1919^ this organism could be found in the water within Barrow Channel, 

 developing in great enough concentrations to discolor the water and to 

 cause strong sheet-type bioluminescence. One observer noted that during 

 the winter along the rocky coast of northwestern Scotland the sea was 

 luminescent. Every stroke of an oar produced a myriad of "green sparks" 

 in the disturbed water, and the wake luminesced for some distance 

 astern. Shoals of jellyfishes, salps, and ctenophores are responsible 

 for much of the summertime bioluminescence in the Irish Sea. Farther 

 north along the Scottish coast some displays due to dinoflagellates 

 and euphausiids often are observed in September. Swarms of herring 

 create bright luminous trails off the Hebrides Islands as they swim 

 through water containing luminescent copepods and dinoflagellates. 



In the waters axound the Faeroe and the Shetland Islands, displays 

 are most frequently observed from May through late October. The dis- 

 plays often are caused by euphausiids, which are common and at times 

 appear in dense concentrations throughout the region in spring, summer, 

 and autumn. The first aggregations of Salpa generally are sighted 

 inside the Faeroe- Shetland Channel in May and June. The water often 

 is so full of these organisms that it appears opaque, and the lumin- 

 escence given off at night can be very strong. 



Norwegian and Greenland Seas 



Strong displays can be expected during the year in the coastal 

 waters of Iceland and Norway and in regions where the WEirm Worth 

 Atlantic Current meets cold cirrrents from the Arctic Ocean. The sea 

 ice also may be luminous because of entrapped luminous organisms. 

 Flashes of light have been seen when sea ice along the west coast of 

 Norway was broken or jarred. This luminescence continues in the melt 

 water. Copepods and dinoflagellates appear to be the organisms frozen, 

 but not dead, within the ice. 



In the offshore waters of the Norwegian and Greenland Seas, Russian 

 observers have noted a considerable eimount of biolximinescence in March 

 and April. In June and July this bioluminescence becomes stronger and 

 often extends over large regions. The organisms responsible probably 

 are dinoflagellates, most likely Ceratium or Peridinium . They can 

 create luminescence in ice-free waters along the coast of eastern 

 Greenland during the year. In August Metridia lucens is abundant in 

 Denmark Strait, and as a result displays of sparkling green light have 

 been observed in the various ice-free fiords along the Greenland coast. 

 Occasional displays also occirr along the coast of Greenland and Iceland 

 from early summer through early autumn. Reports dating back to the 

 early l8th century make reference to the red discoloration of water in 

 southern Icelandic fiords, which turned into "sea fire" at night. Dis- 

 plays such as these are unusual for regions in such high latitudes. 



Mediterranean Sea 



The western basin Is the most luminescent part of the Mediter- 

 ranean Sea except for the Adriatic Sea. Most of the displays observed 



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