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Priest Rapids Dam on the Columbia River produces large daily and hourly streamflow fluctuations throughout the Hanford Reach during the period when fall Chinook salmon Oncorhynchus tshawytscha are selecting spawning habitat, constructing redds, and actively engaged in spawning. Concern over the detrimental effects of these fluctuations prompted us to quantify the effects of variable flows on the amount and persistence of fall Chinook salmon spawning habitat in the Hanford Reach. Specifically, our goal was to develop a management tool capable of quantifying the effects of current and alternative hydrographs on predicted spawning habitat in a spatially explicit manner. Toward this goal, we modeled the water velocities...
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The Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix are nonnative species that pose a threat to Great Lakes ecosystems should they advance into those areas. Thus, technologies to impede Asian carp movement into the Great Lakes are needed; one potential technology is the seismic water gun. We evaluated the efficacy of a water gun array as a behavioral deterrent to the movement of acoustic-tagged Bighead Carp and Silver Carp in an experimental pond. Behavioral responses were evaluated by using four metrics: (1) fish distance from the water guns (D); (2) spatial area of the fish's utilization distribution (UD); (3) persistence velocity (Vp); and (4) number of times a fish transited the water gun...
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We measured the initial mortality (fish judged nonreleasable at weigh-in), prerelease mortality (fish judged nonreleasable 1–2 h after weigh-in [which includes initial mortality]), and postrelease mortality (fish that died during a 5-d retention in net-pens) in 14 live-release tournaments for walleye Sander vitreus conducted in April–October 2006 and April–July 2007 in lakes and rivers in Michigan, Minnesota, North Dakota, South Dakota, and Wisconsin. Among the 14 events, initial mortality was 0–28%, prerelease mortality was 3–54%, and postrelease mortality was 0–100%; the mortality of reference fish (walleyes ≥31 cm long that were captured by electrofishing and held in net-pens with tournament-caught walleyes to...
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Little is known about the variability in the spatial and temporal distribution of spawning potamodromous trout despite decades of research directed at salmonid spawning ecology and the increased awareness that conserving life history diversity should be a focus of management. We monitored a population of fluvial–resident Bonneville Cutthroat Trout Oncorhynchus clarkii utah in a tributary to the Logan River, Utah, from 2006 to 2012 to gain insight into the distribution and timing of spawning and what factors may influence these spawning activities. We monitored Bonneville Cutthroat Trout using redd surveys with multiple observers and georeferenced redd locations. We documented an extended spawning period that lasted...
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We compared the precision and bias of age estimates derived from scales, whole otoliths, and sectioned otoliths and by readers of varying experience level for largemouth bass Micropterus salmoides, smallmouth bass M. dolomieu, and spotted bass M. punctulatus from Skiatook Lake, Oklahoma. Precision was assessed with the coefficient of variation of age estimates for each fish. Bias was determined among readers and structures from age bias graphs derived from least squares regression. Precision was similar among species for all three structures and among structures for any species, except for smallmouth bass; its age estimates were more precise with whole otoliths. Bias between pairs of readers was found for scales...
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Palmetto bass (Striped Bass Morone saxatilis x White Bass M. chrysops) have been stocked into reservoirs in the southeastern USA since the late 1960s and have gained widespread acceptance as a sport fish. These fisheries are growing in popularity and catch-and-release (CR) fishing is commonplace; however, there is a dearth of information on CR mortality of palmetto bass. We experimentally angled palmetto bass (n = 56; >373-mm TL) in a Tennessee reservoir using traditional angling gear in water temperatures ranging from 13 °C to 32 °C. Ultrasonic transmitters equipped with floats were externally attached to fish, which were released immediately and tracked multiple times within 10 d of release. Mortality was negligible...
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The Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri is native to the Rocky Mountains and has declined in abundance and distribution as a result of habitat degradation and introduced salmonid species. Many of its remaining strongholds are in headwater basins with minimal human disturbances. Understanding the life histories, vital rates, and behaviors of Yellowstone Cutthroat Trout within headwater stream networks remains limited yet is critical for effective management and conservation. We estimated annual relative growth in length and weight, annual survival rates, and movement patterns of Yellowstone Cutthroat Trout from three tributaries of Spread Creek, Wyoming, and two tributaries of Shields River,...
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We determined the capture efficiency of a beach seine as a means of improving abundance estimates of small fishes in littoral areas. Capture efficiency for 14 taxa (individual species or species groups) was determined by seining within an enclosure at night over fine and coarse substrates in the John Day Reservoir, Oregon–Washington. Mean efficiency ranged from 12% for prickly sculpin Cottus asper captured over coarse substrates to 96% for peamouth Mylocheilus caurinus captured over fine substrates. Mean capture efficiency for a taxon (genus or species) was generally higher over fine substrates than over coarse substrates, although mean capture efficiencies over fine substrates were significantly greater for only...
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Rainbow trout Oncorhynchus mykiss in Cayuga Lake, New York, appear to be suffering from a thiamine deficiency because their progeny develop general weakness, loss of equilibrium, and increased mortality, which are prevented by treatment with thiamine. Thiamine status and its effect on adults are unknown. In 2000 and 2002, we captured, tagged, and released 64 and 189 prespawning rainbow trout, respectively, in Cayuga Inlet at a collection weir to evaluate their thiamine status and the effect of thiamine injection (150 nmol/g) on instream migration. Half of the rainbow trout in each year (32 in 2000 and 95 in 2002) were injected with thiamine and half were uninjected; all rainbow trout were released above the weir...
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Rotenone, antimycin, permethrin, pydrin, and Salicylanilide I were tested for their toxicities against fathead minnows (Pimephales promelas) in the presence of Canadian waterweed (Elodea canadensis) or suspended clay. The plants had little effect on the activity of rotenone and antimycin but substantially reduced the activity of permethrin and pydrin (synthetic pyrethroids). Bentonite severely inhibited the activity of all chemicals tested. Salicylanilide I was affected least and pydrin most (27 times as much pydrin was required when I g/liter of bentonite was present in 96-hour tests). The efficacy of the registered fish toxicants rotenone and antimycin is probably not significantly affected by vegetation under...
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We collected otoliths from saugers Stizostedion canadense in Boysen Reservoir, Bighorn Reservoir, and the Bighorn River in Wyoming to evaluate age and growth. All otoliths in our samples (264 fish) were irregularly shaped, and the irregularities became more pronounced with increasing age of the fish. Age estimates with irregular otoliths were possible, but back-calculation of length at previous ages was not possible as a result of radically inconsistent lengths of radii. It should not be assumed that otoliths can be used for back calculation of length at age among all stocks of sauger. The assumption of regular otolith formation within a stock should be tested before obtaining samples of otoliths for age and growth...
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In 2002 and 2003 we released a total of 66 hatchery-reared, juvenile paddlefish Polyodon spathula (249-318 mm eye-to-fork length) in Pennsylvania's upper Ohio River system and tracked them with radiotelemetry in two different pools of the Ohio and Allegheny rivers to determine (1) poststocking survival, (2) whether release site influences survival, (3) dispersal distance and direction of movement, and (4) habitat selection. Survival was fair (mean = 78% in 2002 and 67% in 2003) for 0.23-0.43-kg paddlefish after 9 weeks. In 2003, fish stocked in the upstream half of the pool had a greater survival (100%) after 63 d than those stocked in the downstream half (44%). Within 4 d of stocking, 77% of juvenile paddlefish...
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Oxytetracycline (OTC) immersion was used to identify black-nosed crappies, a morphological variation of black crappie Pomoxis nigromaculatus, stocked into Normandy Reservoir, Tennessee, during fall 1997. The technique effectively marked 97% of the treated fish. Analysis of one otolith per fish by one reader successfully identified 98% of marked and unmarked fish in a blind test. Marks were formed before annulus formation and were not obscured by annulus-related autofluorescence, suggesting that OTC can be effectively used late in the year (October and November) in Tennessee.
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Summer flow augmentation to increase the survival of wild subyearling fall chinook salmon Oncorhynchus tshawytscha is implemented annually to mitigate for the development of the hydropower system in the Snake River basin, but the efficacy of this practice has been disputed. We studied some of the factors affecting survival of wild subyearling fall chinook salmon from capture, tagging, and release in the free-flowing Snake River to the tailrace of the first dam encountered by smolts en route to the sea. We then assessed the effects of summer flow augmentation on survival to the tailrace of this dam. We tagged and released 5,030 wild juvenile fall chinook salmon in the free-flowing Snake River from 1998 to 2000. We...
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We tested the performance of two stationary interrogation systems designed for detecting the movement of fish with passive integrated transponder (PIT) tags. These systems allowed us to determine the direction of fish movement with high detection efficiency and high precision in a dynamic stream environment. We describe an indirect method for deriving an estimate for detection efficiency and the associated variance that does not rely on a known number of fish passing the system. By using six antennas arranged in a longitudinal series of three arrays, we attained detection efficiencies for downstream- and upstream-moving fish exceeding 96% during high-flow periods and approached 100% during low-flow periods for the...
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Since 1979, abundances of sauger Stizostedion canadense have declined in the Tennessee River system. Reasons for this decline may include overharvest, loss of spawning habitat, and low recruitment due to extreme flows. The purpose of this study was to investigate the movements of saugers following winter concentration below Pickwick Dam, Tennessee. Thirty-seven saugers were implanted with radio transmitters directly below Pickwick Dam and were tracked between December 1992 and June 1993. Four saugers moved upstream through the locks at Pickwick Dam; the remaining fish stayed within the first 30 km of the tailwater throughout the spawning season. Three areas below Pickwick Dam were identified as possible March pre-spawn...
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Little is known about the distribution, movement, and home ranges of bluegills Lepomis macrochirus in lentic environments. Therefore, the objectives of this study were to evaluate the seasonal and diel differences in movement rates, site fidelity, and home range of bluegills in a shallow, natural Great Plains lake. A total of 78 bluegills (200-273 mm total length) were implanted with radio transmitters in March and May 2000. Of these fish, 10 males and 10 females were randomly selected and located every 2 h during one 24-h period each month from April to September 2000. Bluegill movement peaked during midsummer: however, there was little difference in diel movements, suggesting relatively consistent movement throughout...
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We used an analysis based on a geographic information system (GIS) to determine the amount of rearing habitat and stranding area for subyearling fall chinook salmon Oncorhynchus tshawytscha in the Hanford Reach of the Columbia River at steady-state flows ranging from 1,416 to 11,328 m3/s. High-resolution river channel bathymetry was used in conjunction with a two-dimensional hydrodynamic model to estimate water velocities, depths, and lateral slopes throughout our 33-km study area. To relate the probability of fish presence in nearshore habitats to measures of physical habitat, we developed a logistic regression model from point electrofishing data. We only considered variables that were compatible with a GIS and...
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Since the mid-1950s, fisheries biologists with the Tennessee Wildlife Resources Agency have stocked walleyes Stizostedion vitreum in several tributary reservoirs of the Cumberland and Tennessee rivers to augment declining native stocks; however, the efficacy of these management actions has never been formally evaluated. The contribution of stocked walleyes in four Tennessee reservoirs was evaluated during 1999 and 2000 by marking fry and fingerlings through oxytetracycline (OTC) immersion. Stocking densities were 13-48 fingerlings/ha, and marking efficacy was high for fish marked as fry (mean = 98%; SE = 1.7%) and fingerlings (mean = 99%; SE = 0.6%). Nearly all (94-100%; N = 509) of the age-1 and age-2 walleyes...