Experimental Design

 

Home

Project Summary

Experimental Design

Slough Monitoring

Results (1)

Results (2)

Recommendations

Archive

The site (Goleta Beach/Slough) was monitored prior to the field work by taking photos of the migrating slough mouth on a weekly basis during the spring and summer until the Slough became impounded and flow stopped.  Preliminary background work  included ocean water sampling and Slough sampling to examine variability associated with the bacteria samples and establish baseline conditions.  The results showed that the variability in term of indicator organisms within each water samples was very high in the ocean samples.  Four replicates for each sample location was chosen because this number represented the maximum number of samples that could be processed with the time and budget constraints of the research.  Further, a scientist from SCCWRP confirmed that the number of replicates (four) was adequate to determine if significant differences existed between the sample sites and control sites (Schiff, pers. comm.,2000).   One day prior to the breach event, group members collected samples from inside the Slough, directly in front of the Slough (ocean sample) and ocean samples 25 yards upcoast and downcoast of the Slough mouth (see schematic below).  The samples were processed for the presence of  total coliform, fecal coliform, and enterococcus using IDEXX Methods.  The results were used to establish background conditions. 

The following day the County artificially breached the Slough during a low tide and sampling began within 4 hours of the breach.  Samples were collected inside the Slough, directly in front of the Slough in the ocean, and downcoast at intervals of 50, 100, 200, and 400 yards from the source (see schematic below).  Samples were also collected upcoast, at a distance of 50 and 250 yards.  Fewer stations were chosen upcoast, because the prevailing ocean current is west to east, and bacteria levels were not expected to be high far upcoast in the direction of the current.  

In addition to the bacterial samples, nitrate samples were collected, and salinity and temperature measurement were taken at each sampling site to be used as tracers parameters.   Further, longshore current velocities and flow rates out of the Slough were measured each sampling day.  

 

 

Last updated April 30, 2001