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Date:    Thu, 11 Feb 1999 02:01:33 EST
From:    C 
Subject: PNNL technologies to study fish behavior and bypass systems at dams

http://www.pnl.gov/news/1999/fish.htmssai99.htmlex.html.
PNNL News & Information - News Releases
February 9, 1999
Contact: Staci West (509) 372-6313


Technologies track, map fish behavior

RICHLAND, Wash. - Scientists at the Department of Energy's
Pacific Northwest National Laboratory have developed tools to
study how fish behave and to evaluate fish bypass systems at
dams. The scientists coupled a multibeam sonar tool with an
interactive computer animation program to track juvenile fish as
they approach a prototype surface flow bypass recently installed
at Bonneville Dam on the Columbia River between Washington and
Oregon.

The multibeam sonar tool, called Dual-Head Multibeam Sonar, is
a modification of a hydroacoustic device commonly used to map the
bottom of oceans. The dual-head sonar nonintrusively tracks a
fish's swimming direction and velocity over a large volume of
water. Information collected by the multibeam sonar tool is
transferred to computer software designed by Pacific Northwest.
This software, called MTrack, tracks individual fish and allows
for creation of a three-dimensional animation of what took place
underwater.

"This is a very sophisticated system," said Robert L. Johnson,
Pacific Northwest principal investigator. "These tools allow us
to see fish movement more completely and take us one step closer
to understanding how fish behave near these test facilities."

The U.S. Army Corps of Engineers, which built and operates
Bonneville Dam, is attempting to find the best combination of
bypass entrance dimensions, river velocity and flow to allow for
safer downstream passage of juvenile salmon. Results from Pacific
Northwest's study could be helpful in designing future surface
flow bypasses, if that option is pursued as an alternative to
passage through turbines.

Using the sonar tool, Pacific Northwest scientists tracked about
15,000 juvenile salmon as they approached the bypass at
Bonneville Dam. The scientists discovered the juvenile salmon,
also called smolt, tend to work harder as they approach the
prototype bypass by swimming against the current, toward the
bottom of the bypass and parallel to the bypass structure.

"This complex behavior could be caused by many factors," Johnson
said, "such as noise from turbines or the existence of a new
structure. While we don't know why the fish act in this manner
yet, we now have the ability to develop that understanding by
studying smolt behavior in great detail."

Pacific Northwest scientists looked at how fish behavior differed
when the prototype bypass entrance was 1.5 meters (five feet)
wide and 6.1 meters (20 feet) wide. The study indicated the
effort fish exerted to get to the bypass entrance was similar
regardless of entrance size.

         
         Click on picture for a larger view. Graphic
         available upon request.

At Bonneville Dam, Pacific Northwest scientists mounted the
dual-head multibeam sonar tool on a platform immediately upstream
of the dam. The device transmits sound on the horizontal sonar
head while receiving echoes on the horizontal and vertical sonar
heads. The sonar tool "pings," or sends out sounds, up to 20
times every second. The combined echoes provide a
three-dimensional location of a fish for every "ping."

The echoes are fed into a computer system on land then sent on
to a third computer, where the information is combined into files
compatible with the MTrack processing software. MTrack uses
algorithms to analyze data and translate it into fish positions.
The data then can be displayed on an interactive
three-dimensional scene graphic that replays fish movement
relative to the dam and the prototype bypass.

Since 1996, Pacific Northwest scientists have done similar
analysis work at Lower Granite Dam, which is operated by the
Corps' Walla Walla District, on the Snake River in southeastern
Washington. Scientists are continuing this work for the Corps'
Portland District, which operates Bonneville and two other dams
on the lower Columbia River. The Corps is gathering information
on many possible methods for improving downstream fish passage
through dams and their turbines, including surface bypasses.

Pacific Northwest is one of DOE's nine multiprogram national
laboratories and conducts research in the fields of environment,
energy, health sciences and national security. Battelle, based
in Columbus, Ohio, has operated Pacific Northwest for DOE since
1965.

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