22 
Fishery Bulletin 95(1 ), 1997 
ant bluefin tuna was successful harvested every few 
seasons by native hunters, this could still constitute 
evidence of a significant population of tuna available 
as a local resource. 
Unfortunately, the time interval between catches 
of bluefin is not precisely determinable from the 
dated archeological deposits; it is impossible at this 
time to determine if catches were made annually, 
every 10 years, or every 100 years. Although expen- 
sive, the use of accelerator 14 C-dating methods on 
small samples of bluefin tuna remains is the only 
way to determine a more precise time frame. The 
remains of bluefin tuna recovered from Barkley 
Sound during several recent field seasons are per- 
haps the best candidates for future analysis because 
there are many vertebral and nonvertebral skeletal 
elements and the remains appear to represent less 
than 2,000 years of harvesting activities (McMillan 
and St. Claire 3 ). 
Geographic range of prehistoric bluefin tuna 
remains 
As discussed at greater length previously (Crockford, 
1994), it appears probable that the ability to hunt 
large Pacific bluefin tuna was strongly correlated 
with native groups who were capable of active whal- 
ing. This possible correlation with active whaling 
rather than with the use of so-called “drift” whales 
(which die naturally and are fortuitously encountered 
at sea or as beached carcasses) is important. No other 
archeological sites in western North America or 
northeastern Asia appear to contain remains of large 
bluefin tuna. No large bluefin tuna have been re- 
ported from sites in southern California where adult 
tuna are occasionally taken today, although the re- 
mains of other large fish, such as marlin, have been 
identified and large marine mammals, such as sea 
lions, were clearly taken (Moratto, 1984; Raab 4 ). We 
cannot assume, however, that large bluefin tuna were 
not present in southern California waters during 
prehistoric times because a lack of whaling technol- 
ogy may have prevented aboriginal Californians from 
harvesting such a resource. 
In northern Japan, active whaling is not clearly 
indicated by the archeological record although hunt- 
ing of sea lions and other large marine mammals was 
practiced. Large bluefin tuna remains have not been 
3 McMillan, A. D., and D. E. St. Claire. 1992. The Toquart ar- 
chaeology project: report on the 1992 excavations. Archaeology 
Branch, British Columbia Ministry of Small Business, Tourism 
and Culture, 800 Johnson St. Victoria, British Columbia, 
Canada V8W 1N3: permit 1991-46. Unpubl. rep., 100 p. 
4 Raab, M. 1994. Anthropology Department, California State 
University, Northridge, CA 91330. Personal commun. 
reported from archeological sites bordering the Sea 
of Okhotsk and the Sea of Japan where large bluefin 
tuna occur today (Niimi, 1994; Otaishi, 1994), but it 
appears that not many large sites in these areas have 
been excavated. As in the case for California, it would 
be inappropriate, given the absence of evidence for 
an active whaling technology, to suggest that adult 
bluefin tuna were absent in Japanese waters during 
prehistoric times. 
In contrast, the recovery of large bluefin tuna 
among dated archeological deposits that span almost 
5,000 years is evidence that the occurrence of adult 
bluefin tuna off the British Columbia coast was 
longstanding. Clearly, large bluefin tuna were a re- 
source consistently (if sporadically) available to ab- 
original people on the central northwest coast until 
relatively recently. The Nuu-chah-nulth people, in 
particular, were especially adept at using this re- 
source, and their material culture included large sea- 
going canoes, detachable harpoon heads, braided 
ropes, and floats required for the successful hunting 
of both whales and large tuna (Huelsbeck, 1983; 
Mitchell and Donald, 1988). Archeological remains 
are, by inference, invaluable indicators that the en- 
vironmental conditions that favored the presence (i.e. 
the inshore surface-feeding behavior ) of bluefin tuna 
must have existed off the coast of British Columbia 
as a recurring pattern for at least 5,000 years. 
Implications 
The lack of reports of adult bluefin tuna off the Brit- 
ish Columbia coast since the late 19th century may 
be due to several factors, including the impact of 20th- 
century fisheries in both the eastern and western 
Pacific, the association of large bluefin in northern 
waters of the eastern Pacific with very specific envi- 
ronmental conditions that have not recurred since 
the late 19th century, and the misidentification of small 
schools of large bluefin tuna as marine mammals. 
Although relative abundance records over the past 
100-150 years are not available for Pacific bluefin 
tuna, it has been shown for other species that when 
abundance decreases, the range of a species often 
contracts (Kawasaki, 1991). In order to investigate 
how 20th-century fisheries may have impacted abun- 
dance and thus the distribution of bluefin tuna, a 
comprehensive record of the history of the bluefin 
tuna fishery as conducted by all nations throughout 
the north Pacific would be needed. This is especially 
true for Japanese waters because of the use there of 
large-scale harvesting methods. 
It is also possible, however, that short- or long-term 
(or both) changes in environmental conditions may 
be affecting bluefin tuna distributions in the east- 
