Documenting giant bluefin tuna off the west coast of Canada - Part 2
The slow slog of confirming the size and identity of ancient tuna bones
See Part 1 here.
I waited impatiently for news back from Dr. Collette at the Smithsonian with an official identification of the bones I’d sent him, and from my colleague at the museum to see if any of the First Nations elders knew anything about tuna.
My museum colleague got back to me first with wonderful stories from the Nuu-chah-nulth elders. It turned out no one had ever asked them about tuna so they hadn’t said anything. All of the elders were too polite to simply presume the anthropologists might want to hear stories about tuna hunting when none of them had ever expressed an interest.
As it happened, several of the elders knew exactly how and when giant bluefin were hunted. The tuna in their stories were always referred to as “big fish, 6-8 ft long.” Their ancestors could tell when the bluefin would appear because the weather and kinds of creatures in the water changed.
Apparently, these conditions almost always happened in August but at irregular intervals. The elders couldn’t say whether tuna appeared every few years or only every 10 years or so, and it seems possible that even every four or five decades was not out of the question. However, a few days advance warning meant the hunters had time to prepare and they knew what to do.
They readied the gear usually reserved for hunting grey and humpback whales: the enormous special canoes and paddles, the long lines of sinew and kelp, the sealskin bladders used as “floats,” and the harpoons tipped with blades made from hardened California mussel.1
Note that whaling was an activity restricted to particular high-status families and surrounded by strict rituals but it seemed from the elders’ stories that tuna hunting was a wide-open event. Not only was it considered OK to use the special whaling gear for tuna, but it appeared anyone could participate.
According to the elders, a tuna hunter hoped for a calm night with moonlight, although a full moon was best. The giant tuna would come right into the relatively shallow waters of Nootka Sound, so a spotter was positioned on a high cliff. The spotter’s job was to alert the paddlers when he saw the characteristic signs of a giant tuna plowing through the surface of the water laden with bioluminescent plankton.
The tuna literally lit up the water with their feeding activity.
Typically, directed by the spotter, the hunters in the canoe would approach the tuna very slowing, and as quietly as possible, and when they got close enough, they’d paddle as fast as they could in the opposite direction.
The elders explained that the line of light that the canoe made as it glided through the bioluminescent plankton attracted the tuna and it would follow. When the big fish reached the stern of the canoe, it would dive beneath and emerge at the surface near the bow, which was the perfect position for the hunter to drive home a harpoon.
And then they were off!
The crew of hunters had to be prepared because a harpooned tuna would run at top speed for miles until it was too tired to continue. The seal skin bladders attached to the line helped slow the fish down and discouraged it from diving. Several stories were told of hunters being towed considerable distances.
On one occasion, one elder said, a tuna was harpooned off Bligh Island in the middle of Nootka Sound (see map below) and towed the crew 20 miles or so (about 31 km) to the head of Tahsis Inlet until it finally got tired and “went belly up.” Then the men had to paddle all the way back home to Yuquot, towing the massive fish behind them.
The elders had no stories of failure or disaster to tell, which is perhaps not surprising. I suspect those are the sad tales told in hushed tones to eager young men as they waited for tuna to show themselves, not the stories used to remind the community about good times.
There must have been times when the tuna couldn’t be struck, or the line broke when the fish ran hard, or when the monster inexplicably ran out to sea and the line had to be cut — or even worse, when one of the giants found deep water and dove, dragging the canoe under, or turned hard and tipped the canoe over. But the stories of success were nevertheless full of extremely useful information.
Another elder from the Ahousaht band near Tofino, said his father had seen these methods of hunting tuna when he was a boy, which means they were still being practiced about 1890. That coincides with sport hunting records of big bluefin caught in California in the 1890s and early 1900s (see Part 1).
The elders had no memories or stories of more recent hunting events since then, and there have been no modern fisheries records of giant bluefin spotted this far north. It appears Nuu-chah-nulth hunters simply stopped taking bluefin because the big fish were no longer available off Vancouver Island.
A few days after hearing these hunting stories, Bruce Collette called me on the telephone from the Smithsonian. He confirmed that the bones I’d sent him were indeed from a bluefin, a giant that he estimated was probably at least 6.5 feet long (about 2m).
I related to him the stories I’d just been told about aboriginal tuna hunting and he said they described giant bluefin behaviour perfectly. The night-time surface feeding in shallow inshore waters, the association with bioluminescent plankton – even the running hard and fast when hit – were all characteristics of big bluefin.
He told me squid feed at night on bioluminescent plankton at the surface and the tuna, in turn, feed on the squid because both squid and bluefin are attracted to light. This attraction to light is what allowed Nuu-chah-nulth hunters to trick big bluefin into following the canoe and position it for being harpooned.
When I expressed an interest in writing up and publishing a description of these finds, he agreed to arrange a loan of the four complete Smithsonian specimens of large Pacific bluefin to the B.C. Museum so that I could use them for comparison. I was astonished to learn these were only such skeletal specimens available anywhere in North America.
I wasn’t going to get paid for most of this work but I carried on regardless. First, I headed to the library to learn what I could about bluefin (remember, 1991 was pre-internet for most of us).
I discovered a paper had been published only the year before that described the commercial harvest of an unusually large number of giant bluefin in southern California in November and December 1988 that turned out to be a goldmine of information.2
The largest of these 1988 fish travelled alone or with a handful of others of similar size. The authors stated that aircraft were used to spot the big fish at night as they fed at the surface because they of the associated bioluminescent plankton.
The giant bluefin were said to have been “wild and uncatchable” during the day.
Purse-seines were set at night in shallow areas near shore, usually in water less than 50 fathoms, with powerful lights used to lead the big fish into the nets.
If the water was too deep, the big fish dove deep and either swam under the nets or ripped right through them. It appeared the fish sensed when there was not enough depth for them to get a good run and so wouldn’t try to escape if the nets were set over shallow water.
The tuna caught in this 1988 event ranged in age from about 5 to 17 years old. The largest fish caught was a new world record for the Eastern Pacific and weighed 1009 lbs or about 458 kgs and measured 8.9 feet long (271 cm).
This was fabulous detail on the biology of big bluefin that I hadn’t found elsewhere and it matched almost perfectly the stories I’d just been told by the Nuu-chah-nulth elders.
I wrote to lead author Terry Foreman about the ancient tuna remains and was encouraged to pull as much data as I could together for a scientific paper.
Here is what that entailed: I had to find out exactly where all ancient tuna remains had been found and see if I could arrange to borrow them for further analysis. When I discovered that an archaeological site in Barkley Sound on the southwest coast of Vancouver Island was turning up surprising numbers of large tuna, I arranged to have them sent to me as they came out of the ground so I could include them in my study.
The comparative skeletons of bluefin sent from the Smithsonian had been prepared decades before using dermestid beetles to consume the flesh. This had left most of the bones of each fish attached together by cartilage and sticky with a thick layer of oil embedded with decades worth of dust and grime. I was given permission to gently boil the vertebrae with Tide (an excellent de-greaser!) to break down the cartilage and dissolve the oil, and then label each bone with its unique Smithsonian collection number.
Because I wanted to estimate how large the fish were that had been caught in the past, I had to put all of the vertebrae for each modern specimen in anatomical order from 1-39 (each one was slightly different from its neighbour), and then measure each individual vertebra. Using the data from these modern specimens, I was able to create a simple formula that would estimate the size of any other Pacific bluefin, modern or ancient, based on the length measurement of a single vertebra.
My sample size of four modern skeletons was not ideal but it was all I had.
Then I had to identify which vertebra number each of the ancient specimens represented, measure them, and calculate the estimated total length of the live fish each vertebra represented.
Most of the ancient bones were vertebrae: only in Nootka and Barkley Sound have any bones from the head of bluefin been found. This pattern is significant, I think, and still holds with finds recovered since my study was done.
My guess is that it was only possible to hunt tuna in Nootka and Barkley Sounds because these were the only feeding ‘hotspots’ that attracted the tuna to come close to shore – or, alternatively, these were the only places that when harpooned, it was highly likely that the big fish would run up the inlets rather than out to sea.
In other words, even if giant bluefin turned up in other places like Hesquiat Harbour to feed, a fish harpooned there had no other option than to run out to sea and dive deep. Hunters simply couldn’t take the risk of being towed 20 miles out on the open ocean or having their canoe pulled under.
I think it’s likely that the vertebrae found in other locations along Vancouver Island, and as far north as Haida Gwaii, were remains of smoked bluefin chunks either traded or given as gifts during potlatches, the traditional Northwest Coast get-togethers of different groups where dancing, story-telling, and gift-giving took place.
The fact that several locations outside Nootka and Barkley Sound yielded sequential vertebrae from a single individual fish, similar to the articulated series I sent to the Smithsonian for identification, suggested that chunks of tuna with the bones in place were being transferred for consumption. Some of the vertebrae recovered were partially burned, suggesting they had been cooked or smoked over an open fire.
The largest fish in my sample came from Barkley Sound and was estimated to have measured about 8 ft long or 243 cm. There were a few individuals in the 4 to 5.5 ft category but most were about 6 ft. long or more. The series of bones from Haida Gwaii I had sent to Bruce Collette at the Smithsonian, for confirmation that these were indeed bluefin tuna, generated an estimated length of 6.4 ft or 196 cm.
The archaeological sites the bones came from were occupied from the late 1800s to perhaps 5,000 years ago, but most of them dated to less than 2,000 years ago.
In the end, I had my comprehensive study published in the premium biological journal Fishery Bulletin, which is produced by the US National Oceanic and Atmospheric Administration (NOAA).3
I knew that biologists almost never read archaeology papers so if I wanted biologists to find out about my work, I had to publish the results in a science journal.
The fact that I was a private contractor without a university affiliation worked against me here, although later I learned to work around it. If I’d been part of academia, the university would have issued a press release about my tuna paper and newspapers would likely have gobbled up the story for public consumption.
As it happened, all I could do was hope that other biologists would see the paper and realize it’s significance.4
This might have been end of the story but it wasn’t. Not quite.
To be continued…
Arima, E. and Hoover, A. (2011). The Whaling People of the West Coast of Vancouver Island and Cape Flattery. Victoria, Royal BC Museum.
McMillan, A.J. (2015). Whales and whalers in Nuu-chah-nulth archaeology. B.C. Studies, 187 (Autumn), 229-261. https://doi.org/10.14288/bcs.v0i187.186163
Foreman, T. J. and Ishizuka, Y. (1990). Giant bluefin tuna off southern California, with a new California size record. California Fish and Game, 76 (3), 181-186. Download volume here.
“Huge Bluefin Tuna have Fisherman Swooning in SB Channel,” San Luis Obispo Tribune, November 12, 1988, p. 4, col. 1. Copied here.
Crockford, S.J. (1994). New archaeological and ethnographic evidence of an extinct fishery for giant bluefin tuna (Thunnus thynnus orientalis) on the Pacific Northwest Coast of North America, in W. Van Neer (ed.), Fish Exploitation in the Past. Annals of the Royal Museum of Central Africa 274, Tervuren, Belgium, pg. 163-168. [conference paper, based on preliminary results]
Crockford, S.J. (1997). Archaeological evidence of large northern bluefin tuna, Thunnus thynnus, in coastal waters of British Columbia and northern Washington. Fishery Bulletin 95 (1), 11-24. Pdf here.
Bayliff, W.H. (2016). The fishery of tunas in the eastern Pacific Ocean. Advances in Tuna Aquiculture, Benetti, D.D. et al. (eds.), Academic Press, Oxford, pg. 21-42. [cites my 1997 paper]