[Coral-List] RMI news: COTS on Ebon atoll

[Dean Jacobson]

Hi:
  A recent visit to Ebon (southern-most RMI atoll, 4
degrees N) revealed good and bad news.  I encountered
my first giant humphead parrots (n=10) and found large
schools of golden trevally, rainbow runners,
fusiliers, and abundant, well mannered grey reef
sharks.  Also, one manta, flying effortlessly into the
pass current.  Fabulous diving!  

Within the small lagoon (8 km diameter)the two patch
reefs I checked (one NW, the other SE)were moonscapes,
almost entirely killed by COTS.  On one large reef,
only shallow reef flat colonies survived, and these
were still being eaten by the few surviving COTS (I
saw a dozen; untold thousands must have previously
starved).  I was told that COTS were a constant
feature on Ebon for several decades, so appearently I
was seeing the last stages of a devastating cycle. 
Reef flat coral survivors are quite diverse, and I
predict a good recovery if COTS numbers remain low for
several decades.  COTS were rare on the ocean side.
  Since water quality is excellent, I would assert
that overfishing (removing Acanthaster predators) is
the issue.  While I saw only two juvenile Napolean
wrasses during 9 hours in the water, there were once
so many of the big wrasses that they could be seen
swimming across shallow reef flats, on their sides. 
This was also the case in Majuro (and, I imagine, all
the atolls).  I am pressing for a nation-wide ban on
taking Napolean Wrasses (currently free divers from
Hawaii fly in to spear them).  But, given that this
was the favorite meal for the previous president, this
may not be easy.  Another predator, the triton
trumpet, was said to be relatively common on Ebon, but
I did not find a single individual.

Another intersting feature of Ebon is the continuous
carpets of a Caulerpa sp. (the one with disc or
lentle-shaped bodies, somewhat mushroom like) that
entirely cover the substrate on the S and W Ocean reef
below 15 meters.  Independent of this, ocean side
Acropora is very rare below the shallows; I saw less
than five tabulate colonies! (i.e. A. cytherea; even
A. robusta is very rare, while it is common on nearby
Jaluit).

Cheers,
Dean Jacobson, College of the Marshall Islands


		
__________________________________ 
Yahoo! Mail Mobile 
Take Yahoo! Mail with you! Check email on your mobile phone. 
http://mobile.yahoo.com/learn/mail