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Badass Shark Teeth Weapons Hint at Shadow Diversity

When life gives you lemons, make lemonade.

When life sticks you on an isolated island surrounded by shark-infested waters, make utterly badass weapons out of shark teeth.

This is what the people of the Pacific Gilbert Islands have been doing for centuries. Sharks are a central part of their lives. Many social customs and taboos revolve around the finer points of shark-hunting. Young boys go through initiation rites where they kneel on a beach, looking towards a rising sun and slice their hairlines open with shark teeth, letting the blood run into their eyes until sunset. And with no metal around, they used shark teeth to adorn their weapons.

A shark is a fast, electric-sensing torpedo, whose business end holds two conveyor belts of regenerating steak knives. To further weaponise its weapons is practically the definition of being badass. Here’s how to do it: You drill a tiny hole in each tooth, and bind them in long rows to a piece of wood, using braided coconut fibres and human hair. Depending on the shape of the wood, you can make a sword. Or a dagger. Or a trident. Or a four-metre-long lance. And then, presumably, you hit people really hard with them.

Shark-tooth sword (left) and a puffer-fish helmet (right). Because, obviously, how else would you defend yourself against someone running at you with a shark-tooth sword? Joshua Drew, Columbia University.
Shark-tooth sword (left) and a puffer-fish helmet (right). Because, obviously, how else would you defend yourself against someone running at you with a shark-tooth sword? Joshua Drew, Columbia University.

No one knows when the Gilbertese first fashioned these arms, but they were already doing so by the time the first Western sailors arrived on the islands in the late 18th century. Many of them ended up in museums and Chicago’s Field Museum of Natural History has a particularly rich collection. It includes 124 specimens, including swords, tridents and a lance that Joshua Drew from Columbia University describes as “2.5 interns tall”.

Drew saw this collection was more than just an amazing armoury. It was also a time capsule. Since every item was carefully tagged with date and place of collection, and since different shark species have distinctively shaped teeth, Drew could use the weapons to identify the sharks that swam round the Gilbert Islands in centuries past.

The teeth came from 8 different species. Tiger sharks feature heavily—their thick, cleaver-like teeth, which can punch through turtle shells, make for good cutting edges. Most of the weapons featured teeth from just one shark species, but several have a rare blue shark tooth in the penultimate position—possibly the signature of an artisan.

But the biggest surprise was that some of the teeth belonged to two species—the dusky and spottail sharks—which no longer exist near the Gilberts!

Back then, they were common enough that their teeth were among the most popular choices for weaponsmiths. Today, no one has seen them within several thousand kilometres of the islands. Even before scientists knew that they were there… they weren’t any more.

(Drew has also found teeth from a third missing species—the bignose shark—on a weapon held at the American Museum of Natural History.)

Shark tooth trident, by Joshua Drew, Columbia University.
Shark tooth trident, by Joshua Drew, Columbia University.

Could these teeth have been imported from neighbouring people? No, says Drew. The Gilbertese had a strong culture of shark-fishing and if they were already heavily catching sharks, why would they trade for teeth? Besides, there is no historical, linguistic or archaeological evidence that these people communicated with those who live in the areas where those missing sharks are now found.

Could it be that the three species still live near the Gilberts but that no one has seen them? Again, it’s unlikely. All three are quite common in the areas where they actually live, so it’s doubtful that biologists have simply missed them.

It’s not clear why the sharks disappeared. Humans may well have been responsible—people were hacking off shark fins in the Gilbert Islands as far back as 1910 and by the 1950s, around 3,000 kilograms of fins were being shipped from the islands ever year. For sharks, many of which grow and reproduce slowly, it doesn’t take long for finning operations to drive a population locally extinct.

Whatever the reason, the teeth are signs of what Drew describes as “shadow diversity”—fleeting ghosts of the vivid splendour that once existed in the same waters. “Today’s Gilbertese live in a fundamentally duller environment than their forefathers,” he says.

That’s an important reminder for conservationists. Both coral reefs and shark populations are under severe threat and scientists are working on ways of restoring them. But what state are we going to restore them to? “Nested within this story is a cautionary tale of… how what we see today is not necessary indicative of the past,” Drew writes. We must not succumb to a “cultural amnesia, where people forget how vibrant reefs really were. “

Shark tooth weapon. By Joshua Drew, Columbia University.
Shark tooth weapon close-up. By Joshua Drew, Columbia University.

Note: I originally covered this research for Nature News when it was presented at the 2012 Ecological Society of America Annual Meeting in August, 2012. Here is the original piece.

Reference: Drew J, Philipp C, Westneat MW (2013) Shark Tooth Weapons from the 19th Century Reflect Shifting Baselines in Central Pacific Predator Assemblies. PLoS ONE 8(4): e59855. http://dx.doi/org/10.1371/journal.pone.0059855

23 thoughts on “Badass Shark Teeth Weapons Hint at Shadow Diversity

  1. Please, Ed. The “Gilbertese” people won their independence in 1979. Refer to them by their rightful and chosen name, the I-Kiribati. They live in the Republic of Kiribati, not in the “Gilbert Islands”, a name given by a self-serving British seaman.

  2. Do you really mean “penultimate” (which means “next to last”) when referring to the position of the rare blue shark tooth? If so, what is the penultimate position on such a weapon? Just short of the tip?

  3. “A fundamentally duller environment” is the story of human experience since the adoption of farming. We move further and further away from the outside world. The Bauhaus movement, with its dull mechanized architecture and furniture, expressed this progression toward sensory deprivation. “Alienation” evokes the image of a lonely person yearning, without the slightest chance of success, for the world from which she has been separated.

  4. Chris, are you going to start calling Germany “Deutschland”? How about Mexico “Me-he-co”?

    This is a great article. Get over yourself.

  5. Interesting but where is the evidence for the statement :“Today’s Gilbertese live in a fundamentally duller environment than their forefathers” Hm? Really? Evidence, please.

  6. @Marianne Wheelaghan, the evidence is the finding that there are more species of shark represented in the old weapons than there are in today’s nearby waters. So “duller” here means (I think) “less rich in species.”

  7. An interesting article, but I think the poster (Chris) who pointed out that these people are from Kiribati, not the ‘Gilbert Islands’ is right. Its no different from calling native American people ‘indians’, or calling Hawaii the Sandwich Islands.

  8. @Dave,
    I’m half Hopi and a quarter Navajo. I (along with most everyone I know here in Tuba city) call ourselves Indians.

  9. really cool. I didn’t know that about the sharks that no longer exist near the island. very fun to read.! 🙂

  10. @alex, if they want to be called I-kirabati then we should call them that. If you want to be called an Indian, the. We’ll call you that. It’s called respect. You should get over yourself, and stop thinking that just because you are a minority that you get to speak for other minorities.

    1. My point is that it’s a great article, and people like you and Dave need to stop being offended on behalf of other people. Just enjoy the article and get over yourselves.

      1. People who write “get over yourself” should realize that grownups don’t express themselves that way. What you are writing is a putdown used only by teens. A grownup who reads that knows the writer is not an adult.

        1. I wish that was true. I’m just a crotchety old man with very little patience for political correctness über alles.

  11. Folks, Kiribati consists of several different archipelagos and the Gilbert Islands are one of them. And that’s the one that Drew focused on in the study. Calling it Kiribati would have extended the geographical range of what we’re talking about, which would have been wrong.

  12. An interesting article somewhat unfortunately sidetracked by a pointless back-and-forth on acceptable labels. To those who feel offended by word choices, and presume to speak for “grownups” or children, as well as people to whom they are not related and know little or nothing about, I not only say “Get over yourself!”, but also “Meh!” and “WHATeverrrr”. Also, too, “Gag me with a spoon.” And for the coup de’ Grace, “23-skiddoo, Herbert.”
    Thank you and goodnight.
    And this is yet another nifty example of sociological ‘neo-paleo-community ecology’, as it were. In a manner of speaking. Keep up the enlightening work!

  13. Alex,

    That’s not the same. The nation is labeled “Kiribati” on all maps and all documentation referring to it as a country. It *is* the name of the country, in whatever language. It is not called “Gilberts”.

    You wouldn’t call New York City “one of the colonies.”

    @Chris M.

    Yes, I know. I lived there for 2 and a half years and I speak the native language.


    It’s fair to refer to the islands as the Gilberts because, as you mentioned, it disambiguates regarding location. But referring to the people who live there as “Gilbertese” is unnecessary, colonial and (unintentionally, I think) borderline arrogant.

    This is National Geographic, for crying out loud, a publication long known for it’s research, accuracy and cultural inclusion. The LA Times does a better job in its article on the same subject. At least it mentions the word “Kiribati.”

  14. Alright, enough. I’m moderating any comments with personal attacks in them, beginning with the one that you now cannot see.

  15. I am surprised at the difference between the description of the islanders as being heavily shark oriented from way back and the description of them as seen and recorded by Arthur Grimble in the 1914 to late 1920’s period. They are certainly mentioned with some respect a few times but not to the extent that I read into this article.

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