Modification of a Passive Gear to Sample Paddlefish Eggs in Sandbed Spawning Reaches of the Lower Yellowstone River

Abstract

A passive sampling technique was developed to collect eggs and confirm potential spawning sites for paddlefish Polyodon spathula in sandbed reaches of the lower Yellowstone River, Montana and North Dakota. In 2000, egg collectors modeled after the mats used in sturgeon research proved difficult to retrieve from the riverbed and did not collect eggs. In 2001 and 2002, tubular egg collectors designed to remain suspended off the bottom were successfully retrieved 97% of the time and collected 130 acipenseriform eggs along suspected spawning sites (99% of differentiable eggs were genetically confirmed as paddlefish). In both years, eggs were typically collected in mid‐June after peak periods of Yellowstone River discharge and at river temperatures of 15–22°C. During collection periods in 2001 and 2002, 20% and 45% of retrieved tubes, respectively, had at least one egg, and 84% of all eggs were found on tubes retrieved from the channel thalweg. Although eggs were spatially distributed in a clumped manner at sample sites, the mean number of eggs per tube was low (<4), suggesting either collector inefficiency, the inability to deploy collectors in close proximity to concentrations of spawning paddlefish, or the widespread distribution of spawning effort over the lower Yellowstone River.

Sturgeon and Paddlefish Migration: Evidence to Support the Need for Interjurisdictional Management

“…Because Lock and Dam 19 was an upstream impediment to movement and the VR2W array did not extend downstream of Caruthersville, Missouri, or more than a few kilometers into major tributaries, movement was likely underestimated. Regardless of the limita tions of the stationary receiver array's spatial extent and the in terrupted connectivity due to dams, we determined that all four species were capable of long range movements (>300 km) and that these seasonal movements were cued by the changing riv er stages and water temperatures, similar to patterns observed in other studies (Rochard et al 1990;Beamesderfer and Farr 1997;Rusak and Mosindy 1997;Billard and Lecointre 2001;Paukert and Fisher 2001;Firehammer et al 2006;O'Keefe et al 2007;DeLonay et al 2009). Migratory fish of all species often exhibited patterns with seasonal movement to specific ar eas followed by movement back to the core areas; nomadic fish showed more varied movements out of the core areas, occur ring at different times of the year and to multiple areas outside the core home range.…”

“…; Beamesderfer and Farr ; Rusak and Mosindy ; Billard and Lecointre ; Paukert and Fisher ; Firehammer et al. ; O'Keefe et al. ; DeLonay et al.…”

“…A one way ANOVA was used to determine whether the mean movement of each species differed among seasons, and observed differences between means were evalu ated by using Tukey's honestly significant difference test, with significance assessed at P < 0.05. Because movements of stur geon and Paddlefish are thought to be prompted by season al variation in water levels and water temperatures (Rochard et al 1990;Beamesderfer and Farr 1997;Firehammer et al 2006;O'Keefe et al 2007;DeLonay et al 2009), Akaike's in formation criterion corrected for small sample sizes (AIC c ) was used to identify the model(s) that best described the cue for Lake Sturgeon, Pallid Sturgeon, Shovelnose Sturgeon, and Paddlefish movement patterns. Specifically, we com pared single variable models (i.e., change in river stage and mean seasonal water temperature) and the interactive effects of these two variables (mean seasonal water temperature × change in river stage).…”

Fisheries Volume 44 Number 4 April 2019

“…Because Lock and Dam 19 was an upstream impediment to movement and the VR2W array did not extend downstream of Caruthersville, Missouri, or more than a few kilometers into major tributaries, movement was likely underestimated. Regardless of the limitations of the stationary receiver array ' s spatial extent and the interrupted connectivity due to dams, we determined that all four species were capable of long-range movements (>300 km) and that these seasonal movements were cued by the changing river stages and water temperatures, similar to patterns observed in other studies (Rochard et al 1990 ;Beamesderfer and Farr 1997 ;Rusak and Mosindy 1997 ;Billard and Lecointre 2001 ;Paukert and Fisher 2001 ;Firehammer et al 2006 ;O ' Keefe et al 2007 ;DeLonay et al 2009 ). Migratory fi sh of all species often exhibited patterns with seasonal movement to specifi c areas followed by movement back to the core areas; nomadic fi sh showed more varied movements out of the core areas, occurring at different times of the year and to multiple areas outside the core home range.…”

“…A one-way ANOVA was used to determine whether the mean movement of each species differed among seasons, and observed differences between means were evaluated by using Tukey ' s honestly signifi cant difference test, with signifi cance assessed at P < 0.05. Because movements of sturgeon and Paddlefi sh are thought to be prompted by seasonal variation in water levels and water temperatures (Rochard et al 1990 ;Beamesderfer and Farr 1997 ;Firehammer et al 2006 ;O ' Keefe et al 2007 ;DeLonay et al 2009 ), Akaike ' s information criterion corrected for small sample sizes (AIC c ) was used to identify the model(s) that best described the cue for Lake Sturgeon, Pallid Sturgeon, Shovelnose Sturgeon, and Paddlefi sh movement patterns. Specifi cally, we compared single-variable models (i.e., change in river stage and mean seasonal water temperature) and the interactive effects of these two variables (mean seasonal water temperature × change in river stage).…”