Stream Habitat Reach Summary - South Coast [ds768]

This database helps identify and describe instream habitat available to anadromous salmonids within the surveyed streams. The data were collected by Department of Fish and Game primarily to: 1) provide a useful source of information for evaluating, designing and monitoring stream habitat improvements for salmonids based on critical fish habitat needs and 2) aid in internal management decisions regarding stream restoration projects and potential. DATA LIMITATIONS AND ASSUMPTIONS For analytical purposes, users should assume that data collection methods were similar enough between streams, years, and observers to allow comparison of relative values. Observer bias is presumed to be low to non-existent. Reach-level in-stream habitat data are designed for suitability assessment of salmonid habitat at local levels. They should not be used for large watershed-level assessment tasks as assessment at this level would require either complete stream sampling or a statistically derived sample design providing for assignment of measured parameters, within acceptable error limits, on a watershed-wide basis. KNOWN CAVEATS OF THE DATA: A significant scaling error often occurs in these data. Some of this error could be from mapping fine-scale ground measurements to a coarser map scale. In most cases, distances measured at a fine scale will exceed measurements at a course scale (Mandelbrot, 1982). Due to this and other error sources, habitat units for some streams may not be accurately placed on the map. GPS units were used to collect latitude/longitude waypoints at various points throughout the survey. These were used to more accurately locate the start and end of stream reaches as opposed to the alternative of using distances upstream and dynamic segmentation. This will hopefully eliminate some of the scaling error. Habitat conditions can change drastically both from year to year and within a season. Factors to consider when comparing between years or seasons include variable stream flows (especially flood events), temperatures and silt loads. Use caution when analyzing these data with other time-dependent data such as stream biological inventories and salmon carcass surveys.