Juvenile Chinook Salmon Survival When Exposed to Simulated Dam Passage after Being Implanted with a New Microacoustic Transmitter. (16th July 2018)

• Record Type: Journal Article
• Authors: Geist, David R.; Liss, Stephanie A.; Harnish, Ryan A.; Deters, Katherine A.; Brown, Richard S.; Deng, Zhiqun Daniel; Martinez, Jayson J.; Mueller, Robert P.; Stephenson, John R.
• Is Part Of: North American journal of fisheries management. Volume 38:Number 4(2018)
• Page Start: 940
• Page End: 952
• Publication Date: 2018-07-16
• Subjects: Fishery management -- United States -- Periodicals; 333.956097305
• DOI: 10.1002/nafm.10198
• Languages: English
• ISSNs: 0275-5947

Abstract

Abstract: The current minimum size for tagging Chinook Salmon Oncorhynchus tshawytscha in the Columbia River basin with acoustic transmitters is ≥95 mm FL. Using a newly developed cylindrical microacoustic transmitter (AT; weight in air, 0.22 g), our objective was to evaluate the minimum size of Chinook Salmon for tagging. We measured Chinook Salmon survival and the retention of transmitters and viscera after their exposure to rapid decompression ( n = 399) or shear forces ( n = 308) that simulated dam passage. Fish (69–107 mm FL) were implanted with an AT (AT‐only) or an AT and a PIT tag (weight in air = 0.10 g; AT+PIT) through a 3‐mm incision with no sutures, or did not receive an incision or tag (untagged control fish). Tag burden averaged 2.9% (range, 1.4–6.2%) in the AT‐only group and 4.2% (range, 2.0–7.9%) in the AT+PIT group. Proportional survival and the retention of transmitters and viscera was significantly lower for AT‐only (0.70) and AT+PIT (0.54) fish than for untagged fish (0.85) after their exposure to pressure change scenarios. No transmitters were fully expelled, but 9% of AT‐only and 22% of AT+PIT salmon had protruding viscera or transmitters. Following shear exposure, the proportional survival and retention of transmitters and viscera was significantly lower for AT‐only (0.70) and AT+PIT (0.61) fish than for untagged fish (0.98). Visceral expulsion was attributed to 90% and 93% of mortal injuries in AT‐only and AT+PIT fish, respectively. In both tests the tagged fish suffered more mortal injuries and death than did untagged fish over the range of tag burdens tested, and no tag burden threshold below which tagged and untagged fish performed similarly was found. As such, a generalized linear model that included tag burden as a predictor variable provided the best fit to the survival data. Without a significant tag burden threshold, we recommend the minimum size for tagging Chinook Salmon using the transmitters and PIT tags evaluated, applied with a 3‐mm incision and no sutures, should remain at 95 mm FL.