THE BLACK SEA 



429 



they are simply an impoverished flora of the Mediterranean Sea. N. Morozova- 

 Wodjanitzkaja points out also the small size of the Black Sea algae — on the 

 average 10 to 30 cm. The largest, Cystozera, is not longer than 1.2 m. 



Quantitative distribution ofphytobenthos. In examining the quantitative distri- 

 bution of macrophy tes in the Black Sea it is necessary first of all to distinguish 

 the marine flowering plant eel-grass which, as has been mentioned above, is 

 represented in the Black Sea by two species. The main mass of eel-grass is 

 found in the northeastern part of Karkinitsk Bay (Fig. 208), where it forms 

 wide submarine meadows at depths of 0-5 to 6 m on sandy mud, at times 



ЕЭ PHYLLOPHORA 

 ШШ ZOSTERA 



Fig. 208. Distribution of Phyllophora and 



Zostera growths in northwestern corner of 



Black Sea (Morozova-Wodjanitzkaja). 



together with Ruppia and Potamogeton ; it is found even deeper (down to 15 or 

 20 m), but only in small amounts. It is found in small amounts along the whole 

 coast of the Black Sea in its inlets and bays. In the most favourable environ- 

 ment the eel-grass biomass reaches 5 kg/m 2 (on the average 1-5 kg/m 2 ). The 

 abundant growths of eel-grass are concentrated off the Black Sea shores ; in 

 the shallows of Karkinitsk Bay they form a mass of no less than 200,000 tons, 

 while V. Wodjanitzky has determined the total amount in the Black Sea as 

 1 million tons (1941). The epidemic caused by the fungus Labirintula, which 

 afflicted the north Atlantic Zostera in the 'thirties, spread to the Black Sea 

 and destroyed Zostera marina wholesale. Besides Zostera the eel-grass 

 Phyllophora rubens var. nervosa should also be discussed separately. Phyllo- 

 phora, probably a special ecological form, is found along the whole shore of 

 the Black Sea, but 95 per cent of its total mass is concentrated in the north- 

 western part of the Sea (Fig. 208). This accumulation of algae, reckoned as 

 not less than 5 to 6 million tons,* covers the mud-shell gravel floor in one 

 huge mass over an area of about 15,000 km 2 in the region called 'Zernov's 

 Phyllophora Sea' in honour of Academician S. Zernov, who discovered it 



* V. Wodjanitzky (1941) determines the bulk of Phyllophora in the northwestern part 

 of the Black Sea as 17 million tons, which is obviously an exaggeration. 



