1. Middle Provo River: History, Regulations, and Population Estimates Jordan Nielson

2. What Happened? Pre-1997 Low flows limited food production and habitat severely restricted. Pre-1997 Low flows limited food production and habitat severely restricted. Post-1997 minimum flows (125 cfs) improved food production and habitat.

3. Pre-1997 Low flows limited food production and habitat severely restricted. Pre-1997 Low flows limited food production and habitat severely restricted. Post-1997 minimum flows (125 cfs) improved food production and habitat. What Happened? 1.Decreased Mortality 2.Increased Recruitment 1.Decreased Mortality 2.Increased Recruitment

4. Current regulations were implemented to protect/enhance the fishery and increase overall size of trout Percent of large brown trout (> 380 mm) declining Current regulations were implemented to protect/enhance the fishery and increase overall size of trout Percent of large brown trout (> 380 mm) declining

5. The Evidence 1997 –Mean Length – 352 mm –Mean Weight – 695 g –Density - 640 fish/mile –Condition Factor – 1.27 1997 –Mean Length – 352 mm –Mean Weight – 695 g –Density - 640 fish/mile –Condition Factor – 1.27 2003 –Mean Length – 298 mm –Mean Weight – 306 g –Density – 2,391 fish/mile –Condition Factor – 0.97 2003 –Mean Length – 298 mm –Mean Weight – 306 g –Density – 2,391 fish/mile –Condition Factor – 0.97

6. Regulations 2003 –Flies and artificial lures only –Brown trout limit 2 under 15 inches –Closed to the possession of cutthroat and rainbow trout. 2004 –Above Legacy Bridge Flies and artificial lures only Trout limit 2 under 15 inches –Below Legacy Bridge General Regulations No gear restrictions, limit 4 trout 2003 –Flies and artificial lures only –Brown trout limit 2 under 15 inches –Closed to the possession of cutthroat and rainbow trout. 2004 –Above Legacy Bridge Flies and artificial lures only Trout limit 2 under 15 inches –Below Legacy Bridge General Regulations No gear restrictions, limit 4 trout

7. Middle Provo River Regulation Change Study Recap Angler survey: –Use increased by 35% to 278 h/acre/month (2002-2007) –Harvest increased in general regulation section –Provided additional opportunity for a more diverse group of anglers –0.91 fish/hour - Special –0.85 fish/hour - General Angler survey: –Use increased by 35% to 278 h/acre/month (2002-2007) –Harvest increased in general regulation section –Provided additional opportunity for a more diverse group of anglers –0.91 fish/hour - Special –0.85 fish/hour - General

8. Middle Provo River Regulation Change Study Recap Angler survey (continued): –Fly fishermen are less likely to harvest fish (65% less 02- 07) Despite education/information –Bait anglers will harvest fish Accounted for 47% of harvest overall Accounted for 2% of total hours overall Angler survey (continued): –Fly fishermen are less likely to harvest fish (65% less 02- 07) Despite education/information –Bait anglers will harvest fish Accounted for 47% of harvest overall Accounted for 2% of total hours overall Provo River 1937

9. Indices Length Weight Condition Factor Proportionate Stock Density Relative Stock Density Length Weight Condition Factor Proportionate Stock Density Relative Stock Density

10. PSD = N≥9 inches X 100 N≥6 inches 62.2 Quality

11. RSD = N≥15 inches X 100 N≥6 inches 10.8 Memorable

12. PSD = N≥18 inches X 100 N≥6 inches 1.2 Trophy

13. Length Across Time 1997 –13.9 in 2010 –10.6 in 24% Reduction 1997 –13.9 in 2010 –10.6 in 24% Reduction

14. Weight Across Time 1997 –695 g/ 1.5 lb 2010 –250 g/ 0.5 lb 64% Reduction 1997 –695 g/ 1.5 lb 2010 –250 g/ 0.5 lb 64% Reduction

15. Condition Factor Across Time 1997 –1.27 2010 –1.0 21% Reduction 1997 –1.27 2010 –1.0 21% Reduction

16. Population Density Across Time 1997 –640 fish/ mile 2010 –2783 fish/ mile 435% Increase 1997 –640 fish/ mile 2010 –2783 fish/ mile 435% Increase

17. Middle Provo River Regulation Change Study Recap Special Regulations are not serving a biological purpose –Fish populations have not been negatively impacted by the regulation change –May need a higher harvest rate to see a positive change in fish size (Donald and Alger 1989) >20% Reduction Special Regulations are not serving a biological purpose –Fish populations have not been negatively impacted by the regulation change –May need a higher harvest rate to see a positive change in fish size (Donald and Alger 1989) >20% Reduction

18. Conclusion General downward trend in population indices Upward Trend in Population Numbers Overharvest = Easy Population Manipulation Changing angler paradigms needs to be a “grassroots” movement General downward trend in population indices Upward Trend in Population Numbers Overharvest = Easy Population Manipulation Changing angler paradigms needs to be a “grassroots” movement

19. Goals: Increase fish health without decreasing the ability to catch fish Encourage angling groups to promote harvest to begin to change angler attitude Increase fish health without decreasing the ability to catch fish Encourage angling groups to promote harvest to begin to change angler attitude