Coho Distribution and Range
This CalFish Data Download contains two shapefiles, Coho_Distribution.shp and Coho_Range.shp. Below are the descriptive abstracts for each shapefile followed by links to their complete metadata. Please read the complete metadata before using these datasets.
Coho Distribution Abstract
June 2012 Version
dataset represents the "Observed Distribution" for coho salmon in
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
To develop this distribution dataset, the species observations were applied to standard k hydrographic features from the National Hydrographic Dataset (NHD). 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.
observation data were compiled from a variety of disparate sources including
but not limited to CDFG,
For suggested data usage and constraints, citation/contact information and detailed processing and attribute information, please follow this link: Complete metadata for Coho_Distribution.shp
June 2012 Version
This data set
contains all CalWater 2.2.1 Planning Watersheds (PWS)
It is important to note that this data set does not attempt to model the entire possible distribution of the species. Rather, it only represents planning watersheds intersecting the known distribution, which is based on where the species has been observed and reported. While the distribution data may indeed represent the extent of the species, generally the upstream extent of the distribution only represents the location of positive sampling or other observations.. Therefore, this data set likely represents an underestimation of the absolute geographic distribution of the species.
This watershed level
data set was derived by intersecting Calwater planning
watersheds with point and line features depicting Coho salmon distribution.
These features are derived from a subset of 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
the California Department of Fish and Game (CDFG), Northern Region,
Environmental Resources Information Services with assistance from CDFG Biogeographic Data Branch and Pacific States Marine
Fisheries Commission. These data are based upon confirmed observations of Coho
salmon. Effort has been made to identify and correct watersheds that were
erroneously selected due to inaccuracies from using data of different scales.
The observation data that are the basis for the distribution were compiled from
a variety of disparate sources including but not limited to
This derived dataset is meant to be continually updated as additional information is acquired. As such, any copy of this dataset is considered to be a snapshot of the known Coho Distribution at the time of release. It is incumbent upon the user to ensure that they have the most recent version prior to making management or planning decisions.
For suggested data usage and constraints, citation/contact information and detailed processing and attribute information, please follow this link: Complete metadata for Coho_Range.shp