Efficacy of Single-Suture Vs. Double-Suture Incision Closures in Seaward-Migrating Juvenile Chinook Salmon Implanted with Jsats Acoustic Transmitters

Reductions in the size of acoustic transmitters implanted in migrating juvenile salmonids have resulted in the ability to make a shorter incision – one that may warrant only a single suture for closure.  However, it is not known whether a single suture will sufficiently hold the incision closed, particularly when outward pressure is placed on the surgical site – for example, when seaward-migrating salmon experience pressure changes associated with passage at hydroelectric dams.  The objective of this research was to evaluate the effectiveness of single-suture incision closures on juvenile Chinook salmon (Oncorhynchus tshawytscha).  Juvenile Chinook salmon were surgically implanted with a 2012 Juvenile Salmon Acoustic Telemetry System (JSATS) transmitter (0.30g) and a passive integrated transponder tag (0.10 g); incisions were closed with either one suture or two sutures.  Surgically implanted fish were held for 14 days to monitor mortality, tag retention, and tissue response.  In a separate experiment, surgically implanted fish were exposed to simulated turbine passage, and then examined for expulsion of transmitters, incision tearing, expulsion of viscera through the incision, and mortal injury.  Overall, mortality rates were low throughout the study, and no tags were expelled during the holding study or due to exposure to simulated turbine passage.  The results of this study suggest that using a single suture is sufficient to close incisions on juvenile salmonids implanted with the 0.30-g 2012 JSATS transmitters.