Assessing the influence of multiple stressors on stream diatom metrics in the upper Midwest, USA

Munn, MD; Waite, Ian; Konrad, CP

HERO ID

5092223

Reference Type

Journal Article

Year

2018

Language

English

HERO ID 5092223
In Press No
Year 2018
Title Assessing the influence of multiple stressors on stream diatom metrics in the upper Midwest, USA
Authors Munn, MD; Waite, Ian; Konrad, CP
Journal Ecological Indicators
Volume 85
Page Numbers 1239-1248
Abstract Water resource managers face increasing challenges in identifying what physical and chemical stressors are responsible for the alteration of biological conditions in streams. The objective of this study was to assess the comparative influence of multiple stressors on benthic diatoms at 98 sites that spanned a range of stressors in an agriculturally dominated region in the upper Midwest, USA. The primary stressors of interest included: nutrients, herbicides and fungicides, sediment, and streamflow; although the influence of physical habitat was incorporated in the assessment. Boosted Regression Tree was used to examine both the sensitivity of various diatom metrics and the relative importance of the primary stressors. Percent Sensitive Taxa, percent Highly Motile Taxa, and percent High Phosphorus Taxa had the strongest response to stressors. Habitat and total phosphorous were the most common discriminators of diatom metrics, with herbicides as secondary factors. A Classification and Regression Tree (CART) model was used to examine conditional relations among stressors and indicated that fine-grain streams had a lower percentage of Sensitive Taxa than coarse-grain streams, with Sensitive Taxa decreasing further with increased water temperature (>30 °C) and triazine concentrations (>1500 ng/L). In contrast, streams dominated by coarse-grain substrate contained a higher percentage of Sensitive Taxa, with relative abundance increasing with lower water temperatures (<29 °C) and shallower water depth (<0.3 m). Quantile regression indicated that maximum water temperature appears to be a major limiting factor in Midwest streams; whereas both total phosphorus and percent fines showed a slight subsidy-stress response. While using benthic algae for assessing stream quality can be challenging, field-based studies can elucidate stressor effects and interactions when the response variables are appropriate, sufficient stressor resolution is achieved, and the number and type of sites represent a gradient of stressor conditions and at least a quasi-factorial design. © 2017
Doi 10.1016/j.ecolind.2017.09.005
Wosid WOS:000430634500121
Is Certified Translation No
Dupe Override No
Comments Scopus URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85038087749&doi=10.1016%2fj.ecolind.2017.09.005&partnerID=40&md5=4f17fc8ae3a5cc6b9329cd99dd15b50b
Is Public Yes
Language Text English
Keyword Diatoms; Metrics; Stressors; Streams; Nutrients; Pesticides