Because different life stages of many species use both 

 estuarine and marine habitats, information on the 

 distribution, abundance, temporal utilization and life 

 history characteristics are needed to understand the 

 coupling of estuarine, nearshore, and offshore habi- 

 tats. Consequently, the ELMR program was developed 

 to integrate fragments of information on these species 

 and theirassociated habitats intoa useful, comprehen- 

 sive and consistent format. A national data base of this 

 type does not presently exist. Results from this pro- 

 gram will complement NOAA efforts to develop a 

 national estuarine assessment capability (NOAA 1 985), 

 identify information gaps, and assess the content and 

 quality of existing estuarine fisheries data. In addition 

 the ELMR data will be integrated with information from 

 NOAA's East Coast of North America Strategic As- 

 sessment Project to provide consistent species distri- 

 bution data in marine, as well as estuarine, environ- 

 ments (NOAA, 1991). 



Data Collection and Organization 



additional estuaries were included. The locations of the 

 17 selected estuaries and their associated salinity 

 zones are shown in Figure 3. 



Data on the spatial and temporal distributions of spe- 

 cies were compiled for the tidal fresh (0.0-0.5 parts per 

 thousand (ppt)), mixing (0.5-25.0 ppt), and seawater 

 (> 25 ppt) zones delineated for each estuary in the NEI. 

 A representative map and data table for Penobscot 

 Bay from the NEI Data Atlas is shown in Appendix 1 . 

 Each salinity zone is represented in 1 2 of the 1 7 North 

 Atlantic estuaries, but for the purposes of this study 5 

 estuaries are considered to be missing at least one of 

 the aforementioned zones (Figure 3). Salinity zones 

 that are only seasonally present or are extremely small 

 (i.e., <1 km 2 ) were generally omitted from this large- 

 scale assessment (see NOAA 1 985 for a discussion of 

 zone delineation). Referto Appendix 2, Estuary notes, 

 for the rationale for additions to the NEI and a discus- 

 sion of unique features of estuaries in the Gulf of Maine 

 region. 



Compiling consistent data nationwide limits the amount 

 of information that may be collected for each species 

 and estuary. It would also be both time and cost- 

 prohibitive to map each species by life stage for each 

 estuary (Monaco 1986). The NOAA framework en- 

 ables a consistent compilation and organization of all 

 available data on the distribution and abundance of 

 fishes and invertebrates in estuaries. Figure 2 summa- 

 rizes the major steps taken to collect and organize this 

 information. The initial steps were selection of the 

 estuaries and species to be studied. 



Selection of estuaries. Thirteen North Atlantic estu- 

 aries were selected from the National Estuarine Inven- 

 tory (NEI) Data Atlas-Volume I (NOAA 1 985) and, after 

 discussions with several regional researchers, four 



Selection of species. ELMR personnel and local 

 reviewers used the following four criteria, together with 

 data availability, to select 58 species for inclusion in the 

 ELMR data base (Table 1 ). The common and scientific 

 names of all species are those adopted by the Ameri- 

 can Fisheries Society (Turgeon et al. 1 988, Williams et 

 al. 1988, Robins et al. 1991): 



• Commercial value — determined by review of catch 

 data and value statistics from NMFS and state agen- 

 cies, e.g., Atlantic cod (Gadus morhua) and softshell 

 clam (Mya arenaria). 



• Recreational value — determined by relative impor- 

 tance in recreational fisheries that may or may not be 

 commercially exploited. Recreational species were 



Figure 2. Major steps taken to complete the North Atlantic ELMR study. 



Peer Review: 

 Data Verification 



Microcomputer 

 Data Base 



Spatial 

 Distribution 



Temporal 

 Distribution 



Relative 

 Abundance 



Data 

 Reliability 



