In 1985, NOAA launched the Estuarine Living Marine Resources (ELMR) Program to develop a consistent data base on the distribution, relative abundance, and life history characteristics of ecologically and economically important fishes and invertebrates in the Nation's estuaries. The Nationwide ELMR data base includes information for 153 species found in 122 estuaries and coastal embayments. Species are selected according to a set of criteria, which consider their commercial, recreational, and ecological value, as well as their utility as an indicator of environmental stress.The data base is divided into five study regions - West Coast, Gulf of Mexico, Southeast, Mid-Atlantic, and North Atlantic. For each species, five life stages are considered - adults, juveniles, larvae, spawning, and eggs - with some exceptions. Each estuary is subdivided into one to five salinity zones. Relative abundance is ranked by month for each life stage of each species, in each salinity zone of each estuary. The program utilized a consistent sampling strategy that enables comparisons to be made among species, specific life stages and times of year within, and to a lesser degree, among estuarine systems.In addition, a series of reports have been published which summarize the methods and results of the ELMR Program. These include a National report (2000), regional data summary reports for the North Atlantic (1994), Mid-Atlantic (1994), Southeast (1991), Gulf of Mexico (1992), and West Coast (1990), and regional life history summary reports for the West Coast (1991) and Gulf of Mexico (1997). Free copies of these reports are available upon request from the Biogeography Program (301-713-3028).