Gender‐ and Year‐Specific Mortality of Yellow Perch with Evidence of Compensatory Mortality

Abstract

Gender‐ and year‐specific survival (S) of yellow perch Perca flavescens, the tag recovery rate (f, i.e., the joint probability of a fish being harvested, the tag being recognized, and the tag being reported, corrected for tag loss and tagging mortality), and natural mortality (v) were estimated using Brownie tag recovery models. These models were constructed from 4 years of tagging and angler tag recovery data to determine whether mortality is additive or compensatory for the high‐ and low‐quality yellow perch fishery types commonly found in eastern South Dakota glacial lakes. Natural mortality comprised the majority of total annual mortality, S was constant among years, and f was female‐biased for both study populations. Survival and f did not vary among years for the low‐quality population, providing inconclusive evidence of mortality function. However, a constant S coupled with annual changes in f and v (i.e., when harvest mortality increased, natural mortality decreased) suggests that mortality was compensatory for the high‐quality population. Received October 13, 2010; accepted March 3, 2011

Quantifying inter-population variability in yellow perch sexual size dimorphism

“…Statistics of linear regression analyses comparing the differences in predicted lengthat-age-3 of female and male yellow perch (female length -male length) to variables of lake productivity, lake morphometry, and perch population dynamics, along with observed ranges of the listed variables. (Schoenebeck and Brown 2011). Neither Lake Winnibigoshish nor the two South Dakota lakes had an agency-imposed minimum length limit so femalebiased harvest likely occurred because of an angler self-imposed minimum length limit coupled with populations that exhibited female-biased SSD.…”

“…Isermann et al (2005) documented that the mean minimum total length of yellow perch harvested in a South Dakota lake was 212 mm, indicating anglers set self-imposed minimum length limits without regard to mandated limits. The combination of female-biased SSD with size-selective angler behavior creates the potential for female-biased harvest (Schoenebeck and Brown 2011). In Lake Winnibigoshish, Minnesota, the yellow perch population exhibited female-biased SSD and Isermann (2007) documented that female yellow perch comprised 73-79% of the total harvest.…”

“…Yellow perch from Ohio were sampled using experimental monofilament gillnets (1.8 m  54.9 m) composed of 3 equal-sized 18.3 m complements of 19, 25, and 32 mm mesh (bar measure) fished during the spring. Yellow perch from South Dakota were sampled using experimental monofilament gillnets (1.8 m  38.0 m) composed of 5 equal-sized 7.6 m complements of 13,19,25,38, and 51 mm mesh (bar measure) fished during July (Schoenebeck and Brown 2011). Yellow perch from Alberta were sampled using experimental monofilament gillnets (1.8 m  61.0 m) composed of 8 equal-sized 7.6 m complements of 25,38,51,64,76,102,127, and 152 mm mesh (bar measure) fished during September and October (Morgan 2002).…”

“…For example, female-biased SSD resulted in female-biased harvest for two South Dakota yellow perch populations (Schoenebeck and Brown 2011). Moreover, female-biased SSD likely resulted in the female-biased commercial harvest of yellow perch in southern Lake Michigan and may have contributed to the decline of that fishery .…”

“…Moreover, female-biased SSD likely resulted in the female-biased commercial harvest of yellow perch in southern Lake Michigan and may have contributed to the decline of that fishery . Gender-selective harvest has been seen in a variety of fisheries and can lead to uneven harvest mortality between genders (Scarnecchia et al 1989;Hoenig and Hewitt 2005;Schoenebeck and Brown 2011) and may potentially reduce reproductive output (Heyer et al 2001;Lauer et al 2005) or lower genetic diversity. Lower allelic diversity in walleye (Sander vitreus) has recently been associated with populations that have biased sex ratios (Waterhouse 2011).…”