[Coral-List] Restoration rationale

[Eugene Shinn]

The coral-list recently hosted several interesting discussions about 
reef rehabilitation and transplanting. Proposed causes of reef decline 
are interesting and varied but not new. Most coral-list readers heard it 
all going back to the 1970s.Steve Gittings recently listed what I 
usually call “/the usual suspects/.” The only thing left out of the list 
was African dust, which periodically and simultaneously impacts the 
entire Caribbean. Such events have increased in recent years. Dust, 
unlike the usual suspects, can affect small isolated reefs where the 
usual suspects are absent. Interestingly there have been few if any 
simple bioassays of dust affects on live corals. African dust collected 
in dust traps in Florida was recently provided to an outstanding high 
school student for use in her science project. In controlled aquarium 
experiments she found all three of the different concentrations tested 
killed A. c/ervicornis/ in about two days. Toxins in the dust that 
caused coral death were not identified. This was what can be called a 
simple ‘proof-of-concept’ experiment. And yes I said it was a high 
school poster project! Shocking!One has to wonder why reputable 
scientists from University, or Government agencies had not performed 
simple bioassays on dust and other chemicals? The major problem is 
finding funding and the behind the scene politics that affects research 
funding. I know many reputable qualified scientists who have submitted 
proposals to test toxicity of African dust. All were rejected! I came to 
the conclusion it will require some motivated self-funded scientist to 
do the needed experiments. I also wonder if the results of such work 
would be accepted for publication if shown to be harmful?

Incidentally that high school student was one of three sisters each of 
which have won awards for high school science posters depicting coral 
research projects. One elegant award-winning poster clearly demonstrated 
in controlled experiments that something in Florida Keys water 
transmitted coral disease to A/. cervicornis/. Another project confirmed 
toxic effects of Oxybenzone/sunscreen on A. /cervicornis /and in 
yet//another coral experiment, one of the common mosquito sprays used in 
the Keys also proved highly toxic to A. /cervicornis/. Who are these 
girls? They are daughters of the geologist who a few years ago headed 
the coral resource protection section at the Florida Keys National 
Marine Sanctuary.

I always found it interesting that FLKNS would never conduct or fund 
these kinds of basic toxicity studies that were needed for reef 
management. I served on many coral reef committees in the Keys beginning 
in the mid 1970s and brought up these subjects at every meeting. 
Discussions always quickly turned to other subjects including anchor 
damage and boat groundings that are easy to observe and photograph. In 
my experience working the in Keys, there was no coral diseases 
(1950-1960s) so anchor damage always healed quickly. Also there were far 
less boats on the water and sanctuaries that attract people to 
sanctuaries did not exist. That all changed in the late 1970s. Some of 
you may remember my simple calculation regarding the proliferation of A. 
/cervicornis /following Hurricane Donna (Shinn /Env Geol/1976). Based on 
the annual growth rate and frequency of branching a healthy A. 
/cervicornis/ colony consisting of 10 branches could potentially produce 
35 miles of branches in just 10 years. Of course that can never happen 
because this shallow water coral would not have room. Growth would stop 
when it reached sea level. There simply is not enough space for them to 
reach their full potential. They basically stopped growing in the late 
1970s with their demise peaking in 1983. The main culprit was white-band 
disease and that disease didn’t just impact corals in Florida but 
throughout the Caribbean. It has been a slippery slope downward ever since.

There was also another basic study that was never conducted. To my 
knowledge there has been only one controlled laboratory study to 
determine the impact of sewage (wastewater) on corals in southeastern 
Florida. It was done using water from the Virginia Key Sewage treatment 
plant in Miami-Dade County. The study showed corals near the outfall 
were not directly affected but alga grew fast and had to be manually 
removed the prevent interference with coral growth. The coral was not 
otherwise affected. That paper was presented by a researcher from the U. 
of Miami Rosenstiel School at the 1981 International Coral Reef 
Symposium in Manila. It was never published. The study was done back 
before coral diseases appeared in the Caribbean and before the /Diadema/ 
plague in 1983.

In the late 1980s we wondered if sewage in ground water might be 
affecting coral growth in the Keys. With State and Federal EPA funding 
we installed around 50 monitoring wells and measured lateral movement of 
sewage contaminated ground water. We found that everywhere in the 
Florida Keys net flow is toward the coral reefs. We had hoped the study 
would show that groundwater flow would correlate with coral diseases. If 
correct, improved wastewater treatment would have had a direct benefit 
to the corals. Unfortunately, our work did not prove corals were being 
affected by groundwater even though it contained fecal bacteria and most 
everything else that goes into keys septic tank drain fields and 
disposal wells. That study did help support installation of a Keys-wide 
sewage system. However, it did not prove sewage water was causing coral 
disease. Coral diseases were breaking out around distant Caribbean 
islands with few or no people that were simultaneously suffering the 
same fate as those in the Florida Keys. Because of these observations we 
began to recognize there might be something else that could 
simultaneously affect the entire Caribbean. It was African dust. The red 
soils and reddish brown crusts found on all Caribbean islands we knew 
came via trade winds from North Africa. African dust transport peaked in 
1983 the same year Diadema died, sea fan disease began, and Acroporid 
corals became diseased most everywhere. Lake Chad in North Africa was 
drying up and its lakebed was blowing away. Hundred-mile wide Lake Chad 
in 1960 has now shrunk to about 6 miles across.

The reader will recognize I am of course beating my favorite drum. 
Science can be a beautiful instrument. Unfortunately scientific 
environmental studies are often held in check and publication of results 
denied for various proprietary or political reasons. There is also often 
a herd instinct among researchers. The herd is generally driven by funding.

Even though straightforward bioassays have not been conducted, the 
recent rash of funding for coral nurturing and out planting has in fact 
stimulated many detailed studies that otherwise might not have been 
attempted. These studies include anatomy, DNA, pH, symboyants, 
temperature, nutrients and many other basics that otherwise might not 
have been considered important enough to be funded. Still however, we 
still do not know what ingredients in African dust kills coral. 
Unfortunately straightforward bioassays of chemical ingredients that 
would supply information needed for reef management are not likely to 
earn striving students advanced degrees or give his or her professor a 
sense of accomplishment. I suspect many basic studies will continue to 
be ignored in the near future. As someone on the coral-list list once 
posted, “Transplanting coral in the Keys is like telling residents they 
can go back into a burning home before the flames have been 
extinguished.” Gene

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No Rocks, No Water, No Ecosystem (EAS)
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E. A. Shinn, Courtesy Professor
University of South Florida
College of Marine Science Room 221A
140 Seventh Avenue South
St. Petersburg, FL 33701
<eugeneshinn at mail.usf.edu>
Tel 727 553-1158
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