Movement of Rainbow Trout in Arkansas Tailwaters Daniel D. Magoulick Arkansas Cooperative Fish and Wildlife Research Unit Department of Biological Sciences University of Arkansas - Fayetteville
Questions About C & R Areas Do resident trout stay within the C & R areas?Do resident trout stay within the C & R areas? Do rainbow trout maintain home ranges?Do rainbow trout maintain home ranges? How do movements compare to the CR lengths?How do movements compare to the CR lengths? Shoals Lake and the White River Bull Shoals Dam & Tailwater
Study Sites Stream Length (m) Bull Shoals = 1400 Norfork = 1600 Rim Shoals = 2600 Sylamore = 4200
Methods Two Approaches I. Radiotelemetry II. Otolith Microchemistry
Part I: Radiotelemetry I.Data Collection II.GIS Analysis III.SAS Analysis IV.SYSTAT Analysis PAIRED STUDY DESIGN 20 IN / 20 OUT in Fall 2005 *Boosted to 20 IN at Bull, Norfork & Rim in Spring 2006
Radiotelemetry Design CaptureCapture TagTag Weekly Locations & FatesWeekly Locations & Fates Norfork Preliminary Study Norfork Preliminary Study Good Retention Good Retention Growth Rates/Condition from Growth Rates/Condition from Population Estimates Population Estimates
Capture & Tagging 1. Capture 2. Sedate 3. Weight (450 g +) & Length 4. Picture & VI Tag
Capture & Tagging 5. Incision 6. Antibiotic Injection (OTC) 7. Tag Insertion 8. Stitches & Ointment 9. Revive and Release Finished
Tracking Summary 230 Total Fish Tagged230 Total Fish Tagged –144 Tagged IN CR –86 Tagged OUT CR 124 (54%) Individuals Tagged had (54%) Individuals Tagged had 15+ –86/144 (60%) Tagged IN –38/86 (44%)Tagged OUT Average of 24 Relocations/Fish Used for Home Range AnalysisAverage of 24 Relocations/Fish Used for Home Range Analysis *All further analysis includes only fish with 15+ locations
Locations: In vs. Out 60/86 Tagged In Stayed In (70%)60/86 Tagged In Stayed In (70%) 22/38 Tagged Out Stayed Out (58%)22/38 Tagged Out Stayed Out (58%) 42/124 Moved In-between (34%)42/124 Moved In-between (34%) –Fish Tagged OUT at Rim Were Found IN on Average 26% of the Time –Fish Tagged IN at Sylamore Were Found OUT on Average 53% of the Time SYLAMORE RIM NORFORK BULL SITE
Movement: Distance vs. CR INOUT TAGGED MAX_RANGE NORFORK INOUT TAGGED BULL SYLAMORE INOUT TAGGED RIM INOUT TAGGED Overall: 24/124 (15%) Moved > Length of Respective CR AreasOverall: 24/124 (15%) Moved > Length of Respective CR Areas Bull: 4/32 (13%) Moved >1700 mBull: 4/32 (13%) Moved >1700 m Norfork: 9/31 (29%) Moved > 1800 mNorfork: 9/31 (29%) Moved > 1800 m Rim: 4/35 (11%) Moved ( > 2600 mRim: 4/35 (11%) Moved ( > 2600 m Sylamore: 7/26 (27%) Moved >4000 mSylamore: 7/26 (27%) Moved >4000 m *NOTE SCALE
95% of time spent between here
SYSTAT: Within Site ANOVA’s Median and range (in parentheses)
SYSTAT: AMONG Site ANOVA’s Median and range (in parentheses)
Discussion At most sites fish tagged OUT were found IN more than vice-versaAt most sites fish tagged OUT were found IN more than vice-versa –At Sylamore, fish movement between areas was common Most fish are moving less than the lengths of their respective CR areasMost fish are moving less than the lengths of their respective CR areas –Sylamore had the largest home range estimates Warm water may force fish to moveWarm water may force fish to move
Conclusions Majority (70%) tagged in the CR have remained there Only 15% of all tagged fish (IN or OUT) had linear distance > the length of their CR areasOnly 15% of all tagged fish (IN or OUT) had linear distance > the length of their CR areas CR areas appear to have no effect on distances movedCR areas appear to have no effect on distances moved Most of the fish tagged IN are being protected from angler mortality, increasing their residence time, allowing them to grow larger