LTRM Fisheries Data - Stratified Random and Fixed Site Sampling

The Long Term Resource Monitoring (LTRM) annual fish monitoring began on the Upper Mississippi and Illinois Rivers in 1989. During the first two years samples were collected at a series of fixed sampling sites, then in 1993 a stratified random sampling approach was added to the collection effort. This approach utilizes a computer routine that randomly selects sampling sites from a pool of potential sites that have been categorized by strata (e.g., aquatic habitat type, distance to shore, connectivity to main channel). The results from these collections are stored in an Oracle database at the Upper Midwest Environmental Science Center (UMESC). UMESC provides free access to the data through the Centers Web site (www.umesc.usgs.gov). [...]