THE LAPTEV SEA 

 Table 111 



259 



and distance from the shore of these zones depend primarily on the quantity 

 of fresh water brought in by the rivers.' Jashnov (1940) points out the very 

 interesting fact that the brackish-water community is the only endemic and 

 autochthonous community of plankton in the Arctic basin. The western limit 

 of its distribution is the Kara Sea. 'All the other plankton forms belong either 

 to the number of widely distributed species or to forms whose existence is 

 conditioned by the penetration of the Atlantic and Pacific waters into the 

 Arctic zone.' Jashnov adds Halitholus cirratus and Calycopsis birulai to the 

 few crustaceans of this community. 



The mean biomass of the summer zooplankton of the Laptev and East 

 Siberian Seas, according to Jashnov (1940), is 72 mg/m 3 , with fluctuations 

 from 24 to 200 mg/m 3 (about 3 tons beneath each 1 km 2 ). The total biomass of 

 summer zooplankton in the Laptev Sea is about 3 million tons, and in the 

 East Siberian Sea about 2 million tons. 



Qualitative composition of zoobenthos 



So far 405 benthos forms are known for the Laptev Sea {Table 112). 



Table 112 



