Big Creek Reserve
Student Volunteer Stream Insect Survey

Kim Smiley, former education coordinator
John Smiley, former reserve manager

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 Big Creek home page
 Drawings of Big Creek stream insects

 stream insect species list
 

The Big Creek Student Volunteer Stream Insect Survey is a part of the Landels-Hill Big Creek Reserve Educational Program, and is designed to teach students of all ages about stream insects as well as to generate useful data about the invertebrate fauna in Big Creek. Before each survey, education coordinator Kim Smiley takes students in Devil's Creek near Redwood Camp and collects examples for demonstration. She uses these live samples to train students to identify morphospecies (see drawings also). After training, she takes students to the field sites where they wade in the creek looking for insects. Each student team consists of up to three samplers and a recorder. The samplers wade in the creek for 20 minutes calling out their finds to the recorder at each site. Kim Smiley resolves identification problems and verifies unusual finds. Kim keeps a voucher collection for identification purposes as well as teaching identification skills. The data are then entered into a summary data sheet which lumps morphospecies into functional feeding groups: collectors, shredders, scrapers, predators, and unknowns. Both the number of individual insects and the number of morphospecies is recorded on the summary sheet. These sheets are then gathered into a summary data table. The graphs below show approximate sample dates (blue) and their relation to creek height and flooding events (red). Another set of graphs show seasonal trends lumping data from before the 1999 fire (blue) and after (magenta). Another set shows that there was no discernible affect of sampler age on either diversity or abundance.

Stream insects in Big Creek have also been surveyd by the Central Coast Ambient Monitoring Program (CCAMP). Pictures of selected stream insects (not necessarily from Big Creek) may be found on a major stream invertebrates web site. There is also a simple key available on line.

Seasonal trends The two graphs below illustrate seasonal trends in insect abundance and diversity. Both abundance and diversity begin at low levels after winter scouring of the stream bed, and may rise in a few months to a plateau which holds into the fall. However, there are samples with low abundance even in summer and fall. Magenta samples are those taken after September of 1999, and are shown separately to see if the 1999 wildfire affected the results. The 1999 Kirk Complex Fire burned much of the Big Creek watershed and affected some measurements of water quality such as turbidity (see water quality page).

 

Number of stream insects found per sampling minute at each site on a given date 1-21-02 
 
 Number of stream insect species found at each site on a given date. 1-21-02

Ages of volunteers This study was carried out by a diverse group of volunteers with varying backgrounds and degrees of skill. One question that might arise is whether the age level of the volunteers affect the results of the survey. To check for these types of effects we have graphed the insect diversity and abundance as a function of season (as above), but with four age groups separated by color to see if, for example, the younger students might have found fewer species or individuals. As shown below, little of the variability can be attributed to the age of the volunteers.

data table