Table 3. — Variances in, and means of, the weights of 

 living seal pups, St. Paul Island, 28-29 August 1969 



Sex 



and 



rookery 



Sample 

 size 



Variance 



Mean 



Number 



Kg- 



All rookeries 



400 



8.6 



Table 4. --Dead seals counted that were older than pups, 

 Pribilof Islands, Alaska, 1965-69 



Dead Pups Counted 



The number of pups that died on the Pribilof 

 Islands in 1969 was the lowest since the counts 

 were begun in 1941. At the current year class 

 size of about 375,000 pups (established in 

 1962), our counts of dead pups have ranged 

 from 14,810 in 1969 to 51,189 in 1962 (table 

 A-12). The mean for the 8-year period was 

 30,493. 



Dead pups counted on St. Paul and St. George 

 Islands in 1969 are given in table A-13 by 

 rookery and rookery section. 



Alton Y. Roppel 



PATHOLOGY 



From 26 June to 15 August, M. C. Keyes 

 and T. A. Gornall collected 208 dead pups from 



catwalks on study areas at Reef and Northeast 

 Point Rookeries (Marine Mammal Biological 

 Laboratory, 1970a) . Keyes and E. W. Giddens 2 

 discarded 20 because of advanced post mortem 

 degeneration and necropsied 188. Tabulations 

 of gross pathologic findings from the 188 form 

 the basis for this report. Giddens and A. D. 

 Carlos 3 will eventually publish histopathologic 

 and microbiologic findings from the tissues of 

 75 pups, and this information will be summar- 

 ized in our report on fur seal investigations in 

 1970. 



A tabulation of primary diagnoses' shows 

 that the main (66.3 percent) causes of death 

 among 208 pups in 1969 were malnutrition, 

 hookworm disease, and microbial infection 

 (table 5) . Trauma, multiple hemorrhage-peri- 

 natal complex, and undetermined causes were 

 less important. A comparison of the incidence 

 of these six causes over a 5-year period for 

 study area 1 and a 3-year period for area 3 

 (figs. 6 and 7) show significant year-to-year 

 variations, particularly for malnutrition. 



A weekly summary of primary diagnoses 

 (table A-14) shows that deaths from malnu- 

 trition were relatively constant from 28 June to 

 15 August, and that 84 percent of the deaths 

 from hookworm occurred between 18 July and 

 8 August. Deaths from microbial infection 

 peaked in mid-July but otherwise occurred 

 throughout the breeding season, whereas most 

 of the deaths from trauma and perinatal com- 

 plex occurred before mid-July. 



Malnutrition 



The overall drop in pup deaths from 379 in 

 1968 to 208 in 1969 was caused mainly by a 

 marked decrease in deaths from apparent 



2 Certified veterinary pathologist, Department of 

 Experimental Animal Medicine, University of Wash- 

 ington School of Medicine, Seattle, Wash. 



1 Veterinary microbiologist, Department of Exper- 

 imental Animal Medicine, University of Washington 

 School of Medicine, Seattle, Wash. 



1 The cause of death for each necropsy is diagnosed 

 as primary, secondary, tertiary, and so on. A specific 

 cause is designated primary if it is the most serious 

 or if it preceded and influenced critical changes that 

 eventually led to death. Secondary and tertiary diag- 

 noses, where indicated, are not tabulated in this re- 

 port but are recorded on individual necropsy forms. 

 The distribution of secondary causes among primary 

 causes was reported for necropsies performed in 1966 

 (Marine Mammal Biological Laboratory, 1969). 



