Coho Distribution [ds326]

November 2022 Version

This dataset represents the "Observed Distribution" for coho salmon in California by using observations made only between 1990 and the present. It was developed for the express purpose of assisting with species recovery planning efforts. The process for developing this dataset was to collect as many observations of the species as possible and derive the stream-based geographic distribution for the species based solely on these positive observations.

For the purpose of this dataset an observation is defined as a report of a sighting or other evidence of the presence of the species at a given place and time. As such, observations are modeled by year observed as point locations in the GIS. All such observations were collected with information regarding who reported the observation, their agency/organization/affiliation, the date that they observed the species, who compiled the information, etc. This information is maintained in the developer's file geodatabase (Environmental Science Research Institute (ESRI) 2016).

To develop this distribution dataset, the species observations were applied to California Streams, a CDFW derivative of USGS National Hydrography Dataset (NHD) High Resolution hydrography. For each observation, a path was traced down the hydrography from the point of observation to the ocean, thereby deriving the shortest migration route from the point of observation to the sea. By appending all of these migration paths together, the "Observed Distribution" for the species is developed.

It is important to note that this layer does not attempt to model the entire possible distribution of the species. Rather, it only represents the known distribution based on where the species has been observed and reported. While some observations indeed represent the upstream extent of the species (e.g., an observation made at a hard barrier), the majority of observations only indicate where the species was sampled for or otherwise observed. Because of this, this dataset likely underestimates the absolute geographic distribution of the species.

It is also important to note that the species may not be found on an annual basis in all indicated reaches due to natural variations in run size, water conditions, and other environmental factors. As such, the information in this dataset should not be used to verify that the species are currently present in a given stream. Conversely, the absence of distribution linework for a given stream does not necessarily indicate that the species does not occur in that stream.

The observation data were compiled from a variety of disparate sources including but not limited to CDFW, USFS, NMFS, timber companies, and the public. Forms of documentation include CDFW administrative reports, personal communications with biologists, observation reports, and literature reviews. The source of each feature (to the best available knowledge) is included in the data attributes for the observations in the geodatabase, but not for the resulting linework. The spatial data has been referenced to California Streams, a CDFW derivative of USGS National Hydrography Dataset (NHD) High Resolution hydrography.

Usage of this dataset:

Examples of appropriate uses include:

- species recovery planning

- Evaluation of future survey sites for the species

- Validating species distribution models

Examples of inappropriate uses include:

- Assuming absence of a line feature means that the species are not present in that stream.

- Using this data to make parcel or ground level land use management decisions.

- Using this dataset to prove or support non-existence of the species at any spatial scale.

- Assuming that the line feature represents the maximum possible extent of species distribution.

All users of this data should seek the assistance of qualified professionals such as surveyors, hydrologists, or fishery biologists as needed to ensure that such users possess complete, precise, and up to date information on species distribution and water body location.

Any copy of this dataset is considered to be a snapshot of the species distribution at the time of release. It is impingent upon the user to ensure that they have the most recent version prior to making management or planning decisions.

Please refer to "Use Constraints" section below.

License : This work is licensed under Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ ). Using the citation standards recommended for BIOS datasets ( https://www.wildlife.ca.gov/Data/BIOS/Citing-BIOS ) satisfies the attribution requirements of this license.

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.

Please read the metadata document completely prior to use of this dataset.

Examples of appropriate uses include:

- Coho salmon recovery planning

- Evaluation of future survey sites for coho

- Validating coho distribution models

Examples of inappropriate uses include:

- Assuming absence of a point feature means that coho are not present in that stream.

- Using this data to make parcel or ground level land use management decisions.

- Using this dataset to prove or support non-existence of coho at any spatial scale.

- Assuming that the point feature represents the maximum possible extent of coho range.

This data attempts to show the latest available observations for coho Salmon in Calfornia, where such information is known. Please note this data is a work in progress and is subject to change/update as new information becomes available. This data contains observations currently entered into ASOD and should NOT be assumed to be all known observations. It is complete as far as time and resources have enabled it to be at this point in time, but as a result of these limitations underestimates the actual distribution of coho salmon observations. Its purpose is to be a guide for future management and planning.

Spatial data has been mapped to USGS National Hydrography Dataset (NHD) High Resolution hydrography. This is NOTan all-inclusive data set of coho salmon observations, as additional streams may exist that are not mapped on this source. Similarly, not every stream that has been mapped has been studied rigorously enough to be definitively ruled out as a coho stream. Because of the inherent inaccuracies involved when mapping data at different scales, moving point features generated from coordinates or digitizing to the hydrography, translating data from textual descriptions as well as from personal interviews, this dataset is not accurate enough to support parcel level analyses; it is suitable for watershed level uses only.

All users of this data should seek the assistance of qualified professionals such as surveyors, hydrologists, or fishery biologists as needed to ensure that such users possess complete, precise, and up to date information on coho salmon distribution and water body location.