Stock Identification of Walleye via Otolith Chemistry in the Eleven Point River, Arkansas

Abstract

Otolith chemistry was used to identify two hatchery stocks (Missouri State Hatchery and Arkansas Federal Hatchery) and a possible wild stock of walleye Sander vitreus in the Eleven Point River in northeastern Arkansas. Previous population estimates by the Arkansas Game and Fish Commission using traditional tag-and-release techniques failed to identify the relative survival of these stocks or their spatial and temporal persistence. Using chemical analysis of otoliths combined with a priori knowledge of the hatchery source, we identified otolith chemical signatures unique to each stock. We collected 51 walleyes that bore the physical tag of a known hatchery, along with 46 nontagged walleyes. The efficacy of otolith chemistry in classifying walleyes to known stocks was assessed by analyzing unknowns via discriminant function analysis. Fish were classified to their respective stocks based on otolith chemistry, and 92% were assigned to known stocks. Fishery managers can assess the persistence of individual stocks and the success rates of stocking practices in riverine systems using this technique.

Sources of Nonnative Centrarchids in the Upper Colorado River Revealed by Stable Isotope and Microchemical Analyses of Otoliths

“…Our findings corroborate those of a few other recent studies that demonstrated that otolith microchemistry and isotopic analysis represent powerful techniques for retrospectively describing the environmental history of fishes that reside solely in freshwaters, including lakes (Joukhadar et al 2002;Brazner et al 2004;Munro et al 2005;Ludsin et al 2006), streams (Wells et al 2003), and small rivers (Bickford and Hannigan 2005). The results of this study demonstrate that otolith elemental and isotopic assays can also be applied to gain valuable insight into fish movement between large rivers and associated lentic floodplain habitats that would be difficult to obtain by other means.…”

“…Strontium concentrations were normalized to Ca concentration based on the consideration of calcium as a pseudointernal standard (Bickford and Hannigan 2005;Ludsin et al 2006); data are reported as Sr:Ca ratios (mmol/mol) for consistency with published otolith microchemistry literature and reflect differences in Sr concentration among samples. Mean limit of detection for 88 Sr was 0.09 lg/g; otolith 88 Sr concentrations ranged from 494 to 6,952 lg/g.…”

“…The significant positive relationship between otolith Sr:Ca ratio and salinity of ponds in our study area is probably the result 1266 of higher Sr concentrations in waters with elevated salinities; concentrations of both Sr and major salinityinfluencing ions are increased by evapotranspiration and influx of irrigation-derived water that has leached elements from Mancos shale underlying much of our study area (Gerner et al 2006). Otolith Sr concentration reflects that of the water in which fish live (Howland et al 2001;Zimmerman 2005); thus, our otolith Sr:Ca data are indicative of differences in Sr concentration among fish (and the environments in which they lived) because we treated Ca as an internal standard (Bickford and Hannigan 2005;Ludsin et al 2006). Strontium : calcium ratios for centrarchids of unknown history collected in riverine habitats were calculated based on integrations over entire laser transects when no evidence of fish movement from high-salinity to low-salinity environments was present (initial Sr:Ca 2.09 mmol/mol; Sr:Ca varied by ,0.5 mmol/mol from beginning to end of transect; Figure 2A).…”

Otolith trace element and stable isotopic compositions differentiate fishes from the Middle Mississippi River, its tributaries, and floodplain lakes

“…Otolith elemental concentrations were calculated from integrations over the final 10 s of laser ablation transects, as the outer portion of the otolith reflects a fish's most recent environmental history. Trace element concentrations were normalized to calcium (Ca) concentration based on the consideration of Ca as a pseudointernal standard (Bickford & Hannigan, 2005;Ludsin et al, 2006); data are reported as element:Ca ratios (mmol/mol).…”

Matching Watershed and Otolith Chemistry to Establish Natal Origin of an Endangered Desert Lake Sucker

“…One of the most critical components to recovery of an endangered fish is that reproduction results in successful recruitment of young into the adult spawning population (NCR 1995;Budy and Schaller 2007 (Campana 1999, Elsdon et al 2008, and along with daily accretions of aragonite, trace elements with a similar charge to calcium are substituted for calcium during crystallization (Bickford and Hannigan 2005). Trace elements are incorporated into the crystalline matrix in proportion to their abundance in the ambient water (Elsdon et al 2008;Pangle et al 2010).…”