Rationale 



Estuaries are among the most productive natural sys- 

 tems and have been shown to be important nursery 

 areas that provide food, refuge from predation, and 

 valuable habitat for many species (Tyler 1971, 

 MacDonald et al. 1984, Langton et al. 1989, Day et al. 

 1989, Ayvazian et al. 1992). Estuarine organisms that 

 support important commercial and recreational fish- 

 eries include bivalves, decapods, and a variety of 

 finfish. In spite of the well documented importance of 

 estuaries to fishes and invertebrates, few consistent 

 and comprehensive data bases exist that allow exami- 

 nations of the relationships between estuarine species 

 found in or among groups of estuaries. Furthermore, 

 much of the distribution and abundance information 

 for estuarine-dependent species (i.e., species that re- 

 quire estuaries during their life cycle) is for offshore 

 life stages and does not adequately describe estuarine 

 distributions (NOAA 1990a, Darnell et al. 1983). 



Only a few sampling programs collect fishes and 

 invertebrates with identical methods across groups of 

 estuaries within a region. Examples include inshore 

 trawl surveys conducted by the Massachusetts Divi- 

 sion of Marine Fisheries (Howe et al. 1991), the Maine 

 Department of Marine Resources (MDMR 1993), and 

 the Texas Parks and Wildlife Department 

 (Hammerschmidt and McEachron 1986). Therefore, 

 most existing estuarine fisheries data cannot be com- 

 pared among estuaries because of the variable sam- 

 pling strategies. In addition, existing research pro- 

 grams do not focus on how groups of estuaries may be 

 important for regional fishery management, and few 

 compile information for species having little or no 

 economic value. 



Because many species use both estuarine and marine 

 habitats during their various life stages, information 

 on their distribution, abundance, temporal utilization 

 and life history characteristics are needed to under- 

 stand the coupling of estuarine, nearshore, and off- 

 shore habitats. Consequently, the ELMR program 

 was developed to integrate fragments of information 

 on these species and their associated habitats into a 

 useful, comprehensive and consistent format. Until 

 recently, a national data base of this type did not exist 

 (Figure 2). 



Results from the ELMR program contribute to NOAA's 

 development of a national estuarine assessment capa- 

 bility (NOAA 1985a), identify information gaps, and 

 assess the content and quality of existing estuarine 

 fisheries data. ELMR data are being incorporated into 

 the National Coastal Assessment and Data Synthesis 

 Framework (CA&DS), which integrates national data 

 sets for 138 estuaries within a spatial framework with 

 analytical capabilities (Orlando 1999). In addition, 

 the ELMR data are being used to define Essential Fish 

 Habitat under the revised Magnuson-Stevens Act 

 (NOAA 1996, NOAA/GMFMC 1998). 



Base ELMR Data Collection 



An initial pilot study was completed in 1986 for U.S. 

 West Coast estuaries to determine the feasibility and 

 scope of a national ELMR program, and to evaluate 

 the proposed ELMR methodology (Monaco 1986). It 

 was determined that the amount of information that 

 could be compiled for each species and estuary on a 

 nationwide basis was limited, and that it would be 

 both time and cost-prohibitive to map each species by 

 life stage for each estuary. Therefore, a spatial frame- 



Table 1. ELMR regional data bases and reports, completion dates, revisions/updates, and applications. 



'Specific applications: 

 GWIS = Gulfwide Information System. 

 EFH = Essential Fish Habitat designation. 

 ESI = Environmental Sensitivity Index maps. 



