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Daniel J Wieferich

Physical Scientist

Science Analytics and Synthesis

Office Phone: 303-202-4603
Fax: 303-202-4710
ORCID: 0000-0003-1554-7992

DFC Bldg 810
Box 25046
Denver Federal Center
Denver , CO 80225-0046

Supervisor: Mark T Wiltermuth
This is the specific version of Watershed Boundary Dataset (WBD) that was used in the National Fish Habitat Partnership's 2015 National Assessment of Fish Habitat. No alterations were made to the data after download. Data and full metadata are attached. Users not interested in the National Fish Habitat Partnership's 2015 National Assessment of Fish Habitat are recommended to download the WBD from official access points hosted by the NRCS or USGS.
The Crystal Darter (Crystallaria asprella) requires large, clear-water streams with clean sand and gravel bottoms and moderate to swift currents. It is intolerant of siltation and other forms of pollution from various land use practices. Direct habitat degradation from damming, channelization, and dredging has also reduced habitat for this species. Remaining populations have become isolated from one another by dams and impoundments. The Mississippi River most likely no longer serves as a usable corridor for the Crystal Darter because of the silt load. The isolated local populations are then vulnerable to single destructive events such as toxic chemical spills.
Big Sauble River draining into Lake Michigan in Ludington, Michigan.
Key elements of the 2015 national assessment of stream fish habitats follow the 2010 assessment, including: 1) the idea that distributions and numbers fishes reflect the quality of habitat in which they live; and 2) human landscape factors pose a risk to the condition of stream habitat, and indirectly, to fishes. The 2015 inland stream assessments for the contiguous United States, Alaska, and Hawaii all followed five broad steps (Figure 1) that are described in detail below for the inland stream assessment for Alaska. Note that analytical details for the Alaska assessment differed in southeast Alaska as compared to the remainder of the state (referred to as greater Alaska) due to differences in the resolution of...
Tags: 2015, Alaska, Method
Accounting for natural variation With the exception of differences in spatial units, assessments for greater Alaska and southeast Alaska were conducted similarly across regions. Because stream fish assemblage data were not available for the state, no steps were taken to account for natural variation in stream habitats for either southeast or greater Alaska. This represents an important need for future work.
Tags: 2015, Alaska, Method
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