Water quality of potential reference lakes in the Arkansas Valley and Ouachita Mountain ecoregions, Arkansas

Environmental Monitoring and Assessment
By:  and 

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Abstract

This report describes a study to identify reference lakes in two lake classifications common to parts of two level III ecoregions in western Arkansas—the Arkansas Valley and Ouachita Mountains. Fifty-two lakes were considered. A screening process that relied on land-use data was followed by reconnaissance water-quality sampling, and two lakes from each ecoregion were selected for intensive water-quality sampling. Our data suggest that Spring Lake is a suitable reference lake for the Arkansas Valley and that Hot Springs Lake is a suitable reference lake for the Ouachita Mountains. Concentrations for five nutrient constituents—orthophosphorus, total phosphorus, total kjeldahl nitrogen, total nitrogen, and total organic carbon—were lower at Spring Lake on all nine sampling occasions and transparency measurements at Spring Lake were significantly deeper than measurements at Cove Lake. For the Ouachita Mountains ecoregion, water quality at Hot Springs Lake slightly exceeded that of Lake Winona. The most apparent water-quality differences for the two lakes were related to transparency and total organic carbon concentrations, which were deeper and lower at Hot Springs Lake, respectively. Our results indicate that when nutrient concentrations are low, transparency may be more valuable for differentiating between lake water quality than chemical constituents that have been useful for distinguishing between water-quality conditions in mesotrophic and eutrophic settings. For example, in this oligotrophic setting, concentrations for chlorophyll a can be less than 5 μg/L and diurnal variability that is typically associated with dissolved oxygen in more productive settings was not evident.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Water quality of potential reference lakes in the Arkansas Valley and Ouachita Mountain ecoregions, Arkansas
Series title Environmental Monitoring and Assessment
DOI 10.1007/s10661-014-3657-1
Volume 186
Issue 6
Year Published 2014
Language English
Publisher Springer
Contributing office(s) Arkansas Water Science Center
Description 16 p.
First page 3785
Last page 3800
Country United States
State Arkansas
Other Geospatial Arkansas Valley; Ouachita Mountain
Online Only (Y/N) N
Additional Online Files (Y/N) N