These conclusions must be considered tentative, however. Despite the 

 indicated non-isolated nature of the population, nothing is yet known about 

 interactions between the apparently resident dolphins and the visitors, and it 

 is not known if the dolphins which died in spring 1992 were resident. If the 

 resident dolphins seldom mate with visitors, loss of all or most residents in 

 an area could have significant impact on the genetic (and perhaps cultural) 

 makeup of dolphins in the area regardless of numeric recovery. This study 

 raises several questions: Are there separate inshore/resident and 

 coastal/ transient bottlenose dolphin stocks on the Texas coast? If so, is there 

 genetic exchange? What sociobiological factors drive the two lifestyles, and 

 would an otherwise non-resident dolphin take up residenc}' in a depleted 

 bay? 



The major ambiguities of population extent and size, social and 

 behavioral patterns, and characterizations of within-bay vs. gulf-coast 

 dolphins can only be answered by further work. We recommend: 

 (1) continued visual and photographic survey efforts, on a monthly basis, to 

 catalogue and reliably re-identify not only human-marked but naturally 

 identifiable dolphins throughout this and other Texas bay systems and along 

 the Texas gulf coast; (2) an intensive genetic study along the entire Texas 

 coast, to coordinate with the ongoing MMRP photo-identification work in the 

 bay systems of Galveston, Matagorda, Corpus Christi, and South Padre Island; 

 and (3) at least two more intensive NMFS-led physiology/radio-tracking 

 efforts to recapture some of the same dolphins for physiology and toxin level 

 follow-up. The second point is especially necessary for proper description of 

 population discreteness and size(s), and evaluation of the effects of mass 

 mortalities. The third recommendation will provide further data on sex and 

 age distributions, necessary for a fuller understanding of the sociobiology of 

 dolphins on the Texas coast. 



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