1. Management of Undesirable Fish Species Chapter 15

2. Undesirable Species Any species that does not meet human needs

3. Undesirable Species Not contribute to sport fishery, forage base Inhibit development, maintenance of desirable fish Detrimental to biological balance

4. Undesirable Species Reservoir for pathogenic organisms (aquaculture) Interfere with other wildlife management practices

5. Most Control Efforts Herrings (gizzard shad) Minnows (common carp) Sunfish Suckers Bullhead catfishes

6. Control Methods Chemical Biological Mechanical

7. Chemical Control Usually used for complete removal Also effective for partial removals Spawning sites Lake sections “Thinning” of stunted game fish stocks

8. Ideal Chemical Species-specific Easy/safe to apply Quickly degrades to harmless form without need for detoxicants Harmless to nontarget organisms

9. Ideal Chemical Effective across range of water quality Registered for aquatic use NO SUCH CHEMICAL!

10. Current Registered Piscicides Rotenone and antimycin General fish toxicants

11. Current Registered Piscicides TFM and Bayluscide Lampricides

12. Lampricides Sea lamprey Larva or ammocoete

13. Lampricides Granular Bayluscide

14. Chemical Control Effective time period - 1 to 15 years most common Effective time period - 1 to 15 years most common Some up to 30 years Some up to 30 years

15. Biological Control Predators to control forage, stunted fish Predators to control forage, stunted fish

16. Biological Control Problems: Problems: Gizzard shad Gizzard shad Yellow perch Yellow perch “Sunfish” “Sunfish” Common carp Common carp Other minnows Other minnows Solutions: Largemouth bass Walleye Northern pike Striped bass Striped bass hybrids Muskellunge

17. Biological Control Controlling reproduction Forage fish introductions Unwanted competitive interactions Underexploited fishes Encourage new sport, commercial fisheries

18. Mechanical Control Water level manipulations Only on reservoirs

19. Mechanical Control Traps Traps Barriers Barriers Commercial fishing Commercial fishing Electricity Electricity Labor-intensive - CPUE declines with decreasing populations Labor-intensive - CPUE declines with decreasing populations Problems: Common carp Other minnows Suckers “Sunfish” Yellow perch