Ocean
Watch
Friday, November 2, 2001
Portuguese man-of-wars
drift at the mercy of winds
About five years ago, I worked with several people to
find a remedy for the pain of jellyfish stings. Each month, when the box
jellyfish came into Waikiki waters to spawn, we trooped down to the beach
and applied hot packs, cold packs, meat tenderizer, Sting Aid and fresh
water to people's stings.
Nothing worked. But we weren't finished. Because box
jellyfish and Portuguese man-of-wars have different kinds of stingers on
their tentacles, we wanted to try our stuff on man-of-wars, too. So we
loaded our buckets with test materials and waited for the blue drifters to
show up.
And waited. And waited. We waited so long that the meat
tenderizer solution in the trunk of my car grew mold.
Entire years passed and still these pesky creatures did
not appear on Oahu in any significant numbers. Then two weeks ago, while I
was visiting relatives in Wisconsin, I checked my e-mail and found this:
"Last week, Susan, walking on the beach was a hazard along the whole
stretch of Kailua Bay. There were more man-of-war than I've ever seen,
plus something more: They were clustered together in big blue bunches.
..."
Great. I look for these things for years, and then when
I'm gone, whole rafts of them show up practically on my doorstep.
The reader went on to ask what attracts these blue
stingers to our beautiful Kailua shores. It's a good question. Portuguese
man-of-wars aren't attracted to our shores, or to any shores, in the
least.
In fact, since getting beached is the death of them,
these creatures are specially built to stay offshore.
Portuguese man-of-wars are wind-blown drifters,
wandering around thousands and thousands of miles of open ocean. They stay
afloat by means of an oblong balloon filled mostly with carbon dioxide.
Stinging tentacles hang below, trolling for fish and invertebrates.
But these creatures don't just bob aimlessly. On top of
their float lies a crest, which the animal can raise and lower. When the
wind is on, the Portuguese man-of-war raises its crest and sails about 45
degrees to the wind.
When the wind blows really hard, however, the little
blue boats get overpowered and drift directly downwind. That's why during
periods of strong, sustained tradewinds, we often see Portuguese
man-of-wars on our beaches.
But this happens only if some of the creatures are
upwind of the islands at the time. This is unpredictable, because even
though Portuguese man-of-wars roam the world's tropical waters, they don't
do it evenly.
I have often been offshore in calm water and not seen a
single man-of-war on the surface. Other times, huge armadas of the
creatures surround the boat.
ONCE, while I was sailing several hundred miles west of
the Big Island, the tradewinds stopped completely.
The wild Pacific suddenly became a big blue lake, and
on top of this lake floated thousands, maybe millions, of man-of-wars. We
dropped our sails (all million of us) and drifted together for days,
waiting for wind.
The experience gave me an appreciation for the beauty,
grace and remarkable adaptations of the Portuguese man-of-war.
And not only does this small creature sail, fish and
reproduce in one of the harshest environments on the planet, its powerful
sting can bring the toughest of us to our knees.
And perhaps one day we will learn what to put on those
stings.
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