Since life stages of many species use both estuarine 

 and marine habitats, information on distribution, 

 abundance, temporal utilization, and life history 

 characteristics are needed tounderstandthe coupling 

 of estuaries and nearshore/offshore areas. To date, 

 a national, comprehensive, and consistent data base 

 of this type does not exist. Consequently, there is a 

 need to develop a program which integrates the 

 disparate information on marine and estuarine species 

 and their associated habitats into a useful, 

 comprehensive, and consistent data base. The 

 ELM R program was designed to help fulfill this need 

 by developing a uniform nationwide data base on 

 selected estuarine species. Results will complement 

 NOAA efforts to have a national estuarine assessment 

 capability (NOAA 1985) and also oceanic fishery 

 sampling programs (Sherman and Alexander 1 985). 

 Compiling this information also identifies information 

 gaps and assesses the content and quality of existing 

 estuarine fisheries data. 



Data Collection and Organization 



Figure 2 summarizes the major steps taken to collect 

 and organize information on the distribution and 

 abundance of fishes and invertebrates in Central 

 Gulf of Mexico estuaries. The initial steps were 

 selection of the estuaries and species to be studied. 



Selection of Estuaries. Estuaries in the Central Gulf 

 of Mexico were initially selected from the National 

 Estuarine Inventory (NEI) Data Atlas - Volume 1 

 (NOAA 1985) and NEI Supplelment 3 (Shirzad et al. 

 1989). The nine estuaries (Figure 3) selected forthe 

 Central Gulf of Mexico are: 



1. Mississippi Sound 



2. Lake Borgne 



3. Lake Pontchartrain 



4. Breton/Chandeleur Sounds 



5. Mississippi River 



6. Barataria Bay 



7. Terrebonne/Timbalier Bays 



8. AtchafalayaA/ermilion Bays 



9. Calcasieu Lake 



Data on spatial and temporal distributions of species 

 were developed and organized based on the tidal 

 fresh (0.0 too. 5 parts perthousand(ppt)), mixing (0.5 

 to 25.0 ppt), and seawater (>25.0 ppt) zones 

 delineated for each estuary in the NEI . Not all salinity 

 zones are represented in each estuary of the Central 

 Gulf of Mexico (Figure 3). The lack of seawater 

 zones in some estuaries is primarily due to freshwater 

 inflow from the Mississippi and Atchafalaya Rivers. 

 A representative map (Barataria Bay) from the NEI 

 Supplement 3 (Shirzad et al. 1989) is shown in 

 Appendix 1. 



Figure 2. Major steps taken to complete the Central Gulf of Mexico study. 



Outputs 



National 

 Estuarine 

 Inventory 

 Data Atlas 



■^ 



Nine 

 Estuaries 



■^ 



Compile 



Estuary 



Inforrnation 



Select 

 Species 



-> 



43 

 Speaes 



^ 



Develop 

 Life History 

 Summaries 



\y 



Prepare 



Species/Estuary 



Data Sheets 



/\ 



Peer Review 



Data 

 Verification 



■^ 



-) 



spatial 

 Distribution 



■^ 



Temporal 

 Distribution 



Microcomputer 

 Database 



^ 



Relative 

 Abundance 



^ 



Data 



Reliability 



