August 14, 2014
DR. ALISTAIR DOVE,
Director of Research and Conservation
Quick word association: I say SHARK and you think…
Something like that right? OK, maybe something simpler like this:
But actually, those are both wrong in a very real and important sense. If you were to take the group that scientists call “sharks” and boil it down to an average, a sort of “typical” shark, it would probably look more like this:
That’s a chain catshark and it is typical of the majority of shark species and individuals in being fewer than 3 feet long, sort of flabby, living on the bottom in water deeper than any human can swim to (1,000ft or more), and feeding on bottom-dwelling invertebrates like squid, shrimp, crabs and small fish (if they’re lucky).
So why the discrepancy? Why does what we think of as a shark bear so little resemblance to the actual average shark?
Well, it’s a combination of things, some ecological and some distinctly cultural. In terms of ecology, the majority of shark species actually live in deep water, not the shallows. And I mean deep; shelf slope deep, perpetually dark and cold deep. But obviously we don’t encounter them unless we’re deep sea explorers or fisheries researchers, so we don’t typically include them in our mental model of what typifies the essence of “shark."
On the cultural side, there are at least two things at play. One is our tendency to recognize (and, unfortunately, value) big critters over small ones; smaller animals, especially uninteresting or shy ones, tend to get by under the radar, attracting little attention, for better or worse. The other factor is of course the massive, MASSIVE, mind-bogglingly HUGE public bias produced by years of saturation exposure to two groups that represent a tiny numerical and ecological minority of sharks: the carcharhinids or requiem sharks like the bull shark and hammerhead, and the lamnids like the mako and great white. It’s hard to overstate how much movies, television and other modes of human storytelling have distorted the true face of sharks as a group, such that they are pretty much universally represented now by the gaping serrated maw of the lunging great white.
It’s a bit like having the diversity of cars on the road represented not by this:
But by this:
This little thought exercise regarding the true “average” shark is also deeply flawed. Averages, by their very nature, dilute the extremes of diversity and into the middle ground. They are helpful to get a feel for what many are like, but averages are hopeless if what you really want to do is develop an appreciation for the range of forms and functions in a group. And in that respect, sharks are nothing short of spectacular. Consider the following examples: whale shark, angel shark, goblin shark, megamouth shark, sawfish, wing head shark, zebra horn shark and wobbegong. What a dizzying array of patterns and forms, commensurate with their diversity of habits and habitats. And those are just the extant ones – the fossil forms are often even crazier!
If I could ask shark fans to do just one thing this shark week, it would be to replace in their minds eye the outdated Jaws image of “shark” and replace it with a more realistic average, and supplement that with a deeper appreciation of the range of forms and function that make up this most ancient and precious lineage. With this more accurate mental image of what sharks really are, we can begin to tear down the misinformation and fear that have plagued sharks and replace it with a fearless wonder and awe that this group richly deserves.