1. New PIT tags - Collision analysis - Approval Process Joseph Zydlewski, Todd Gilmore USFSW – CRFPO, Vancouver, WA Sean Casey Digital Angel/ Destron Fearing Gayle Zydlewski USFWS-AFTC

2. Increasing read range Antenna Read Distance PIT Transceiver Improvements to the transceiver and antenna Use of larger tag (e.g. the 23 mm tags currently available) Improvement to the tag (ongoing improvements to the 12 mm tag)

3. Benefits of increased read range Higher efficiency in antennas Ability to use larger antenna Is there a problem ?

4. RISK OF COLLISION How big is the risk? With some 2,000,000 fish released above dams, there is concern as read ranges increase.

5. Solution- Assess risk to a possible problem spot Calculate risks of data loss due to collisions

6. Case Study - McNary Juvenile By-pass Data from the McNary bypass was queried for 9 days that spanned a range from high “tag returns” to “low tag returns” RecordsTagsBeginEndDuration Records/ hFish/h 4-May41925104685/4/02 0:005/5/02 23:5947:59:04873.72218.15 9-May41263105695/8/02 0:005/9/02 23:5947:59:54859.67220.19 19-May65536168135/18/02 0:005/21/02 23:5995:59:48682.69175.14 25-May48261125565/25/02 0:005/27/02 0:0047:59:361005.58261.62 4-Jun887522636/3/02 0:006/5/02 5:1053:10:36166.9042.56 25-Jun725018736/25/02 0:006/26/02 23:5947:58:53151.1039.04 10-Jul43201109907/9/02 0:007/12/02 23:5795:57:36450.20114.53 25-Jul17904467/24/02 0:377/25/02 23:4547:07:3337.989.46 16-Aug7101808/15/02 0:268/16/02 23:2647:00:0515.113.83

7. Juvenile by-pass d 1 = 10.21m d 2 = 6.32m d 3 = 10.21m Coil 1Coil 2Coil 3Coil 4

8. For a given fish passing the coils, information can be extracted Coil 1Coil 2Coil 3Coil 4 Average speed Reads per coil 210 1

9. Calculations For multiple reads – an average time was calculated (a single time point was used) For a missed read… –If reads “stradle” the miss, average speed was used to calculate time of passing (e.g. speed from coil 1 to coil 3 to calculate time at coil 2) –If reads were “on the ends” (coils 1 or 4) but multiple coils picked up the fish, times were extrapolated using speeds between coils –If a single coil picked up the fish, group average speeds were used to calculate time passing other antennas

10. Proximity Calculations So for each fish that was read on at least one antenna, three pieces of information were now available for each antenna –Was the fish read ? –Time passing the antenna –Speed NOW calculate, for each fish, what the closest fish (temporally) was to a given fish !

11. 17 percent of the tags are read at <1 second interval No significant decrease in the proportion of tags read in this bin – range from 81-93%, average 88%, 1 sec bin is 82% Reads Fails This resolution is not fine enough to demonstrate collisions >10

12. At this resolution (1 second), fish can range from being 0-290 cm apart (based on average speeds) Approximately 17 percent of read fish fall into this category Assume –Even temporal distribution of fish between 0 and 1 second –B- tag interferes with another B tag at 15 cm (approx 6 inches)

13. Increased incidence of collisions influenced by: Tag strength (presented as multiples of B-tag read range) –Suppose a new tag has read range 5 times that of a B-tag Proportion of “high strength” tags in the system

14. For example, if 50% of all tags were 5x as strong, the collision rate would be blamed for 2.7% loss (per coil) vs 0.8% (using just B-tags)

15. With four coils – what percent of total misses are there? Assume a low coil efficiency (without collisions) of 80% With B-tags, one would expect an average of 79.2% efficiency With 50% B-tags and 50 % “new” tags, one would expect a 77.3% efficiency No collisions = 0.16% B-tag collisions=0.18% 50/50 B-tag/new tag= 0.27%

16. How about the worst of the worst scenerio? A tag that has a read range 20X that of the B tag Used as the standard in the basin (100%) The loss at McNary? 1.4% (Recall that 0.2 is from antenna efficiency)

17. Conclusions Use of tags with increased read range are likely to have an imperceptible effect on read efficiency – but should be considered! Collisions do occur, regardless of the tag being used and efforts to reduce these should be taken where convenient –e.g. “clamping” the field

18. PIT Tag Steering Committee Role Encourage and take measures to reduce collisions Support the use of increased read range tags in Columbia basin Delineate and implement tests to estimate impact of increased read range tags on “tag of choice”

19. Tag coating Reasons for new coating –Reduce size of coat –Increase “room” for tag coil Several potential synthetic polymers Thicker wall Thinner wall

20. Major Questions Tag retention Survival Growth Smolt Physiology Adult return rates Use in wild fish Short term Long term

21. Evaluation of growth in Chinook juveniles Teflon Epoxy Polyethylene Glass Control 9 replicate tanks –27 fish per group (5 groups/tank) Monitor –Daily survival –Daily tag loss –Bi-weekly inventory for growth, retention

22. GLASS PET EPOXY TEFLON

23. *

24. Ultrasound image of PIT tag in juvenile Chinook

26. Preliminary Summary No apparent effect of polyethylene, epoxy, and glass on growth (by 28 days) Teflon effect on growth may be due to encapsulation shape

27. FDA approved materials for implantation Assess effects on growth, survival and retention Wide scale implementation on hatchery fish with monitoring Routine use in hatchery and wild fish Approach to new materials