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Ontogenetic Habitat Shift Of Juvenile Bear Lake Sculpin (Cottus Extensus), James R. Ruzycki

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bear Lake sculpin (Cottus extensus) exhibited an ontogenetic habitat shift during their first year of life. Soon after hatching in the littoral zone, the fry swam to the surface where they dispersed throughout the lake. Most juveniles that initially settled in the profundal zone returned to the littoral zone during their first summer. Patterns in the daily growth increments of otoliths confirmed the history of habitat residence and the individual size at the habitat switch. We used this habitat shift to test a μ/g model incorporating a growth rate-mortality risk trade-off. A trade-off occurred in the littoral …

Diel Vertical Migration And Feeding Of Underyearling Bear Lake Sculpin Cottus Extensus (Pisces, Cottidae), Darcy Neverman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Underyearling Bear Lake sculpin exhibit a diel pattern of vertical migration throughout the pelagic region of Bear Lake (Utah-Idaho) until they are approximately 22 mm standard length. Individuals move from the bottom of the lake (5° C) during the day into the water column (13-16° C) at night. The migration, however, is not related to feeding. Although the dominant copepod in the water column, Epischura nevadensis, do undergo a similar diel vertical migration, stomach analysis of juvenile sculpin captured by trawling shows that they do not feed in the water column. Instead, from July through October, their diet is dominated …

Some Aspects Of Geochemistry Of The Water And Sediment Of Bear Lake, Idaho-Utah, Richard H. Fuller

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Development by man through the last half century has caused a number of changes in Bear Lake. These changes include the diversion of Bear River water into Bear Lake, the pumping of lake water back into the river, and the building of breakwaters and other obstructions along the shore of Bear Lake.

The diversion of Bear River water into the lake has resulted in a yearly addition of an estimated 36,000 metric tons of calcium into the lake, which has caused the precipitation of an estimated minimum 90,000 metric tons of aragonite. The pumping of Bear Lake water back into …

Some Aspects Of Geochemistry And Mineralogy Of Bear Lake Sediments, Utah-Idaho, Dean F. Davidson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bear Lake is located in southeastern Idaho and north-central Utah. The lake has a maximum altitude of 5923 feet and an area of approximately 110 square miles. Surrounding the lake are carbonates, shales, and sandstones of lower Paleozoic through middle Mesozoic ages. The many streams and springs that originate in these rocks are probably the main contributors to the chemistry of the lake. Water from Bear River, which flows into the north end of the lake, also contributes to its chemistry.

Quartz, aragonite, dolomite, calcite and clay minerals are the main minerals in the lake-bottom sediments. Quartz is generally the …