Acoustic Tagging in San Joaquin River Seeks to Solve
Salmon Mystery
 |
| The
transmitter is the size of a pencil eraser. |
DFG Press Release
May 12, 2008. A new study is under way in the South
Delta portion of the San Joaquin River system to figure
out how to increase young salmon survival as they travel
down stream to the ocean. Scientists are tracking tiny
salmon called smolts in real time from sounds emitted by
acoustic tags implanted inside them. The goal is to
figure out what is killing the young salmon during their
journey and solve those problems.
Some years up to 90 out of 100 of the young salmon
called smolts died while migrating through the South
Delta scientists estimate. Up to now, figuring out
specifically where the main losses occur has been
exceedingly difficult. This long term study will help
solve these mysteries.
 |
Sara
McCullock, DFG performs
fish surgery |
Tim Heyne Department of Fish and Game biologist said,
"The results of this study and other evaluations
being conducted in the San Joaquin River basin will
determine the streamflows that are needed to overcome
all the impediments to adequate salmon and steelhead
production in this river system."
Tracking is done in river and South Delta waters with
acoustic receiver buoys. Buoys have been anchored in key
locations through out the river system and water
diversion pathways to track the fish.
1,000 smolts are being implanted with the
transmitters at the Merced Hatchery by DFG personnel and
private consultants as part of the Vernalis Adaptive
Management Plan in the San Joaquin River Agreement. The
transmitters are being programmed by the United States
Geological Service. The United State Fish and Wildlife
Service is providing technical expertise along with two
private consultant firms.
The young salmon were reared at the Merced Hatchery.
Eggs spawned and reared at the hatchery each fall will
produce the fish for this study over the next four
years.
 |
| A smolt on
the operating table |
Releases of smolts carrying the transmitters began
the last week in April. All of the fish will be released
prior to May 15.
The Vernalis Adaptive Management Plan is a
multi-agency program aimed at better understanding the
relationship between South Delta inflow, Delta exports,
and juvenile salmon survival.
Learn more about the San Joaquin River Agreement and
the Vernalis Adaptive Management Plan at www.sjrg.org.
