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USGS - science for a changing world


Daniel J Wieferich

Physical Scientist

Biogeographic Characterization

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

Supervisor: Sky Bristol
The Ironcolor Shiner (Notropis chalybaeus) is found in deep pool areas of creeks and small rivers and is often associated with aquatic vegetation. This species needs clear sandy areas for spawning. Populations of Ironcolor Shiner are in decline due to increased turbidity, siltation, and pollution.
The Waccamaw Silverside (Menidia extensa) has a very limited distribution confined to Lake Waccamaw in North Carolina, a lake with neutral pH levels from underlying limestone formations in an area of acidic natural waters. This species is found in large schools and often over dark-colored substrates. Its limited habitat is threatened by nutrient loading caused by the runoff of organic matter and agricultural chemicals.
This item provides the ScienceBase query that identifies components of the fish habitat assessments within the Central Midwest States. It also contains a link to a configuration file that pulls these pieces of information into a logical order. This information can be accessed through the ScienceBase API to display a summary of fish habitat assessment information for the Central Mississippi River States.
State-wide data on fish populations were limited in Alaska for use in this assessment, as was a detailed spatial (mapping) framework that fully characterizes watersheds throughout the state at the time this assessment was conducted. Because of these factors, we modified our assessment methods to account for these limitations. Twenty-one landscape disturbance variables were assembled from medium-sized watersheds throughout the state (i.e., 12-digit hydrologic unit code watersheds). Variables were then assigned to one of six categories based on their disturbances to stream habitats. Categories include: urban land use, agricultural land use, point source pollution and water quality, barriers to fish movement, human...
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