Meta Identifier	SFEI_Leidy
Type of Data	Vertebrate sampling by electrofishing
Originator	Robert A. Leidy
Description	Field data were collected by Robert A. Leidy of USEPA and others under his direct supervision. Data were collected between April 1992 and July 1998. A total of 277 survey events took place at 263 stations on 79 creeks. Information collected during each survey event was reported on an individual, two-sided field datasheet. A sample of the field datasheets can be seen in Appendix 1. Copies of the original datasheets may be viewed at the SFEI Library. Survey stations represented 20m-50m reaches of streams and were marked and annotated on 7.5 minute USGS quadsheet maps with pencil crosshatches. Cumulative error (using the root-mean-squares method) is 27m. This error is within the range of station ground location lengths. It should be noted that error resulting from the relationship between the points marked on the USGS quadsheet and their actual field position was not assessed by SFEI. It should also be noted that the most detailed record of the survey location is the narrative description recorded in the "Location" field in the database. This field describes the specific location and extent of the survey station in relation to local landmarks. The GIS coverage represents the general location of the survey stations in a digital form, but does not replace the specific narrative location description.
Area	San Francisco Bay Area tributaries
Metadata Date	2/28/2003
Metadata Contact	Gary Reedy
Contact Person Primary	Robin Grossinger
Status	complete
Request Log	Need electronic database from SFEI. Robin asked that I call Rob Leidy again and then send email to SFEI re: request
Follow Up Date Request	12/16/2002
Receipt Log	Received 2/26/03
Access Constraints	Presentation to be limited to indices until further discussions with SFEI and Rob Leidy.
Lead Person	Gary
Notes	Metadata from SFEI pasted here in following fields: Description, Purpose, Supplemental Info
Data Set Name	fish_leidy_marin.db, fish_leidy_sonoma.db, fish_leidy_sonomarin.db
Date of Content Start	6/1/1992
Date of Content End	10/15/1998
Purpose	The primary goal of fish sampling was to document the present distribution and abundance of native stream fishes in the Bay Area. Stream locations known to contain native fishes based on historical records were surveyed to document local species distribution and abundance. Additional locations were surveyed where historical information was incomplete. At each location, an effort was made to survey the full range of habitat types (e.g., riffle, run, pool) within representative stream reaches and geomorphic settings (e.g., high-elevation, high-gradient, bedrock controlled; low-elevation, low gradient, alluvial unconsolidated bottom, etc.). Stations were selected to maximize the diversity of habitat types in different geomorphic settings. Stream reaches were typically sampled above the influence of diel tidal fluctuations, but there were exceptions. Selection of fish survey techniques depended on site-specific physical characteristics and conditions. The method employed was the one that would survey a site most thoroughly. Fish survey relied on one or more of the following techniques: electrofisher, minnow or beach seine, dip net, gill net, and snorkel and mask. Surveying with a Smith-Root Type XI backpack electrofisher was the most often employed method, primarily in reaches with depths of less than 1 meter (m) and water velocities of less than 3 second-feet. Electrofishing was conducted in a downstream-to-upstream direction for a minimum distance of 30 m, except in two situations. First, many survey locations were characterized by isolated pools less than 30 m in length, which were embedded within a matrix of dry stream bed. In these situations single or multiple pools were surveyed. Although an effort was made to survey a minimum of 30 m, survey distance often exceeded this. Second, distances of greater than 30 m were electrofished when either no, or few, fishes were collected within the first 30 m surveyed. This additional effort was directed at certifying the presence or absence of species. An effort was made to survey all habitats within a reach with equal effort (i.e., survey time and area surveyed), however, habitats immediately adjacent to stream banks often received more intensive surveying because these areas typically provided the most complex habitat for fishes, and therefore required the most attention. Block nets were used at the upstream and downstream ends of the survey location if physical conditions (e.g., high water velocities, poor water clarity, etc.) warranted their use. Electrofishing was conducted by either 2 or 3 person crews, with all members of the crew collecting stunned fish by dip net. Fish surveying at depths greater than 1 m was typically accomplished by minnow and/or beach seine, gill nets, or snorkeling with a mask. Surveying effort varied among these methods although most surveys conformed to the minimum 30 m survey distance. A student minnow seine was used to depths of 1 m while depths of between 1 m - 2 m were surveyed with a beach seine. Student and beach seines were constructed of 6-mm mesh and both were 1.5 m x 2 m and 2 m x 4 m in depth and width, respectively. Very shallow habitats (typically < 5 cm depth), where electrofishing and larger nets were not effective were surveyed with either small-size mesh dip nets (4-6 mm mesh) or fish were identified in-situ. Depths greater than 2 m were typically surveyed with gill nets (13- and 19-mm mesh nets, 2 m deep and 10 and 20 m in length) or by in-situ observation with a snorkel and mask. Gill nets were set for a period of two hours. The time of day of net set and retrieval varied. A mid-water trawl was used to survey sites in the Napa and Sonoma Marsh complex. For each collection site the following information was recorded: survey date and time; stream name(s) and narrative location; survey station (numbered sequentially for all sites surveyed on the same date); county name; and USGS 7.5 minute quadrangle name. The following data were collected: mm fork length (FL) or total length (TL), unless more than 30 individuals of a species were caught, in which case a representative 30 fish were measured and additional information were summarized with a narrative comment; the total number of species; the percentage native fish species in the collection. Estimates were made of the abundance in the sample of young-of-the-year, salmonids, and sculpins (0-3 scale, where 0 = no individuals, 1 = 1-24 individuals, 2 = 25-50 individuals, and 3 = >50 individuals); percentage of sample consisting of native species by abundance (1-3 scale, where 0 = no native fishes, 1 = 1-33% of the total number of individuals collected were native, 2 = 34-66% of the total number of individuals collected were native; and 3 = 67-100% of the total number of individuals collected were native).
Data Quality Information	High
Use Constraints	Presentation to be limited to indices until further discussions with SFEI and Rob Leidy.
Supplemental Information	Field survey station locations and descriptions were verified during database record entry. To create the GIS coverage, the station locations were first copied from the original USGS Quadrangle maps at the EPA to a second set of USGS Quadrangle maps housed at SFEI, and checked against the original set. These maps were then "heads-up" digitized using SFEI EcoAtlas control points and registered quadsheet images. 30% of the digitized station location points in the coverage were checked and verified against their original paper USGS quadsheet sources. A local assemblage of fishes may be defined as those fishes that would be found together at one particular place or locality. Fish assemblage structure (e.g., number of species, distribution or abundance of species at a locality, number of prey species versus piscivorous species, proportional composition of the assemblage by trophic groups or functional groups, body-size patterns for an assemblage, etc.) may vary considerably over time (i.e., morning to night, season to season, year to year) and space (e.g., riffle vs. pool, high-elevation headwater stream reach versus low-elevation reach near the stream mouth). Therefore, caution should be exercised in the data interpretation and any subsequent application of the data to define both broad- and fine-scale ecological patterns. Specific attention should be given to the limitations of the survey objectives and methods of this study when extending the data to other applications. For example, data on the distribution and abundance of fishes in this study was collected during the years 1992-1998. However, for many streams sampling was limited to a single sampling event. Any conclusions drawn from the data must therefore be drawn within the context of the natural temporal and spatial variability of stream ecosystems, as well as the objectives and methods of the study design. For more information, contact Robert A. Leidy, USEPA, Region 9. The database was modeled off the field datasheets. The design consists of three major groups of linked tables. The first group stores information about species nomenclature, such as scientific name, common name, family name, native designation, and phylogenetic order. The second group stores information about the survey stations and other location information, such as stream, watershed, county, and respective USGS 7.5 minute quadrangle. The final group stores the survey event data, namely, collection date, collection time, list of observed species and associated measured fork or total lengths, and any survey collector assigned species ratings. As a group, this latter set of tables serves as the link between the other two sets, the species nomenclature group and station location group. Data were transcribed from copies of the original datasheets during January to May 1999. The datasheet copies were sorted and organized by SFEI and assigned a distinct ID (SFEI Sheet ID number). Each datasheet represents one survey event. Please note, there are no field datasheets for SFEI Sheet ID# LF185 or LF203; these IDs were assigned to duplicate datasheets and subsequently discarded. The master list of fish species and families was provided by Robert Leidy. This list represents possible species within Bay Area streams, and not just those surveyed in the 1992 to 1998 fish survey. Species information about each survey event was taken from the field datasheets. All surveyed fish have been made to conform to the above master species list. Instances of no observed species at survey event have been flagged in the database. Cases of no individuals or no measured lengths are coded as -9 in the database. All field collector-assigned species abundance ratings were taken directly off the field datasheets. The master list of stations and associated information was compiled and organized by SFEI based upon the field datasheets. Each station has been assigned a distinct ID (SFEI Station ID number). Station location narrative descriptions were transcribed off the field datasheets with minimal editing. Stream names were taken primarily from the USGS 7.5 minute quadrangles. In cases of duplicate stream names within the Bay Area, the county name for that stream was included into the stream name designation. Watershed designations were assigned by SFEI and U.S. EPA based upon the name of the main channel connecting to the Bay. For sample stations in tidal sloughs, the corresponding Baylands Segment (Goals Project 1999, p.95) is identified. Several streams and watersheds remain unnamed. Please see Appendix 2 of the Bay Area Stream Fishes: Robert A. Leidy Fish Survey 1992-1998 Documentation summary and datasheet reports, Version 1.2 for specific details on the database design and table structure.
Counties	San Francisco Bay Area counties
Keywords	fish, stream
Publisher	SFEI
Title	Bay Area Stream Fishes Database
Other Citation Details	San Francisco Estuary Institute has worked up some of these data.
Contact Organization	San Francisco Estuary Institute
Contact Address	7770 Pardee Lane, 2nd Floor
Contact City	Oakland
Contact State	CA
Contact Zip Code	94621-1424
Contact Voice Telephone	510-746-SFEI (7334)
Contact Email	robin@sfei.org

 
 
 

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