MDC Resource Science Movement and Survival of Juvenile Walleye in the Current and Black Rivers s e t o N e c n e i c S Missouri Department of Conservation (MDC) 2007 VOLUME 2 NO. 17 Movement and Survival of Juvenile Walleye in the Current and Black Rivers By Dave Knuth, Riley Harper, Ryan Hostetler, and Michael Siepker SUMMARY Preliminary Results The “Black River” strain of walleye is stocked in both the Movement Current and Black Rivers to supplement wild fish • Walleye movement was greater and occurred earlier on populations. However, when conducting population the Current River than on the Black River (Figure 1). estimates, biologists have continually sampled very low • Initial movement was high in both rivers. After the 7th numbers of young week most walleye took residence in a particular area walleye. This study Objective: Determine movement and remained there for the duration of the study (Figure was implemented and survival of stocked walleye in 1). to track the a closed and open river system. • Most movement was upstream in the Current River, with movement and only one fish settling below the release site (moved into habitat selection of young walleye to better understand their Arkansas and then back into Missouri). movement patterns. This information will help biologists further refine stocking locations and standardize sampling • On the Black River, upstream movement was impeded methods to more effectively sample juvenile walleye in these by Clearwater Dam. rivers. • Tagged fish were normally found in deeper water near boulders or downed trees during the day; fish moved Project Details onto the shallow shoals at night to feed. • Radio telemetry was used to track movement of 15 walleye in each river (April thru August 2007) Survival and Growth • Locations of tagged fish were recorded each week • Total mortality was much lower in the Current River (Table 1). • Depth and habitat at each location was examined • Great blue herons were a major source of mortality in • Survival and habitat use at each location was confirmed the Black River; fish moved into shallow slack water with snorkeling below the dam at night allowing herons to effectively • Day vs. night movement was examined by tracking fish prey upon them. continuously for 24 hours • Fish recovered from the Current River were larger in size • Several tagged fish were recaptured at end of study to and in better condition than fish from the Black River. compare growth rates between river systems - TTaabbllee 11:: PPeerrcceenntt mmoorrttaalliittyy ooff wwaalllleeyyee 18000 ((NN == 1155)) iinn tthhee CCuurrrreenntt aanndd BBllaacckk RRiivveerrss m) = Black River nt ( 15000 Current River e m BBllaacckk CCuurrrreenntt ve 12000 o M -RReeaassoonn ffoorr LLoossss -RRiivveerr -RRiivveerr kly 9000 e e GGrreeaatt bblluuee hheerroonn 3333 %% 77 %% W e 6000 g a UUnnkknnoowwnn 1133 %% 1133 %% ver 3000 A 0 TToottaall MMoorrttaalliittyy 4466 %% 2200 %% 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Week Figure 1. Average weekly movement (meters) by juvenile walleye in the Current and Black Rivers. Error bars represent one standard error of the averages for each week. For more information, contact: Keywords: walleye, Current River, Black River, Missouri Department of Conservation movement, survival Forest Systems Field Station P.O. Box 138 West Plains, MO 65775 417/256-7161 ext 306 2007 VOLUME 2 NO. 17 [email protected]