Information was compiled for each of five life stages. 

 Adults were defined as sexually mature individuals, 

 juveniles as immature but otherwise similar to adults, 

 and spawning adults as those releasing eggs or sperm. 

 A few exceptions existed to these defined life stages, 

 such as mating of crabs and spiny lobster, and partu- 

 rition (live birth) of the viviparous bull shark. 



For well-studied species such as shrimp, quantitative 

 data were used to estimate abundance levels. For 

 many species, however, reliable quantitative data were 

 limited. Therefore, regional and local experts were 

 consulted to estimate relative abundances based on 

 the above criteria. Several reference or "guide" spe- 

 cies with abundance levels corresponding to the above 

 criteria were identified for each estuary. These guide 

 species typified fishes and invertebrates belonging to 

 a particular life mode (e.g., pelagic, demersal) or 

 occupying similar habitats. Once guide species were 

 selected, other species were then placed into the 

 appropriate abundance categories relative to them. 

 These data represent relative abundance levels within 

 a specific estuary only; relative abundance levels across 

 Gulf of Mexico estuaries could not be determined. 



Information was compiled for each species and estu- 

 ary combination, and organized into four data summa- 

 ries in Volume I : 



• Presence/absence 



• Spatial distribution and relative abundance 



• Temporal distribution 



• Data reliability 



The presence/absence information is also presented 

 here in Volume II, with some minor revisions based on 

 peer review. Table 4 (p. 8-9) was developed to readily 

 convey the occurrence of each of the 44 ELMR species 

 in each of the 31 Gulf of Mexico estuaries. This table 

 depicts the highest relative abundance of the adult or 

 juvenile life stage of each species, in any month, in any 

 salinity zone within each estuary. The spawning, egg, 

 and larval life stages are not considered. This table 

 also suggests the zoogeographic distribution of spe- 

 cies among Gulf of Mexico estuaries. 



Data Verification. Several years were required to 

 develop the 1,364 data sheets and consult with re- 

 gional and local experts. Each data sheet was carefully 

 reviewed during consultations or by mail. These con- 

 sultations complemented the published and unpub- 

 lished literature and data sets compiled by NOAA. 

 Over 100 scientists at approximately 50 institutions or 

 agencies were consulted. Local experts were particu- 

 larly helpful in providing estuary/species-specific infor- 

 mation. They also provided additional references and 

 contacts and identified additional species to be in- 

 cluded in the ELMR data base. 



Life History Summaries and Tables 



Life History Summaries. A concise life history sum- 

 mary was written for each species to provide an over- 

 view of how and when a species uses estuaries and 

 what specific habitats it uses. The summaries empha- 

 size species-specific life history characteristics that 

 relate directly to estuarine spatial and temporal distri- 

 bution and abundance (e.g., many molluscs have 

 particular salinity and substrate preferences). Informa- 

 tion for the species life history summaries was gath- 

 ered primarily from published and unpublished litera- 

 ture, and experts with species-specific knowledge were 

 also consulted. Summaries were written using the 

 format shown in Table 3, p. 7. A glossary of scientific 

 terms used is provided on pages 341-353. 



Included with each summary is a relative abundance 

 table based on ELMR data from Volume I, with minor 

 revisions based on review. These tables (Tables 5.01 - 

 5.44) provide a synopsis of the species' occurrence in 

 the 31 ELMR Gulf of Mexico estuaries. Information for 

 each table was obtained by summarizing the ELMR 

 data for each month of the year and across all salinity 

 zones to obtain the highest level of abundance for each 

 life stage. Hence, these tables depict a species' 

 highest abundance within an estuary, but lack the 

 temporal and spatial resolution provided in Volume I. 



Life History Tables. While the species life history 

 summaries provide brief accounts of important life 

 history attributes, they do not permit a direct and simple 

 assessment of characteristics that a species shares 

 with others. Furthermore, many life history attributes 

 are categorical (e.g., feeding types can be classified as 

 carnivore, herbivore, detritivore, etc.) and more easily 

 viewed in a tabular format. Therefore, information 

 found in the species life history summaries was aug- 

 mented with additional physical and biological criteria 

 and condensed into three life history tables: Table 6, 

 Habitat Associations, p. 355-363; Table 7, Biological 

 Attributes, p. 365-373; and Table 8, Reproduction, p. 

 375-377. Column headers for these three tables are 

 depicted in Figure 5. These tables present life history 

 characteristics for each species along with behavior 

 traits and preferred habitats. They reflect the most 

 current information about a species as gathered from 

 published and unpublished literature and can be used 

 to quickly identify species with similar traits. For 

 example, a reader interested in only benthic species 

 can use Table 6, Habitat Associations, to identify 

 relevant species. Terms used in the life history tables 

 are defined at the beginning of each table, and in the 

 Glossary, p. 341-353. 



