[Coral-List] African dust and Caribbean Saragasum

[Eugene Shinn]

Listers will find this interesting... I just experienced 2 weeks of red 
dust and strong winds in the lower Florida Keys.. This just received 
from Ken Banks. Gene

Observe the air; it was so difficult to breathe for several months. Then 
this ocean, covered with Sargassum seaweed. The two phenomena are 
linked, which was revealed by U.S. scientists in Missouri. Their study 
is not new (we had already mentioned it) but it is the right time to 
bring it out again because both phenomena are currently affecting us. 
Scientists studied the invasion of seaweed in 2011 on all Caribbean 
coasts. [. . .]

At the time, everyone thought that the /sargassum/ came from the 
Sargasso Sea, located in the North Atlantic. The assumption, however, 
was never verified. Despite their attempts, American scientists “have 
not succeeded in linking the Caribbean invasion to the North Atlantic 
and the Sargasso Sea.”  However, they used a numerical model for current 
flows. Thus, they discovered that the seaweed actually grew in the South 
Atlantic, at the level of the “North Equatorial Recirculation Region” 
(NERR).

This is a swirling ocean current where growing conditions are ideal for 
seaweed. The waters are warm there, and nutrients are plentiful. This is 
where our sandy mist comes in!

Indeed, if a significant quantity of nutrients comes from the River 
Congo (in Central Africa), the Amazon, and the upwelling of cold waters 
from the deep, the [in]famous sandy dust also plays a role. These are 
especially rich in iron and phosphates and when their path meets the 
Sargassum seaweed, they feed it. On the 2011 episode, Franck Mazeas—of 
the Environment, Planning and Housing Office of Guadeloupe—commented: 
“The unusual nature of this event could be associated with greater 
fluctuations of the dynamics of regional ecosystems, particularly in 
connection with climate change.” It seems that the years that followed 
vindicated the scientists [and their work, published as “The Sargassum 
Invasion of the Eastern Caribbean and Dynamics of the Equatorial North 
Atlantic” by Donald R. Johnson, Dong S. Ko, James S. Franks, Paula 
Moreno, and Guillermo Sanchez-Rubio (Center for Fisheries Research and 
Development, Gulf Coast Research Laboratory, University of Southern 
Mississippi, Mississippi; Ocean Dynamics and Prediction Branch, Naval 
Research Laboratory, Stennis Space Center, Mississippi).

For full article, see 
_http://www.martinique.franceantilles.fr/actualite/environnement/quand-la-brume-de-sable-profite-aux-sargasses-313557.php_

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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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