TABLE B. - ITINRRARY AND OBSERVATIONS OF FUR SEALS 
FROM EBISHO MARU, 1948-49 a/ (CORT'D) 
Distance No of 
Traveled Seals 
(miles) Observed 
Onahama to Ayukawa, Honshu 
Onagawa to Hosoura, Honshu 
Hosoura to Ozuchi, Honshu 
Off Oxzuchi, Honehu 
Off Kamnishi, Honshu 
Off Hosoura, Honshu 
Off Hosoura, Honehu 
Hosoura to Onagawa, Honshu 
Off Onagawa, Honshu 
Mar 49 
Mar 49 
Mar 49 
Mar 49 
Mar 49 
Mar 49 
Mar 49 
Mar 49 
Mar 49 
coumSa0roe 
7 
13 
14 
15 
18 
21 
23 
23 
aA 
TOTAL 
~ 
an 
Average observed population density ¢/ 1 seal per 2.1 square miles 

a/ One seal per 3.4 square miles of water area wae obeerved from the 
Shinsburu Maru on its northward voyage of 828 miles from Onahama 
to Todohokke 7 May-2 June 1949. 
b/ Trip made on United States Air Force crash boat. 
c/ 1,404 miles x .114 miles (200 yards) divided by 75 equals 2.1 square 
miles per seal. 
While the maximum number of seals wintering in this area cannot be established 
from the evidence at hand, it is clearly far less than 1,030,000 postulated by the Japanese 
in 1938 (Appendix 0, Item 2), even though the aggregate North Pacific fur seal population 
has increased since then. However, if it be assumed that only 50 percent of the seals in 
the area covered were observed, and that the population density of the sampled area was 50 
percent of that of the total area, then the gross population would be 4 x 81,000 or 324,000. 
These are the most reasonable assumptions under the circumstances. It is extremely un- 
likely that more than 50 percent of the animals in the area scanned were overlooked. It is 
possible, though improbable, that the observed sample density may be less than one-half 
the actual density in the entire area. If it be assumed to be 33 1/3 percent instead of 
50 percent, the total becomes 6 x 81,000, or 486,000, which from other evidence seems mani- 
festly too high. 
Another estimate can be made on the basis of the potential contributions to the 
total from each of the respective breeding grounds, where more accurate counts can be made 
than at sea. Unfortunately no recent estimates of the Robben and Commander Island herds 
are available. The last figures for Robben Ieland show its herd to have numbered about 
50,000 animals in 1941, and the Commander Ieland rookeries are believed to be about equal 
in size. Because of the apparent over-exploitation during the war years these herds prob- 
ably have not increased. For the purpose of this estimate, therefore, the combined Robben 
and Commander Island herds are assumed to number roughly 100,000 seals. The number may be 
considerably lower but cannot well be much higher (cf p 29). It ie further assumed, in 
the absence of any evidence to the contrary, that practically all of these seals nigrate 
southward into the waters off Japan. 
The contributions to the total from the Fribilofs are even more uncertain. Any 
estimate of the percentage of the Pribilof herd to visit Japan must be based on a series 
of questionable assumptions. Starting with the assumptions that the three 1947 Pribilof 
tags recovered in 1949 are a fair sample and that only one-half of the tage taken were re- 
ported, then 1,200 Pribilof seals were killed off Japan during the 1948-1949 season (see 
P %). In actuality, probably less than one-half of the tage were reported, so this esti- 
mate of the kill is likely to be low. 
