372 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1957 



the blooming of one of the diatoms, a form of microscopic plant life 

 of the sea known as Rhizosolenia. The abundance of another micro- 

 scopic plant, the alga Trichodesmium, is responsible for the color 

 which gives its name to the Red Sea, and to the Vermillion Sea in 

 the Gulf of California. Blue-green algae in the Baltic Sea and Sea 

 of Azov are often so numerous that the sea surface has been compared 

 in color to a green meadow. In other places and times bacteria cause 

 the Sicilian "Lake of Blood," and some of the shallow European seas, 

 too, become discolored. 



The most striking of all these plankton blooms are the red waters, 

 known as red tides. Some were reported off the coast of Chile as long 

 ago as 1832 by Charles Darwin on the voyage of HMS Beagle, and 

 from such widely scattered places as British Columbia, the Gulf of 

 Mexico, South Africa, Japan, and Australia. 



Not all red tides are accompanied by the death of fishes, nor are 

 they all caused by the same organism. During the past year a red 

 tide off the coast of Chile was investigated by an expedition of the 

 University of Miami and found to be due to a bloom of a diatom 

 called Prorocentrum micans. In other places bacteria, algae, and 

 another microscopic form of sea life, dinoflagellates, have been found 

 responsible. In some cases jellyfishes and small crustaceans such as 

 copepods and euphausids, the krill or food of whales, have caused the 

 discoloration. 



CAUGHT BY SURPRISE 



Few people in Florida, other than fishermen, had ever heard of red 

 tides before the latter part of 1946, when the poisonous red water began 

 its disastrous work. Nevertheless, the records show that the discolor- 

 ation of water and death of fishes were seen off the coast of Florida as 

 early as 1844 and on several occasions since then. But the west coast 

 of Florida was not then the popular area for anglers, tourists, and 

 those who wish to retire in the sun. 



In November 1946 patches of brownish water containing dead or 

 dying fishes were seen by fishermen about 14 miles off the coast of 

 Naples. The pestilence began to spread northward, and during the 

 following three or four months it appeared at Sanibel and Captiva 

 Islands just off the coast. From Cape Romano in the south to Engle- 

 wood Beach in the north dead fishes were found floating in the water. 

 Huge quantities of the dead carcasses were washed ashore, in places 

 as much as 100 pounds to the front foot. Dr. Gordon Gunter and 

 fellow scientists from Miami found dead turtles, shrimps, crabs, 

 and oysters as well as an impressive list of the various species of 

 commercial and noncommercial fishes before the first series of outbreaks 

 died down in March 1947. 



