Compiling consistent data nationwide limits the 

 amou nt of information that may be compiled for each 

 species and estuary. Also, it would be time and cost 

 prohibitive to map each species by life stage for each 

 estuary (Monaco 1986). This framework enables a 

 consistent compilation and organization of available 

 information on the distribution of fishes and 

 invertebrates in estuaries. 



Although necessary forthis study, the NEI Data Atlas 

 (NOAA 1 985) does not contain sufficient information 

 on some physical parameters that affect species 

 distributions. Additional information was compiled 

 on geological history, bottom type, watertemperature, 

 tidal and freshwater circulation, and water quality to 

 help understand the reported distribution of 

 organisms. These additional data helped filter out 

 seasonal anomalies and reports of unusual species 

 distributions. Therefore, the information developed 

 represents a species usual spatial and temporal 

 distributions. 



Selection of Species. Four criteria were used to 

 identify 43 species that had enough available 

 information for inclusion in the ELMR data base. The 

 four criteria were: 



1 ) Commercial value - determined by review of 

 catch data and value statistics from NMFS and state 

 agencies (e.g.. Gulf menhaden, Brevoortiapatronus, 

 and shrimp, Penaeus species) 



2) Recreational value - defined as a species that 

 recreational fishermen specifically try to catch that 

 may or may not be of commercial importance. 

 Recreational species were determined by consulting 

 regional experts and NMFS reports, e.g., spotted 

 seatrout, Cynoscion nebulosus, and red drum, 

 Sciaenops ocellatus. 



3) Indicator species of environmental stress - 

 identified from the literature, discussions with fisheries 

 experts, and from monitoring programs such as 

 NOAA's National Status and Trends Program (NOAA 

 1984). These species (e.g., American oyster, 



Figure 3. ELMR Central Gulf of Mexico estuaries and associated salinity zones. 



Estuarv 



1. Mississippi Sound 



2. Lake Borgne 



3. Lake Pontchartrain 



4. Breton/Chandeleur Sounds 



5. Mississippi River 



6. Barataria Bay 



7. Terrebonne/Timballer Bays 



8. AtchafalayaA/ermilion Bays 



9. Calcasieu Lake 



Salinity zones present 



Legend: 



T = Tidal fresh zone 



M = Mixing zone 



S = Seawaler zone 



* = Salinity zone not present 



