Water Resources of Oregon

USGS Oregon WSC Highlights

USGS Study of Upper Klamath Lake Links Circulation Patterns and Water Quality

Summer algae blooms in Upper Klamath Lake create water-quality conditions that are stressful for fish. (Photograph by Mary Lindenberg, U.S. Geological Survey, September 26, 2006.)

Upper Klamath Lake is a large, shallow lake in southern Oregon, just east of the Cascades. Land use changes in the basin during the 19^th and 20^th centuries led to increased inputs of sediments and nutrients to the lake, creating an ideal environment for the proliferation of the blue-green alga Aphanizomenon flos-aquae. Extensive annual blooms of this alga through the summer and subsequent bloom declines create conditions that are detrimental to the well being of fish that live in the lake, including the endangered shortnose and Lost River suckers. These conditions include large daily fluctuations of dissolved oxygen and pH, as well as occasionally high amounts of un-ionized ammonia. Fish die-offs have occurred during and following extended periods of oxygen depletion, either because of the low dissolved oxygen or disease epidemics resulting from stressed fish crowding together while seeking refuge from the unfavorable conditions.

The extended periods of oxygen depletion have been more severe in the northern part of Upper Klamath Lake than in areas of similar depth throughout the rest of the lake, suggesting that circulation patterns affect the distribution and severity of unfavorable water-quality conditions. A recent USGS Oregon Water Science Center study, in cooperation with the Bureau of Reclamation, used hydrologic, water-quality, and meteorological data collected continuously since 2002, as well as current velocity profiles and other data, to model lake circulation and heat transport. The model used is called UnTRIM, which is a three-dimensional hydrodynamic and constituent transport model.

Water in Upper Klamath Lake circulates clockwise in two gyres owing to the influence of prevailing westerly to northwesterly winds and the configuration of the lake basin, but circulation occasionally reverses when winds blow from the southeast for extended periods. Current speed generally fluctuates between 0 and 4 inches per second over most of the lake, which averages less than 10 feet in depth but has a narrow, deep trench as much as 40 feet deep along the western shore. Water in the trench moves faster than elsewhere, typically exceeding 8 inches per second.

The study found that water exiting the northern end of the trench had two components: a surface component that flows toward the southern part of the lake and a deep component that flows into the northern part of the lake, which is prime habitat for endangered suckers. Under certain conditions the deeper component exits the trench with a very low dissolved oxygen content, which is stressful to fish. This is because light does not penetrate to the deeper water, so there is no oxygen-producing photosynthesis, and oxygen-consuming processes such as algal respiration and decay, and sediment oxygen demand predominate. Why the oxygen depletion persists when the deeper water exits the trench and travels through shallow areas where photosynthesis should occur, though, is unknown. Explanations might be that algae entrained in the deeper water are either not as healthy as the more buoyant colonies in the surface water or that they have settled out of the water altogether. Answers to this question await further study.

Read the report from this study at http://pubs.usgs.gov/sir/2008/5076/.

Read about other USGS Oregon Water Science Center Klamath Basin studies at http://or.water.usgs.gov/klamath/.

Study: Emerging Contaminants are Widespread in Stream Sediments of the Lower Columbia Basin

Columbia Slough, an urban waterway that receives surface runoff and combined sewer overflows, is a hotspot for PPCPs, AWIs, and EDCs. (Photo courtesy of Lyn Topinka, Columbia River Images, Vancouver, WA)

A recent USGS reconnaissance study in the lower Columbia River Basin found a widespread occurrence of pharmaceuticals and personal care products (PPCPs) and anthropogenic (human-produced) waste indicators (AWIs) in streambed sediments— 49 compounds in all. Some of these chemicals are endocrine disrupting compounds (EDCs) that can affect reproduction in wildlife and in humans. Sediment samples were collected from the Columbia River, the Willamette River, the Tualatin River, and several small urban creeks that enter the Columbia River or the River. Concentrations and frequency of detection were higher in tributaries and small urban creeks than in the Columbia River itself, pointing to a higher risk of impacts on juvenile salmonids and other aquatic life in smaller streams. At least one EDC was detected at 22 of 23 sites sampled; several EDCs were widespread among the sites.

The USGS study is the first to document the occurrence of PPCPs and AWIs in the sediments of the Columbia River Basin. The role of sediments in exposure of aquatic organisms to these chemicals is not well understood. Some of these compounds are known to have detrimental impacts on aquatic life, while the effects of others are unknown and require further study. Their presence in the sediments raises the possibility that the compounds could be ingested by organisms that feed in and on the sediment and concentrate up the food chain. There is clearly a need for a monitoring strategy for these classes of emerging contaminants, especially because their use and subsequent discharge into the environment is likely to increase in the future.

Read more about this study:

Drugs Climbing Food Chain? (Portland Tribune, December 14, 2007)

A Medicine Cabinet Runs Through It (Oregonian article, March 10, 2008)

Pharmaceuticals and Personal Care Products Detected in Streambed Sediments of the Lower Columbia River and Selected Tributaries (Proceedings paper from NOAA Coastal Zone ’07 meetings; PDF, 0.2 MB)

Pharmaceuticals, Personal Care Products, and Anthropogenic Waste Indicators Detected in Streambed Sediments of the Lower Columbia River and Selected Tributaries (Proceedings paper from 6th International Conference on Pharmaceuticals and Endocrine Disrupting Chemicals in Water, National Ground Water Association; PDF, 0.6 MB)

Poster (PDF, 2.3 MB)