Table 5. --Primary diagnoses 



1/ 



for causes of death among seal pups, three mortality study areas, St. Paul Island, 

 26 June to 15 August 1969 



1/ See footnote 4 of text. 



malnutrition (181 in 1968 to 56 in 1969). 

 Marked fluctuations in apparent malnutrition 

 may be the main cause of marked fluctuations 

 in pup mortality from year to year. 



The pathogenesis of malnutrition is not 

 known. Possibly 1 percent of pup deaths from 

 malnutrition is frank starvation because of 

 the usual mortality of post partum females. 

 In 1968 (Marine Mammal Biological Labora- 

 tory, 1970b) we stated that at the present pop- 

 ulation level, separation of mother and pup 

 owing to crowding is probably not the only — 

 and possibly not the most important — cause 

 of malnutrition, and that perhaps some disease 

 process is involved. From an epizootiological 

 standpoint, malnutrition has fluctuated like an 



infectious disease since 1964 when we began 

 our studies of mortality. In the last 3 years, 

 the total number of deaths from malnutrition 

 on the three study areas has varied from 72 

 to 181 to 56, although the total number of pups 

 born on St. Paul Island has stayed about the 

 same. One disease process that has been re- 

 lated to malnutrition to some degree year after 

 year is necrotic and necrohemorrhagic enteritis. 

 Figure 8 shows the relation between the num- 

 ber of pups that have died of apparent mal- 

 nutrition and the number of these pups that 

 also have had enteritis. The incidence of en- 

 teritis seems to be positively correlated with, 

 but not proportional to, the incidence of mal- 

 nutrition. 



