July 24, 2009
New Technology Improves Salmon Passage At Hydropower Dams
Acoustic tags and numerical river models are two technologies developed by researchers at the Department of Energy's Pacific Northwest National Laboratory that are helping improve salmon passage at the Columbia Basin's hydroelectric dams.
PNNL researchers will discuss these technologies and how they make scientific contributions to the endangered fish's survival during group technical presentations at Waterpower XVI, a conference for professionals in the hydroelectric industry. The conference will run July 27 to 30 at the Spokane Convention Center in Spokane, Wash.
Acoustic tags measure survival rates
An average of 76 percent of juvenile Chinook salmon that pass through the lower 100 miles of the Snake River and its three hydroelectric dams survived the trek in the spring of 2008, according to a joint study between PNNL and the U.S. Army Corps of Engineers' Portland District.
The information was gathered by surgically implanting 4,140 young salmon with a tag that's part of the Juvenile Salmon Acoustic Telemetry System (JSATS). The JSATS-tagged fish were released from the Lower Granite Dam on the Snake River, where hydrophone receivers in the river picked up small sounds, or "pings," that the tags emit. PNNL and NOAA Fisheries began developing JSATS in 2001 to determine the survival rate of subyearling Chinook salmon in the Columbia River estuary.
PNNL researcher Tom Carlson will discuss the JSATS technology and more of the study's findings during a presentation Wednesday at Waterpower XVI.
8:30-10 a.m., Wednesday, July 29, Session 2G: Solving Fish Passage Challenges.
Juvenile Salmon Acoustic Telemetry System (JSATS) Used to Collect Route- and Reach-Specific Mortality Information in the Lower Columbia River and Estuary. Authors: Thomas J. Carlson, PhD, Geoffrey A. McMichael, Jessica A. Carter, and Mark A. Weiland, Pacific Northwest National Laboratory; M. Brad Eppard and Blaine D. Ebberts, U.S. Army Corps of Engineers.
Hydro model helps fish avoid becoming dinner
Migrating salmon will soon be directed away from predatory fish near The Dalles Dam, thanks in part to a detailed 3-D computational fluid dynamic model created by researchers at PNNL and the Corps' Portland District. The Corps is building a concrete guide wall downstream of the dam's spillbays. The researchers' computer model showed such a wall would help move fish away from shallow waters downstream.
Predatory fish like northern pikeminnow gather in the shallow waters and eat passing salmon. The new guide wall should direct salmon toward the Columbia River's deeper channels, where predatory fish are less abundant.
PNNL hydraulic engineer Marshall Richmond will explain the complex computational model that he and his colleagues developed during a presentation Wednesday at Waterpower XVI. The 3-D model was unusual because it included breaking waves on the surface, while most other river models use flat "lids" at the water surface. One of PNNL's supercomputers processed the model, while commercially available software helped create the model.
Image 1: The Juvenile Salmon Acoustic Telemetry System (JSATS) helps determine the survival rate of juvenile salmon in the Columbia River estuary by tracking fish as they migrate to the ocean. Just 0.43 grams and smaller than a pencil eraser, JSATS tags are the smallest acoustic tags available. After being inserted into the belly of juvenile salmon, acoustic tags emit a small sound, or "ping," every few seconds that is detected by receivers strategically placed in waterways. Each tag transmits a different code, which allows individual fish to be identified. The receivers record the ping's position and use that data to trace where each tagged fish travels. Pacific Northwest National Laboratory and NOAA Fisheries began developing JSATS in 2001 for the U.S. Army Corps of Engineer's Portland District. Credit: PNNL
Image 2: A computer-generated image shows how the proposed construction of a guide wall downstream of The Dalles Dam would alter the water's direction on the Columbia River. Credit: PNNL
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