Why Biological Monitoring?
Nebraska has over 81,000 miles of streams of which approximately 18,000 miles flow continuously. Streams in Nebraska are capable of containing a rich diversity of aquatic life including aquatic macroinvertebrates (i.e. small animals living in water that can be seen with a naked eye), fish, amphibians, and mammals. Nitrogen, phosphorus, pesticides, sediment, and other pollutants are stressors that can degrade stream conditions for aquatic life, and can be potentially harmful to us. The aim of the Stream Biological Monitoring Program (SBMP) is to provide accurate statewide assessments of the biological conditions of Nebraska’s streams so that sound decisions in management, planning, and regulation can be made or revised
History of the Stream Biological Monitoring Program:
The Department began biological monitoring in 1983 with a targeted approach for classifying stream segments for Title 117 (Nebraska Surface Water Quality Standards). These sites were typically located at bridges. Over 900 stream sites were sampled for fish and macroinvertebrates over a 14 year period. In 1997, the Department added a probabilistic monitoring design that involved the sampling of randomly selected sites to it’s SBMP in order to address statewide and regional questions about water quality. Data to answer such questions as “How good is the water quality in Nebraska?” is best obtained from sample locations chosen so that all streams have an equal chance of being sampled. These monitoring sites are generated by a computer program that randomly chooses sites on streams throughout Nebraska. From 1997-2009, the biological communities of 444 randomly selected stream sites were sampled.
Where is the Monitoring Conducted?
Each year 34-40 randomly selected wadeable stream sites (i.e. streams that are shallow enough to sample without boats) are chosen for study in two or three river basins throughout Nebraska. During a six-year cycle, all 13 major river basins in the state are intensively monitored (see map above for basin divisions).
What is Monitored?
Routine chemical analyses of water samples provide water quality information for a snapshot in time and short-term pollution events may never be detected. Chemical analyses also provide no indication of the stream’s physical nature or habitat. The “health” of a stream depends on not only the contaminants present or absent, but the quality of the habitat and the creatures living there. NDEQ’s SBMP assesses the health of streams by evaluating the composition and numbers of resident aquatic macroinvertebrate and fish communities. Assessments are made by comparing the macroinvertebrate and fish communities at “reference condition” streams where there are no significant disturbances, to the communities collected from the randomly selected stream sites.
Aquatic macroinvertebrates are small creatures that live in streams attached to rocks, vegetation, or woody debris, or burrowed into the stream bottom. They include aquatic larval stages of insects such as mayflies and dragonflies; crustaceans such as crayfish and clams; and worms and snails. Because they are extremely sensitive to pollutants, macroinvertebrate populations often respond to changes in water quality caused by the introduction of various contaminants into the stream. Department personnel have collected nearly 600 different species of macroinvertebrates since 1997 through the sampling effort associated with the SBMP. In addition, numerous new species not previously found in Nebraska have been recorded.
From small coldwater trout streams to large warm rivers, Nebraska streams support about 50 species of fish. As with macroinvertebrates, fish display varying habitat requirements and water quality tolerances making them excellent indicators of stream health. The majority of Nebraska’s species are small, with adults generally less than 5 inches long. The Department’s fish surveys have also provided information on changing abundances and ranges of fish in the state. Some species have been found to occur in many more places than previously thought, while others have shown dramatic declines over the last 30 years.
How are the Data Used?
The biological data collected through the SBMP are used to inform a variety of management activities, such as:
Under the federal Clean Water Act, states are required to develop programs to evaluate the physical, chemical, and biological integrity of the Nation’s waters and to adopt water quality standards to restore and maintain that integrity. States must report to Congress on the condition of all waters within their boundaries every two years. The information collected by the Department’s SBMP satisfies these requirements for assessing the biological integrity of Nebraska’s streams.
- Documenting current statewide biological conditions in Nebraska’s streams to track water quality status and trends.
- Identifying streams that do not attain their assigned environmental goals and are in need of restoration or remedial action. Where significant problems were found (i.e. streams were assessed as having poor biological conditions), these stream segments are placed on the 303(d) List of Impaired Water Bodies (as required by the federal Clean Water Act) with regard to aquatic life.
- Identifying exceptional stream segments (reference conditions).
- Providing accurate biological distribution information.
For More Information
The Stream Biological Monitoring Program 2004-2008 can be found on this web site by going to Publications/Surface Water Monitoring Assessment Program/Reports. Or, the direct URL is: http://deq.ne.gov/Publica.nsf/pages/WAT170
The complete 2010 Water Quality Monitoring Report can be found on this web site by going to Publications/Water Quality/Annual Reports. Or, the direct URL is: http://deq.ne.gov/Publica.nsf/pages/WAT169
2010 Nebraska Water Monitoring Report
Nebraska Stream Classifications for the 2004-2005 Stream Biological Monitoring Program.