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Stream and River Condition Across the BLM's National System of Public Lands.
Citation:
Courtwright, J., S. Miller, Steve Paulsen, Tony Olsen, AND Phil Kaufmann. Stream and River Condition Across the BLM's National System of Public Lands. Society for Freshwater Science, Sacramento, CA, May 21 - 26, 2016.
Impact/Purpose:
This presentation will discuss options for combining survey data to answer a broad assessment question.
Description:
The Bureau of Land Management (BLM), in collaboration with the U.S. Environmental Protection Agency, conducted the first ever Western Rivers and Streams Assessment (WRSA), a survey of the condition of BLM streams and rivers throughout the contiguous western U.S. The WRSA was designed to answer three central questions: 1. What percentage of BLM’s streams and rivers exhibit minimal, moderate or significant departure from biological reference conditions; 2. What is the linear extent of streams and rivers experiencing stressors such as nutrient, salinity and sediment loading; and 3. What is the risk posed by the observed stressors to biological condition?West-wide, preliminary results suggest that 30% of BLM streams and rivers exhibit minimal departure, 23% moderate departure and 47% significant departure from biological reference conditions, as measured by aquatic macroinvertebrates. The most ubiquitous stressors were excessive salinity, nutrient loading and reduced levels of canopy cover and instream habitat complexity. These same stressors were associated with increased risk of macroinvertebrate biological condition being in poor condition. In this talk, we will present final results for the WRSA.