Evaluation of Novel Methods of Incision Closure for Surgically Implanting Transmitters in Juvenile Salmonids

Each year, thousands of juvenile salmonids are surgically implanted with telemetry tags to evaluate their behavior and survival associated with migration through several hydroelectric facilities in the Snake and Columbia Rivers.  A basic assumption of telemetry studies is that tagged individuals accurately represent the population of inference.  However, the presence of a telemetry tag and the tagging process may influence the fish and violate this assumption.  Recently, various surgical methods have been studied to minimize the impacts of the tag on fish and to decrease tagging effects.  Currently, the most common method of incision closure is using sutures.  However, knots used to secure the suture material have been shown to irritate the skin and this can result in infection and inflammation.  Some preliminary use of a novel wound closure device (i.e., barbed “sutures”) for incision closure has been favorable, warranting further investigation.  This technology is potentially advantageous due to the lack of knotting necessary, reducing the potential for skin irritation.  Another possible advantage of using barbed sutures is the reduced time required for surgery, translating into reduced time that a fish is under anesthesia and handled by the surgeon, all beneficial for reducing the influence of the tagging process on the fish.  The objective of this study was to outline and test several different methods of incision closure with barbed sutures, in comparison with our traditional suturing technique.  Incision closure techniques were also exposed to challenges, consisting of swimming performance tests and exposure to simulated turbine passage in a laboratory.  The results of this study are important for improving surgery techniques and reducing any differences in survival or behavior that may exist between tagged fish and the population at large.