young animals in the sample. For this reason, comparisons of the available age samples were 

 considered inconclusive. The length structure of the stranded animals, although only a gross 

 approximation of age, was not considered biased and indicated that proportionally fewer 

 younger animals (<1 year old) stranded during 1990 than during previous years. 



Food Habits 



Due to the implication of feeding habits in the recent mortalities of bottlenose 

 dolphins (Geraci 1989) and humpback whales (Geraci et al. 1989) along the eastern U.S. 

 coast, there was concern of a sirnilar occurrence in the Gulf of Mexico during 1990. This 

 study examined the food habits of bottlenose dolphins stranded along the coast of Texas 

 during January-April 1990 and compared the results with a previous study of bottlenose 

 dolphin stranded during 1986-87 in the same area (Barros and Odell 1990), 



Entire stomachs were collected from 38 stranded bottlenose dolphins and frozen for 

 analysis. A total of 15,950 otohths, 1,681 squid beaks and remains of 59 crustaceans were 

 found, representing 7,109 fish, 915 squid and 59 crustaceans. Prey items averaged 219.1 and 

 prey taxa 9.4 per stomach. Altogether, 46 species of fish (from 11 families), 3 species of 

 cephalopods and 2 species of crustaceans were identified. Six prey species occurred in more 

 than 50% of the stomachs and accoimted for 57% of all prey. These species were: the 

 Atlantic croaker (Micropogonias undulatus), silver perch (Bairdiella chrysoura), brief squid 

 {Lolliquncula brevis), sand seatrout {Cynoscion arenarius) and an unidentified telelost. 



Wet weight of the stomach contents (an indicator of stomach fullness), the numbers 

 of prey items and prey taxa in each stomach, and the categories of prey types (fish, 

 cephalopod, crustacean) were not significantly different from those reported in Barros and, 

 Odell (1990). The four most commonly and numerically important prey (M. undulatus, C. 

 arenarius, B. chrysoura, and L. brevis) were represented in both 1986-87 and 1990. The 

 results obtained in the present study show that bottlenose dolphins stranded during the 1990 

 Gulf of Mexico mortality event had a similar prey spectrum as dolphins stranded in previous 

 years, and suggest that the food habits of the dolphins stranded during 1990 were not 

 significantly different from 1986-87. 



Environmental Factors 



The Texas marine mammal stranding data base allowed analysis of bottlenose dolphin 

 stranding in relation to certain physical factors of the environment. Bottlenose dolphin 

 stranding records for the period January 1986-June 1990, were analyzed by linear regression 

 with monthly mean sea surface and air temperatures, salinity, and offshore transport. 



Bottlenose dolphin stranding on the Texas Gulf Coast peaked significantly in March; 

 otherwise, stranding rates did not differ significantly among the months January-June. No 



