Gene R. Wilde

Tournament-associated Mortality in Black Bass

Abstract I compiled estimates of tournament-associated mortality in black basses (Micropterus spp.) for 130 tournaments held between 1972 and 1996. Initial mortality decreased significantly (P < 0.0001) between the 1970s (19.5%), and the 1980s (6.6%) and 1990s (6.5%). I found no difference in initial mortality (P = 0.9885) between the 1980s and 1990s. Delayed mortality was 10.4% in the 1970s based on limited data. Estimates of delayed and total mortality for the 1980s (20.9% and 26.2%, respectively) and 1990s (23.3% and 28.3%, respectively) were not significantly different (P ≥ 0.7222). Thus, no evidence exists of a decline in initial, delayed, or total mortality since at least the mid-1980s. This suggests that recommendations made by previous researchers for reducing tournament-associated mortality were disregarded or ineffective. Meta-analysis of correlations shows a strong positive relationship between water temperature, and initial (r = 0.51 ± 0.00) and delayed mortality (r = 0.36 ± 0.000). There was ...

Largemouth Bass Fishery Responses to Length Limits

Abstract I compiled quantitative information from published and unpublished studies that evaluated largemouth bass fishery responses to minimum-length and slot-length limits. My data set includes results from 91 evaluations conducted on 88 lakes located across the United States. Forty-nine evaluations were of minimum-length limits, and 42 were of slot-length limits. The most commonly evaluated regulations were 12- (n = 13) and 14-in (n = 14) minimum-length limits and 12- to 15-in slot-length limits (n = 23). I constructed and tested six hypotheses about largemouth bass fishery responses to minimum-length and slot-length limits. Minimum-length limits increased largemouth bass population size when all minimum-length limits were included (P = 0.034) but not when 12-in minimum-length limits were excluded. Minimum-length limits failed to increase the proportion of larger fish (proportional stock density, relative stock density) and the number and weight of fish harvested by anglers, but did increase angler cat...

Changes in the Canadian River fish assemblage associated with reservoir construction

ABSTRACT The fish assemblage of the Canadian River in Texas historically was dominated by Hybognathus placitus and Notropis girardi. These species represented > 90% of fishes collected from the Canadian River in 1954–1955. Construction of two reservoirs on the Canadian River in the 1960s (Ute Reservoir, New Mexico, 1962; Lake Meredith, Texas, 1965) altered hydrologic conditions in the river and affected the fish assemblage. Downstream from Ute Reservoir, mean annual discharge decreased by about 38% after impoundment, but H. placitus, N. girardi, and other mainstem species still dominate the assemblage. Downstream from Lake Meredith, mean annual discharge decreased by 76% and the historic mainstem fish assemblage has been almost completely replaced by species that formerly were restricted to tributary streams. The magnitude of post-impoundment changes in the fish assemblage of the Canadian River appears to be related to the degree that discharge has declined, especially during the spawning season.

Effects of Turbidity on Prey Consumption by Prairie Stream Fishes

Abstract Reduced suspended-sediment loads (i.e., turbidity) in many Midwestern prairie rivers have been hypothesized as contributing to the replacement of species that historically occupied highly turbid main-channel habitats by visually feeding species that are competitively superior in less-turbid waters. We examined the relationship between prey consumption and turbidity for six fish species from the Canadian River (New Mexico, Oklahoma, and Texas) and found experimental support for this hypothesis. Among species adapted to highly turbid main-channel habitats, we found that prey consumption by the peppered chub Macrhybopsis tetranema and flathead chub Platygobio gracilis was unaffected (P > 0.12) by elevated turbidity, whereas prey consumption by the Arkansas River shiner Notropis girardi was reduced (P < 0.01). Among species characteristic of less-turbid habitats, prey consumption by the emerald shiner N. atherinoides, red shiner Cyprinella lutrensis, and sand shiner N. stramineus was reduced (P < 0.0...

Temperature, Dissolved Oxygen, and Salinity Tolerances of Five Prairie Stream Fishes and Their Role in Explaining Fish Assemblage Patterns

Abstract We compared the maximum temperature, maximum salinity, and minimum dissolved oxygen tolerances of two cyprinodontids and three cyprinids to identify the abiotic factors that determine assemblage structure in drying streambed pools. Red River pupfish Cyprinodon rubrofluviatilis, plains killifish Fundulus zebrinus, plains minnow Hybognathus placitus, smalleye shiner Notropis buccula, and sharpnose shiner N. oxyrhynchus all have high thermal, low dissolved oxygen, and high salinity tolerances. Cyprinodontids were able to tolerate temperatures between 39°C and 42°C, salinities up to 40‰, and dissolved oxygen concentrations as low as 0.95 mg/L, whereas cyprinids were tolerant of temperatures between 37°C and 41°C, salinities up to 14‰, and dissolved oxygen concentrations as low as 2.1 mg/L. Our laboratory results provide compelling evidence that the greater salinity tolerances of cyprinodontids can explain temporal changes in fish assemblages in evaporating streambed pools and may in part explain the ...

Influence of Stream Discharge on Reproductive Success of a Prairie Stream Fish Assemblage

Abstract We studied the relationship between stream discharge and reproductive success for five members of a prairie stream fish assemblage. Based on information obtained from the literature, we constructed seven models relating stream discharge to successful reproduction. To assess the utility of our models, we collected larval and juvenile Arkansas River shiners Notropis girardi, peppered chub Macrhybopsis tetranema, plains minnow Hybognathus placitus, flathead chub Platygobio gracilis, and red shiners Cyprinella lutrensis from the Canadian River, Texas, during 2000–2001. We removed otoliths and counted daily growth increments to determine ages. Models were parameterized by use of age and discharge data. Models were evaluated with the Akaike information criterion likelihood statistic to assess which model(s) best described reproductive success for each species. Of the seven models evaluated, the best overall model predicted that reproductive success was uniform across dates when discharge was present in...

Differences in Attitudes, Fishing Motives, and Demographic Characteristics between Tournament and Nontournament Black Bass Anglers in Texas

Abstract We tested for differences between tournament and nontournament black bass anglers in their motives for fishing, attitudes, and demographic characteristics. Fewer than one-fifth (17.8%) of black bass anglers in Texas participated in black bass fishing tournaments. Tournament anglers were younger, fished more frequently, and were more likely to be male and belong to fishing clubs than nontournament anglers. Tournament anglers viewed themselves as more skilled than nontournament anglers. Also, tournament anglers differed significantly from nontournament anglers on each of 7 catch-related motives studied and on 2 of 10 noncatch motives (“experience adventure and excitement” and “experience new and different things”). Tournament anglers differed significantly from nontournament anglers on 11 of 15 attitudinal statements regarding catch. Our results were generally consistent with those from two previous studies of saltwater tournament anglers. Differences between tournament and nontournament anglers al...

Does venting promote survival of released fish

Abstract Fishes captured and brought to the surface by commercial and recreational fishers may suffer a variety of injuries that collectively are referred to as barotrauma. To relieve barotrauma symptoms, particularly those associated with an expanded swim bladder, some anglers deflate, or vent, the swim bladder (or body cavity when the swim bladder has ruptured) of fishes before releasing them. I compiled 17 studies that assessed the potential benefits of venting in 21 fish species and 1 composite group. These studies provided 39 sample estimates that compare survival (N = 18) and recapture rates (N = 21) of vented and unvented fish. I used relative risk to summarize results of individual studies, which allowed me to combine results from experimental and capture-recapture studies. Overall, there was little evidence that venting benefited fish survival. Venting was equally ineffective for freshwater and marine fishes and its efficacy was unaffected based on whether venting was performed by fishery biologi...

Bait and temperature effects on striped bass hooking mortality in freshwater.

Abstract We compiled results of published and unpublished studies of hooking mortality for striped bass Morone saxatilis that were conducted in freshwater. We used logistic regression to model the effects of bait type and water temperature on mortality of 1,275 striped bass. Both factors were significant predictors (P < 0.0001) of hooking mortality. Striped bass hooking mortality was greater in fish captured with natural baits than with artificial baits and was positively related to water temperature. These results allow prediction of striped bass hooking mortality based on bait type and water temperature. For a smaller data set that also included total lengths of fish captured, we used logistic regression to model hooking mortality as a function of bait type, water temperature, and total length for 549 fish. There were significant bait and temperature effects (P < 0.0001), but there was no evidence (P = 0.2994) that striped bass hooking mortality was size dependent.

Effects of Streamflow and Intermittency on the Reproductive Success of Two Broadcast-spawning Cyprinid Fishes

Abstract We studied daily growth-increment formation in the otoliths of early life history stages of Sharpnose Shiner, Notropis oxyrhynchus, and Smalleye Shiner, Notropis buccula, in the Brazos River, Texas to investigate the influence of streamflow and intermittency on the production of young. Both species successfully produced offspring throughout a four- to five-month period. Successful reproduction occurred over a longer period in 2004 than in 2003. The results of our study revealed that recruitment by N. oxyrhynchus and N. buccula populations in the Brazos River, Texas are related to streamflow in two principal ways. First, the greatest proportion of young-of-year produced during the reproductive season is associated with elevated streamflow events. Second, no young-of-year are successfully produced during periods of intermittency when the river is not flowing. Our results suggest that the focus of conservation efforts, which to date have primarily concentrated on creating proper streamflow conditions for spawning, should also be focused toward ensuring proper conditions for survival of ova and young larvae.