A Sad Day on the PAR Or Food For Thought

   Early last week I took a swim out on Paul Allen's Reef.  It was an average sort of day until I passed over the first out cropping beyond the entrance to Paul's private lagoon.  On the other side of the submerged lava there was a green sea turtle.  He was just poking along about ten feet below the surface.  As do most of us

who enjoy the wildlife in Hawaiian waters, I delight when I see one of our turtles.  I have a feeling that the native Hawaiians treasured them, as well.  The honu is widely depicted in petroglyphs and other Polynesian art.  So intrinsic is the turtle to our combined culture, that if one knows only a dozen words in Hawaiian, it is likely that honu will be one of them.

    As I approached this turtle, I realized that something was wrong.  He had a drastically mutilated left anterior flipper.  Us humans are full of hubris and as such when something is awry we wonder, "How did we (humans) cause this?"  I immediately wondered if the honu had been clipped by the propeller of  a power boat.  Or did it somehow damage his limb getting caught in a net.

     It took me a couple minutes, but I soon concluded that I must be looking at a shark bite.  For some time I have known that tiger sharks eat sea turtles.  A simple google search  retrieved an article from the Japanese Journal of Herpetology, 1987 by  W. N. Witzell.  Here is a link to the article:

  http://www.sefsc.noaa.gov/turtles/PR_Witzell_1987_JapJHerp.pdf

    Dr. Witzell looked at data from 25 studies from around the world, Capetown to  California, in which Tiger sharks were captured and their stomach contents examined.   Of over 400 sharks examined, about 70% had food in their stomach and 21% of those had large sea turtle remains in their stomachs.  His review took in all comers, not just sharks living in areas where large turtles were common.  He concludes that this is a really big number.

   The article goes on to tell us that tiger sharks are unique among sharks in having the correct type of teeth,  heavy kinetic jaw, etc. to chew through a large turtle shell.  In fact, tiger sharks are the only species that take large sea turtles as prey.

    I especially liked this bit, "Tiger sharks have developed a feeding behavior that enables them to successfully prey on large turtles by using a combination of stealth and speed, a strong sawing bite and the ability to easily regurgitate indigestible pieces of material....(tiger) sharks cruise...in a slow, sinuous movement

Tiger Shark

that seems deceptively sluggish, and would not draw immediate attention to their presence.. However, when attacking prey, the tiger shark is one of the most vigorous and strong swimming of the carcharhiniid sharks, this speed burst enabling them to quickly disable their prey..."

   When I first came to the big Island of Hawai'i, I went to Kahalu'u and was so pleased when I saw my first green sea turtle.  Those were the days when the obnoxious among us would sneak up on a turtle and grab its shell for a thrilling ride.  Suffice it to say, we have come a long way in turtle protection.  That year (1981) I accepted the local myth that there had never been a shark attack on the leeward side of the Big Island.  NOAA fisheries tells us that over the last 25 years, green sea turtle population in Hawaii has increased 53%,  despite declines in much of the rest of the world.  And yes, Virginia, according to Hawaii.gov the incidence of shark attacks in the Rainbow State has increased dramatically since 1980.  From about one a year, it peaked in 2012 at 13 attacks, with

When the Indianapolis Went Down We Was Like a Bunch of Sea Turtles

two of them fatal.  

   For a few years I have been aware of much of this and I am more than a little concerned that a snorkeler, from the right perspective, may look a hell of a lot like a green sea turtle.  Suffice it to say, Dr. Witzell has done little to reassure me.  More and more when I am swimming in the open, especially when I am by myself,  I find myself turning around to see who might be following me.  Even if I saw him coming, would I be able to withstand a vigorous attack by a determined 10 foot tiger shark?   Should I call it a day,  paint myself day-glo pink and put a treble hook where the sun don't shine?  Now that is what I call food for thought.

jeff

Snorkel Bob Cares (if you get attacked by a shark!)