C II A P T K Tt V 1 T 1 . 



THE CAUSE OF THE DECLINE. 



JOINT AGREEMENT OF 1892. 



At the Joint meetiug of American anil British investigators in 1892, i>rececliDg 

 the Paris Arbitration, an agreement was reachert that " since the Ahiska purchase a 

 marked diminution in the number of seals" on the Pribilof Islands had taken place, 

 and that this diminution was " the result of excessive killing by man." But when an 

 attempt was made to analyze what was meant by "excessive killing" each commission 

 took a different view. The commission for the Tnited States claimed that it was the 

 slaughter at sea of female seals that was responsible; the commissioners for tireat 

 Britain held that laud killing was chietly, if not wholly, responsible. 



As has already been shown, the decline admitted in 1892 has continued to the 

 present time and is still going on. It only remains for us now to locate if possible 

 the cause of the decline, to distinguish between land and pelagic killing. 



NO NATURAL CAUSE COMPETENT TO EXPLAIN THE DECLINE. 



It may be remarked at the outset that the investigations of the past two seasons 

 have brought to light no natural cause of injury to the herd which can be connected 

 with its decline. The subject of mortality among the fur seals is discussed in detail 

 in Part III of this report. It is only necessary here to say that among the adult .seals 

 no mortality was found which was not due, directly or indirectly, to contests among 

 the bulls, or to rough treatment of the cows by the bulls. In the case of the very 

 young pups an hitherto unknown but apparentlj- customary cause of death, due to the 

 ravages of a parasitic worm infesting crowded and sandy breeding areas, was found 

 to be responsible for a large number of deaths. In the case of very young pups a 

 certain number are also trampled to death by the bulls. The number dead from these 

 causes in 1896 as counted amounted to 11,000. Doubtless a considerable number wei'e 

 overlooked. 



NATURAL CAUSES OF MORTALITY CONSTANT. 



It may be said, however, that l)oth these causes of death are as old as the herd 

 itself, and were more active when the herd was in its prime. They are directly related 

 to the crowded condition of the rookeries and are, therefore, to-day, at a minimum. 

 The photographs ' taken by the British commissioners in 1891 and 1892 show that the 



' A jjhotograpli taken in 1891 by Dr. George M. Dawson shows a part of the sandy northern end 

 of Tolstoi rookery thickly strewn with dead pups, evidently killed by the worm. The photograph 

 will lie found among the- illustrations in Appendix III. In the following year Mr. Macoiin reports 

 Hndiug liy actual count 4,000 dead jiups nu the sand Hat of this rookery. These faets, tending to 

 show the presenre of breeding seals and their young in territory far bey onil the present confines of 

 Tolstoi rookery, .are also valuable as proving the great shrinkage of this rookery since 1891. 



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