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Ostracode endemism in Bear Lake, Utah and Idaho
| Content Provider | Semantic Scholar |
|---|---|
| Author | Bright, Jordon |
| Copyright Year | 2009 |
| Abstract | Bear Lake, Utah and Idaho, is one of only a few lakes worldwide with endemic ostracode species. In most lakes, ostracode species distributions vary systematically with depth, but in Bear Lake, there is a distinct boundary in the abundances of cosmopolitan and endemic valves in surface sediments at ~7 m water depth. This boundary seems to coincide with the depth distribution of endemic fi sh, indicating a biological rather than environmental control on ostracode species distributions. The cosmopolitan versus endemic ostracode species distribution persisted through time in Bear Lake and in a neighboring wetland. The endemic ostracode fauna in Bear Lake implies a complex ecosystem that evolved in a hydrologically stable, but not invariant, environmental setting that was long lived. Long-lived (geologic time scale) hydrologic stability implies the lake persisted for hundreds of thousands of years despite climate variability that likely involved times when effective moisture and lake levels were lower than today. The hydrologic budget of the lake is dominated by snowpack meltwater, as it likely was during past climates. The fractured and karstic bedrock in the Bear Lake catchment sustains local stream fl ow through the dry summer and sustains stream and groundwater fl ow to the lake during dry years, buffering the lake hydrology from climate variability and providing a stable environment for the evolution of endemic species. Bright, J., 2009, Ostracode endemism in Bear Lake, Utah and Idaho, in Rosenbaum, J.G., and Kaufman, D.S., eds., Paleoenvironments of Bear Lake, Utah and Idaho, and its catchment: Geological Society of America Special Paper 450, p. 197–216, doi: 10.1130/2009.2450(08). For permission to copy, contact editing@ geosociety.org. ©2009 The Geological Society of America. All rights reserved. INTRODUCTION Bear Lake, Utah and Idaho, is an interesting lake for several reasons. It is one of the most long-lived extant lakes in North America, if not the most long-lived extant lake on the continent (Bright et al., 2006; Colman, 2006). The limestoneand dolomite-rich watershed surrounding the lake generates an unusual water chemistry within the lake (Dean et al., 2007, this volume). Throughout much of the Holocene (and other relatively arid, Holocene-like climates) Bear Lake has precipitated aragonite as the dominant carbonate mineral (Bright et al., 2006; Dean et al., 2006, Dean, this volume), which is also unusual for a highaltitude, northern temperate lake (Dean et al., 2007). Bear Lake also contains four endemic fi sh species (Sigler and Sigler, 1996), which, excluding the Great Lakes basin (Smith, 1981; Smith and Todd, 1984; Reed et al., 1998), is the largest number of endemic fi shes in any extant North American lake. Recent studies have suggested that the speciation of the Bear Lake whitefi sh is a recent event, and may still be occurring today (Vuorinen et al., 1998; Toline et al., 1999; Miller, 2006). Bear Lake also contains an endemic deep-water ostracode fauna. Cosmopolitan ostracodes are uncommon in the lake and are primarily restricted to the shallowest littoral zone or lake margins, which again is unusual. Lakes normally exhibit an ostracode distribution associated with environmental change along a depth gradient from the lake margin through the littoral zone and |
| Starting Page | 197 |
| Ending Page | 216 |
| Page Count | 20 |
| File Format | PDF HTM / HTML |
| DOI | 10.1130/2009.2450(08) |
| Volume Number | 450 |
| Alternate Webpage(s) | https://bearrivercommission.org/docs/8%20USGS%20Reports.pdf |
| Alternate Webpage(s) | https://doi.org/10.1130/2009.2450%2808%29 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
