Factors Influencing Brown Trout Reproductive Success in Ozark Tailwater Rivers

Abstract

The reproductive success of brown trout Salmo trutta in White River, Arkansas, tailwater reaches is highly variable, resulting in the need for supplemental stocking. A better understanding of the physical and biotic factors affecting reproduction and survival would enhance the contribution of wild fish. We compared fecundity, reproductive chronology, physical habitat, water quality, trout density, food availability, diet, predation, and competitive interactions among four tailwater reaches to identify factors influencing brown trout reproductive success. The fecundity and condition factor of prespawning brown trout were significantly lower at Beaver Tailwater, a reach known for reproductive failure, than at other sites, among which no differences were found. Brown trout spawning was observed from 11 October to 23 November 1996, and juvenile emergence began on 28 February 1997. Significant among‐site differences were detected for spawning and juvenile microhabitat variables, but the variables fell within or near suitable or optimal ranges reported in the literature for this species. Age‐0 brown trout density differed significantly among sites, but growth and condition did not. Predation by Ozark sculpin Cottus hypselurus on trout eggs or age‐0 trout of any species was not observed among the 418 stomachs examined. Ozark sculpin density and diet overlap with age‐0 brown trout were highest and invertebrate food availability and water fertility were lowest at Beaver Tailwater relative to the other reaches. Our findings indicate that differences in trophic conditions occur among tailwater reaches, and a lower system productive capacity was identified at Beaver Tailwater. We suggest that management efforts include refining the multispecies trout stocking regime to improve production efficiency, enhancing flow regulation, and increasing habitat complexity to increase invertebrate and fish productivity. Such efforts may lead to improved natural reproduction and the increased abundance and quality of wild trout in this system and other regulated rivers.

Seasonal feeding selectivity of brown trout Salmo trutta in five groundwater-dominated streams

“…The positive selection by brown trout for Gammarus and Physella, and avoidance of Dipterans, is consistent with studies in other regions (Cada, Loar, Sale 1987;Pender and Kwak 2002;Fochetti et al 2003;Johnson et al 2007;Sanchez-Hernandez et al 2011), although Pender and Kwak (2002) found positive selection for Chironomidae among age-0 trout. Physella did not constitute a high proportion of either prey availability or prey consumed, but brown trout consistently favored Physella in the benthos and drift.…”

The reproductive traits of brown trout (Salmo trutta fario L.) from the Yadong River, Tibet

“…As has been documented in the literature on this subject, the spawning time in brown trout occurs during the autumn-winter period (Hobbs 1937;Needham et al 1945;Horton 1961;Thomas 1964;Hopkins 1970). Some more recent reports also indicate similar spawning periodicity (Pender and Kwak 2002;Alp et al 2003;Estay et al 2004;Rubin et al 2005;Arslan and Aras 2007).…”

“…The reproductive traits of brown trout have been described in geographically different populations previously (Hegge et al 1991;Crisp 1994;Sorensen et al 1995;Garcia-Vazquez et al 2001;Nicola and Almodovar 2002;Pender and Kwak 2002;Alp et al 2003;Estay et al 2004;Olsen and Vollestad 2005;Rubin et al 2005;Arslan and Aras 2007).…”

Effect of Culture Conditions on Reproductive Traits of Brown Trout Salmo Trutta L.

“…The age at which the farmed fish matured did not differ from natural conditions (TAUBE, 1976;LUSK, 1968a). Reproduction of the farmed fish annually occurred in November, which was the usual period under conditions corresponding to this latitude (PENDER and KWAK, 2002). The reproductive period of the farmed fish corresponded with that of the reference wild population.…”