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Research about Washington, Oregon

Source-linked reports with geographic coverage including Washington, Oregon.

5 recordsLinked to original sources
USGS2021

Calcium concentrations in the lower Columbia River, USA, are generally sufficient to support invasive bivalve spread

Dissolved calcium concentration [Ca 2+ ] is thought to be a major factor limiting the establishment and thus the spread of invasive bivalves such as zebra ( Dreissena polymorpha ) and quagga ( Dreissena bugensis ) mussels. We measured [Ca 2+ ] in 168 water samples collected along ~100 river-km of the lower Columbia River, USA, between June 2018 and March 2020. We found [Ca 2+ ] to range from 13 to 18 mg L −1 during summer/fall and 5 to 22 mg L −1 during the winter/spring. Previous research indicates that [Ca 2+ ] < 12 mg L −1 are likely to limit the establishment and spread of invasive bivalves. Thus, our results indicate that there is sufficient Ca 2+ in most locations in the lower Columbia River to support the establishment of invasive dreissenid mussels, which could join the already widespread and abundant Asian clam ( Corbicula fluminea ) as the newest invader to an already heavily invaded Columbia River ecosystem. These new data provide important measurements from a heretofore undersampled region of the Columbia River and have important implications for the spread of invasive bivalves and, by extension, the conservation and management of native species and ecosystems.

Washington, Oregon↗
USGS2020

Assessment of multi-stressors on compositional turnover of diatom, invertebrate and fish assemblages along an urban gradient in Pacific Northwest streams (USA)

This study is part of the regional stream-quality assessment (RSQA) conducted by the U.S. Geological Survey (USGS) National Water Quality Assessment (NAWQA) project. The purpose of this study is to examine small streams along land-use and stressor gradients at the regional scale and to evaluate the relative importance of instream stressors on diatom, macroinvertebrate, and fish assemblages. In 2015, the RSQA project assessed stream quality in 82 wadeable streams that were selected along an urban land-use gradient in the Pacific Northwest Region (PNW) of the United States. This study evaluates the effects of four major categories of measured instream stressors – flow (i.e. alteration), water quality, habitat, and contaminants (in water and sediment) – on stream biota. We used gradient forest (GF) models to evaluate taxon specific responses to the various stressors for the three biotic assemblages. Results for diatom, invertebrate and fish assemblages showed that several environmental variables including substrate size, dissolved oxygen, and two or more different contaminants were selected in each of the GF models. In general, all three assemblages were negatively associated with any contaminant measures above zero, except the more tolerant taxa in each assemblage, which responded positively to contaminants. Total nitrogen (TN) and total phosphorus (TP) were important in both the diatom and invertebrate GF models but not in the fish models, which were related to temperature and stream flow. TP and TN were the top two variables for diatom GF models and various taxa responded at a range of nutrient concentrations; however, some taxa responded at low concentrations, for example around 0.02 for TP and 0.5 mg/L for TN. In general, the three biotic assemblages responded to multiple stressors following general patterns of known sensitive versus tolerant taxa for each of the biotic groups studied, yet the GF models allow us to explore taxon specific responses. For example, most of the sensitive Ephemeroptera, Plecoptera, Trichoptera invertebrate taxa (EPT) responded negatively when any contaminant increased above zero; yet some taxa such as the tolerant Trichoptera Cheumatopsyche responded positively to contaminants and many of the other stressors. The findings of this study demonstrate the value of using multiple assemblages to monitoring stressor gradients associated with urban stream systems and the importance of evaluating the responses of individual taxa to stressors.

Washington, Oregon↗
USGS1965

Geology and ground-water resources of the Walla Walla River basin Washington-Oregon

The Walla Walla River, whose drainage basin of about 1,330 square miles lies astride the Washington-Oregon boundary, drains westward to empty into the Columbia River. The basin slopes from the 5,000-foot crest of the Blue Mountains through a structural and topographic basin to the terraced lands adjoining the Columbia River at an altitude of about 340 feet. The main unit of the topographic basin is the valley plain, commonly called the Walla Walla Valley, which descends from about 1,500 feet at the foot of the mountain slopes to about 500 feet in altitude where the river cuts through the bedrock ridge near Divide. In the Blue Mountains the streams flow in rockbound canyons. Beyond the canyons, near Milton-Freewater and Walla Walla, they pass onto the broad alluvial fans and the terrace lands of the valley.

Washington, Oregon↗