SMB KnowThyEnemy

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Information about SMB KnowThyEnemy

Published on January 12, 2008

Author: Manfred


Slide1:  Nonnative Fish Control Workshop Grand Junction, CO December 12, 2006 Smallmouth Bass Life History: Know Thy Enemy Patrick J. Martinez Colorado Div. of Wildlife Grand Junction Slide2:  Habitat: Water, substrate & thermal conditions Biological: Age & growth, diet, reproduction Ecological: Interactions with other biota UCRB: Distribution in rivers & reservoirs; invasiveness Control: Mechanical, habitat, chemical, policies? Smallmouth Bass Micropterus dolomieu Slide3:  Smallmouth Bass - Habitat Slide4:  Smallmouth Bass - BIOLOGICAL Slide5:  Age & Growth: SMB Age & Growth and Body Condition Colorado River in Grand Valley & Middle Yampa River Slide6:  Some SMB cannibalism SMB prey on native fishes Smallmouth Bass - Ecological SMB prey energy content (cal./kg): insects@400, fish@600 & crayfish@800; crayfish absent in YAR in 1977, now abundant Slide7:  Colorado Yampa Slide8:  Small-bodied Fish (SBF) Equivalents Estimated SBF biomass+annual production = 160 kg/km Slide9:  Smallmouth Bass - UCRB Slide12:  SMB Origins & Invasiveness in UCRB: Blue Mesa? Bottle Hollow Rifle Gap Flaming Gorge Starvation Lake Powell McPhee Harvey Gap Rio Blanco Elkhead Juniata Slide13:  Time late 1800’s & 1970’s & 1990’s & establ. early 1900’s 1980’s 2000’s COR abundant rare common GUR none rare none WHR common rare rare YAR abundant abundant abundant In CO Slide14:  - Key issue in native fish protection scenario becomes how feasible would it be to encourage angler harvest as supplemental means of SMB reduction & control in YAR - SMB maintain widespread abundance, high densities in some reaches, and have recently expanded their range into DNM Despite reported & purported angler enthusiasm for & utilization of SMB fishery in Yampa River: - SMB retain high PSD despite demographics suggesting only moderately productive population characteristics - SMB display high Wr, which is more attributable to crayfish availability than to removal by angler harvest Slide15:  The Use of Water Temperature, Discharge & Turbidity to Approximate the Duration of Optimal Conditions for Smallmouth Bass Angling in the Yampa River Slide16:  RBT: decline in foraging strikes & feeding behavior at higher turbidity, also prey within visual field often ignored SMB: increased turbidity reduced reaction to prey, but not foraging success upon reacting to prey Slide17:  Suspended sediment transport: - YAR above LSR near Maybell, 1998-2002 QS = 0.0000581 Q2.13, where QS = sediment discharge in tons per day; Q = water discharge in cfs - Elliot, J. G. & S. P. Anders. 2005. Summary of sediment data from the YAR & Upper GRR Basins, CO & UT, 1993-2003. Suspended sediment concentration (SSC): QS = QW * SSC * 0.0027, where QS = sediment discharge in tons per day; QW = water discharge in cfs; SSC = suspended sediment concentration in mg/l - Dinehart, R. L. ????. Sediment transport at gaging stations near Mt. St. Helens, WA, 1980-1990. Data collection & analysis. USGS. Slide18:  Convert SSC to NTU (Nephlometric Turbidity Units): - SCCmg/l = 3.399 NTU – 5.603 - Barrett, J. C., et al. 1992. Turbidity-induced changes in reactive distance of rainbow trout. TAFS 121:437-443. Rainbow trout reactive distance vs. turbidity (NTU): - RDcm = -1.09 NTU + 52.81, where RD = reactive distance in cm - Barrett, J. C., et al. 1992. Turbidity-induced changes in reactive distance of rainbow trout. TAFS 121:437-443. Smallmouth bass RD vs. NTU: - RDcm = 65.0 * 2.718(-0.05 NTU) - Sweka, J. A. & K. J. Hartman. 2003. Reduction of reactive distance & foraging success in smallmouth bass exposed to elevated turbidity levels. Environ. Bio. of Fishes 121:437-443. Slide19: Slide21:  1996-2005 Discharge 1998 “High” flow 2004 “Low” flow Slide22:  1998-2005 Temperature 1998 2004 Slide23:  Jun 15- Sept 30= 16 weeks 1998 Temperature Slide24:  Aug 7- Sept 30= 8 weeks 1998 Discharge Access by boat = 5 weeks Slide25:  Jun 1- Sept 30= 18 weeks 2004 Temperature Slide26:  Jul 7- Sept 30= 12 weeks 2004 Discharge Access by boat = 5 weeks Slide27:  Yampa River smallmouth bass sport fishery - SMB fishability 6-10 weeks due to turbidity & access - further restricted by base flow storm induced turbidity - angler use characterized as low, fish “unpressured” - <200 cfs limits boat access for anglers to only 5 weeks - private land restricts public access in some reaches - shore access limited due to road conditions (storms) - angling unable to control SMB due to local conditions - unpredictable access & turbidity limits organized derby - restricted to 8-12 optimum weeks in Jul, Aug & Sep Slide28:  June 2005 August 2005 Slide29:  Smallmouth Bass - Control

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