[Coral-List] Observations of Thermal Bleaching and Irresponsible Development
James M. Cervino
cnidaria at earthlink.net
Sat Oct 22 16:18:36 EDT 2005
Dear Coral Reef Scientists,
Observations of Coral Thermal Bleaching and Disease indices in Guana
Key, Bahamas and a statement opposing any nutrient enriching golf
course surrounding these sensitive reef systems.
This development will fertilize and increase the abundance of macro
algae species within this habitat, thereby threatening this already
thermally stressed coral reef ecosystem. We are surprised that a
team of marine scientists financially supported by the developer
would claim that a golf course and dredge project will not harm the
host tissues along with their symbioants on the surfaces of these
diverse coral reefs 10 meters away from this proposed development
site. There are many publications out there that show how sediment
loading can effect coral physiology (Peters, E. 1984. A survey of
cellular reactions to environmental stress and disease in Caribbean
scleractinian corals. Helgol. Meeresunters. 37: 113-137. I would be
glad to supply these papers to the developers and their scientific
advisors so that they can re-think their unsustainable development
plans. Many marine biologists may not have an understanding of the
sensitive cellular mechanisms and physiology of symbiotic corals.
Therefore, we would be more than glad to provide the advisory board
of Discovery Land and Co. with this literature.
Coral Diversity was high and overall reef health was in good
condition before this recent thermal expulsion event. Temperatures
were 84.5F at 60-70 feet. 86F at surface.
North Side of the Island (furthest tip) adjacent to the proposed
development project and golf course. Thermal Coral Reef Bleaching was
in critical stages of expulsion of symbiotic algae of the following
Method: 90 meter horizontal transect (1m/sq) at12 meters depth
1001individual counts of Montastraea sp. (not M. cavernosa) revealed
959 in critical stages of bleaching of the 1001 counted. This is the
only species that I calculated exact numbers. The below species is
based on approximate estimate:
Gorgonians Plexaurella nutans, Eunicea calculata 25-30% critical
bleaching. Pseudopterogorgia sp. were unaffected.
One indices of YBD, however, it is important to note that the YB
disease signs may be difficult to calculate due to the bleached
tissue appearance. However, the one case was evident.
Acropora palmata on surface approximately 1-2 meters. All older
colonies were dead (local reports claim WBD and storm damage).
However, new recruits were evident with not White Pox or WBD lesions.
Colonies of A cervicornis were not evident, only dead rubble was seen.
Montastraea cavernosa showed signs of brown spots lesions. On 25% of
the colonies observed at all North and South dive locations.
50% Porites sp. were in critical stages of thermal bleaching which
was surprising due this species ability to withstand high thermal
Siderastrea siderea all showed signs of minor or early stages of DSD
or past tissue necrosis with exposed skeleton.
Stephanocoenia mechelinii were not seen bleaching. However, necrotic
tissue was evident, causes wee unknown. Non appeared to have DSD
lesions on the tissue surface.
Diploria strigosa all colonies showed minor to middle stages of bleaching.
Meandrina meandrites all appeared healthy. Very few were in direct sunlight.
Colpophyllia natans all colonies showed minor to middle stages of
bleaching. Parrot fish lesions were seen, however, small lesions
approximately 1-2 cm was the average size. Not one observation of
10-20 inch lesions were evident within a 24 hr time period as seen
during the PFWSB/RWD debate during 1996-97. All of the lesions seen
during this time showed no necrotic tissue border after the biting.
Fungiida (Leptoseris cacullata) all appeared healthy.
Agaricia lamarcki all that were in direct light appeared mildly
bleached. In the more dark areas, all appeared healthy.
Agaricia tenuifolia were all in mid to late stages of bleaching.
Symbiotic algae were seen in mucus streams above the coralite.
Madracis Formosa were seen in mild stages of bleaching.
Oculina tenella were in mild stages of bleaching.
Sea-fans all appeared healthy, outside of 2 cases of Sea fan Disease
that were effecting the older colonies. All healthy Seaman's were
juveniles between 5-10 cm long.
All reef fish were abundant and diversity seemed to be high.
Macro Algae and Ecology of this habitat.
As many of us coral biologists understand, coral reefs are known to
be the most nutrient sensitive ecosystems. Coral reefs can become
"eutrophic", that is, overgrown by weedy algae, at nutrient levels
that are so low that they would indicate nutrient starvation in any
other ecosystem (P. Bell,1992, Eutrophication and coral reefs: some
examples in the Great Barrier Reef lagoon, Water Research, 26:
553-568; B. Lapointe, & M. Clark, 1992, Nutrient inputs from the
watershed and coastal eutrophication in the Florida Keys, Estuaries,
15: 465-476; B. Lapointe, in press, Eutrophication thresholds for
macroalgal overgrowth of coral reefs, in K. Thacker (Ed.) Protecting
Jamaica's Coral Reefs: Water quality issues). Therefore, an
immediate stop work order on the proposed development location should
be established as a result of human-caused nutrient additions from
The Discovery Corp. to these coastal waters surrounding Guana Key.
This is needed to prevent the corals from being overgrown and killed
by weedy algae. This golf course will be a point source and will
create dangerously high levels of nutrients. Any nutrient drainage
into this area will cause the reefs to deteriorate further. This
includes nutrients from development projects involving dredging,
which will lead to sediment loading on the surfaces of corals on the
north and south side of Guana Key, as well as from construction of
the golf course and excess sewage that is usually accompanied by such
projects. The Discovery & Co. EIA plans are to dredge up a portion of
the 1 mile island, dump the sediment onto the surrounding reef and
add soil fill combined with quartz sand for this golf course. This
limestone substrate will act as a permeable filter for the nutrients
to leach out into the reef thereby feeding the invasive species.
The dominant macro algae were species indicative of moderate or low
nutrients, primarily Dictyota pinnatifida, Laurencia poiteaui,
Halimeda sp., Udotea sp,. and Penicillus sp. These were not at
invasive levels at this point in time. However, All cyanobacteria
spp. (blue-green algae) Lyngbya penicilliformis were in low
abundance. Nutrient analysis is need at this point in time to
establish a base line of the chemical signatures surrounding this
reef around the proposed development site and surrounding Guana Key.
Only stressed corals were in competition with Lyngbya, and all dead
corals were overgrown with mixed algal tufts. High densities of
cyanbacteria are indicative of excessive pollution, in particular of
phosphorus, and are common near sewage inputs. On shallow and deeper
sandy areas the algae were more typical of lower nutrients, primarily
Halimeda, Udotea, and Penicillus species. It is important to note
that acceptable water quality standards for coral reefs has been
established by Lapointe and Bell, and show that over fertilization by
nutrients, not the lack of fishes and sea urchins, are the major
reason for the almost complete replacement of corals with weedy algae
(Goreau et al. http://globalcoral.org/). All areas show healthy
abundance of seagrasses with low macro-algal overgrowth.
Recent research in the Caribbean and in the Great Barrier Reef of
Australia has established the critical levels of nitrogen and
phosphorous which must not be exceeded if reefs are to remain healthy
without being overgrown by weedy algae (Lapointe et al., 1992, 1993;
Bell, 1992). These concentrations are:
1.0 micromoles per litre of nitrogen as nitrate and ammonia
0.1 micromoles per litre of phosphorous as ortho-phosphate and organophosphate.
These values are in the molecular concentration units used by
chemists and oceanographers. In the weight units more often used in
the wastewater literature these translate into:
Nitrogen: 0.014 ppm N or 0.040 ppm NO3
Phosphorous 0.003 ppm P or 0.007 ppm PO4
This 1-2mm layer of skin (epidermis) living on the surfaces of corals
is subjected to extreme conditions and are living at their critical
maximum stress threshold levels during this current time. Given the
state of the worlds reefs is it wise for the Bahamian Govt. and an
American Company to allow such an irresponsible project to take place
? Thermal coral-bleaching will intensify along with the rise in heat
trapping gasses over this next century. Since we cannot convince and
control the current Cheney/Bush administration to control atmospheric
carbon dioxide (heat trapping gasses partly responsible for global
warming) would it not be wise to at least address localized threats
to coral reefs ? My research assistant and I would like to thank the
local environmental group on Guana Key for their efforts in
preserving and respecting this coral reef ecosystem.
Dr. James M. Cervino, MS, Ph.D.
Department of Biological & Health Sciences
Pace University New York NYC
Phone: (917) 620-5287
Web site: http://www.globalcoral.org
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