SCIENCE AND THE SEA 



discolored water, and where there is a variable ecological 

 regime, discoloration occurs only sporadically. 



IMPORTANCE 



The interest in discolored water is not limited to the mariner. 

 Inhabitants of shore communities where discolored water recurs, 

 find the phenomenon very disturbing. In many of the outbreaks, 

 notably the ones in Florida in recent years, the great numbers 

 of organisms dying and decomposing in the water praluced an 

 ugly, evil-smelling scum, and with the rapidly depl-eted oxygen 

 supply killing fishes by the millions and driving them ashore, 

 the stench becomes unbearable. The decay and anaerobic 

 conditions frequently also contribute to the production of 

 lydrogen sulfide gas, the substance with the "rotten egg smell" 

 which has blackened the paint on houses near the beach and 

 the brightwork on ships passing through it. Because this 

 aspect is so conspicuous, the Peruvian outbreaks are called 

 "El Pintor", "The Callao Painter." 



Besides these odors, an irritating vapor was noted in these 

 outbreaks which affected the mucus membrane of the nose 

 and throat, causing extreme discomfort even to people living 

 several miles from the beach. 



Certain of the discoloring organisms have been found to be 

 definitely poisonous, and it is believed the mortality among 



the invertebrates and fish is caused by the toxins as well as 

 by the oxygen depletion. Although the exact nature of the 

 poison is not yet known, it is known to be sufficiently potent 

 to be fatal even to humans who may eat oysters, clams, 

 mussels, etc., which have the organisms in their stomachs. 



These conditions and tfie red water may last only a few 

 hours, washing away with the tide, or may persist for days 

 and weeks until dispersed by the wind, which mixes the water 

 and causes the products of the decomposition to sink to the 

 bottom, or to be diluted until they are no longer critical. 



The losses to the shell fisheries industries are tremendous 

 for, although some fish caught by the tide can swim out of the 

 area, the sessile animals can protect themselves only by 

 closing their shells. If the outbreak lasts more than a few 

 hours they are annihilated. Even among the birds which are 

 dependent on marine forms for food, the mortality is extensive. 

 The Guano industry in Peru is imperiled regularly by El Nino 

 and the Aquaje. 



Not all discoloring organisms are poisonous, of course, and 

 discolored water is not always destructive. Some outbreaks 

 in fact, would pass unnoticed if they did not occur in a locality 

 under the attention of hydrologists. 



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