REPORT OF COMMISSIONERS OF INLAND FISHERIES. 23 



IV. Further Investigation of the Red-Water Plaque. 



The remarkable occurrence of red-water in the Bay, particularly 

 in the Providence River, has been observed for many years. Some- 

 times it becomes exceedingly annoying- on account of the bad odor 

 which accompanies it. On some occasions, when it has occurred 

 in very great abundance, it has seemed to be responsible for the 

 death of vast quantities of marine animals. Shrimp, crabs, eels, 

 menhaden, flat-fish, and many other animals have been stupefied 

 and washed ashore in windrows. The commission, in 1898, made a 

 preliminary investigation of the matter, and discovered that it was 

 caused by the excessive abundance of a microscopic animal (or 

 plant) organism— Peridinium. (See report for 1898.) The cause of 

 its sudden appearance and disappearance, the explanation of its 

 effect upon fish, and the general facts of its life-history are un- 

 known. It is indeed a new species. The commission have en- 

 trusted the thorough investigation of the subject to Mr. E. W. 

 Barnes, whose paper will appear in a future report. 



