278 



Samples for blood oxygen and carbon dioxide levels were available and taken 

 by means of instrumentation for blood pressure. Chamber oxygen was measured 

 during hypoxia experiments. Diving physiology experiments were conducted in a 

 tank, from a boat, or from a seaside landing. The rational for obcaining diving 

 physio:ogy data was that it showed the natural capacity of the fur seal to with- 

 stand high carbon dioxide and low oxygen tensions to which they were subjected 

 in experiments of euthanasia by hypoxia. 



There is no question but that fur seals can support vigorous activity under 

 water for extended i>eriods of time. Their ability to do this is not fully under- 

 stood but is presently believed to be owing more to a higher packed red cell vol- 

 ume, more eflBcient uptake of hemoglobin-bound oxygen by the tissues (oxygen 

 unloaded at lower tensions; more favorable dissociation curve), greater toler- 

 ance for oxygen debt by the muscle tissues, and other mechanisms, than to unique 

 cardiovascular adjustments. 



Eight seals instrumented for telemetered electrocardiograms and electro- 

 encephalogram were killed by stunning and bleeding; half of these were also 

 instrumented for blood flow. 



Six seals, also instrumented for telemetered electrocardiogram and electro- 

 encephalogram, were killed by gas-induced hypoxia ; two at rest and four after 

 exercise (taken from a drive) ; half by carbon dioxide and half by nitrogen. 



Six seals were killed by injection of succinylcholine. 



Analyses of all the data are not expected to be completed until late December 

 1970 but preliminary observations indicate that, in general, the approximate 

 times required from exposure to gas, injection of drug, or impact of club to 

 ac^hieve death as indicated by zero blood pressure or flow, flattened brain wavea 

 (electroencephalogram), and marked aberration of the heart potentials (electro- 

 cardiogram), were 6 to 9 minutes for nitrogen, 6 to 8 minutes for carbon dioxide, 

 13 to 15 minutes for succinylcholine, and % to 1% minutes for stunning and 

 bleeding. 



Dr. K. C. Kim began studies of fur seal lice in 1969. Although he found lice 

 on pups both in cages away from the rookeries, it was not conclusive proof that 

 the pups had been infested by lice that had overwintered on their mothers be- 

 cause their mothers had been captured from the rookery where they had been in 

 contact with other louse-infested seals. Also inconclusive was the recovery of 

 three adult lice from a digested bachelor skin because these were no more than 

 might have been recovered from an inanimate object off the rookery. 



The breakthrough came this past spring when Dr. Kim recovered over 70 

 nymphs from the digested skins of a female seal collected off the coast of Wash- 

 ington. Nymphs were recovered from nine other skins of fur seals collected under 

 similar circumstances. This evidence finally established that adult seals were 

 the source of infestation for newborn pups, particularly the mother seal because 

 Dr. Kim found the nymphs concentrated in the area of the mammary glands. 



Apparently, adult fur is not a suitable habitat for adult lice because no one, 

 including Dr. Kim, has ever found significant numbers of adult lice on adult fur 

 seals ; however, resting nymphs are able to over-winter on adults and subadults in 

 close association with the skin and probably undergo a final molt to adult lice 

 near the time of parturition when they quickly desert the mother for the advan- 

 tage of a much more available blood supply of the pup. 



During the 1970 season Dr. Kim spent 1 week studying multiplication, growth, 

 development, and behavior of lice on pups from the rookeries and on pups bom 

 in cages away from the rookeries. 



Dr. Joe Daniel, Jr. has been studying the phenomenon of delayed implanta- 

 tion in fur seals since 1965 when he came to St. Paul Island and incubated fur 

 seal blastocysts in vitro under the influence of 34 different nutrients, hormones, 

 and other substances. None of these stimulated the blastocysts to speed up 

 their development. 



The next year he sent two graduate students, Messrs. John Cowen and 

 Bela Gulyas, to measure the metabolic rate of fur seal blastocysts. They found 

 that a fur seal blastocyst consumes an average of 8 millimicroliters of oxygen 

 per hour, and Dr. Daniel concluded that control of the delay in implantation, 

 in fur seals, did not lie in the realm of respiratory changes. 



In 1967, Dr. Daniel demonstrated accelerated growth of fur seal blastocysts 

 by incubating them with specific protein fractions found in the uterine fluids 

 of animals that implant rapidly. 



