Kirkpatrick Lake, Florida, between 1 May 2002 and 1 May 2003.

Habitat type % Use % Available
Pelagic zone 68.4 60.2
Littoral zone 31.6 39.8

Pelagic habitats
Sunken trees 11.5 3.4
Aerators/feeders 2.8 2.2
Fish attracting devices 5.5 2.5
Open water 48.6 52.1

Littoral habitats
Brushpiles 0.5 3.0
Humps/boulders 1.6 1.3
Shallows/saddles 7.4 15.4
Non-structural 22.1 20.1

Shoreline
Brushy 0.2 9.5
Clean 6.5 90.5


Structural habitats were not heavily utilized by largemouth bass in Kirkpatrick

Lake (Tables 3 and 4). Sunken trees were the only structural habitat significantly utilized

by largemouth bass (p < 0.001, Table 5). Other structural habitats had generally neutral

L-values. Areas within 5 m of the shoreline were strongly avoided (p < 0.001).

Pelagic areas were selected over littoral areas during the summer and fall/winter

periods (p = 0.022). Only one fish (784) utilized littoral areas more than pelagic areas

during this period. During the fall/winter period, the lake destratified and the dissolved










oxygen and temperature readings became uniform. Positive L-values for open water were

higher than in the summer, indicating increased use of open water areas.

Littoral areas seemed to be selected over pelagic areas in the spring. L-values

were positive for four of the five remaining fish but no significance was found because of

the low number of replicates (n=5). Fish 411, the largest fish in the study and possibly a

female, seemed to utilize open water areas most of the time.


Table 3. Values of the linear selection index L for littoral habitat use by largemouth bass
in Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003. Positive values
indicate preference; negative values indicate avoidance.

Fish Littoral Brushy Clean Brush Humps/ Shallows/
number zone shore shore piles boulders saddles
Summer
411 -0.16 -0.10 -0.90 -0.03 0.04 -0.10
471 -0.20 -0.10 -0.90 -0.03 -0.01 -0.15
501 -0.21 -0.10 -0.88 -0.03 -0.01 -0.15
561 0.00 -0.10 -0.90 -0.03 -0.01 -0.15
684 -0.26 -0.10 -0.82 -0.03 0.04 -0.04
704 -0.14 -0.05 -0.82 0.01 -0.01 -0.11
725 -0.09 -0.10 -0.83 -0.03 -0.01 -0.15
744 0.00 -0.10 -0.77 -0.03 -0.01 -0.15
764 -0.01 -0.10 -0.83 -0.03 -0.01 -0.08
784 0.13 -0.10 -0.88 -0.03 0.01 -0.05
804 -0.02 -0.10 -0.82 -0.03 -0.01 -0.10
825 -0.07 -0.10 -0.76 -0.03 0.04 -0.01
Fall/Winter
411 -0.31 -0.10 -0.81 -0.03 0.17 -0.15
501 -0.30 -0.10 -0.90 -0.03 -0.01 -0.15
744 -0.22 -0.10 -0.81 -0.03 -0.01 -0.15
784 0.33 -0.10 -0.90 -0.03 -0.01 0.12
804 -0.22 -0.10 -0.90 -0.03 -0.01 -0.15
Spring
411 -0.21 -0.10 -0.85 -0.03 0.05 0.03
501 0.04 -0.10 -0.73 -0.03 -0.01 0.03
744 0.33 -0.10 -0.72 0.04 -0.01 0.11
784 0.40 -0.10 -0.84 -0.03 -0.01 0.38
804 0.13 -0.10 -0.85 -0.03 -0.01 -0.10










Table 4. Values of the linear selection index L for pelagic habitat use by largemouth
bass in Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003. Positive
values indicate preference; negative values indicate avoidance.

Fish Pelagic Sunken Aerators/ Fish attracting
number zone trees feeders devices1
Summer
411 0.16 0.02 -0.02 0.07
471 0.20 0.23 0.05 --
501 0.21 0.28 0.06 -0.03
561 0.00 0.07 -0.02 --
684 0.26 -0.01 0.01 -0.03
704 0.14 0.23 -0.02 --
725 0.09 -0.03 -0.02 --
744 0.00 0.10 0.00 -0.03
764 0.01 0.04 -0.02 --
784 -0.13 -0.01 0.03 -0.03
804 0.02 0.05 0.03 -0.03
825 0.07 0.01 -0.02 -----
Fall/Winter
411 0.31 0.06 0.25 -0.03
501 0.30 -0.03 0.08 0.07
744 0.22 0.15 -0.02 0.16
784 -0.33 -0.03 -0.02 -0.03
804 0.22 0.15 0.07 -0.03
Spring
411 0.21 0.03 0.10 0.11
501 -0.04 0.09 0.04 -0.03
744 -0.33 0.03 -0.02 -0.03
784 -0.40 0.03 -0.02 -0.03
804 -0.13 0.08 -0.02 0.10
1Fish without an L-value were no longer being located when the fish attracting devices
were deployed.

Table 5. Mean values of the linear selection index L for habitat use by largemouth bass in
Kirkpatrick Lake, Florida, from 1 May 2002 to 1 May 2003. Positive values
indicate preference; negative values indicate avoidance. Values with asterisks (*)
are significantly different (p < 0.05) from zero.

Littoral Brushy Clean Brush Shallows/
Season zone shore shore piles saddles
Summer/Winter -0.10* -0.09* -0.85* -0.03* -0.10*
Spring 0.14 -0.10 -0.80 -0.02 0.09

Pelagic Sunken Aerators/ Fish attracting Humps/
Season zone trees feeders devices boulders
Summer/Winter 0.10* 0.07* 0.02 0.01 0.01
Spring -0.14 0.05 0.02 0.03 0.00









Home Range

For this study, home range was defined as the area through which a fish traveled

during the study period (Burt 1943). One outlier was removed from each of the home

range estimates of Fish 471, 501, and 684. Home range estimates varied from 0.56 to

4.84 ha with a mean of 3.04 ha (Table 6). Home range was correlated with days sampled

(n = 12; r = 0.69; p = 0.01). After equalizing the number of observations by removing the

fish that were not located for the duration of the study, total length and weight were not

correlated with home range (n = 5, r = 0.57, p = 0.31; n = 5, r = 0.52, p = 0.36,

respectively), and mean home range increased to 4.09 ha.

Seasonal home ranges were calculated for the five fish that were located for the

duration of the study (Table 7). Mean home range was 2.82, 2.23, and 2.72 ha for the

summer, fall/winter, and spring periods, respectively. No seasonal trends were evident in

home range size. Fish 804 established a separate winter home range primarily in the

southernmost sub-basin from 9 January 2003 to 18 February 2003, after which, it

returned to its spring/summer range in the three northern sub-basins of the lake.

Diel Sampling

Largemouth bass locations, observed during both diel tracking sessions, were

consistent with weekly daytime data collected during the course of the study. No

day/night or spring/summer differences in movement or habitat preference were detected.

Fish exhibited constant movement during diel sampling periods. No fish was found in the

same location more than two consecutive times. Movement between sub-basins was

common for both the spring and summer sampling dates (Table 8). There was no

evidence of any diel on-shore/off-shore movement patterns among the fish.












Table 6. Number of observations and home range (ha) for largemouth bass in Kirkpatrick
Lake, Florida, from 1 May 2002 to 1 May 2003.

Fish Number of Home
number observations range (ha)
411 66 4.57
471 16 0.56
501 65 3.49
561 21 2.64
684 37 1.82
704 24 2.42
725 14 2.08
744 65 4.30
764 13 3.79
784 65 4.84
804 66 3.27
825 22 2.74
mean 3.04


Table 7. Seasonal home ranges for largemouth bass in Kirkpatrick Lake, Florida, from 1
May 2002 to 1 May 2003.

Summer Winter Spring
Fish home home home
number range (ha) range (ha) range (ha)
411 3.59 1.38 2.74
501 1.11 1.99 3.47
744 2.85 3.36 2.84
784 4.53 3.07 2.28
804 2.01 1.38 2.25
mean 2.82 2.23 2.72


Fish Attracting Device Utilization

After FAD deployment, four of the five remaining fish utilized a FAD at least

once (8 out of 146 observations). However, preference values were generally neutral and

the FADs were not a significant habitat for the largemouth bass. Largemouth bass


selected sunken trees over FADs, based on the preference values.











Table 8. Number and percent of follow-up largemouth bass locations that were in a
different sub-basin during two diel sampling dates in Kirkpatrick Lake, Florida,
on 22 August 2002 and 17 April 2003. Fish were located every four hours. Four
observations per fish per sampling date.

Fish 22/23 August 2002 17/18 April 20031 Total % of total
411 0 1 1 12.5
501 0 2 2 25.0
561 2 ---- 2 25.0
684 2 ---- 2 25.0
704 3 ---- 3 37.5
744 2 2 4 50.0
784 2 3 5 62.5
804 3 0 3 37.5
825 0 ---- 0 0.0
1 Fish without a value were no longer being located when the second diel sampling was
performed.















DISCUSSION

General

Several studies have documented seasonal use of off-shore areas by largemouth

bass in the winter after lake destratification (Warden and Lorio 1975; Prince and

Maughan 1979; Betsill 1986; Woodward and Noble 1997). Most of these locations were

oriented to structural habitat. Pelagic areas were utilized night and day, and year-round,

except during the spawning season, in Kirkpatrick Lake. The majority of these locations

were in the open water limnetic zone not associated with any structural habitat. Mesing

and Wicker (1986), Wanjala (1986), and Colle et al. (1989) also found utilization of the

open water limnetic zone by largemouth bass.

It is a common perception that only mid-size largemouth bass utilize the open

water limnetic zone with any regularity. Wanjala (1986) concluded that largemouth bass

longer than 380 mm TL in an Arizona lake could not forage effectively in open water

because of their bulky body shape. However, fish up to 556 mm TL utilized open water

regions of Kirkpatrick Lake. Mesing and Wicker (1986) and Colle et al. (1989) radio-

tracked largemouth bass up to 615 mm and 499 mm TL, respectively, that utilized open

water most of the time. This indicates that big largemouth bass are capable of feeding

efficiently in open water when it is energetically productive to do so.

The mean home range of 3.04 ha for the largemouth bass in Kirkpatrick Lake is

larger than means reported for largemouth bass in larger systems ( [1.06 ha] Winter 1977;

[< 0.5 ha] Nieman and Clady 1980; [1.0 and 1.4 ha] Mesing and Wicker 1986; [1.37 and









1.73 ha] Boyer 1994; [2.11 ha] Woodward and Noble 1997). The larger home range size

in Kirkpatrick Lake probably reflects the more mobile lifestyle of open water fish. Colle

et al. (1989) found a larger mean of 21 ha in the off-shore component of largemouth bass

in 80-ha Lake Baldwin, Florida. This may be because the fish had to range further to

forage effectively based on the larger size and simpler morphometry of Lake Baldwin.

Fish 804 established a separate winter home range and then returned to its prior

home range before spawning season. This agrees with Woodward and Noble's (1997)

findings for Jordan Lake, North Carolina, where four of eleven adult largemouth bass

established separate winter home ranges and returned to prior home ranges in early

spring. This had only been observed previously in sub-adult largemouth bass (Woodward

1996).

There was considerable overlap in largemouth bass home ranges in Kirkpatrick

Lake. One fish was located in the same spot as another fish on several occasions. This

indicates possible shoaling activity. Large shoals of mobile largemouth bass were

observed on three different occasions. These shoals contained 20 to 30 fish that ranged in

size from an estimated 300 to 425 mm TL. Shoaling behavior in predatory fish is

commonly associated with foraging activity for open water prey. Betsill (1983) and

Wildhaber (1985) found a lack of overlap in individual home ranges of largemouth bass

in two small Texas impoundments. This indicates the largemouth bass normally did not

occupy the same areas and possibly defended territories. There were no pelagic prey

species present in these impoundments; sunfish were the primary forage (Betsill 1983;

Wildhaber 1985). Habitat may be a more important component of the life history of

largemouth bass when the primary forage are littoral species such as sunfish.









Structural habitat was not utilized extensively by largemouth bass in Kirkpatrick

Lake based on the preference values. Largemouth bass were often observed in open water

chasing shad to the surface. Angling efforts verified that these fish were largemouth bass.

Therefore, pelagic clupeids are most likely the primary forage for largemouth bass in the

lake. Diet studies should confirm this. Increasing structural habitat may not measurably

increase angler catch rates for largemouth bass in lakes where open water prey are the

principal forage.

Sunfish may not be utilized in Kirkpatrick Lake to the extent they are in most

other systems for two reasons. Based on observation, there seems to be a lack of suitable

spawning substrate for sunfish; this would reduce overall production of adequately-sized

prey. The fish in the lake are also fed with floating fish food and many of the sunfish

present are too large to be consumed by most largemouth bass. If production of young

sunfish were increased, largemouth bass would likely utilize littoral areas more often.

Although FADs were offered as habitat to attract largemouth bass and possibly

alter their habits from actively hunting in open water to ambush predation, this did not

occur in any of the five fish radio-tracked after FAD deployment. The odds of detecting a

change in habit depend on what mechanisms are driving the largemouth bass to utilize

open water. If largemouth bass utilize open water because structural habitat is limited,

adding habitat could allow some fish to revert to ambush predation, assuming a source of

forage is available near the habitat. If the fish utilize open water as a means of procuring

pelagic prey, however, increasing structural habitat probably will not alter the food base

and therefore will be less likely to elicit a response in the behavior of the largemouth

bass. Although it potentially only takes one fish to illustrate a shift in habit, the odds of









detecting a change in a natural system are low. Therefore, behavioral questions such as

this may best be answered in an experimental setting, where environmental variables can

be better controlled.

Genetics

Adult largemouth bass from area lakes have been stocked into Kirkpatrick Lake

for the last several years (Dr. Dan Canfield, Jr., Department of Fisheries and Aquatic

Sciences, University of Florida). It is unknown where the fish first stocked into the lake

originated. These fish would likely have the most input on the genetics of the current

population. Kirkpatrick Lake lies between the Suwannee River, Florida, and Orange

Lake, Florida. The percentage of the Florida largemouth bass subspecies genome was

estimated to be 96.25% for the Suwannee River population and 97.5% for the Orange

Lake population (Phillip et al. 1983). This indicates that while largemouth bass

populations in this region are intergraded, the percentage of northern subspecific input is

low. Because of the conflicting results from microsatellite genetic analysis, further

genetic testing is necessary to determine the percentage of Florida subspecific input on

largemouth bass in Kirkpatrick Lake. Although no direct comparisons between the

northern and Florida largemouth bass subspecies were made in this study, subspecific

information may be useful to future researchers as more and more largemouth bass

studies are performed at the subspecies level.

Transmitters

Transmitter size was more important than weight during implantation of

largemouth bass in Kirkpatrick Lake. Although Ross and McCormick (1981) recommend

transmitters weigh less than 2% of the weight of the fish, it has been shown that fish

quickly adapt to transmitter weights of 2.4 to 4.3% of body weight (Crumpton 1982;









Connors 2002). The transmitter was 2.5% of the body weight and 17.8% of the total

length for the smallest fish in this study. Although a smaller fish could have been used

based on the percent transmitter weight, we found insertion and suturing difficult when

the transmitter was greater than 20% of the total length of the fish (using practice

specimens prior to initiating this study) because of the physical constraints of the

abdominal cavity. Since most internal radio transmitters are cylindrical, transmitter length

can be used to estimate the minimum size fish needed for implantation. Also, length of a

fish does not fluctuate seasonally like weight. Based on our experience, transmitter length

should be no more than 18% of the total length of the fish.

Temperature data from the transmitters were often inconsistent with the data from

the temperature profiles. Thirty percent of the temperature calculations from the

transmitter calibration curves were higher than the surface water temperatures. This could

have been due to changes in the transmitters. Since depth was not an important part of

this study, the data were only used to illustrate general trends. In retrospect, the money

used to purchase the temperature-sensing feature would have been better spent buying

extra transmitters as insurance against transmitter loss or failure.

Management Implications

Although much time and effort has been spent planting bulrush and putting

brushpiles, trees, and FADs into Kirkpatrick Lake, the results from this study indicate

that most of these habitats were not significantly utilized by largemouth bass. Thus,

increasing structural habitat may not measurably increase angler catch rates, by

attracting/concentrating adult largemouth bass, in lakes where open water prey are the

principal forage.









Fisheries managers should consider the behavioral ecology of the largemouth bass as well

as the human dimensions of the anglers before implementing habitat enhancement

strategies. The shoreline was the most often fished area by anglers in Kirkpatrick Lake

(Daniel E. Canfield, Jr., personal communication) while the largemouth bass were found

mostly in open water areas. In order to increase catch rates, it is necessary that either the

anglers fish open water areas more often or the largemouth bass utilize littoral areas more

often. Littoral habitat use by largemouth bass may be increased if production of littoral

prey, such as sunfish, is increased. In addition to liming/fertilization programs, fish

production in quarry lakes may possibly be increased with habitat manipulations that

create more shallow, flat areas for spawning. Marked FADs placed into open water may

have an indirect positive effect on angler catch rates by attracting anglers to under fished

open water areas. Since habitat manipulations may not be cost-effective (based on

utilization by largemouth bass) in lakes where open water prey are the principal forage,

fisheries managers should focus their efforts on angler education.
















LIST OF REFERENCES


Anderson, J. K. 1964. Pre- and post-impoundment limnological studies and lake
investigations. State of Kentucky Dingell Johnson Project F-19. Progress Report:
Fish Attractors. 3pp.

Ball, R. C. 1947. A tagging experiment on the fish population on Third Sister Lake,
Michigan. Trans. Am. Fish. Soc. 74:360-369.

Betsill, R. K., R. L. Noble, and W. H. Neill. 1986. Distribution and habitat selection of
telemetered northern and Florida largemouth bass in 2 small Texas
impoundments. Proc. Annu. Conf. Southeast. Assoc. Fish and Wildl. Agencies
40:275-286.

Burt, W. H. 1943. Territoriality and home range concepts as applied to mammals. Journal
ofMammology. 24:346-352.

Boyer, M. G. 1994. Effect of 2,4-D amine on the movement and feeding behavior of
largemouth bass. Master's Thesis. University of Florida, Gainesville, Florida.
133pp.

Chappell, J. A. 1974. Response of largemouth bass to thermal effluent from Oconee
Nuclear Power Plant. Master's Thesis. Clemson University, Clemson, South
Carolina.

Chew, R. L. 1975. The Florida largemouth bass. Pages 450-458 in R. H. Stroud and H.
Clepper, eds. Black bass biology and management. Sport Fishing Institute,
Washington, D.C. 534 pp.

Colle, D. E., R. L. Calteux, and J. V. Shireman, 1989. Distribution of Florida
largemouth bass in a lake after elimination of all submersed aquatic vegetation. N.
Amer. J. Fish. Manage. 9:213-218.

Connors, K. B., D. Scruton, J. A. Brown, and R. S. McKinley. 2002. The effects of
surgically-implanted dummy radio transmitters on the behavior of wild Atlantic
salmon smolts. Hydrobiologia 483:231-237.

Crumpton, J. E. 1982. Effects of dummy radio transmitters on the behavior of largemouth
bass. Proc. Annu. Conf. Southeast. Assoc. Fish and Wildl. Agencies
36:351-357.









Doerzbacher, J. F. 1980. Movements and home range of largemouth bass (Micropterus
salmoides) in relation to water quality of the Atchafayala river basin, Louisiana.
Master's Thesis. Louisiana State University, Baton Rouge, Louisiana.

Fetterolf, Carlos de la Mesa. 1952. A population study of the fishes of Wintergreen Lake,
Kalamazoo County, Michigan: with notes on movement and effect of netting on
condition. Master's Thesis. Michigan State University, East Lansing, Michigan.
127pp.

Fish, P. A., and J. Savitz. 1983. Variations in home range of largemouth bass, yellow
perch, bluegill, and pumpkinseeds in an Illinois lake. Trans. Am. Fish. Soc.
112:147-153.

Forsburg, C., and S.O. Ryding, 1980. Eutrophication parameters and trophic state indices
In 30 Swedish waste-receiving lakes. Archiv fur Hydrobiologie 88:189-207.

Funk, J. L. 1957. Movement of stream fishes in Missouri. Trans. Am. Fish. Soc. 85:39-
57.

Hazzard, A. S. 1937. Results of stream and lake improvement in Michigan. Trans. 2nd
North Am. Wildl. Nat. Resour. Conf. 1937:620-624.

Hollander, M., and D. A. Wolfe. 1973. Nonparametric statistical methods. John Wiley
and Sons, Inc. New York. 503pp.

La Roche, S. 1972. Statewide lake and stream investigation. State of Maine. Dingell
Johnson Project F-8. Final Job Report: Fish haven study. 6pp.

Manges, D. E. 1959. Large impoundment investigations. State of Tennessee. Dingell
Johnson Project F-12. Final Job Report: Study of the construction and value of
brush shelters. 27pp.

Mesing, C. L., and A. M. Wicker. 1986. Home range, spawning migrations, and homing
of radio-tagged Florida largemouth bass in two central Florida lakes. Trans. Am.
Fish. Soc. 115: 286-295.

Miller, R. J. 1975. Comparitive behavior of centrarchid basses. Pages 85-94 in R. H.
Stroud and H. Clepper, eds. Black bass biology and management. Sport Fishing
Institute, Washington, D.C. 534 pp.

Moody, H. L. 1960. Recaptures of adult largemouth bass from the St. Johns River,
Florida. Trans. Am. Fish. Soc. 89:295-300.

Nieman, D. A., and M.D. Clady. 1980. Winter movement of Florida and northern
largemouth bass near a heated effluent. Proc. Annu. Conf. Southeast Assoc. Fish
and Wildl. Agencies 34:11-18.










Odum, E. P., and E. J. Kuenzler. 1955. Measurement of territory and home range size in
birds. Auk 72:128-137.

Phillip, D. P., W. F. Childers, and G. S. Whitt. 1983. A biochemical genetic evaluation of
the northern and Florida subspecies of largemouth bass. Trans. Am. Fish. Soc.
112:1-20.

Poddubnyi, A. G., N. A. Gordeev, and I. E. Permitin. 1974. Migration pattern of the
feeding fish populations in relation to environmental factors (translated from
Russian). Pages 278-349 in B. S. Kuzin, ed. Biological and hydrological factors
of local movements of fish in reservoirs. U.S. Bur. Sport Fish. and Wildl. And
Nat. Sci. Found., Washington, D.C.

Prince, E. D., and 0. E. Maughan. 1979. Telemetric observations of largemouth bass near
underwater structures in Smith Mountain Lake, Virginia. Pages 26-32 in D. L.
Johnson and R. A. Stein, eds., Response of fish to habitat structure in standing
water. North Cent. Div. Am. Fish. Soc. Spec. Publ. 6.

Prince, E. D., R. F. Raleigh, and R. V. Coming. 1975. Artificial structures and
centrarchid basses. Pages 498-505 in R. H. Stroud and H. Clepper, eds. Black
bass biology and management. Sport Fishing Institute, Washington, D. C. 534 pp.

Rodeheffer, I. A. 1939. Experiments in the use of brush shelters by fish in Michigan
lakes. Pap. Mich. Acad. Sci. Arts Lett. 24(1938):183-193.

Rodeheffer, I. A. 1940. The use of brush shelters by fish in Douglas Lake, Michigan. Pap.
Mich. Acad. Sci. Arts Lett. 25(1939):357-366.

Rodeheffer, I. A. 1945. Fish populations in and around brush shelters of different sizes
placed at varying depths and distances apart in Douglas Lake, Michigan. Pap.
Mich. Acad. Sci. Arts Lett. 30(1944):321-345.

Ross. M. J., and J. H. McCormick. 1981. Effects of external radio transmitters on fish.
Prog. Fish Cult. 43:67-72.

Smith, S. M., and D. J. Orth. 1990. Distributions of largemouth bass in relation to aquatic
vegetation in Flat Top Lake, West Virginia. Proc. Annu. Conf. Southeast Assoc.
Fish. And Wildl. Agencies 44:36-44.

Strauss. R. E. 1979. Reliability of estimates for Ivlev's electivity index, the forage ratio,
and a proposed linear index of food selection. Trans. Am. Fish. Soc. 108:344-352.

Wanjala, B. S., J. C. Tash, W. J. Matter, and C. D. Ziebell. 1986. Food and habitat use by
different sizes of largemouth bass (Micropterus salmoides) in Alamo Lake,
Arizona. J. Freshwater Ecol. 3:359-369.










Warden, R. L., and W. J. Lorio. 1975. Movements of largemouth bass (Micropterus
salmoides) in impounded waters as determined by underwater telemetry. Trans.
Am. Fish. Soc. 104:696-702.

Wilbur, R. L. 1978. Two types of fish attractors compared in Lake Tohopekaliga, Florida.
Trans. Am. Fish. Soc. 107:689-695.

Wildhaber, M. L. 1985. Activity and distribution of northern and Florida largemouth bass
(Micropterus salmoides salmoides and M. s. floridanus) relative to environmental
features of a small impoundment in central Texas. Master's Thesis. Texas A&M
University, College Station, Texas. 99 pp.

Winter, J. D. 1977. Summer home range movements and habitat use by four largemouth
bass in Mary Lake, Minnesota. Trans. Am. Fish. Soc. 106:323-330.

Woodward, K. O. 1996. Reservoir movements of sub-adult largemouth bass (Micropterus
salmoides). M.S. Thesis, North Carolina State University, Raleigh, North
Carolina. 47pp.

Woodward, K. O., and R. L. Noble. 1997. Over-winter movements of adult largemouth
bass in a North Carolina reservoir. Proc. Annu. Conf. Southeast Assoc.
Fish. And Wildl. Agencies 51:113-122.















BIOGRAPHICAL SKETCH

Troy McDaniel Thompson, Jr. was born in Martinsville, Virginia, on 2 June

1975. He spent most of his spare time hunting and fishing in a three-county area of

Virginia known as "the moonshine capital of the world." In 1993, he graduated from

Fieldale-Collinsville High School knowing that he wanted a career in fisheries or

wildlife management. After two years of classes at Patrick Henry Community

College, Troy transferred to the Virginia Polytechnical Institute and State University

in 1995. After being told that there were twice as many wildlife graduates as fisheries

graduates, but the same number of jobs available for each, he did the math and

decided on a career in fisheries. In May 1998, he graduated cum laude with a

Bachelor of Science in Forestry and Wildlife with a concentration in fisheries. In July

1998, he began working as a technician for the Virginia Department of Game and

Inland Fisheries in Forest, VA. It took him three short years to realize that working 3%

time with no benefits was not the career apex he had in mind when he left Virginia

Tech. In August 2001, Troy enrolled as a graduate student under Dr. Chuck Cichra in

the Department of Fisheries and Aquatic Sciences at the University of Florida to

pursue a graduate degree. He will receive his Master of Science degree in December

2003. With increased knowledge, skills, and abilities, Troy hopes to pursue a

research/management position as an agency biologist.