Summer Steelhead Range - Internal Ed [ds339]

Summer Steelhead Range PWS October 2009 version Please do not distribute. This dataset is made available for internal CDFG use only. This polygon dataset depicts summer-run steelhead, Oncorhynchus mykiss irideus (O. mykiss), range in California. It was developed for the express purpose of assisting with anadromous steelhead management and recovery efforts. Please note: A separate layer is available depicting winter-run steelhead range. The data represented in this dataset are a subset of the data contained in the Aquatic Species Observation Database (ASOD), a Microsoft Access multi-species observation data capture application. ASOD is an ongoing project developed by CDFG NR-Environmental Resources Information Services with assistance from CDFG Fisheries Branch and the Pacific States Marine Fisheries Commission. ASOD is a project designed to compile as complete a set of statewide inland aquatic vertebrate species observation information as possible. These data are based primarily upon confirmed observations of anadromous steelhead. Secondarily, biologists may have reason to believe that anadromous steelhead inhabit a particular stream reach when there is no documented observation there; these reaches are classified as anadromous 'Suspected' present based on the biologists best judgement. The distribution data used to develop this range dataset has recently undergone some review but may still vary in accuracy. In order to develop this Steelhead range dataset, the ASOD project steelhead distribution (Steelhead_Distribution_Summer), was used to select and attribute Planning Watersheds (PWS). The California Interagency Watershed Map of 1999 (Calwater 2.2, updated May 2004, "Calw221" [excerpt from calw221 metadata]). is the State of California's working definition of watershed boundaries. Watersheds selected were then attributed with either Anad Present, Anad Suspected, or Disputed-Anad Present, as was indicated in the distribution. Several other fields from the calw221 polygon coverage were also captured for the attribute table. These help identify the watersheds and create a link back to the Calwater dataset. In some cases the USGS National Hydrography Dataset High Resolution Hydrography linework, used to develop the distribution, and the PWS watershed boundaries were very close. Only those PWS watersheds that had documented presence or that clearly contained segments of streams identified in the distribution were attributed to steelhead range. All watersheds in the "calw221" were assigned a value of either Anad Present (Anadromous present), Anad Suspected (Anadromous suspected), Disputed-Anad Present (Disputed Anadromous present) or No data. A PWS classified as 'No data' does not always indicate that anadromous steelhead do not utilize that planning watershed. For example, their occurrence may not be well documented and/or our records may be incomplete. Conversely, anadromous steelhead may not be prevalent throughout the entire area of the watershed. It is important to note that this data may underestimate or overestimate the true range of anadromous steelhead. CalWater PWS polygons were intersected with points and lines from the ASOD observation and distribution datasets. Watersheds that were positive for steelhead salmon distribution were then selected and attributed. A PWS containing 'Anad Present' was weighted higher than steelhead 'Anad Suspected', and 'Anad Suspected. For example, when linework for both present and suspected occurrence were found to be within the same watershed, then the PWS was attributed to 'Anad Present. Once anadromous steelhead watersheds were identified and attributed the remaining watersheds were examined and those identified as being above migration barriers were attributed as 'Excluded'. This was done by comparing this range dataset with the PWS_Summary dataset (draft) being developed by NR-ERIS. Those data were originally drawn from the Calfish Passage Assessment Database. Information from biologists was also used to mark some watersheds as 'Excluded'. The statewide PSW polygon layer was then trimmed to encompass watersheds positive for summer-run steelhead together with adjacent watersheds.

Please read the metadata document completely prior to use of this dataset. Examples of appropriate uses include: - Anadromous O. mykiss salmon recovery planning - Evaluation of future survey sites for O. mykiss - Validating anadromous O. mykiss range in California Examples of inappropriate uses include: - Assuming that a watershed attributed "No data" means that O. mykiss are not present. - Using this data to make parcel or ground level land use management decisions. - Using this dataset to prove or support non-existence of O. mykiss at any spatial scale. - Assuming that the range indicated represents the maximum possible extent of steelhead range.

Disclaimer: The State makes no claims, promises, or guarantees about the accuracy, completeness, reliability, or adequacy of these data and expressly disclaims liability for errors and omissions in these data. No warranty of any kind, implied, expressed, or statutory, including but not limited to the warranties of non-infringement of third party rights, title, merchantability, fitness for a particular purpose, and freedom from computer virus, is given with respect to these data.