84 



the three majoritive marine mammal species in captivity. For many of the pinniped 

 species, individuals entering captivity were originally stranded and rehabilitated, 

 not captured. 



We would Uke particularly to emphasize that throughout these years, the num- 

 bersof cetaceans and pinnipeds taken from the wild for captive display are ABSO- 

 LUTELY INSIGNIFICANT. Even more so in light of the numbers of marine mam- 

 mal deaths in the wild associated with incidental take, commercial hunting and 

 whaling and those p>ermitted in field research studies. 



Furthermore, with the success of captive breeding programs in the subsequent 

 years, there has been a continuing dechne in the capture of marine mammals from 

 wild populations for public display (Fig. 1). For example, for all pinniped species as 

 a whole, the percentage of animals captured from wild populations during subse- 

 auent census periods (1976-1979, 1979-1983 to 1983-1990) went from 58 percent of 

 tne acquisitions in the 1976-1979 census period being captured from the wild to 4 

 percent in 1983-1990. In this latter census period, nearly all of the pinnipeds added 

 to zoological displays were captive bom or stranded. For cetacean species, the per- 

 centage of animals which were captured from wild populations dropped from 92 per- 

 cent of the actjuisitions in 1976-1979 to 72 percent in 1983-1990, captive breeding 

 programs providing an increasing percentage of the acquisitions. 



L^ss than 25 pinnipeds and cetaceans have been captured from the wild for cap- 

 tive display in the United States and Canada since 1990. 



Reproduction has been reported for 18 of the 25 marine mammal species in the 

 zoological community (Table 1). The remaining 7 species are represented by only one 

 or two individual animals in non-breeding situations. In the 17 years of the cen- 

 suses, there have been over 1900 marine mammal births recorded; the majoriW of 

 these to the three major species; California sea lions (997 births), harbor seals (314 

 births) and bottlenose dolphins (298 births). 



The average annual birth rates for the three major species, California sea lions, 

 bottlenose dolphins and harbor seals have demonstrated a consistent increase 

 throughout the census periods. 



The success of captive marine mammal breeding programs is reflected in the fact 

 that as much as 56 percent of the current inventories for some of these species were 

 bom in captive propagation programs (Fig. 2; Table 2). Second-generation and third- 

 generation births are now occurring, as well. For a number of species all acquisi- 

 tions in the past three years have been from captive births and over 90 percent of 

 the current captive populations are in breeding or potential breeding situations. 



Age distributions of the current live inventories for various marine mammal spe- 

 cies are illustrated in Fig. 3. Similar age distributions for wild marine mammal pop- 

 ulations are not available for most species. However, comparisons are possible for 

 the bottlenose dolphin (Dufiield and Wells, 1990; Fig. 4a) and North Atlantic killer 

 whales (Christensen, 1984; Fig. 4b). For both of these species, the captive population 

 currently has an age distribution approximating that reported for those particular 

 wild populations and for both of these species, individuals from the original capture 

 years are still alive and annually increasing the maximum longevity records for 

 these species in captivity. Maximum longevities observed to-date for these and other 

 marine mammal species in captivity are given Table 3. 



We would like to submit these numbers as part of the Congressional Record. We 

 feel that they demonstrate the tremendously positive trends and successes exhibited 

 by the zoological community with respect to the maintenance of marine wammal 

 species. 



There is no way for us to adequately measure the wealth of knowledge that we 

 see has been and is bein^ gainea about the biology of marine mammals and their 

 needs in the natural environment, nor to describe the impact we feel this has on 

 the milhons of visitors who share in this knowledge and appreciation. The united 

 States remains a leader in this area and the zoological community continues to ac- 

 cess, revise, develop and improve captive environments for all species of marine 

 mammals on display. 



Table 1. — Marine Mammal Births in Aquariums, Zoos, and Marine Zoological Parks in North 

 America From Census Data. 1976-June 1993 



Species 



No. ol births 197&- 

 Jufie 1993 



Pjnnipedia: 



California sea Uon(Zalophu8 californianus) 

 Harbor seal (Phoca vitulina) 



997 

 314 



