Mammals in NFLA 



The marine mammals sighted within the NFLA subunit during August were 

 distributed into three assemblages on the basis of water depth. Bottlenose dolphins were 

 conspicuously concentrated inshore in relatively shallow waters (Map 17). Of 14 groups 

 recorded, 9 (64%) were in waters less than 10 m deep, and all were in depths less than 

 80 m. All Stenella species (including the spotted dolphin, striped dolphin, and 

 unidentified Stenella) were in waters deeper than 25 m (Map 18). Two groups of striped 

 dolphins (25% of all Stenella ) were near the 200-m contour and nearly 200 km offshore. 

 Three groups of saddleback dolphins were near the 100-m contour. A single unidentified 

 whale can be considered a deepwater constituent. It was sighted over 200 km from shore 

 and beyond the 200-m contour (Map 17). 



During November bottlenose dolphins were in waters with a mean depth of 17.7 m 

 (the August mean was 35.9 m). Unidentified Stenella also appeared in shallower water 

 during November (August x = 78.7 m; November x = 58.8 m). 



Mammals in SFLA 



The mammals observed in SFLA during August consisted of a shallow water form, 

 bottlenose dolphins, and several mid to deep water species, including Stenella species and 

 unidentified dolphins. The five bottlenose dolphin groups identified were within the 30-m 

 depth contour (Map 19). Of the unidentified dolphin groups, seven (38.9%) were within 

 the 30-m contour and were suspected to represent bottlenose dolphin groups (Map 19). 

 The remaining unidentified dolphins (ca. 60%) were in waters 30 to 70 m deep. Two 

 groups of unidentified Stenella (Map 20) were sighted at similar depths (i.e., between the 

 35- and 45-m contours). Striped dolphins (Map 20) occurred in waters 20 to 80 m in depth 

 (x = 43.3 m); 56% of these were outside the 30-m depth contour. Only a small percentage 

 of the striped dolphins and the unidentified dolphin groups were seen in the extreme 

 seaward sections of the SFLA survey subunit. 



During November surveys of SFLA, 10 groups of bottlenose dolphins were sighted 

 in waters less than 50 m deep; 80% were in waters within the 30-m contour. A single 

 striped dolphin group was sighted in 18-m water, the shallow extreme of all August 

 sightings for this species. Unidentified Stenella were in waters with a mean depth of 

 28.9 m. 



Birds in STEX 



STEX has the narrowest continental shelf of any of the survey subunits, so a 

 higher proportion of the survey time was spent flying over deep water in this subunit than 

 in the others. This was reflected in the bird fauna, for the offshore component was more 

 prominent here than in the other survey subunits. 



All of the summer migrant pelagic species seen in the surveys were present in 

 STEX during August; no other survey subunit had even half these species. The only brown 

 booby seen in the surveys was here, in water 650 m deep (ca. 100 km offshore). More 

 Cory's shearwaters than had been recorded previously from Texas were seen in our STEX- 

 August survey. Our nine sightings (Map 21), involving about 200 birds, were clustered in 

 waters 130 to 800 m deep, although one was in water over 1,000 m deep. Audubon's 

 shearwater, storm-petrel, and unidentified shearwater records are displayed on Map 22. 



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