Muskellunge Management: Fifty Years of Cooperation Among Anglers, Scientists, and Fisheries Biologists

<em>Abstract</em>.—Tiger muskellunge (Muskellunge <em>Esox masquinongy </em>× Northern Pike <em>E. lucius</em>) growth, condition, and diet, as well as the effect of stocking on Northern Pikeminnow <em>Ptychocheilus oregonensis</em>, were studied at Curlew Lake, Washington from 2001 to 2006. Curlew Lake (373 ha) was stocked with tiger muskellunge beginning in 1998 to reduce an overabundant Northern Pikeminnow population and to create a unique trophy fishery. Historically, Curlew Lake had provided good fishing opportunity for stocked Rainbow Trout <em>Oncorhynchus mykiss</em>, as well as naturally reproducing Largemouth Bass <em>Micropterus salmoides </em>and Smallmouth Bass <em>M. dolomieu</em>. The quality of trout fishing, however, had declined throughout the 1990s, commensurate with anecdotal observations of increased numbers of Northern Pikeminnow in the sport catch. To monitor changes in species relative abundance, the lake was sampled annually in the fall with standardized boat electrofishing surveys. Additionally, the lake was sampled by boat electrofishing monthly, from spring through fall, to collect tiger muskellunge diet samples by gastric lavage. Rainbow Trout and Northern Pikeminnow were the most important prey species for tiger muskellunge in Curlew Lake while Largemouth Bass were a distant third. Diet varied seasonally, with Rainbow Trout being the most important prey during spring, while Northern Pikeminnow was most important in summer. Both Rainbow Trout and Northern Pikeminnow were important in the fall. The relative abundance of Northern Pikeminnow in Curlew Lake significantly declined over the duration of the study. The high proportion of Northern Pikeminnow observed in the tiger muskellunge diet analysis indicates that the reduction can be attributed to the added presence of tiger muskellunge to the community. Therefore, the goal of Northern Pikeminnow population reduction through tiger muskellunge introduction (biological control via predation) has been successful. Continued biannual monitoring of the fish community to assess Northern Pikeminnow abundance should provide the necessary data to refine future tiger muskellunge stocking rates in Curlew Lake.

<em>Abstract.</em>—This paper describes a database of fish stocking in Idaho dating from 1913. The database contains more than 75,000 complete records on stocking since 1967 and more than 50,000 partial records prior to that date. Information contained in the complete records includes watershed and water body, species and variety, size, stocking method, number per pound, pounds stocked, rearing hatchery, haul mortality, county, and management region. In order to compare numbers of salmonids stocked at differing life stages, we converted weight of stocked salmonids to a catch equivalent index (catch equivalent [CEQ] = weight of fish stocked/0.33). Our analysis of the data from the database indicated that since the 1960s, more than 2 million CEQ of rainbow trout <em>Oncorhynchus mykiss </em>have been stocked annually in Idaho. These comprise 23 different stocks, including Kamloops rainbow trout, redband trout, and 16 varieties of domestic rainbow trout. Since 1970, the number of rainbow trout stocked in Yellowstone cutthroat trout <em>O. clarkii </em>range has decreased by more than one-third. Triploid rainbow trout stocking commenced in 2000 and now exceeds 2 million CEQ annually. Largemouth bass <em>Micropterus salmoides </em>and smallmouth bass <em>M. dolomieu </em>stocking comprises nearly 1,814.4 kg per year. Crappie species are stocked at the rate of 590 kg annually. The rate of increase in stocking by the Idaho Department of Fish and Game has been about 300% in each of the last three decades, largely due to the construction of four large anadromous mitigation hatcheries. The human population in Idaho grew 22% per decade during that same time period, suggesting increasing reliance on stocked fish.


<em>Abstract.</em>—An investigation of historical fisheries information for pools 4–13 of the upper Mississippi River (UMR) was conducted to 1) determine the pre-1938 relative abundance and distribution of bluegill <em>Lepomis macrochirus </em>and largemouth bass <em>Micropterus salmoides, </em>2) determine the composition and relative abundance of the preimpoundment fish assemblage, and 3) determine if a shift in frequency of occurrence and relative abundance has occurred due to impoundment.


<em>Abstract</em>.—Long-term studies in Ontario, Canada on Largemouth Bass <em>Micropterus salmoides</em> and Smallmouth Bass <em>M. dolomieu</em> have demonstrated that angling nesting males (both catch and harvest and catch and release) can have negative impacts on the reproductive success for the captured individual. They have also demonstrated that within a population, the male bass that provide the best and longest parental care for their offspring are the most capable of having the greatest relative contribution to the year-class. Furthermore, those males are also the most aggressive toward potential brood predators and, hence, the most vulnerable to angling. Based on those relationships, we postulated that angling in general, and especially angling for nesting bass, results in selection against aggressive individuals in a population, and as a result, the angled population evolves to become less aggressive, containing males with diminished parental care attributes, an example of fisheries-induced evolution (FIE). We recognize, however, that some change towards less aggressive behaviors may also result from learning and phenotypic plasticity. Controlled, long-term selective breeding experiments over 30+ years have, however, documented the heritability of vulnerability of bass to angling and, hence, the potential for selection to act on that trait. Reproductive competition experiments further demonstrated that the highly vulnerable strain of bass produced in those selective breeding experiments indeed had greater reproductive success than the less vulnerable strain. Because angling for Largemouth Bass has been occurring for decades, we also postulated that there should be some evidence in the wild of this FIE. In fact, we did find that the level of vulnerability to angling of nesting male Largemouth Bass in lakes that have had little to no exploitation was significantly greater than that observed for nesting males in moderately and heavily angled populations.


2016 ◽  
Vol 73 (9) ◽  
pp. 1330-1341 ◽  
Author(s):  
William W. Fetzer ◽  
Collin J. Farrell ◽  
James R. Jackson ◽  
Lars G. Rudstam

Walleye (Sander vitreus), smallmouth bass (Micropterus dolomieu), and largemouth bass (Micropterus salmoides) are common top predators across many north temperate lakes, but no previous analyses have assessed factors driving their combined impact on mortality of a shared prey, yellow perch (Perca flavescens). We estimated consumption dynamics of walleye, smallmouth bass, and largemouth bass during 3 years that differed in age-0 yellow perch year-class strength and evaluated the relative contribution of each predator to age-0 yellow perch mortality, in Oneida Lake, New York, USA. Habitat-specific diet composition and population densities were integrated with temperature and growth rates to parameterize a bioenergetics model and estimate annual consumption of major diet items. Walleye were the dominant predator in both offshore and inshore habitats, while smallmouth bass and largemouth bass were also important inshore predators. Consumption of age-0 yellow perch by all three predators was positively correlated to age-0 yellow perch year-class strength, but our ability to account for age-0 yellow perch mortality decreased during years when year-class strength was strong. Within each year, predation by the three species accounted for all observed age-0 yellow perch mortality in late summer and fall, but not in the early summer, suggesting other predators in the lake likely predate on the youngest, most vulnerable yellow perch. These results are important for understanding how diverse predator communities can alter the spatial and temporal availability of prey refuges and influence mortality of a shared prey.


2002 ◽  
Vol 80 (4) ◽  
pp. 756-770 ◽  
Author(s):  
Steven J Cooke ◽  
David P Philipp ◽  
Patrick J Weatherhead

Male smallmouth bass (Micropterus dolomieu) and largemouth bass (Micropterus salmoides) care for their offspring from fertilization until the offspring disperse after becoming capable of avoiding predators. We used activity transmitters to monitor round-the-clock parental activity of both species throughout the nesting period, coupled with direct observational data collected while snorkeling, to determine whether nocturnal behaviour varied similarly to diurnal behaviour. In general, nesting males of both species were equally active during day and night, developmental-stage-specific patterns being evident during both periods. Consistent with theory, parental males of both species exhibited elevated levels of burst swimming (indicative of chasing nest predators) early in the nesting period. Unlike male smallmouth bass, however, male largemouth bass showed no decline in overall activity and energy expenditure in the later nesting stages as predicted from the greater mobility and dispersion of their broods, although burst-swimming activity decreased. Activity of nesting fish was approximately double that of non-nesting conspecifics, causing an increase in respiration rates of fish, estimated using a bioenergetics model. The results of our study suggest that physiological telemetry devices which provide both behavioural and energetic information enhance the study of parental care activity in centrarchid fishes, and may be equally useful in a variety of other taxa.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
David O Norris ◽  
Angela Geiger ◽  
Alan Milan Vajda

Abstract The widespread occurrence of gonadal intersex (presence of testicular oocytes) has been recently reported in populations of Largemouth Bass (Micropterus salmoides) and Smallmouth Bass Micropterus dolomieu) from populations across North America. To evaluate the historical occurrence of intersex in bass species, gonads were examined visually and histologically from Largemouth Bass and Smallmouth Bass from museum specimens collected from 16 States. These fishes were collected between 1823-1965, before the widespread discharge of estrogenic chemicals to surface waters via wastewater effluents. All females examined had normal ovaries. Intersex gonads were identified in 17.8 % of male Largemouth Bass, and in 14.2% of male Smallmouth Bass. The intensity of testicular oocytes in some males was as great as observed since 2000. These results indicate that the occurrence of this form of intersex in these bass species is not a recent phenomenon.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9614
Author(s):  
Jessica K. Leet ◽  
Catherine A. Richter ◽  
Robert S. Cornman ◽  
Jason P. Berninger ◽  
Ramji K. Bhandari ◽  
...  

Endocrine disrupting contaminants are of continuing concern for potentially contributing to reproductive dysfunction in largemouth and smallmouth bass in the Chesapeake Bay watershed (CBW) and elsewhere. Exposures to atrazine (ATR) have been hypothesized to have estrogenic effects on vertebrate endocrine systems. The incidence of intersex in male smallmouth bass from some regions of CBW has been correlated with ATR concentrations in water. Fish early life stages may be particularly vulnerable to ATR exposure in agricultural areas, as a spring influx of pesticides coincides with spawning and early development. Our objectives were to investigate the effects of early life stage exposure to ATR or the model estrogen 17α-ethinylestradiol (EE2) on sexual differentiation and gene expression in gonad tissue. We exposed newly hatched largemouth bass (LMB, Micropterus salmoides) from 7 to 80 days post-spawn to nominal concentrations of 1, 10, or 100 µg ATR/L or 1 or 10 ng EE2/L and monitored histological development and transcriptomic changes in gonad tissue. We observed a nearly 100% female sex ratio in LMB exposed to EE2 at 10 ng/L, presumably due to sex reversal of males. Many gonad genes were differentially expressed between sexes. Multidimensional scaling revealed clustering by gene expression of the 1 ng EE2/L and 100 µg ATR/L-treated male fish. Some pathways responsive to EE2 exposure were not sex-specific. We observed differential expression in male gonad in LMB exposed to EE2 at 1 ng/L of several genes involved in reproductive development and function, including star, cyp11a2, ddx4 (previously vasa), wnt5b, cyp1a and samhd1. Expression of star, cyp11a2 and cyp1a in males was also responsive to ATR exposure. Overall, our results confirm that early development is a sensitive window for estrogenic endocrine disruption in LMB and are consistent with the hypothesis that ATR exposure induces some estrogenic responses in the developing gonad. However, ATR-specific and EE2-specific responses were also observed.


<em>Abstract.-</em>Demographic studies have indicated that, since 1990, Kentucky’s urban population has experienced an 18% increase while its rural population has expanded by less than 1%. These demographic changes, coupled with a decline in fishing license sales, focused the need to develop and increase fishing opportunities in and around urban areas. In 2005, the Kentucky Department of Fish and Wildlife Resources initiated a pilot urban fishing program aimed at providing urban residents with high quality fishing opportunities close to home. Five pilot lakes, located within four of Kentucky’s most populated counties, were selected to receive regular stockings of rainbow trout <em>Oncorhynchus mykiss</em>, channel catfish <em>Ictalurus punctatus</em>, largemouth bass <em>Micropterus salmoides</em>, and hybrid bluegill <em>Lepomis macrochirus </em>x <em>L. cyanellus</em>. Rainbow trout were stocked at each lake in April and October. Channel catfish, largemouth bass, and hybrid bluegill were stocked in May and June. Monthly stocking rates were 202 trout/ha, 34 channel catfish/ha, 12 largemouth bass/ha, and 81 hybrid bluegill/ha. Creel and angler attitude surveys were conducted at two of the pilot lakes from April through August 2006 to determine angler catch and satisfaction. Although fishing pressure at these two lakes was high, most anglers practiced catch and release. Catch rates were 1.03 fish/h at Stein Lake and 0.79 fish/h at Upper Sportsman’s Lake. Angler attitude survey results indicated that the majority of anglers interviewed were not aware of the program and did not know that regular fish stockings were occurring at the lakes. The typical angler fishing these lakes was a white male between the ages of 30 and 49, who was satisfied with his fishing experience regardless of the number or size of fish caught. Further studies need to be completed to compare results from this study, and to refine stocking and marketing techniques used in the program.


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