Reefs at Risk

[Paul Hoetjes]

Dear all,

During the recent discussion of the state of the reefs, several
references were made to the die off of Acropora cervicornis and A.
palmata due to white-band disease. In the whole discussion however, no
mention was made of Montastrea annularis/faveolata. Yet here on the
island of Curacao in the Southern Caribbean (supposedly not getting any
polluted water from the rest of the Caribbean as may be the case in the
Florida region)  we are seeing a frightening amount of dead/partly dead
Montastreas.

During a quarterly reef monitoring program employing triplicate point
intersect line transects, that we (Reef Care Curacao, a volunteer ngo)
have been doing since May 1997, we have found that between 30 and 40 %
and in some cases close to 50 % of Montastrea colonies show recently
dead patches (more than 10 % of colony area). Some of this may be due to
the 1995 bleaching which was very serious here. However we also found
close to 20 % of colonies diseased (in addition to the partly dead
colonies), mostly with  yellow-band/blotch disease, but also rapid
wasting syndrome. Whatever the cause, reefs that were healthy and
unmarked in 1993, look like a disaster area now.

This is the case not only in areas where human impact might be the/a
cause but also in an area far removed upstream and upwind from any
coastal development or pollution sources.

Is Montastrea showing signs of die off elsewhere in the Caribbean or are
we unique in this respect? If so, is our island perhaps in the vanguard
of a new wave of destruction about to sweep through the Caribbean? It
may sound dramatic, but who suspected that most Acroporas in the
Caribbean would disappear when White-band disease first started. By the
way, has any epidemiological analysis ever been made of how white-band
spread and whether that might indicate its origins or vector(s)?

Regards,

Paul C. Hoetjes
Scientific Coordinator, Reef Care Curacao