U.S. Department of the InteriorU.S. Geological Survey

General Principles General Principles of Telemetry Studiesof Telemetry Studies

Theresa L. Liedtke

Western Fisheries Research Center Columbia River Research Laboratory

Surgical Techniques Workshop, September 4, 2011

Workshop Approach

Recently completed AFS book chapter on tagging techniques

Follow outline in chapter

GoalGoal Provide background and frameworkProvide background and framework

• Light touch on broad topicsLight touch on broad topics• Later talks provide detailsLater talks provide details

• General recommendationsGeneral recommendations

OutlineOutline• Background on my perspectiveBackground on my perspective• Telemetry study assumptionsTelemetry study assumptions• General PrinciplesGeneral Principles

BackgroundBackground Telemetry studies in Telemetry studies in

Columbia River BasinColumbia River Basin Largest known telemetry Largest known telemetry

studiesstudies• 40,000 juvenile salmon40,000 juvenile salmon

Measure fish survival at Measure fish survival at dams & reservoirsdams & reservoirs

Study Results:Study Results:• Legal implicationsLegal implications• ContentiousContentious• Critically reviewedCritically reviewed

Telemetry Study AssumptionsTelemetry Study Assumptions Inherent assumptions: presence of the transmitter and the

procedure used to secure the transmitter have no effect on the tagged fish

Tagged fish represent untagged fish• Survival• Behavior (feeding, spawning)• Performance (swimming, buoyancy)

Unlikely that there will be “no effect” Diligent effort to minimize effects

General PrinciplesGeneral Principles Recommended actions to minimize effects & Recommended actions to minimize effects &

support the assumptionsupport the assumption General Principles:General Principles:

1)1) Consider transmitter and attachment methodConsider transmitter and attachment method

2)2) Use best practices for fish handling & holdingUse best practices for fish handling & holding

3)3) Develop and enforce a SOPDevelop and enforce a SOP

4)4) Train taggers and manage tagger effectsTrain taggers and manage tagger effects

5)5) Manage anesthesiaManage anesthesia

6)6) Use aseptic techniqueUse aseptic technique

7)7) Evaluate transmitter effectsEvaluate transmitter effects

It’s a matter of scale...or is it?It’s a matter of scale...or is it? My study is smaller scale, so I don’t My study is smaller scale, so I don’t

need all this stuff!need all this stuff!

A study with n=1 makes the same basic A study with n=1 makes the same basic assumptions assumptions

If you want to make inferences to the If you want to make inferences to the untagged population untagged population (and you know you do!) (and you know you do!) consider these principlesconsider these principles

Monitor Tagged fish

DescribeUntagged fish

INFERENCE

1) Transmitter Selection1) Transmitter Selection

Define study requirementsDefine study requirements• Radio vs. acousticRadio vs. acoustic• Battery lifeBattery life• SensorsSensors• Will the smallest available tag work?Will the smallest available tag work?

Predict transmitter impact to fishPredict transmitter impact to fish• Tag burden (typically 1 to 5%)Tag burden (typically 1 to 5%)• Dimensions and volumeDimensions and volume• Consult literature for same species & sizeConsult literature for same species & size

• What’s been published? What is defensible?What’s been published? What is defensible?

1) Attachment Method1) Attachment Method ExternalExternal Gastric / StomachGastric / Stomach

SurgicalSurgical

1) Attachment Method

1) Transmitter & Attachment1) Transmitter & Attachment

Relative to the assumption, ask yourself:Relative to the assumption, ask yourself:• Can I defend my choice of transmitter?Can I defend my choice of transmitter?• Have I considered the impact to the fish?Have I considered the impact to the fish?• Will a smaller tag meet my needs?Will a smaller tag meet my needs?• Have others used similar methods for Have others used similar methods for

this fish?this fish?

2) Fish Handling & Holding2) Fish Handling & Holding

Best practices defined—just apply them!Best practices defined—just apply them! Often seen as trivial, Often seen as trivial, butbut…………

• Stressors can be cumulativeStressors can be cumulative• Can have large impacts on tagging outcomeCan have large impacts on tagging outcome

Critical to best outcome & defense of Critical to best outcome & defense of assumptionassumption

2) Handling & Holding2) Handling & Holding Fish collection methodFish collection method Holding (before and/or after tagging)Holding (before and/or after tagging)

• Density and species interactionsDensity and species interactions

Transport considerationsTransport considerations• Density and temperatureDensity and temperature

Water quality conditionsWater quality conditions Fish transfersFish transfers

• Minimize them!!!Minimize them!!!• Transfer the container, not the fishTransfer the container, not the fish• Water to water transfersWater to water transfers

2) Handling and Holding2) Handling and Holding

Tagging stationTagging station• Orients and holds fishOrients and holds fish• Enables anesthesiaEnables anesthesia• Aids aseptic techniqueAids aseptic technique• Comfortable for taggerComfortable for tagger

3) Develop & Enforce a SOP3) Develop & Enforce a SOP Standard Operating Procedure (SOP)Standard Operating Procedure (SOP)

• Describe steps in the processDescribe steps in the process• Defines acceptable levels of parametersDefines acceptable levels of parameters• Consistent application of techniqueConsistent application of technique

Where do you start?Where do you start?• Modify from existing Modify from existing • Build your ownBuild your own

Test compliance (QA-QC monitoring)Test compliance (QA-QC monitoring)

4) Taggers & Tagger Effects 4) Taggers & Tagger Effects

Practice, practice, practicePractice, practice, practice Training program:Training program:

• ““Best-match” fishBest-match” fish• Mentor (DVM?)Mentor (DVM?)• Assess proficiencyAssess proficiency• Feedback loopFeedback loop• Short-term holding Short-term holding

When to train:When to train:• New species or life stageNew species or life stage• After inactivityAfter inactivity

4) Taggers & Tagger Effects4) Taggers & Tagger Effects

Study Design• Minimize number of

taggers• Balance tagger

contribution to study groups

• Consider a tank study to support field effort

Analysis• Be prepared to test

for tagger effects• Response variables

can be survival, average distance moved, etc.

• EXAMPLE

Tagger effects are REAL....anticipate them

4) Tagger Effects Juvenile salmon

survival study Multiple taggers High sample sizes

Survival

Time

S = 92%

Survival

Time

A

B

S = 98%

S = 86%

A A A BB B

Tagger N S

A 50% 98%

B 50% 86%

5) Manage Anesthesia

Critical part of tagging operation “Ideal anesthetic” *

• Short induction time & fast recovery • No persistent effects • Rapidly excreted = no withdrawal time• Safe for humans to handle

Know the legal status• Some information today during lunch

* Summerfelt and Smith in Methods for Fish Biology 1990

5) Manage AnesthesiaMake your selectionRun some trials

• Match fish and water temperature• Vary concentration• Time induction and recovery

Finalize procedures and put into SOPBe rigorous with application

• Measure dosage• Refresh working solution• Log induction, recovery, exposure times

6) Use Aseptic Technique More detail later today

Goal: minimize contamination by pathogens• Clean instruments, wear gloves, etc.

Cannot attain “sterile” conditions with fish Field conditions ≠ Surgical Suite Fish in water ≠ mammal on table

• Do the best you can!!

6) Use Aseptic Technique6) Use Aseptic Technique

Why bother…who knows if it works? 1) Telemetry assumption

• Best possible care will minimize effects

2) Animal welfare concerns

3) Why not?• Err on the side of caution• If there is not a large “cost”

7) Evaluate Transmitter Effects7) Evaluate Transmitter Effects

LiteratureLiterature• Match species, life Match species, life

stage & sizestage & size• Lab vs. field Lab vs. field

studies…get the studies…get the best matchbest match

MeasurementMeasurement• Commonly done in labCommonly done in lab

• Tagged vs. controlsTagged vs. controls• Try to incorporate field Try to incorporate field

elementelement• What response What response

variable?variable?

“Heart” of the assumption, so it has to be evaluated

7) Evaluate Transmitter Effects7) Evaluate Transmitter Effects

SurvivalSurvival• Easy to measure in labEasy to measure in lab• Crude indicator Crude indicator

• Death is a late Death is a late indicator of stressindicator of stress

Physiological ResponsePhysiological Response• Sub-lethal effectsSub-lethal effects• Stress responseStress response• DiseaseDisease• HistologyHistology

Potential response variables…more to come later

suture

fibrosis

7) Evaluate Transmitter Effects7) Evaluate Transmitter Effects

Swimming Swimming PerformancePerformance• Prolonged swimmingProlonged swimming• Burst swimmingBurst swimming

Buoyancy Buoyancy CompensationCompensation• Can fish compensate Can fish compensate

for extra mass?for extra mass?• How soon?How soon?

7) Transmitter Effects7) Transmitter Effects

Predator Avoidance Predator Avoidance AbilityAbility• Tag may affect Tag may affect

mobilitymobility• Use a realistic Use a realistic

systemsystem

A little bit of A little bit of everythingeverything• Use a combination of Use a combination of

these performance these performance measuresmeasures

• Use field responses Use field responses with lab findingswith lab findings

SummarySummary General Principles:General Principles:

1)1) Consider transmitter and attachment methodConsider transmitter and attachment method

2)2) Use best practices for fish handling & holdingUse best practices for fish handling & holding

3)3) Develop and enforce a SOPDevelop and enforce a SOP

4)4) Train taggers and manage tagger effectsTrain taggers and manage tagger effects

5)5) Manage anesthesiaManage anesthesia

6)6) Use aseptic techniqueUse aseptic technique

7)7) Evaluate transmitter effectsEvaluate transmitter effects

Check out the new book for more Check out the new book for more detailsdetails

Acknowledgments & Confessions

Lots of folks involved

We’ve made ALL the big mistakes….

Always striving to improve

QUESTIONS?