Management of Management of Undesirable Fish SpeciesUndesirable Fish Species

Chapter 15Chapter 15

Undesirable SpeciesUndesirable Species

Any species that Any species that does not meet does not meet human needshuman needs

Undesirable SpeciesUndesirable Species

Not contribute to Not contribute to sport fishery, sport fishery, forage baseforage base

Inhibit Inhibit development, development, maintenance of maintenance of desirable fishdesirable fish

Detrimental to Detrimental to biological balancebiological balance

Undesirable SpeciesUndesirable Species

Reservoir for Reservoir for pathogenic pathogenic organisms organisms (aquaculture)(aquaculture)

Interfere with Interfere with other wildlife other wildlife management management practicespractices

Most Control EffortsMost Control Efforts

Herrings (gizzard Herrings (gizzard shad)shad)

Minnows (common Minnows (common carp)carp)

Sunfish Sunfish Suckers Suckers Bullhead catfishesBullhead catfishes

Control MethodsControl Methods

ChemicalChemical BiologicalBiological MechanicalMechanical

Chemical ControlChemical Control

Usually used for Usually used for complete removalcomplete removal

Also effective for Also effective for partial removalspartial removals Spawning sitesSpawning sites Lake sectionsLake sections ““Thinning” of Thinning” of

stunted game fish stunted game fish stocksstocks

Ideal ChemicalIdeal Chemical

Species-specificSpecies-specific Easy/safe to applyEasy/safe to apply Quickly degrades Quickly degrades

to harmless form to harmless form without need for without need for detoxicantsdetoxicants

Harmless to Harmless to nontarget nontarget organismsorganisms

Ideal ChemicalIdeal Chemical

Effective across Effective across range of water range of water qualityquality

Registered for Registered for aquatic useaquatic use

NO SUCH NO SUCH CHEMICAL!CHEMICAL!

Current Registered Current Registered PiscicidesPiscicides

Rotenone and Rotenone and antimycinantimycin

General fish General fish toxicantstoxicants

Current Registered Current Registered PiscicidesPiscicides

TFM and TFM and BayluscideBayluscide

LampricidesLampricides

LampricidesLampricidesSea lamprey

Larva or ammocoete

LampricidesLampricidesLarva or ammocoete

Granular Bayluscide

Chemical ControlChemical Control

Effective time Effective time period - 1 to 15 period - 1 to 15 years most years most commoncommon

Some up to 30 Some up to 30 yearsyears

Biological ControlBiological Control

Predators to Predators to control forage, control forage, stunted fishstunted fish

Biological ControlBiological Control

Problems:Problems: Gizzard shadGizzard shad Yellow perchYellow perch ““Sunfish”Sunfish” Common carpCommon carp Other minnowsOther minnows

Solutions:Solutions: Largemouth bassLargemouth bass WalleyeWalleye Northern pikeNorthern pike Striped bassStriped bass Striped bass Striped bass

hybridshybrids Muskellunge Muskellunge

Biological ControlBiological Control

Controlling Controlling reproductionreproduction

Forage fish Forage fish introductionsintroductions Unwanted Unwanted

competitive competitive interactionsinteractions

Underexploited Underexploited fishesfishes Encourage new sport, Encourage new sport,

commercial fisheriescommercial fisheries

Mechanical ControlMechanical Control

Water level Water level manipulationsmanipulations

Only on reservoirsOnly on reservoirs

Mechanical ControlMechanical Control

TrapsTraps BarriersBarriers Commercial fishingCommercial fishing ElectricityElectricity

Labor-intensive - Labor-intensive - CPUE declines CPUE declines with decreasing with decreasing populationspopulations

Problems:Problems: Common carpCommon carp Other minnowsOther minnows SuckersSuckers ““Sunfish”Sunfish” Yellow perchYellow perch