KMZs and other files showing the distribution of CA Steelhead are available from the download system.
Steelhead run across virtually the entire California coast from the Oregon border to San Diego. We’ve created KMZs that provide 3 complementary datasets: 1) Distribution, 2) Critical Habitat, and 3) Abundance. We’ll describe each in turn.
California Steelhead Distribution
These KMLs simply provide stream distribution without much additional data. They are a useful base layer. The summer run, coded orange, is much smaller than the winter run, coded turquoise, which spans the entire coast and parts of the central valley and entirely overlaps the summer run. You can see parts of the winter run which aren’t coded “critical habitat” as the turquoise lines in the photo.
As part of the process under the Endangered Species Act (“ESA”), Federal and state agencies are charged with creating a list of “critical habitat” for special protection. There’s a complicated definition but (to oversimplify) it’s habitat that’s considered both to be under threat and to be critical to health of the species.
In the photo, critical habitat is colored purple to blue to gray. The coloring we chose here is based on the quality of the “rearing” habitat. This is a vector dataset, and you can view the data record for each reach by clicking on the stream segment. Each reach record describes use (e.g. rearing, migration, spawning) and many provide an estimate of habitat quality.
As you can see in the photo, much habitat is coded “critical”. Where it’s not,we assume it’s because the water is NOT considered to be under threat. Logically speaking, you would assume much of the best fishing water would NOT be critical habitat, as the best habitat wouldn’t be threatened. However, within the critical habitat areas, this is a very useful dataset.
Photo Source: Google Earth image with distribution data from CalFish sponsored Anadromous Distribution Program and California Department of Fish and Game; critical habitat data compiled by the National Marine Fisheries Service (NOAA Fisheries) Southwest Regional Office (SWR)
For many years, CDFG personnel have been measuring the abundance of steelhead runs in various ways. All of this data is collected in a StreamNet database, and much of it is easily accessible using this KMZ.
Data (which can see plotted below) is available only for a relatively small number of streams, all of which are in the northern part of the state. It is color coded according to the average fish count ranging from dark green (10’s) to bright red (100,000’s). Each color step is a factor of 10x.
You can click on the each stream segment, and bring up a balloon with information about the segment. Even more useful, you can click on the hyperlink, and see a complete history of the segment and all of the survey findings. (scroll down to bottom photo).
Source: CalFish Abundance Database; images in Google Earth