Issue Three: Why are we seasick?

NOAA TEACHER AT SEA
CATHRINE PRENOT FOX
ONBOARD NOAA SHIP OSCAR DYSON
JULY 24 – AUGUST 14, 2011

Personal Log
Every year on my birthday my Nana sent me a card with a $20 bill tucked into it.  Her written instructions were: "do something nice."  Without fail, the entire sum would be spent on ride tickets at the Dutchess County Fair for the roller coaster, tea-cup spin, high swings, pirate ship and the 'round-up' ride (an old fashioned gravitron).  Evidently, I assumed that she meant "do something nice (for yourself)."

I still love a good stomach dropping roller-coaster ride but as a scientist I have grown curious about the biology of balance.  Why is it that I occasionally suffer from motion sickness but other times can eat funnel cakes, ride the spinniest amusement park ride and have no fear of the aftermath?   Furthermore, when I was on a ship in high seas of the North Atlantic Ocean around the Hebrides (west of Scotland) I didn't even have a stomach quiver... ...once I put foot on shore though, my body decided that land was moving alarmingly.

The most frequent question of all Teacher at Sea Blogs that I have read in the past two months is a variation on this: "Are you seasick?"    Since the word 'Nausea' stems from the Greek 'naus,' or ship, I think it seems very appropriate to address this question through Issue 3: Why are we seasick?  (Again, if you click on the cartoon it should open in another window so you can read it more easily and magnify.) 

Adventures in a Blue World.  Issue 3.  Cathrine Prenot Fox, 2011.

Motion sickness in general seems to arise from the brain's inability to resolve a conflict between the senses of balance.  When input from the eyes, fine motor muscles, skin receptors and the organs of the inner ear don't add up, your brain assumes that something must be adversely effecting the body.  A cascade of events takes place: cold sweats, the pyloric valve of the stomach closes up, letting no food pass to the intestines, dizziness, vertigo, nausea and sometimes...well, you know.  The most common theory is that the brain thinks the body's discordant messages mean that it is hallucinating and has ingested a poison.  Response?  Get rid of it.

Techniques to help resolve your brain's conflict include napping and snacking (which I happen to be excellent at!), avoiding greasy or acidic foods and simply keeping a visual reference point on the horizon.  Although I am bringing some OTC meds in case I get desperate, I have also stocked up on ginger chew candy.  Ginger loosens up the pyloric valve, letting your stomach empty out, and making it less likely that you will "chum the waters."

Commander Richard Behn, 1979.  NOAA.

If the Oscar Dyson gets into waves anything like these onboard the Discoverer in the Bering Sea in 1979 (yes, I know, very unlikely), I don't know if ginger and snacking will do me any good.

Whatever the result, at least I will have something to ponder if I have to take a few trips to the rail.

Until our next adventure,
Cat