Hey Don,
 
So the moral is to grab onto the starfish whose spines stuck you (thus
getting a few more sticks) to be sure of getting the correct culprit!
Makes sense to me.  I'll bet there is heavy predation on these guys when
they are young and this is what is interrupted by storms and such to
cause a bloom.
 
Around here (the deserts of New Mexico) I grew up "knowing" there was a
seven year cycle in the jack rabbit population as well as a matching
cycle in the coyote population.  Well, it is not necessarily seven years
but there is a cycle and it also matches the cycle in the pinon tree.
About every seven years they produce a lot of pinon nuts, off years very
few (thus more rodents thus more coyotes).  But if you dig deep enough
it all actually seems to hinge on water.  When we gets early rains
(every seven years or so) we gets these population blooms.
 
Okay, okay, soooo what does all of this have to do with the crown of
thorns and triton trumpets?  Well, the point is the controlling factor
is bottom up: from the environmental change to the prey to the predator;
rather than top down: where the predator controls the prey population.
And who knows, it all may be linked to sunspots!  My point is that
nothing is ever as simple or linear as many people like to think in the
natural world.  The equation contains more than just the triton and the
starfish.
 
My oldest daughter has been doing research here on the effects of a
herbivorous beetle on the cottonwood forest along the Rio Grande river.
Everyone just assumed the beetles ate some of the tree foliage but not
enough to really do damage.  Then folks noticed that some trees were
being damaged or killed and interest picked up.  Few predators eat this
beetle so what kept some forests healthy while others became invested?
It turns out, it may be linked to the tree's proximity to an urban area
and thus pollution and thus increased levels of ozone which damage the
tree and make it more vulnerable to the beetle.
 
The same could be true with the crown of thorns where pollution, whether
from a series of storms or urban runoff, causes the population blooms
and the tritons may not be the controlling factor.  Who knows?
 
Tom Eichhorst in New Mexico, USA