Spaxk-type bioluminescence caused by swarms of euphausiids also may 

 be observed in the Sea of Japan; it is blue and prevalent in- the northern 

 part. The light given off by these and other crustaceans is very intense 

 in April and is used by fishermen to detect moving herring schools. 



Although reports of glowing-ball bioluminescence are lacking for the 

 Sea of Japan, this type of display probably occurs within the Tsushima 

 Current. Both Pyrosoma and Salpa often are observed in the Sea of Japan, 

 the former restricted to warm water regions in the south and east. 

 Haneda (1955) noted that numerous individuals of Beroe (a luminescent 

 ctenophore) often were mixed with specimens of the luminescent squid 

 Watasenia scintillans in nets retrieved from the waters of Toyama Bay. 



In the Sea of Okhotsk the spark type is the most commonly observed 

 bioluminescence. The displays are frequent from August through December 

 and often very intense, especially in September. According to Stixkalin 

 (193^)^ unusually bright greenish white light may be observed in August 

 and September. The regions of cold water and the fronts of the cold 

 water masses appear to be the most favorable regions for the development 

 of many luminescent forms. Noctiluca occurs in large numbers in the sur- 

 face waters of the Gulf of Terpeniya and off southern Sakhalin in spring. 

 An influx of luminescent organisms, including ostracods, often occurs 

 along the north coast of Hokkaido and east coast of Sakhalin in Septem- 

 ber. Copepods such as Metridia are responsible for displays during May 

 and June. 



Icebreakers in the Sea of Okhotsk have created some strong scintil- 

 lating green bioluminescence as they crashed their way through icefields 

 or bumped floating chunks. The light probably is given off by im- 

 prisoned luminescent organisms. These organisms occasionally make the 

 ice appear red, from which the term "bloody ice" has been derived. 



Certain other luminescent displays, the shapes and movement of which 

 are unexplainable at this time, have been observed by observers in the 

 Sea of Okhotsk. These displays are best described as large expanding 

 circles of light which appear suddenly in the sea, or as waves of light, 

 or strips of light extending in various directions. Occasionally these 

 strips of light will rotate, resembling a "phosphorescent wheel" (see 

 section on this subject). Observers from the Sakhalin Branch of the 

 Russian Oceanological Institute on a research expedition noted such an 

 appearance (Priroda, 195^) ih miles east of Cape Aniva in September 1953- 

 They reported as follows: 



"On the night of the 9-10 of September unexpected bright 

 luminescence of the sea was observed across the stern of 

 the ship, which progressed rapidly, forming a rather large 

 ring in the center of Which was the ship. It was very 

 brilliant near the ship, and was strongly luminescent as 

 it rapidly increased in size progressing from the ship to 

 the invisible horizon. The luminescence was intense and 



2I1 



