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Dissolved oxygen fluctuations in karst spring flow and implications for endemic species: Barton Springs, Edwards aquifer, Texas, USA

Journal of Hydrology

By:
and
DOI: 10.1016/j.jhydrol.2013.10.004

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Abstract

Karst aquifers and springs provide the dissolved oxygen critical for survival of endemic stygophiles worldwide, but little is known about fluctuations of dissolved oxygen concentrations (DO) and factors that control those concentrations. We investigated temporal variation in DO at Barton Springs, Austin, Texas, USA. During 2006–2012, DO fluctuated by as much as a factor of 2, and at some periods decreased to concentrations that adversely affect the Barton Springs salamander (Eurycea sorosum) (≤4.4 mg/L), a federally listed endangered species endemic to Barton Springs. DO was lowest (≤4.4 mg/L) when discharge was low (≤1 m3/s) and spring water temperature was >21 °C, although not at a maximum; the minimum DO recorded was 4.0 mg/L. Relatively low DO (<6 mg/L) also was measured at relatively high discharge (3.2 m3/s) and maximum T (22.2 °C). A four-segment linear regression model with daily data for discharge and spring water temperature as explanatory variables provided an excellent fit for mean daily DO (Nash–Sutcliffe coefficient for the validation period of 0.90). DO also fluctuated at short-term timescales in response to storms, and DO measured at 15-min intervals could be simulated with a combination of discharge, spring temperature, and specific conductance as explanatory variables. On the basis of the daily-data regression model, we hypothesize that more frequent low DO corresponding to salamander mortality could result from (i) lower discharge from Barton Springs resulting from increased groundwater withdrawals or decreased recharge as a result of climate change, and (or) (ii) higher groundwater temperature as a result of climate change.

Geospatial Extents

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Dissolved oxygen fluctuations in karst spring flow and implications for endemic species: Barton Springs, Edwards aquifer, Texas, USA
Series title:
Journal of Hydrology
DOI:
10.1016/j.jhydrol.2013.10.004
Volume
505
Year Published:
2013
Language:
English
Publisher:
Elsevier
Contributing office(s):
South Dakota Water Science Center
Description:
8 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Hydrology
First page:
291
Last page:
298
Number of Pages:
8
Country:
United States
State:
Texas
Other Geospatial:
Barton Springs;Edwards Aquifer