Department of Water Resources Home
IEP Banner

Georgiana Slough Acoustic Barrier Test, 1993

Program Manager:
Darryl Hayes
California Department of Water Resources
3251 S Street, Sacramento CA 95816
(916) 227-7546

Purpose:
The purpose of this project is to determine the effectiveness and
feasibility of utilizing acoustic barriers to guide out-migrating
salmon down the Sacramento River.

Graphic range of field work:
The barrier was installed at the confluence of the Sacramento River
and Georgiana Slough: 380 14' 20" N, 1210 31' 0" W

Number of sites:
The barrier consisted of 10 speakers spaced at 30 - 80 foot intervals
and was anchored at the upstream edge of the Sacramento River and
Georgiana Slough confluence.  The barrier was rearranged weekly to try
various configurations and note its effect.  Two main sampling locations
were utilized in the study: one downstream of the confluence in the
Sacramento River and one downstream of the confluence in Georgiana Slough.
A third infrequently used station was in the Sacramento River upstream of
the barrier.

Period of record:
This database covers the 1993 study

Size of complete data base for program element in KB (MB):
This data base consists of one file and is 265 KB.  The first five columns
of the database are of the format required in the IEP Data Files.  

Sample frequency per time unit:
This project strived to take 10 minute samples 10 hours a day using 1
Kodiak trawling team.  One set consists of six trawls:  Three trawls
were be performed in the Sacramento River (one on the left, one in the
middle and one on the right), then the boats would move to Georgiana
Slough and perform three trawls in the center (the slough was too narrow 
to perform bank trawls).  The trawls were performed Monday through 
Thursday from 5/6/93 through 6/10/93 (the permit did not allow for 
trawling Friday through Sunday).  During the testing period, the barrier 
was cycled on and off  at set intervals.  This permitted data to be 
collected which could be used to determine the barriers effectiveness.

General category of data collected:
The type of data collected were the number of fish caught, number of fish 
per volume of water sampled and the number of fish per minute of trawling.
The latter two types of data are termed Catch Per Unit Effort (CPUE).   
Barrier operation was noted in the data sheets.

Gear type or field instrument used:
The type of gear used was Kodiak trawl

Brief description of field sampling procedure:
Two boats were used in performing the Kodiak trawls, the net boat and the 
tow boat.  The net boat was operated by three people and would initiate 
the trawl by backing upstream as the Kodiak trawl was laid out into the 
water. Once accomplished, the boat operator would spin the boat around 
and take up the tension on the tow lines.  The crew then pass one tow 
line to the tow boat.  The boats  separate and tow the net at a set RPM 
for ten minutes.  At the end of the trawl the flow through the net was 
calculated from a flow meter which was placed in the water when the tow 
began and removed when the boats came together.  The tow boat would pass 
back the line to the net boat, which would then spin around to face 
downstream as the crew pulled in the net.  The live box was brought 
aboard and the fish placed in a holding tank.  The net would be re-set 
in the manner described above.  During the next trawl the crew of the net 
boat anaesthetized the fish with carbon dioxide,  identified and measured 
the fish.  The boat operator recorded the data, along with the flow meter 
readings and the temperature.  Any processed fish from a previous trawl 
would be passed to the tow boat, which released the fish downstream and
out of the study area.