CONCLUSIONS 



Aerial surveys in the Gulf of Mexico completed during the Pilot Study provided 

 unique data on the distribution, relative abundance, and ecology of 13 mammal, 35 bird, 

 and 5 turtle taxa, including several endangered and threatened species. Precise 

 locational and environmental data on approximately 3,000 sightings allowed formation of 

 a preliminary data base for multidimensional analyses. Once data cover an adequate 

 time period, analyses of species composition, temporal and spatial distributions, 

 movements, areas of special significance, and relative abundance will be possible. The 

 combined effect of the small number of samples (2) and the interval between samples (3 

 months) precludes such analyses at present. Knowledge of OCS areas must be based on 

 more frequent samples conducted over annual cycles. 



The results of the present study indicate that large voids in the knowledge of 

 endangered and vulnerable animals in OCS areas can be filled by future studies. 

 Preliminary maps of the distribution of taxa within the study area illustrate relationships 

 and zonation within surveyed areas and adjacent waters. These maps, although based on 

 observations over a short time, illustrate distributions on a more detailed scale than 

 previously available. 



A greater number of mammal species, including several whales, were found off 

 Texas than off western Florida. This may reflect the narrower continental shelf of Texas 

 waters. The importance of the waters off of southern Texas as marine mammal habitats 

 was illustrated by the frequency of sightings in this area. The discovery of the 

 endangered sperm whale in both Texas survey subunits is remarkable in providing the 

 first observations of living individuals of this species in the western Gulf of Mexico in 

 several decades. 



Seasonal movements of terns, shearwaters, and several dolphin taxa are evident. 

 Royal terns and other species were noted to extend further offshore over deeper waters 

 in November than in August. Understanding of these patterns would be important in 

 evaluating of oil and gas impacts on these and other migratory species. 



More turtle species and a higher density of turtles were observed in Florida than 

 in Texas during both survey periods. Loggerhead turtles were exceptionally abundant in 

 Florida waters. Some evidence exists for long-distance movements of loggerhead turtles 

 from the western Florida coast to the lower Keys and Dry Tortugas. Magnificent 

 frigatebirds and other birds appear to move along similar routes. Of the Stenella species 

 encountered, spotted dolphins were most conspicuous in Texas waters. Striped dolphins 

 were in Florida waters on a seasonal basis. 



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