Shark or dolphin in the California surf? Dolphin

We posted this story in leftovers but it continues to be debated and is making the rounds in major media. The photo is compelling and concerning but, not that concerning anymore.

Experts debate beach photobomber: Shark or dolphin? – CNN.com.

A shadowy figure in a wave near children swimming at a southern California beach has experts disagreeing.

Discovery Channel shark expert Jeff Kurr calls it a great white shark, but shark expert David Shiffman believes it was a dolphin.

The beast was caught on camera lurking near June Emerson’s 12-year-old son and three young friends as they played in the Manhattan Beach surf Friday afternoon.

The difference in the experts’ opinions centers on how they view the tail.

Shiffman, a recognized shark expert, noted in a Facebook posting that “the tail is flat,” like a dolphin, and unlike a shark.

But in an interview with CNN, Kurr concluded it was “a juvenile great white shark about 10 to 12 feet long.”

Video from CNN:

I’d say the experts are done debating, have concluded: it’s a dolphin (Southern Fried Science).

On a great white shark, the pectoral fins are relatively far from the head and relatively close to the first dorsal fin (#1) . Like all sharks, great whites have a second dorsal fin (#2). Like all sharks, great whites swim by moving their tail side-to-side (#3).

Shark_fig1

On a dolphin, pectoral fins are relatively close to the head and relatively far from the dorsal fin (#1). There is no second dorsal fin (#2). Unlike sharks, dolphins swim by moving their tails up and down, resulting in a drastically different tail shape (#3).

dolphin_fig1

Here is a close up of the creature in the picture:

Photo credit: Emerson

Photo credit: June Emerson

It better matches the dolphin.

It’s a cool photobomb, though.

  7 comments for “Shark or dolphin in the California surf? Dolphin

  1. spookyparadigm
    December 31, 2013 at 1:16 PM

    1. I “intuitively” grasped the morphological differences made explicit here, thinking it was a dolphin. I focused on the tail, but something about the front and the slender proportions felt “off,” but as someone who hasn’t spent that much time explicitly thinking about dolphin or shark morphology, I was not able to explicitly go “oh yeah, look at the placement of the pectoral fins.” I feel good about being right, but worse about not being able to express why. Hmm.

    2. “Discovery Channel shark expert Jeff Kurr calls it a great white shark, but shark expert David Shiffman believes it was a dolphin.”

    That sentence sums up Discovery and the rest of basic cable “science” programming, doesn’t it? Everything on cable tv needs to be treated as if the Executive Producer was P. T. Barnum.

  2. Lagaya1
    December 31, 2013 at 2:14 PM

    I think it looks more like a shark in the body lines, but what do I know? Though I can’t argue with their conclusion, one thing I find jarring in their comments (if they were correctly quoted). “Unlike sharks, dolphins swim by moving their tails up and down, resulting in drastically different tail shape.” It sounds like they’re confusing cause and effect to me.

  3. December 31, 2013 at 3:27 PM

    Being native Northern Irish & failed most of me science exams,ergo being thick as champ, it’s still pretty clear to me for a start the silhouette is distorted through the water, looking larger than it really is, & it is further behind than it seems & magnified by refraction & light. Shark or dolphin i doubt it’s of any real threat. It’s a big fish even if it is a shark, & the world’s waters are full of them, & shark attacks are minimal. Great whites have begun to infest the Med too, & mauling or fatal attacks are minimal. I see little cause to be worried. After a few near drowning incidents i’m chary of the sea, but i’d be more excited to see a shark than scared.

  4. Michael Hayden
    December 31, 2013 at 11:55 PM

    As a guy who grew up on an island I can tell you that if you are in the ocean there is a shark nearby every time. No big deal even if it was a shark.

    • Chris Howard
      January 1, 2014 at 12:53 PM

      Yep. Used to see them, nearly, every time I paddled out. SoCal, The Outerbanks, Mexico, they are everywhere I’ve ever surfed.

  5. January 1, 2014 at 11:41 AM

    Even in my natal Northern Ireland, the shores are surrounded by sharks, though mostly huge but harmless basking sharks. The young “doggies” are frequently caught & used for bait, for other fish. The two legged sharks on land scare me more. Sure i’ve even seen several shark fins off shore, when visited the Morbihan in south Britanny, France, in summer, at sis in law to be’s place. They never came too close inshore despite plenty of tasty kids playing alone in water, & only probs the kids had swimming were the jellyfish. More on power of belief on the human psyche Sharon – poured “special water” on the kids stings, they stopped crying & returned to the sea for more of the same, despite it only being ordinary bottled water in an unfamiliar labelled bottle from the north, they don’t see in Bretagne. Sharks like most other animals will only attack when you bug em. How many videos have we seen online of folk diving in shark infested custard & feeding these supposed vicious raptors by hand. The real monsters are in peoples’ minds.

  6. January 1, 2014 at 3:11 PM

    Oh arse – probably time to trot out the old probably aprocryphal line – more people killed & injured by falling coconuts than any other cause. Now a story about a surfer killed by a shark weilding a coconut might be interesting.

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