African dust degrades Florida Everglades and Florida ecosystem, hundreds of millions of tons of Saharan dust and chemicals flow yearly to southern US, Caribbean, and other areas-USGS

12/6/2004, "Atmospheric Deposition of African Dust in the Everglades and Florida Bay Ecosystem," E. A. Shinn, USGS, St. Petersburg, FL

USGS map

 
"Significant degradation in the Everglades and Florida Bay ecosystem usually associated with human factors also coincides with the long-term African drought and a four-fold influx of dust that began impacting Florida in the early 1970s. African soil dust delivers arsenic, phosphorous, sulfates, pesticides, microbes, pollen, and probably seeds and insects to all south Florida environments. Dust-borne elements can also benefit flora and have been shown to deliver essential nutrients to the Amazon rain forest. Atmospheric dust likely is both a benefit and detriment to Florida’s environment. The USGS Global Dust project is attempting to characterize and determine the effects of dust borne nutrients, toxics, and exotics on south Florida. Previous studies show that about half the atmospheric particles that settle in south Florida during summer months originate in North Africa."... 

USGS Map caption: "Transport of African dust to the Americas: map from Perry, K.D., Cahill, T.A., Eldred, R.A., and Dutcher, D.D., 1997, Long-range transport of North African dust to the eastern United States: Journal of Geophysical Research, v. 102, no. D10, p. 11225-11238."

March 2002, "Caribbean Coral-Reef Ecologist Studies Dust from the African Sahel," soundwaves.usgs.gov, Ginger Garrison

"Every year, hundreds of millions of tons of African dust are carried from the Sahara and Sahel across the Atlantic to the Caribbean and the southeastern United States. In the Caribbean, the sky becomes hazy, visibility decreases to a few kilometers, a fine red dust settles on surfaces, and residents complain of sinus problems, coughs, and other ailments said to be caused by the dust. Although the dust has been carried to the Caribbean for thousands of years, the amount transported varies from year to year and has increased drastically since the early 1970s with the beginning of the drought in the Sahel.

Composed primarily of soil particles so small (less than 2.5 µm) that our lungs cannot expel them, the dust may transport various microorganisms and chemicals that hitchhike on the small particles. Charles Darwin, on his 1845 voyage aboard the surveying ship H.M.S. Beagle, collected African dust in the Atlantic and, using a microscope, saw live microorganisms on the soil particles. Even larger organisms, African desert locusts (Schistocerca gregaria, as much as 3 inches long or longer), arrived alive in Antigua, Barbados, and Trinidad during a large dust event in 1988."...

 



.