caa a22 4500 467904782 CHVBK 20180406152830.0 cr unu---uuuuu 170328e20060401xx s 000 0 eng 10.1007/s10661-006-6553-5 doi (NATIONALLICENCE)springer-10.1007/s10661-006-6553-5 Characterization of Benthic Communities and Physical Habitat in the Stanislaus, Tuolumne, and Merced Rivers, California [Elektronische Daten] [Lenwood Hall Jr., William Killen, Ronald Anderson] The primary goal of this study was to characterize physical habitat and benthic communities (macroinvertebrates) in the Stanislaus, Tuolumne and Merced Rivers in California's San Joaquin Valley in 2003. These rivers have been listed as impaired water bodies (303 (d) list) by the State of California due to the presence of organophosphate (OP) insecticides chlorpyrifos and diazinon, Group A pesticides (i.e., organochlorine pesticides), mercury, or unknown toxicity. Based on 10 instream and riparian physical habitat metrics, total physical habitat scores in the Stanislaus River ranged from 124 to 188 (maximum possible total score is 200). The highest total habitat score was reported at the upstream site. Tuolumne River physical habitat scores ranged from 86 to 167. Various Tuolumne River physical habitat metrics, including total habitat score, increased from downstream to upstream in this river. Merced River physical habitat scores ranged from 121 to 170 with a significant increase in various physical habitat metrics, including total habitat score, reported from downstream to upstream. Channel flow (an instream metric) and bank stability (a riparian metric) were the most important physical habitat metrics influencing the various benthic metrics for all three rivers. Abundance measures of benthic macroinvertebrates (5,100 to 5,400 individuals) were similar among the three rivers in the San Joaquin watershed. Benthic communities in all three rivers were generally dominated by: (1) Baetidae species (mayflies) which are a component of EPT taxa generally considered sensitive to environmental degradation; (2) Chironomidae (midges) which can be either tolerant or sensitive to environmental stressors depending on the species; (3) Ephemerellidae (mayflies) which are considered sensitive to pollution stress; and (4) Naididae (aquatic worms) which are generally considered tolerant to environmental stressors. The presence of 117 taxa in the Stanislaus River, 114 taxa in the Tuolumne River and 96 taxa in the Merced River implies that the benthic communities in these streams are fairly diverse but without a clear definition of benthic community expectations it is unknown if these water bodies are actually impaired. Springer Science + Business Media, Inc., 2006 benthic communities nationallicence physical habitat nationallicence San Joaquin River watershed nationallicence Hall Jr. Lenwood Agricultural Experiment Station, Wye Research and Education Center, University of Maryland, Queenstown, Maryland, USA aut Killen William Agricultural Experiment Station, Wye Research and Education Center, University of Maryland, Queenstown, Maryland, USA aut Anderson Ronald Agricultural Experiment Station, Wye Research and Education Center, University of Maryland, Queenstown, Maryland, USA aut Environmental Monitoring and Assessment Kluwer Academic Publishers 115/1-3(2006-04-01), 223-264 0167-6369 115:1-3<223 2006 115 10661 https://doi.org/10.1007/s10661-006-6553-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10661-006-6553-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hall Jr Lenwood Agricultural Experiment Station, Wye Research and Education Center, University of Maryland, Queenstown, Maryland, USA aut NATIONALLICENCE 700 1- Killen William Agricultural Experiment Station, Wye Research and Education Center, University of Maryland, Queenstown, Maryland, USA aut NATIONALLICENCE 700 1- Anderson Ronald Agricultural Experiment Station, Wye Research and Education Center, University of Maryland, Queenstown, Maryland, USA aut NATIONALLICENCE 773 0- Environmental Monitoring and Assessment Kluwer Academic Publishers 115/1-3(2006-04-01), 223-264 0167-6369 115:1-3<223 2006 115 10661 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer