Thesis (M.A.) B.Y.U. Dept. of history. / Electronic thesis. Also available in print ed.

Thesis (M.A.)--Brigham Young University. Dept. of Anthropology and Archaeology. / Includes bibliographical references (leaves 148-153).

Thesis (M.S.)--Brigham Young University. Dept. of Geography. / Bibliography: leaves 174-179.

Thesis (M.S.)--Brigham Young University. Dept. of Geography. / Includes bibliographical references (leaves 117-118).

Thesis (M.S.)--Brigham Young University. Dept. of Geography. / Electronic thesis. Bibliography: leaves 174-179. Also available in print ed.

Due to the inconveniences associated with under ice population studies, most aquatic population studies are made during the spring, summer, and fall seasons. Like most lakes little is known about the fall and winter popu-lations of the Utah Lake invertebrates. The purpose of this study is to classify, determine quantitative fall and winter population fluctuations, and obtain life history and ecological information of the macro-invertebrates at . Lincoln Beach, Utah Lake. This lake is the largest, natural occurring body of fresh water in the state and has a high potential for the production of gamefish and water-fowl. As Smart (1960) points out, an estimate of the amount of bottom fauna is the most important single stand-ard for evaluating the potential of a lake to produce fish. It is also an important consideration in the evaluation of waterfowl habitats (Barnett, 1964).

Information on the nesting of the White-faced Ibis (Plegadis chihi) in Utah County is presented for the first time. Nests built in hardstem bulrush (Sciprus acutus) settled from an average height of 120.8cm on June 9 to 93.6cm on June 27, 1971. Nest spacing ranged from 2m to 9m, averaging 4.6m. Invertebrates of the class Arachnida and the insect orders Coleoptera, Homoptera, Lepidoptera, and Thysanoptera were collected in a Berlese funnel. Average clutch size was 3.17. Egg length and width averaged 51.40mm X 36.75mm. Average volume was 36.93cc. In 21 study nests, 45.8 percent of the eggs hatched, beginning on June 8 and ending on June 27. The young weighed approximately 26gm at hatching, with tarsometatarsus and bill each 15mm long. These increased to 400gm, 70mm, and 45mm, respectively, in 15 days. Feather shaft had grown to over 100mm. Major food items of the nestlings were larvae of the insect families Dytiscidae, Hydrophylidae (O. Coleoptera) and Stratiomyidae (O. Diptera). Ectoparasites collected were a louse, plegadiphilus plegadis, and three unidentified flies.

This study of the distribution of the fresh-water sponge, Meyenia fluviatilis, at the Lincoln Beach area of Utah Lake involved the following: First, sampling of the area for the presence or absence of the species. Second, sampling at two separate areas at different depth intervals to determine if the number of sponge colonies and colony size were in any way related to depth. Finally, monthly sampling at one area to determine when gemmules of M. fluviatilis were present in the sponge colonies. Meyenia fluviatilis was found to be commonly distributed in 1-2 m of water on the lower surface of the larger rocks at 30 transects approximately 100 m apart. At the 1-2 m depth interval, the largest number of colonies (36 colonies per 50 rocks at area A and 69 colonies at area 8) were recorded. The average colony size was also greatest at this same depth (21.5 cm for area A and 26 cm for area 8). The lowest monthly percent of gemmules observed at area 8 occurred in June (22 %), while August was the highest observation with 70 %. Gemmules were observed every month and no sponge colony disintegration was observed during any month.

Information about the benthic macroinvertebrate populations along the eastern shore of Goshen Bay, Utah Lake, Utah, can be used, in part, to determine future management of the lake. In the project herein reported, cement artificial substrate samplers were used to sample two types of substrate: rubble and compacted calcareous tufa. Monthly samples were obtained from each type of substrate from March 1972 to May 1973. An amphipod, Hyalela azteca and a chironomid, Dicrotendipes fumidus were the dominant organisms in numbers and tiomass. Amphipod numbers were dependent upon the amount of algal standing crop. Elimination of this area could affect the trophic structure of the lake by effectively reducing the macroinvertebrate population of the lake.

Utah Lake, located in Utah County, north-central Utah, is one of the most important natural fishing lakes in the state. The spawning ecology of the white bass (Roccus chrysops) was studied in Utah Lake between 1964 and 1966. Gill nets and seining were the primary means of sampling. The spawning location was sampled every other day throughout the spring and early summer of 1966. Three major winter schooling areas were found: Provo Bay - Creer Access south to the mouth of Spanish Fork River, Lincoln Beach, and off Ludlow Barn. There appears to be extensive winter feeding and movement among the white bass populations. Immature white bass of both sexes were found in large numbers throughout the entire lake during the summer. In the early spring months, bisexual schools of mature bass concentrated in the southern portions of the lake before forming into unisexual schools in mid-April. Spawning activities were restricted to an area adjacent to Lincoln Beach, 0.25 mile and to a depth of 60 inches. Rubble, interspersed with ledge rock and boulders, were the only bottom types selected for spawning. An area surrounding Bird Island also simulated the bottom types off Lincoln Beach, but was not utilized for spawning. Gravid females were taken in the vicinity of Lincoln Beach on May 6, 1966 when water temperatures had reached 63° F. Spawning activity lasted from 10 to 15 days in mid-June in water temperatures of 69° F. Unisexual schools of gravid females were found off Creer Access a distance of three miles from the spawning grounds. Small numbers of female bass would migrate to the spawning site, spawn, and return to the vicinity of Creer Access, never remaining over the spawning site longer than to spawn. Tributaries were not utilized for spawning, although bass were sampled feeding in the Provo River in mid-August. Turbidity of Utah Lake during the spring and summer prevented any observations of spawning activity or behavior. Summer sampling throughout Utah Lake in 1965 resulted in a 2:1 (174 males - 93 females) sex ratio. However, these figures are in conclusive as they did not include gravid females.