182 THE OCEAN RIVER 



water, made the sea slimy to the touch and highly poisonous 

 to fishes. Over 50 million fishes died as a result of this out- 

 burst of invisible plant life, littering the beaches with their 

 decaying remains. Less harmful but more permanent is the 

 growth of another type of microscopic drifting sea plant, Tri- 

 chodesmium erythraeum, which is said to cause the color of 

 the Red Sea and the sea of Baja California. Important as the 

 diatoms and dinoflagellates are, there is reason to believe today 

 that even smaller plantlike creatures, less than one ten-thou- 

 sandth of an inch in size and passing through the finest silk 

 nets, may in many places form the greater bulk of the sea- 

 going pasturage, and that this nannoplankton, or ultraplank- 

 ton, is the most productive food source of the oceans. 



The detailed exploration of this great and complicated chain 

 of sea life and its relation to the currents and drifts of the 

 Ocean River has been partly carried out by the expeditions we 

 have mentioned and by their more recent successors. The work 

 begun from the heaving decks of exploring vessels could never 

 have been completed, however, without the painstaking re- 

 searches of men in the marine laboratories that developed side 

 by side with them along the shores of the Ocean River. One of 

 the first laboratories to be established and one of the most 

 famous was founded at Naples in 1874; but scientific interest 

 was already roused along the shores of other tributary seas and 

 along the seaboard of the River itself. The Marine Biological 

 Association of the United Kingdom opened its laboratory at 

 the entrance to the English Channel at Plymouth in 1879, 

 under the sponsorship of the great biologist Thomas Henry 

 Huxley. Its contributions to our knowledge of plankton and 

 of the complicated effects which water currents and the chemi- 

 cal makeup of sea water have on marine life have done much 

 to lay the foundations of our present understanding of these 

 problems. 



The list of marine research laboratories that grew up in the 



