Transcript Methods to Mitigate Tagging Effects (Actual & Perceived) Scott McCutcheon Ryan Richmond Methods to Mitigate Tagging Effects.

Methods to Mitigate Tagging
Effects (Actual & Perceived)
Scott McCutcheon
Ryan Richmond
Methods to Mitigate Tagging Effects
Acknowledgements
Contributed data:
Doug Marsh, NMFS
Nate Wiese, USFWS Hagerman NFH
Tom Kahler, Douglas County PUD
Comparing Preloaded Single Use Injectors to Multiple Use Injectors
Goal
Take away question:
– If a study is conducted with better methods and
material, will the results be significantly
different?
Methods to Mitigate Tagging Effects
Introduction
• PIT tags give us the ability to tag a smaller but
significant portion of a population while allowing us
to monitor individuals.
• Since we have the ability to monitor individuals, it is
imperative that we:
• Use methods material that will give the fish the
greatest chance of survival.
• And, use methods and material that accurately account
for all tags at release and return.
Methods to Mitigate Tagging Effects
Scope
• During this presentation I will:
1. Define what “Tag Effects” are.
2. Then list some of the causes and effects.
3. And, finally I will list some preventative
measures
•
With examples
Methods to Mitigate Tagging Effects
What are Tagging Effects?
•
1.
2.
3.
What are tagging effects that reduce your data quality or fish quality and
survival?
Reduced growth
Decreased survival
Lost data
1.
Tag shedding
•
•
2.
Tagged fish mortality
•
•
3.
Mortality post release
Unaccounted mortality prior to release
Misplaced data
•
4.
Post tagging lost data files or tags
Unread tags
•
•
•
Tag shedding post release
Unaccounted tag shedding prior to release
Unread tags during release
Unread tags during adult return
Are these anomalies actual “Tag Effects” or improper methods and
material that are perceived to be tag effects?
Methods to Mitigate Tagging Effects
Discussion of Tag Effects
I will now discuss each Tag Effect in detail.
• Beginning with Reduced Growth
Methods to Mitigate Tagging Effects
Tagging Effects that may reduced growth
•
What is the end result of reduced growth?
a) Smaller juveniles fish - more susceptible to predation.
b) Smaller adults - may result in lower fecundity.


Was the difference significant?
Did you examine the growth of the individual?
Methods to Mitigate Tagging Effects
Reduced Growth
•
What tagging related problems lead to reduced
growth?
1.
Tag wound
•
•
Why?
•
The body is repairing itself rather than building body mass.
Prevention
•
Sharp needles
•
Training
Photo provided by:
Nate Wiese, USFWS Hagerman NFH
Methods to Mitigate Tagging Effects
Reduced Growth
•
What tagging related problems might lead to reduced
growth?
1.
2.
Tag wound
Tag size
•
•
Depending on the size of the fish
•
Tag may take space that can be used for:
•
food storage
•
fat reserves.
Prevention
•
Use smaller tags with small fish when ever possible
• Use 12mm tags with fish > 65mm
• Use 9mm tags with fish < 65mm
Methods to Mitigate Tagging Effects
Decreased Survival
•
What tagging related problems might decrease survival?
1.
Tag wound
•
•
•
Why?
•
Entry point for infection
•
Punctured organs
•
Puncture gut without killing the fish (shed tag)
Cause?
•
Dull needles
•
Deep insertion
•
Tagging angle
Prevention
•
Training
•
Use sharp needles
Single Use Injector
Proper angle
Proper location
Methods to Mitigate Tagging Effects
Decreased Survival
•
What tagging related problems might decrease survival?
1. Tag wound
2.
Double Marking
o
o
Studies have shown decreased survival
•
Does PIT or CWT lower survival or is it double stress?
Prevention
•
Avoid
•
Avoiding double marking studies is not practical and not
recommended.
•
Allow recovery
•
between tagging events
•
and prior to release
Methods to Mitigate Tagging Effects
Decreased Survival
•
What tagging related problems might decreased survival?
1. Tag wound
2. Double Marking
3.
Improper Handling during tagging
o
o
Cause
•
Too long in the anesthetic
•
Too many fish in the net (O2 depletion within the net)
Prevention
•
Training
•
Do not put more fish in the net than can be tagged in a safe
amount of time
Example of over crowded net
Methods to Mitigate Tagging Effects
Decreased Survival
•
What tagging related problems might decrease survival?
1. Tag wound
2. Double Marking
3. Improper Handling during tagging
4. Tagging unhealthy fish
o
o
Effect
•
Higher pre release mortality
•
And/or, higher post release mortality
Prevention
•
Only tag healthy fish
Methods to Mitigate Tagging Effects
Data Loss
1. What is the cause of Data
Loss?
1.
Tags lost during tagging
•
•
•
o
Effect to Project
o
o
Broken tags
Non-functional tags
Lost tags
Reduction in number of fish tagged
Prevention
•
•
Training
•
Needle bevel should by against the
fish to avoid tags not entering the
fish
•
(example: incorrect method)
Account for all missing tags
•
Count
•
Collect
Methods to Mitigate Tagging Effects
Data Loss
1.
What is the cause of Data Loss?
1.
2.
Tags lost during tagging
Tags shed prior to release
o
Cause
•
•
•
o
Improper tagging methods
Dull needle
Excessive movement immediately after tagging.
Prevention
•
•
•
•
Training
Only use sharp needles
Whenever possible, hold fish in a calm after tagging
Search for shed tags in the holding facility
Methods to Mitigate Tagging Effects
Mortalities and shed tags collected by week during 10 weeks of
yearling Chinook holding at Wells Hatchery, 2010.
80
70
60
50
Morts
40
Sheds
30
20
10
0
Week 1
Week 2
Week 3
Week 4
Week 5
Week 6
(Most shedding occurs in the first 7 days post tagging. The
tags collected later are presumed to be tag consumed and
later passed by other fish. This theory is supported by the
USFWS study at Hagerman NFH, ID.) (Tag consumption varies
by species and age of fish.)
Comparing Preloaded Single Use Injectors to Multiple Use Injectors
Week 7
Week 8
Week 9
Week 10
Total tagged = 80,487
shedding = 127 (0.16%)
mortality = 380 (0.47%)
Tag seeding evaluation of Steelhead
• The USFWS at Hagerman NFH tested their shed recovery efficiency in
December 2009.
– By placing twenty-five tags into 4 raceways via a standpipe
• (so they were not ingested while falling into the raceways).
– Four days later, a blind routine magnetic sweeping of the raceways yielded
zero tags.
– After the blind sweeping, they returned to the four experimental raceways
and re-swept them with magnets and inspected likely areas for shed tags.
These additional efforts recovered zero PIT tags.
– However, 46% of these PIT tags were detected when the fish were pumped
through a PIT tag array.
– USFWS hypothesized:
• Loose PIT tags were ingested and lodged in the intestinal tract.
• Some of the ingested tags may have occurred in already tagged smolts or smolts that
ingested multiple tags effectively cancelling both PIT tags.
• Ingestion could explain the lack of shed tag recoveries and some of the lower detection
rate.
Comparing Preloaded Single Use Injectors to Multiple Use Injectors
Data Loss
1. What is the cause of Data Loss?
1. Tags lost during tagging
2. Tags shed prior to release
3. Tags are not detected during release monitoring
o
Cause
•
•
•
o
Unaccounted shed tags
Tag collision
Tag orientation
Prevention
•
•
•
Collect shed tags consistently during the holding period
Use multiple release monitors
Use only fish detected during releases.
Methods to Mitigate Tagging Effects
Example of Release Monitors
At Rapid River
•Monitors installed at
raceway exit.
•Used when:
• A portion of the
population is tagged.
• Fish are released
directly from raceway
or pond.
•Most effective when
fish are allowed to
volitionally exit over
several weeks.
Methods to Mitigate Tagging Effects
Example of Release Monitors
At Chewuch Acclamation Site
•
•
•
•
Installed at the raceway exit
Single read system
Two antenna to spread out fish
Driven by FS2001 readers
Methods to Mitigate Tagging Effects
Example of Release Monitors
Truck Loading at Turtle Rock
•Used when:
• Small portions of a
large population of PIT
tagged fish is released
at different locations.
(Each truck load has a
different release file.)
•4 FS2001 readers (1
on intake and 3 on exit
pipe)
•Avoid tag collision by
not over crowding.
Methods to Mitigate Tagging Effects
Data Loss
1.
What is the cause of tags not being read?
1.
2.
3.
Tags lost during tagging
Tags shed prior to release
Tags are missed during release monitoring
4.
Tags are not detected during adult return monitoring
•
•
Cause
•
Monitoring fish using hand held readers
Prevention
•
Monitor fish using stationary monitor systems
•
Examples:
•
IDFG, Sawtooth and South Fork Traps:
•
10 to 30% of fish detected by the stationary monitor
system were missed by hand held readers.
•
NMFS at Lower Granite:
•
18% of the fish detected by stationary monitor systems
were missed by hand held readers.
Methods to Mitigate Tagging Effects
Examples of Adult monitor systems
The following series of slides show examples of adult
monitor systems used in the Columbia basin.
Methods to Mitigate Tagging Effects
Adult Monitor
Sawtooth Hatchery Trap
Stationary readers demonstrated 30% greater detection efficiency than
hand held readers.
Methods to Mitigate Tagging Effects
Adult Monitor
South Fork Salmon River Trap
Stationary readers demonstrated 10 to 12% greater detection
efficiency than hand held readers.
Methods to Mitigate Tagging Effects
Adult Monitor System
Dworshak NFH
Methods to Mitigate Tagging Effects
Adult Monitor System
Gumboot Weir on the Imnaha River
Methods to Mitigate Tagging Effects
Adult Monitor
Leavenworth NFH
Methods to Mitigate Tagging Effects
Adult Monitor
Ladder monitor at Priest Rapids
Methods to Mitigate Tagging Effects
Recommendations
I recommend:
1. Use properly trained personnel
2. Whenever possible, hold fish post tagging for wound
recovery (2 weeks)
3. Use 9mm tags when tagging fish < 65mm
4. Use only sharp needles
•
•
If using MUI – limit their use to < 10 times
Or, use SUI
5. Account for all tags
And/or
6. Use monitors during juvenile releases
•
Only use data from fish detected at time of release.
7. Monitor adult returns with stationary monitors
Comparing Preloaded Single Use Injectors to Multiple Use Injectors
Questions
Contact:
Scott McCutcheon or Ryan Richmond
At:
Biomark, Inc.
703 S. Americana Blvd.
Suite 150
Boise Idaho 83702
(208)275-0011
[email protected]
[email protected]
Comparing Preloaded Single Use Injectors to Multiple Use Injectors