Survival of Gizzard Shad from Surgical Implantation of Acoustic Transmitters

Following the Missouri River flood of 2011, habitat alterations disconnected known Gizzard Shad spawning and winter-use habitats from Lake Sharpe in central South Dakota. Thus, South Dakota Game, Fish and Parks started a telemetry project to track movements and habitat use of this important species. This is the first time that Gizzard Shad have been implanted with acoustic transmitters so a general understanding of post-surgery survival is needed. We examined post-surgery survival of Gizzard Shad implanted with acoustic transmitters in April and May of 2014. Twenty-nine fish were surgically implanted with VEMCO V13 dummy transmitters while 20 were considered “controls” and no surgery performed. Fish were placed in 4m x 4m x 2m floating net pens. At 3 days post-surgery, total survival was 55% (16-April), 85% (22-April) and 100% (19-May). Approximately 30% of mortalities were “control” fish were no surgery took place. Increasing survival corresponded to decreased surgery times and increasing water temperature at the time of capture and holding. This study will be expanded spring of 2015 but initial results suggest decreasing surgery times and collecting and holding fish at warmer water temperatures increase initial survival of implanted Gizzard Shad.