Packed with news and information for serious bass fishermen, BASS Times goes beyond the basics to improve your fishing success. Click here to learn more about a one-year subscription to BASS Times for only $12.
WASHINGTON Almost half of the streams in the continental United States are in poor condition, according to a recent study conducted by the U.S. Environmental Protection Agency (EPA).
The Wadeable Streams Assessment (WSA) is the first comprehensive analysis of U.S. streams ever conducted.
For the purposes of the study, a "wadeable" stream was defined as any stream or river that can be crossed without a boat. This definition describes 90 percent of all river and stream miles in the lower 48 states.
Over the course of five years (2000-2004), researchers collected and analyzed samples from nearly 1,400 locations. Among other things, the samples consisted of tiny creatures known as benthic macroinvertebrates which are found under rocks and debris on stream bottoms. Examples of benthic macroinvertebrates include crawfish, snails, worms and the aquatic larval stages of insects.
To organize and present the results of the WSA, the authors utilized percentages of stream miles in specific geographical areas to describe the overall health of streams nationwide. Several characteristics of the streams were examined, including nitrogen and phosphate levels, excessive streambed sediment and the condition of stream banks.
The study contained an overall assessment of the continental United States as well as an individual assessment for each of the nation's three general regions East, Midwest and West. The report also divided the country into nine "eco-regions," which differed significantly from each other in terms of stream mileage and other characteristics.
The results of the study indicate that 41.9 percent of the stream miles in the lower 48 states are significantly degraded. The percentage of stream miles rated in good condition was only 28.2 percent.
For the Eastern region, only 18.2 percent of the streams are considered to be in good condition while almost 52 percent were rated as poor. In the Midwestern states, the WSA reported that 29 percent of stream miles were in good condition while 40 percent were considered poor. In the West, 45.1 percent of streams rated as good while 27.4 percent were considered poor.
The researchers found that a small number of chemicals and conditions are responsible for the poor quality of many streams in the country. These causes are known as stressors. The stressors most commonly found in or around streams are nitrogen, phosphate, excessive sediment and riparian disturbances.
Nitrogen and phosphate, two types of nutrients commonly used by the agriculture industry, are particularly harmful to benthic macroinvertebrates. Excessive sediment, which may be sand, mud or other similar material, can coat stream bottoms and suffocate bottom dwelling creatures.
Riparian disturbances were classified as any human activity that negatively impacted stream banks. These activities may include construction projects, pipe laying or clearing stream banks of trees and bushes.
Riparian areas are often not recognized as critical to the health of streams, even though trees, bushes and tall weeds protect streams from erosion and create shady areas that are beneficial to aquatic life during warmer months. The excess branches and leaves from trees provide habitat and food for stream dwellers.
While the WSA does not provide starting conclusions or recommendations for action, it adds significantly to the body of knowledge about an important natural resource. The WSA was not conducted in isolation. A number of government and private sector partners were included in the assessment. The EPA will be able to use the results from the WSA as part of its efforts to better define water quality criteria.
"The WSA is the latest in a series of surveys that the EPA is conducting on all surface waters in the United States," said the EPA in a statement.
"Coastal condition has already been evaluated. Over the next five years, the EPA will sample the condition of lakes, large rivers and wetlands. Then the process will be repeated in order to provide an ongoing comparison of the state of the water."
An assessment of the nation's lakes is expected to start in 2007.