National Geographic FAIL: shark vs. octopus

Having worked in both a public aquarium and a marine science lab, I know how badly most nature shows mangle the facts. The Discovery Channel is one of the worst offenders. But I always thought I could count on National Geographic.

This video clip, which sounds as if it might be aimed at young viewers, is a perfect example of why you really shouldn’t believe what you hear or see on TV — especially if the information is presented to you in the breathless, hyped-up tones of this narrator.

Let’s debunk some of this crap. First of all, pretty much everything in the ocean is a “voracious predator,” except phytoplankton and grazers. Everybody else eats whatever they can catch, whenever they can catch it.

Second: I note that at no time in this video does the narrator ever mention that the spiny dogfish is a small shark — a 10-year-old might be two feet (0.6 meters) long. They don’t usually get bigger than 4 feet (1.2 meters) and top out at a little over 5 feet (1.5 meters). So, it’s not exactly Clash of the Titans here.

Third: Dogfish will eat octopuses when they can, but again, there’s a size issue. They’ll only go after octopuses they have a fair chance of overcoming. My guess is that this octopus’ main worry, if it had one, would be the dogfish biting off the tips of its arms while mistaking them for sea cucumbers.

Fourth: “Sharp spines jutting up from its dorsal fin that can puncture anything that touches them!” Oh, please. Let’s think about this for a moment. Why would a shark need a dorsal spine? To “puncture” its prey? Um, no. Dorsal spines (and tail spines on fish such as stingrays) are a defensive weapon. They’re designed to keep somebody else from eating the shark! And indeed, our little shark has a lot of creatures wanting to eat it, including California sea lions, elephant seals, lingcod, sablefish and other sharks.

Fifth: “The shark — menacing — on the prowl — just itching to use those rows of teeth to crush its next meal.” (Please excuse me while I take an antacid. This kind of hyperbole makes my stomach churn.) Setting aside the characterization of the shark as “menacing,” which is a human emotional term and kind of hard to apply to a two-foot shark, let’s talk about the phrase “on the prowl.” Is the narrator aware that most species of sharks respire more efficiently while moving than while resting? (In fact, there are a few species called “obligate ram breathers” which absolutely must swim in order to ram water across their gills. Great whites fall into this category.) No doubt this shark is constantly keeping an eye open for food, as do all predators, but it’s also swimming in order to reduce the effort needed to get oxygen.

I won’t even get into the “just itching to crush its next meal” crapola.

Sixth: Take a look at the rostrum of the shark. (That’s just the proper term for its snout.) See how white it is? It’s not supposed to look like that, it’s supposed to be just as dark as the rest of the shark’s upper surface. The reason it’s white is because it is badly abraded — think of having all of the skin scraped off your nose.

Sharks are very hard to keep in captivity because most of them are designed for active swimming. (Some species are designed to lie in wait on the ocean floor, and they’re much easier to keep captive — but they aren’t nearly so whizbang as swimming sharks, because half the time visitors can’t even see them.) They do not adapt well to the concept of a walled environment, and will often swim right into the walls of their tank. That abrades the rostrum, and with the loss of rostrum tissues comes a loss of sensing abilities. Sharks have a whole net of wonderfully sensitive electrical sensors in their rostrums, which helps them find food and avoid danger. Without it, they are half blind. Which means this shark was at a tremendous disadvantage in its tank, and likely was unable to sense the octopus’ presence.

I call FAIL on National Geographic for this one. However, I did not see the whole episode of which this clip was a part. Maybe the strategy was to present all the usual hyperbole about sharks and then follow it up with the real facts, in which case I would rescind my failing grade. But I’d still give it a bad grade, because breathless hyperbole is what people remember. Not the facts.