Aquaculture and Fisheries Commons^™

Effects Of Epilimnetic Versus Metalimnetic Fertilization On The Phytoplankton And Periphyton Of A Mountain Lake With A Deep Chlorophyll Maxima, Wayne A. Wurtsbaugh, H. P. Gross, Phaedra E. Budy, Chris Luecke

Watershed Sciences Faculty Publications

Nutrients can load directly to either the epilimnion or metalimnion of lakes via either differential inflow depths of tributaries or intentional fertilization of discrete strata. We evaluated the differential effects of epilimnetic versus metalimnetic nutrient loading using 17-m-deep mesocosms that extended into the deep chlorophyll layer of oligotrophic Pettit Lake in the Sawtooth Mountains of Idaho. Addition of nitrogen plus phosphorus stimulated primary production nearly identically (2.4- to 4-fold on different dates) in both treatments, with the production peaks occurring in the strata where nutrients were added. The metalimnetic fertilization, however, resulted in equal or greater stimulation of chlorophyll a …

Salmonine Consumption And Competition For Endemic Prey Fishes In Bear Lake, Utah-Idaho, J. R. Ruzycki, Wayne A. Wurtsbaugh, Chris Luecke

Watershed Sciences Faculty Publications

Two principal sport fish—the indigenous Bonneville cutthroat trout Oncorhynchus clarki utah and the introduced lake trout Salvelinus namaycush—are the dominant piscivores in Bear Lake, a 282-km^2 oligotrophic system. These piscivores rely predominantly on four endemic prey fish species that make up a major portion of the unique Bear Lake fish assemblage. We estimated the annual biomass of pelagic and benthic prey fish by using hydroacoustic and trawling techniques. We also estimated the lakewide abundance of piscivores with a multiple mark–recapture survey and used a bioenergetics model to compare the population-level consumption of prey fish with prey fish production. Prey fish …

Bird Predation In Juvenile Colorado Pikeminnow Habitat At Ouray National Wildlife Refuge, Utah, Julie R. Stiver

Undergraduate Honors Capstone Projects

Four endangered endemic fishes inhabit waters in the Upper Colorado River basin. These species are Colorado pikeminnow (Ptychocheilus lucius), humpback chub (Xyrauchen texanus), bonytail chub (Gila elegans), and humpback chub (G. cypha). Water development throughout the basin has altered turbidity, water temperature, salinity, and flow creating a less suitable habitat for these species (Miller and Hubert 1990). Non-native fish species have also been introduced to the  system, creating competition for the native species.  Piscivorus bird species and their hunting behavior in juvenile Colorado pikeminnow habitat was analyzed. Piscivorus birds were frequent visitors …

Under-Ice Diel Vertical Migrations Of Oncorhynchus Nerka And Their Zooplankton Prey, G. B. Steinhart, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

We used stationary hydroacoustics and measures of environmental conditions (water temperature, dissolved oxygen, light levels, and zooplankton) to determine what factors, foraging or predation risk, influenced diel vertical migrations of Oncorhynchus nerka during winter in three high-mountain lakes. The Sawtooth Valley lakes are deep, oligotrophic, glacial lakes located in central Idaho, U.S.A., and historically contained populations of anadromous O. nerka. In general, low light intensities limited foraging opportunities of O. nerka under ice, especially at night. In Stanley Lake, O. nerka underwent diel vertical migrations to exploit available light to feed. Oncorhynchus nerka occupied shallow water at night, where there …

Ontogenetic Habitat Shifts Of Juvenile Bear Lake Sculpin, J. Ruzycki, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Bear lake sculpin Cottus extensus exhibit ontogenetic habitat shifts during their initial year of life. Distribution and habitat switching was measured with bimonthly bottom-trawl surveys repeated throughout the summer. Patterns of daily growth increments on otoliths were used to measure the history of habitat residence, individual size at the time of the habitat switch, and habitat-specific growth rates. Laboratory experiments and known-age fish confirmed daily increment formation of otoliths. After dispersing during an initial pelagic larval stage, postlarval juveniles settled in both the warm, food-rich littoral zone and the cold, unproductive profundal zone. During summer, initial profundal-zone inhabitants underwent a …

Effects Of Uv-B Radiation On Egg And Larval Golden Shiner (Notemigonus Crysoleucas) In Castle Lake, California, Jai-Ku Kim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I studied effects of UV-B radiation on egg and larval golden shiner (Notemigonus crysoleucas) in Castle Lake, California, USA. To compare egg hatching and survival of larval golden shiner, I exposed eggs and larval fish to three different UV-B treatments, low UV-B (4% UV-B), high UV-B (92% UV-B), and ambient (100% UV-B). The egg experiment was conducted in lake and pond water, whereas proto- and mesolarval stage experiments were conducted in lake water only.

High and ambient UV-B radiation affected the hatching rate of golden shiner eggs. The mean hatching rate was 13% lower in high UV-B, and …

Kokanee Fry Recruitment And Early Life History In The Lake Tahoe Basin, Christine K. Gemperle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lake Tahoe kokanee salmon have experienced decreasing mean adult size and fluctuating populations since 1970. We proposed to determine whether fish production was limited by spawning and incubation processes in Taylor Creek, or by growth constraints, or by mortality in the lake by studying egg-to-fry survival rates and early life history. Estimated egg-to-fry survival was 15. 9% for the 1994 brood year and 1.5% for the 1995 brood year. Egg-to-adult survival was 3.5% for the 1991 brood year and 5.9% for the 1992 brood year. Of the 35 possible survival scenarios, egg-to-fry survival was 7.5-20% and fry-to-adult survival (inlake phase) …

The Role Of Anadromous Sockeye Salmon (Oncorhynchus Nerka) In The Nutrient Loading And Productivity Of The Sawtooth Valley Lakes, Idaho, H. P. Gross, Wayne A. Wurtsbaugh, Chris Luecke

Watershed Sciences Faculty Publications

We constructed a simulation model for Redfish Lake, Idaho, using water budget and nutrient loading measurements, to predict the dependence of lake production on nutrients from the watershed, precipitation, lake fertilization, and marine-derived nutrients from sockeye salmon Oncorhynchus nerka, which historically have reared in the lake. We also used the model to simulate different management scenarios to help restore the endangered Snake River sockeye salmon. The model and other empirical evidence indicated that even before hydropower dams were present in the migration corridor, marine-derived nutrients were not of major importance to lake production, contributing only about 3% of the annual …

Adding Nutrients To Enhance The Growth Of Endangered Sockeye Salmon: Trophic Transfer In An Oligotrophic Lake, Phaedra E. Budy, Chris Luecke, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Snake River sockeye salmon Oncorhynchus nerka, listed under U.S. law as endangered in 1991 in response to a decline in anadromous adult numbers, spend their first 1–2 years in Redfish Lake, Idaho, before migrating to the sea. To determine how nutrient enhancement might influence phytoplankton, zooplankton, and fish production, we performed fertilization experiments in large enclosures in this oligotrophic lake using juvenile kokanee (lacustrine O. nerka) as analogues for endangered sockeye salmon. Fertilization of the metalimnion substantially increased chlorophyll a (150%), phytoplankton biovolume (75%), primary productivity (250%), and zooplankton biomass (200%), and moderately increased fish growth (12%) over our control …

Dispersal Patterns Of Subadult And Adult Colorado Squawfish In The Upper Colorado River, D. B. Osmundson, Ronald J. Ryel, M. E. Tucker, D. B. Burdick, W. R. Elmblad, T. E. Chart

Wildland Resources Faculty Publications

Abstract.—We investigated distribution and dispersal patterns of subadult and adult Colorado squawfish Ptychocheilus lucius (recently renamed the Colorado pikeminnow) throughout their range in the upper Colorado River. Annual, river-wide, capture–recapture data were used to document movements during a 5-year period (1991–1995). Average total length of Colorado squawfish progressively increased upstream: juveniles and subadults occurred almost exclusively in the lowermost 105 km of the 298-km study area, whereas most adults were concentrated in the uppermost 98 km. This was most pronounced early in the study and less so later due to the effect of two or three strong year-classes that dispersed …

Evaluation Of Translocation Criteria For Trumpeter Swans Reintroduced To Northern Utah: Habitat Quality And Interactions With Tundra Swans, Katharina A. M. Engelhardt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fifty-seven Trumpeter swans (Cygnus buccinator) were translocated to the Bear River Migratory Bird Refuge and the Bear River Club Company in northern Utah. The purpose of this effort was to encourage dispersal of the Rocky Mountain population of Trumpeter swans during the winter, and to reestablish a migratory route to southern wintering grounds. I assessed the success of the translocation by evaluating 13 translocation criteria proposed in the literature. In this study I addressed two of these criteria in detail by evaluating habitat quality at the translocation sites and by analyzing potential competitive interactions with Tundra swans ( …

Fertilization Of An Oligotrophic Lake With A Deep Chlorophyll Maximum: Predicting The Effect On Primary Productivity, H. P. Gross, Wayne A. Wurtsbaugh, Phaedra E. Budy, Chris Luecke

Watershed Sciences Faculty Publications

We investigated how epilimnetic fertilization would affect chlorophyll levels and light penetration of oligotrophic sockeye salmon (Oncorhynchus nerka) lakes and how the resulting self-shading would affect primary production of the prominent deep chlorophyll maxima (DCM) of the lakes. Epilimnetic nutrient additions to large mesocosms (330 m3) in Redfish Lake, Idaho, increased levels of primary productivity and chlorophyll a but decreased Secchi depths and light available in the metalimnion and hypolimnion. Redfish Lake and other Sawtooth Valley (Idaho) lakes had DCM in which the mean chlorophyll a peaks were 240-1000% of mean epilimnetic chlorophyll a concentrations. The DCM existed at low …

Hydroacoustic Assessment Of Abundance And Diel Distribution Of Sockeye Salmon And Kokanee In The Sawtooth Valley Lakes, Idaho, D. Beauchamp, Chris Luecke, Wayne A. Wurtsbaugh, H. G. Gross, Phaedra E. Budy, S. Spaulding, R. Dilenger, C. P. Gubala

Watershed Sciences Faculty Publications

We used dual-beam hydroacoustics and echo integration techniques, combined with midwater trawling and gillnetting, to assess the abundance and distribution of the endangered Snake River juvenile sockeye salmon and resident kokanee (both Oncorhynchus nerka) in Sawtooth Valley lakes of Idaho during September 1991 and 1992. Abundance of O. nerka varied among the four lakes containing this species (12,500–257,000) and varied between years in Redfish Lake (86,400 in 1994 and 241,000 in 1992) and Alturas Lake (230,000 in 1991 and 257,000 in 1992). In Alturas Lake, where piscivore densities were high and zooplankton densities were low, small acoustic targets (≤18 cm …

Nutrient Limitation Of Oligotrophic Sockeye Salmon Lakes Of Idaho (Usa), Wayne A. Wurtsbaugh, H. P. Gross, Chris Luecke, Phaedra E. Budy

Watershed Sciences Faculty Publications

"Phytoplankton production in lake ecosystems is frequently controlled by amounts of nitrogen and phosphorus (Smith 1982, Elser et al. 1990), as well as minor- and micro-nutrients (Wurtsbaugh & Horne 1983, Wurtsbaugh 1988, Lovstad & Bjorndalen 1990). Nutrient limitation is often studied to determine which nutrient(s) should be reduced to control lake eutrophication (Schindler 1974(. Conversely, nutrients have been used for decades to stimulate plankton and, subsequently, fish production in aquaculture (Bardach et al. 1972). More recently, lake fertilization has been used to augment salmon runs for commercial exploitation (Hyatt & Stockner 1985, lye et al. 1988), and it has been …

Comparison Of The Aquatic Ecology Of Side-Canyons And The Main Channel Of Lake Powell 1997, Wayne A. Wurtsbaugh, Kirsten L. Gallo

Watershed Sciences Faculty Publications

Physical characteristics of lakes are highly interrelated with biological characteristics. We measured and analyzed the physical characteristics of two side canyons in order to better understand differences in productivity between side canyons and the main channel and to provide general information on the characteristics of the lake.

Growth And Survival Of Colorado Squawfish In The Upper Colorado River, D. B. Osmundson, Ronald J. Ryel, T. E. Mourning

Wildland Resources Faculty Publications

Growth and adult survival rates were estimated for the endangered Colorado squawfish Ptychocheilus lucius inhabiting the upper Colorado River by using data from fish captured during 1990–1995. Mean annual growth rates of fish aged 3–6 years ranged from 32.2 (age 6) to 82.0 (age 3) mm/year. Growth rates for older fish were highest for fish 400–449 mm total length, TL, (42.7 mm/year) and declined to 19.8 mm/year for fish 500–549 mm TL. Fish 550 mm and longer grew an average 9.5 mm/year. Survival rates for fish 550 mm and longer were estimated by comparing measured size distributions with simulated stable …

Physical Factors Influencing Survival To Emergence And Time Of Emergence Of Shoreslope-Spawned Kokanee Salmon In Flaming Gorge Reservoir, Utah-Wyoming, Randall J. Jeric

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I used incubation baskets containing viable eggs and spawning substrate to estimate the survival to emergence and time of emergence of kokanee salmon Oncorhynchus nerka at depths to 20 m in Flaming Gorge Reservoir, Utah-Wyoming. Traps on the incubation baskets captured fry emerging from a known quantity of eggs. Water drawn into a syringe from an intragravel pipe buried near each incubation basket was used to determine intragravel dissolved oxygen concentrations throughout the intragravel period. Water from control baskets without eggs did not have significantly greater dissolved oxygen concentrations than adjacent water. A jar associated with each incubation basket collected …

Assessment Of Kokanee Salmon, Oncorhynchus Nerka, Genetic Stocks In Flaming Gorge Reservoir, Utah-Wyoming, Michael F. Canning

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I investigated the relative abundance, spatial distributions, return to the creel, and growth rates of two genetic stocks of kokanee salmon, Oncorhynchus nerka, in Flaming Gorge Reservoir, Utah-Wyoming. The two genetic stocks consist of fish from the two major spawning populations of kokanee in the reservoir. One population, Shore Spawners, spawns along the eastern shoreline of the Open Hills area of the reservoir. The other population, Sheep Creek, spawns in Sheep Creek, a tributary located in the Canyon area of the reservoir.

Mitochondrial DNA of kokanee from each population was analyzed to determine haplotype differences between stocks. These haplotype …

Habitat Selection And Movement Of A Stream-Resident Salmonid In A Regulated River And Tests Of Four Bioenergetic Optimization Models, Mark D. Bowen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A bioenergetics model was constructed for stream-resident drift-feeding salmonids. Model predictions of surplus power (energy available per unit time for growth and reproduction) were not statistically distinguishable from observations of surplus power in three laboratory studies. Of 40 experimental trials in these three studies, the model correctly predicted surplus power in 39 cases (p < 0.05).

I collected observations of rainbow trout (Oncorhynchus mykiss) focal velocity and physical habitat availability in the Green River of northeastern Utah, USA (1988-1990). In the winter of 1988, Flaming Gorge Dam generated hydropower and delivered an lJDStable discharge regime with a higher mean discharge …

Simulated Growth And Production Of Endangered Snake River Sockeye Salmon: Assessing Management Strategies For The Nursery Lakes, Chris Luecke, Wayne A. Wurtsbaugh, Phaedra E. Budy, H. P. Gross

Watershed Sciences Faculty Publications

We examined the potential of employing a series of lake management strategies to enhance production of endangered Snake River sockeye salmon (Oncorhynchus nerka) in its historical nursery lakes in central Idaho. We used a combination of limnological sampling, experimentation, and simulation modeling to assess effects of lake fertilization and kokanee reduction on growth and survival of juvenile sockeye salmon. Juvenile sockeye salmon from a broodstock of this endangered species are being introduced into the lakes from 1995 to 1998. Results of our analyses indicated that several lakes were suitable for receiving broodstock progeny. Field experimentation and simulation modeling indicated that …

Comparison Of The Aquatic Ecology Of Side-Canyons And The Main Channel Of Lake Powell, Wayne A. Wurtsbaugh, Kirsten L. Gallo

Watershed Sciences Faculty Publications

From 18-21 April 1996, students in a Utah State University class (Aquatic Ecology Laboratory; FW 560) measured limnological and fisheries characteristics in two side canyons (Halls Creek Bay and Moki Canyon) and the main channel of Lake Powell. Inclement weather precluded sampling of two other side canyons. Most of the sub-projects, directed by indiVIdual students, addressed the following two hypotheses: (1) productivity gradients existed from the inflows of the side canyons toward the main channel and; (2) productivity was higher in the side canyons than in the main channel of the lake. In most cases, parameters were measured at 3-5 …

Effects Of Daphnia Availability On Growth And Food Consumption Of Rainbow Trout In Two Utah Reservoirs, R. Tabor, Chris Luecke, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

We monitored the diet and growth of stocked rainbow trout Oncorhynchus mykiss in two Utah reservoirs during 1986 and 1989–1990. For the first month after stocking, juvenile rainbow trout in both reservoirs fed extensively on large Daphnia spp. In East Canyon Reservoir where Daphnia were abundant, this pattern continued throughout the summer, fall, and winter. Growth of rainbow trout in East Canyon Reservoir was generally good throughout 1989–1990. In Causey Reservoir, where Daphnia were less abundant and smaller, rainbow trout fed progressively less on smaller Daphnia throughout the summer, fall, and winter, while other prey items (snails, aquatic insects, and …

Brine Shrimp Ecology In The Great Salt Lake, Utah, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Hypersaline lakes are noted for their simple communities which facilitate understanding ecological interactions (Williams et al. 1990; Wurtsbaugh 1992; Jellison and Melack 1988). Nevertheless, we still cannot easily predict how environmental changes will effect the population dynamics in these lakes, at least in part because even these simple ecosystems may be more complex than we .realize. Many hypersaline lakes are dominated by the brine shrimp Artemia spp. The production of brine shrimp is often very high because the terminal, saline lakes accumulate nutrients that make them rich, and because the short food chains in them (nutrients-->phytoplankton-->brine shrimp) minim …

The Trophic Gradient In Lake Powell, Wayne A. Wurtsbaugh, G. Steinhart

Watershed Sciences Faculty Publications

From April 21 st to April 25th, 1995 students from Utah State University's FW 462 class sampled the trophic gradient in Lake Powell between Bullfrog (Mile 99) and Hite Marinas (Mile 144). We sampled at 3-12 stations along the gradient, depending on the parameter measured. The purpose of the trip was three-fold. First, the primary objective of the class was to provide field and laboratory experiences in aquatic ecology for the students. Secondly, we wished to provide data on the trophic environment that the endangered razorback sucker larvae from the Colorado River would encounter when the entered the reservoir. Thirdly, …

Snake River Sockeye Salmon Habitat And Limnological Research, David Teuscher, Doug Taki, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Historically, thousands of Snake River Sockeye salmon returned to the Sawtooth Valley to spawn. Evermann (1896) reported that the Sawtooth Valley Lakes were teeming with red fish. Bjornn (1968) estimated that 4,360 sockeye returned to Redfish Lake in 1955. These numbers no longer exist. In the 1980's, less than 50 . Snake River sockeye salmon survived to spawn (Bowler 1990). Since 1990, only 14 sockeye have returned. Because of recent declines, the Shoshone-Bannock Tribes (SBT) petitioned the National - Marine Fisheries Service (NMFS) to list · Snake River sockeye as endangered. As a result, Snake River sockeye were listed and …

Summer Habitat Use Of Littoral-Zone Fishes In Lake Tahoe And The Effects Of Shoreline Structures, D. Beauchamp, E. Byron, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

We used scuba observations to determine summer habitat use and the effects of piers on the littoral-zone fish community in Lake Tahoe, California–Nevada. Habitat complexity declined with depth. Over 50% of the littoral zone less than 2 m deep was composed of complex boulder substrates, but this substrate represented less than 10% of the habitat between 10 and 18 m deep. A severe drought lowered the surface elevation of the lake 2 m and reduced the wetted complex rocky habitat by 20% between the 0- and l0-m isobaths (referenced to the mean lake level of 1,899 m above sea level). …

A Trophic Gradient Analysis Of Lake Powell: The 1994 Utah State University Aquatic Ecology Laboratory Analyses, Wayne A. Wurtsbaugh, Megan Barker, Ron Brunson, David Fogle, Scott Hawxhurst, Chad Mellison, Lis Phillips, Felipe Queiroz, Daniel Zamecnik

Watershed Sciences Faculty Publications

From 9-11 April, 1994, the Aquatic Ecology Laboratory Class (FW462) of Utah State University sampled the upper reaches of Lake Powell to assess if a trophic gradient existed. We °ampled physical and chemical parameters (temperature, oxygen, conductivity, and total phosphorus), phytoplankton chlorophyll a, littoral and pelagic zooplankton biomass and composition, littoral and profundal benthic invertebrates, and fish abundance measured in the littoral zone (gill nets) and the pelagic zone (hydroacoustics). Data was collected along the upper 50 miles of the reservoir between Bullfrog and the Hite marina near the Colorado River inflow.

Our field trip was done just prior to …

Habitat Selection By Lacustrine Rainbow Trout Within Gradients Of Temperature, Oxygen, And Food Availability, Chris Luecke, D. Teuscher

Watershed Sciences Faculty Publications

Rainbow trout (Oncorhynchus mykiss [Walbaum]) in Castle Lake, California were concentrated at certain depths during day and evening hours. A fish bioenergetics simulation model based on vertical gradients of temperature, oxygen concentration, and food availability indicated that rainbow trout selected habitats that maximized growth rate. In 1 of the 2 years of study, a strong pattern of diel vertical migration of rainbow trout was evident and was associated with vertical migrations of daphnids in the lake. The simulation model correctly predicted the occurrence and magnitude of fish migration. During the day some trout resided at depths with little potential for …

Effects Of Moonlight And Daylight On Hydroacoustic Estimates Of Pelagic Fish Abundance, Chris Luecke, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

To determine how moonlight and daylight affect hydroacoustic estimates of fish abundance, we used a dual-beam transducer and echo integration to survey pelagic fish (primarily Bonneville ciscoes Prosopium gemmifer) in Bear Lake, Utah and Idaho. During the new moon, the fish were dispersed (not schooling) below the thermocline, chiefly at the depths of 10–20 m. At full moon, they were dispersed but much closer to the bottom, where they were difficult to detect. Acoustic estimates offish density and biomass during full moons were approximately 50% of values derived during new moons. A diel survey during a new moon indicated that …

An Empirical Model Of Gastric Evacuation Rates For Fish And An Analysis Of Digestion In Piscivorous Brown Trout, E. He, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

The gastric evacuation rates of brown trout Salmo trutta (0.9–1.6 kg) feeding on fingerling rainbow trout Oncorhynchus mykiss (3.5–7.6 g) were measured in the laboratory at five temperatures (4.5, 9.0, 14.0, 19.0, and 22.5°C). Instantaneous gut evacuation rates (Re) increased exponentially with temperature (T): Re = 0.053se^0.073T, r^2 = 0.98; they varyied from 7%sh^–1 at 4.5°C to 29%sh^–1 at 22.5°C. Linear regressions described the relationship between time and qualitative measures of fish digestion, thus allowing investigators to determine how long an ingested fish would be identifiable at different temperatures. An analysis of published evacuation rates (N = 121) of 22 …