Coho Distribution and Range

Background

Since 2002 the Department of Fish and Game's Northern Region Environmental Resources Information Services in conjunction with the Fisheries Branch has been developing an observation-based distribution model for coho salmon in California. This model consists of a series of interrelated datasets that depict the known distribution and range of coho salmon in California based on recorded observations (e.g., field reports, incidental observations, surveys, etc.).

No new field data are collected specifically for this effort. Rather, both new and previously documented observation data are compiled from a variety of agencies and organizations (e.g., USFS, CDFG, StreamNet, etc.) as they become available to us. The observation and distribution data are processed and evaluated, and a series of standard techniques are utilized to develop coho range and distribution GIS layers that are based on the observation data.

Utilizing the methodology described on the Anadromous Distribution page, we are able to fairly rapidly put together a baseline, linear distribution dataset for the species and a polygonal range by overlaying the distribution on Calwater planning watersheds (Figure 1). Given the current sensitivity of issues surrounding this species, we also spend a fair amount of time working with CDFG Fisheries Biologists to verify each record in the database. This verification process is critical to ensuring the validity of the dataset.

Project Status

The first publically available version of the coho distribution was published on CalFish in July, 2007. It was updated in April, 2009, December 2010 and most recently June 2012 to include over 9,000 newly compiled coho salmon observations. You can view the data via CalFish Fish Maps and you can download the data from CalFish Data Downloads.

We intend for this to be an ongoing and ever-improving dataset. We anticipate continuing to compile documented coho observation information and further refine the distribution layers. If you have observation data for coho and would like to include it in the statewide coho distribution dataset, please contact us.

Connie Shannon - PSMFC Data Management Specialist
California Dept. of Fish and Wildlife
2440 Athens Ave
Redding, CA 96001
(530)-225-2155
connie.shannon@wildlife.ca.gov

Tom Christy - ERIS GIS Analyst
California Dept. of Fish and Wildlife
2440 Athens Ave
Redding, CA 96001
(530)-225-2276
tom.christy@wildlife.ca.gov