USGS - science for a changing world

Open File Report 20071276

U.S. GEOLOGICAL SURVEY
Open File Report 20071276

Quantifying the Benthic Source of Nutrients to the Water Column of Upper Klamath Lake, Oregon

Prepared in cooperation with the U.S. Bureau of Reclamation

By James S. Kuwabara, Dennis D. Lynch, Brent R. Topping, Fred Murphy, James L. Carter, Nancy S. Simon, Francis Parchaso, Tamara M. Wood, Mary K. Lindenberg, Katryn Wiese, Ronald J. Avanzino

Executive Summary

Five sampling trips were coordinated in April, May and August 2006, and May and July 2007 to sample the water column and be nthos of Upper Klamath Lake, OR ( Fig. 1 ; Table 1 ), before, during and after the annual cyanophyte bloom of Aphanizomenon flos-aquae (AFA). A pore-water profiler was designed and fab ricated to obtain the first high-resolution (centimeter-scale) estimates of the vertical concentration gradients for diffusive-flux deter minations. Estimates based on molecular diffusion m ay underestimate benthic flux because solute transport across the sediment-water interface c an be enhanced by proces ses including bioturbation, b ioirrigation and ground-water advection. Water-column and benthic samples were also collec ted to help interpret spatial and temporal trends in diffusive-flux estimates. Data from these samples complement geochemical analyses of bottom-sediments taken from Upper Klamath Lake (UKL) in 2 005.

This ongoing study provides information necessary for developing process-interdependent solute-transport models for the watershed (that is, models integrating physical, geochemical and biological processes), and supports efforts to evaluate remediation or load-allocation strategies. To augment studies funded by the U.S. Bureau of Reclamation (USBR), the Department of Inter ior supported an additional full deployment of pore-water profilers in July 2007, during the summer AFA bloom. Results from this recent field trip are not fully completed. Data not presented herein will be included in a subsequent publication, scheduled for March 2009.

Contents

Executive Summary
Background
Objectives
Results and Discussion
Study Design and Methods
Referenced Cited
Acknowledgments

This report is available online in Portable Document Format (PDF). If you do not have the Adobe Acrobat PDF Reader, it is available for free download from Adobe Systems Incorporated.

Download the report (PDF, 1.2 MB)

Document Accessibility: Adobe Systems Incorporated has information about PDFs and the visually impaired. This information provides tools to help make PDF files accessible. These tools convert Adobe PDF documents into HTML or ASCII text, which then can be read by a number of common screen-reading programs that synthesize text as audible speech. In addition, an accessible version of Adobe Reader 8.0 for Windows (English only), which contains support for screen readers, is available. These tools and the accessible reader may be obtained free from Adobe at Adobe Access.

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
Persistent URL: http://pubs.usgs.gov/ofr/2007/1276
Page Contact Information: Publications Team
Page Last Modified: Friday, 11-Jan-2013 04:54:16 EST