[Coral-List] SCTLD in ballast water

Eugene Shinn eugeneshinn at mail.usf.edu
Sat Jul 30 19:46:00 UTC 2022

I scanned the interesting research paper that blames coral disease is 
spread by ships ballast water. It is a reasonable hypothesis. However, I 
agree with Alina Szmant. I too have not seen the proof. She pointed out 
that the paper was not peer reviewed. The first thing I noticed in the 
papers title were the words, “simulated ballast water.” If I were a 
shipping company owner and that study was being used as proof my ballast 
water was the major spreader and cause of coral reef demise I would 
surely have my high paid lawyers go on the attack. They could quickly 
point out that the study of simulated ballast water does not prove my 
ballast water causes disease. That otherwise excellent study made me 
wonder why did the authors not sample water from actual ship ballast 
tanks? Why use simulated ballast water? At the same time I have to agree 
there is no evidence that real ballast water is not a carrier of coral 
disease. Ballast water may actually be spreading coral toxins from reef 
to reef. However, the real question is If there are disease organisms in 
ballast water, where did they come from in the first place. Clearly once 
these agents are in the water column they can easily be moved along with 
water currents. They do need ballast water for transport. The major 
current flow directions in the Caribbean are well known and the 
strongest of these currents flow past the Belize and Florida Keys reefs.

As many list readers know I have been advocating since the 1980s that 
disease agents in the Caribbean were originally brought to the western 
Atlantic/Caribbean in dust clouds transported by the Tradewinds. Dust 
particles carrying disease causing agents are constantly dropping out as 
the dust clouds move along. Many even cross over into the Pacific. Once 
corals and other organisms including /Diadema/ and Seafan diseases 
become established they are easily transmitted down current to affect 
other marine organisms. I have often suggested the demise of the 
staghorn fields at San Salvador in 1983, was a starting point for such 

Back when my USGS dust study team was active in the late 1990s they 
cultured and identified around 200 microbes and fungi that were being 
transmitted in African dust clouds. At the time we knew asthma was 
rampant in children on those windward islands in the Bahamas. Even 
Puerto Rico is well known for its respiratory diseases. In those days it 
baffled me why so many competent scientists rejected the dust 
hypothesis. Later as I matured I realized it was all about politics and 
funding. I suppose blaming coral diseases on ballast water these days is 
politically correct. Gene

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