In 2021, FISHBIO collaborated with Innovasea Systems Inc. to design and perform laboratory experiments to test the newest version of their smallest predation transmitter, the V3D As part of the study, largemouth bass (Micropterus salmoides) were fed a single rainbow trout (Oncorhynchus mykiss) tagged with a V3D tag each week for six weeks. Feeding trials were conducted at two temperature regimes (18.5 C and 23.5 C) to better understand the effect of temperature on tag performance. The tags activated faster in the warmer trials, with a median trigger time of 6 hours (compared to a median trigger time of 14 hours in the cooler trials), which was likely associated with faster metabolic processes. This study highlights the utility of this novel, commercially available technology, and provides context for future field efforts seeking to use these tags to directly measure the effect of predation in salmonid survival studies.

1. Cal Neva AFS Date: May 26, 2022
1
FISHBIO, Oakdale, California
2
Innovasea, Nova Scotia, Canada
Brian Slusher1
, Matt Peterson1
, Michael Hellmair1
, Jason Guignard1
,
and Dale Webber2
Preliminary Findings on the Efficacy and
Performance of the Innovasea V3D Predation Tag

2. V3D Transmitter Overview
• 307 kHz, 4x15mm, 0.33g
in air
• “Pings” every 5 seconds
• Polymer trigger
mechanism
• Reactive w/ stomach acids
• Untriggered vs Triggered
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xxxx-xxxx-1001
V3D Trigger Mechanism

3. 000-000-000

4. 000-000-000
Predator digests tag…

5. 000-000-000
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Predator digests tag…

6. Research Objectives
1. Assess false trigger rate in control tagged O. mykiss
2. Measure efficacy of corrosive trigger during a predation event
3. Quantify performance metrics on the novel transmitters’
corrosive trigger
4. Determine tag expulsion metrics at two temperature regimes
(cool, warm)

7. Methods
Experiment 1
False Trigger
Assessment
(Rainbow Trout)
Predator
(Largemouth Bass)
Feeding Trials
n=8 n=8
n=8
Experiment 2
Cool (18.5 o
C)
Warm (23.5 o
C)
n = 24
n=20

8. Methods
Tagged Control Group
• Rainbow trout (prey)
• n = 20
• Smolt size
• Held at 18.5 o
C, 21
days

9. Methods
Predator Feeding Trials
• Largemouth Bass x
Rainbow Trout
• 9 predators used
throughout
• 3 replicates per temp.
• 8 feedings/trial
• n = 24 feedings/temp.
• n = 48 feedings total

10. Methods
• Predator FL (mm), Weight (g) prior to each temperature trial
• Prey FL (mm), Weight (g) prior to tagging
• Surgically implanted transmitter
• Surgical equipment sanitized using betadine solution
• Closed using surgical adhesive (3M Vetbond)

11. Methods
• Predation, evacuation, and trigger events recorded
• 24 hr infrared video observation
• Welch’s t-test, Wilcoxon Rank-Sum test, Linear Regression

12. Research Objectives
1. Assess false trigger rate in control tagged O. mykiss
2. Measure efficacy of corrosive trigger during a predation event
3. Quantify performance metrics on the novel transmitters’
corrosive trigger
4. Determine tag expulsion metrics at two temperature regimes
(cool, warm)

13. Tag Triggers and Performance
General Summary
● No triggers in tagged control
○ Observed slight trigger erosion in control tags
● 100% trigger rate in all predator feeding trials
○ 96% of tags triggered within 24 hours
○ All tags triggered before evacuation from predators
○ Expulsion times varied widely between trials
○ Most tags were expelled within 200 hours after
consumption

14. Research Objectives
1. Assess false trigger rate in control tagged O. mykiss
2. Measure efficacy of corrosive trigger during a predation event
3. Quantify performance metrics on the novel transmitters’
corrosive trigger
4. Determine tag expulsion metrics at two temperature regimes
(cool, warm)

15. Faster Tag Triggers in Warm Treatment
Predator Feeding Trials
• Median cool; 14 h
(IQR: 11.50-18.25 h)
• Median warm; 6 hours
(IQR; 5.75-8.25 h)
• Statistical difference
Wilcoxon Rank-Sum; p < 0.001
20
10
0
Hours
Cool 18.5°C Warm 23.5°C

16. Individual Feeding Trial Results
Warm 23.5°C Cool 18.5°C

17. Weight Ratios Impact on Trigger Time
Predator- Prey Mass/
Trigger Time
• Cool trial
• P-value = 0.01*
• R2
= 0.26
• Warm trial
• P-value = 0.22

18. Research Objectives
1. Assess false trigger rate in control tagged O. mykiss
2. Measure efficacy of corrosive trigger during a predation event
3. Quantify performance metrics on the novel transmitters’
corrosive trigger
4. Determine tag expulsion metrics at two temperature regimes
(cool, warm)

19. Tag Retention and Expulsion
Predator V3D Retention
• 66.7% tag expulsion
• Regurgitation ~ 1 week
(median = 162.0 h)
• Defecation ~ 1 week
(median = 164.8 h)
• Range 38-600 h
• regurgitations >defecations
• Not all tags expelled
Warm 23.5°C Cool 18.5°C

20. Summary
• No false positives observed
• No false negatives observed
• Tag triggers all relatively similar
• Apparent temperature effect (metabolic influence on predator
digestion)
• Trigger times increased with predator/prey size relationship
• Predator tag retention ~ 1 week (* tested feeding rate,
temps.)

21. Looking forward
● Applications
○ A valuable tool to help answer predation effects in
acoustic tag and predator studies
● Additional studies
○ Different predators and/or prey
○ Colder temperatures
○ Field testing

22. Acknowledgements
Key Collaborators, and Funding: Innovasea
We thank the following people for their efforts, support, and
advice:
FISHBIO – Sara Dart, Nichole Dart, Ricky Biedenweg, Jim
Inman, Elizabeth Ramsay
Questions?
www.FISHBIO.com