Archeological evidence of large 
northern bluefin tuna, 
Thunnus thynnus, in coastal 
waters of British Columbia and 
northern Washington 
Susan Janet Croekford 
Pacific Identifications 
601 1 Oldfield Rd., RR #3, Victoria, British Columbia, Canada V8X 3X1 
E-mail address: Vo anthuvic@uwm.uvic.ca 
Abstract .—This study presents ar- 
cheological evidence for the presence of 
adult bluefin tuna, Thunnus thynnus , 
in waters off the west coast of British 
Columbia and northern Washington 
State for the past 5,000 years. Skeletal 
remains of large bluefin tuna have been 
recovered from 13 archeological sites 
between the southern Queen Charlotte 
Islands, British Columbia, and Cape 
Flattery, Washington, the majority 
found on the west coast of Vancouver 
Island. 
Vertebrae from at least 45 fish from 8 
sites were analyzed. Regression analy- 
sis (based on the measurement and 
analysis of modern skeletal specimens) 
was used to estimate fork lengths of the 
fish when alive; corresponding weight 
and age estimates were derived from 
published sources. Results indicate that 
bluefin tuna between at least 120 and 
240 cm total length (TL) (45-290 kg) 
were successfully harvested by aborigi- 
nal hunters: 83% of these were 160 cm 
TL or longer. Archeological evidence is 
augmented by the oral accounts of na- 
tive aboriginal elders who have de- 
scribed strategies used until the late 
19th century for hunting bluefin tuna. 
Despite this information, there are no 
20th-century records of adult bluefin 
tuna in the northeastern Pacific. Ar- 
cheological evidence suggests that ei- 
ther perturbations in the distribution 
of Pacific bluefin have occurred rela- 
tively recently or the specific environ- 
mental conditions favoring the move- 
ment of large tuna into northeastern 
Pacific waters have not occurred in this 
century. 
Manuscript accepted 4 September 1996. 
Fishery Bulletin 95:11-24 (1997). 
Evidence is presented here for the 
occurrence of adult bluefin tuna, 
Thunnus thynnus , in waters of the 
northeastern Pacific, off the coast 
of British Columbia and northern 
Washington, for the past 5,000 
years. The physical evidence con- 
sists of archeological remains of 
large bluefin tuna harvested by ab- 
original hunters. Aboriginal North 
Americans of this area (part of the 
so-called “Northwest Coast” culture 
region) were accomplished seamen 
and skilled hunters of marine mam- 
mals (Mitchell and Donald, 1988). 
Coastal archeological sites through- 
out this region often contain abun- 
dant skeletal remains of the many 
fish and marine mammal species that 
sustained human populations over 
thousands of years (Calvert, 1980; 
Huelsbeck, 1983; Mitchell, 1988). 
Skeletal remains of large bluefin 
tuna have been recovered from 13 
archeological sites. The archeologi- 
cal deposits containing tuna date 
from at least 5,000 years ago until 
the early 20th century. The exist- 
ence of bluefin tuna remains from 
this region have been previously 
reported (McMillan, 1979), but none 
were systematically analyzed until 
now. 
For this study, 78 intact vertebrae 
from 8 archeological sites were mea- 
sured and the data compared with 
those from vertebrae of modern 
specimens (specimens from the re- 
maining 5 sites could not be exam- 
ined, owing largely to difficulties in 
retrieving archived specimens but, 
in one case, because all skeletal 
material had been discarded by 
museum staff). Tentative estimates 
of the size of the archeological speci- 
mens were made by comparing the 
size of vertebrae from modern speci- 
mens of known length with the size 
of vertebrae collected from archeo- 
logical deposits. The resulting 
length estimates were then used to 
calculate weight and age estimates 
by using length-weight algorithms 
derived from recent data. Data are 
presented in a manner that should 
facilitate the analysis of any addi- 
tional archeological specimens 
recovered. 
In addition to the results of the 
analysis of the archeological mate- 
rial, anecdotal evidence is presented 
from ethnographic accounts of tuna- 
fishing methods related by native 
elders of the Mowachaht tribe who 
live on the west coast of Vancouver 
Island. These recent oral accounts 
substantiate and augment the physi- 
cal evidence: they describe bluefin 
tuna ethology, pinpoint the time of 
year that bluefin tuna were present 
and confirm that large bluefin tuna 
were being harvested in the north- 
eastern Pacific until the late 19th 
century. The historic evidence for 
bluefin tuna occurrence in this area, 
although sparse, is also presented. 
