[Coral-List] Lyngbya bloom

Gene Shinn eshinn at marine.usf.edu
Fri Apr 16 18:05:36 EDT 2010

Kevin, Recent studies at the Smithsonian Lab in Ft Pierce found  that 
iron is the primary nutrient that  that stimulates Lyngbya growth. 
The question is what is the source of iron? Sewage is not normally a 
source of iron. One  source is African dust. The dust  contains 
between 5 and 6 percent iron. The dust blows in to south Florida 
every summer beginning in June and lasting until November. Due to 
climate changes in North Africa and increased use of water (Lake Chad 
once 100 miles across is now about 10  miles across) the amount of 
dust blowing in from Africa began increasing in the early 1970s and 
peaked in 1983 and 84. 1983 and 1984 was when Lyngbya  as well as 
various green algae proliferated on the reef tract and in Florida 
Bay. Another peak year for dust was 1998. Coral lovers will know what 
happened during those years. The amount of dust leaving Africa is 
around 1 billon tons each year of which hundreds of Millions of tons 
reach our shores. For example the amount of African dust reaching 
Miami  exceeds EPA particulate standards several times a year during 
summer months. Sorry, not much we can do about it. Gene

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