STRUCTURE AND EVOLUTION OF THE SEA GRASS 



COMMUNITIES POSIDONIA AND CYMODOCEA IN 



THE SOUTHEASTERN MEDITERRANEAN 



By 



Anwar Abdel Aleem 



Associate Professor of Oceanography 



University of Alexandria 



and 



Fulbright Scholar at the Hancock Foundation 



The ecology of marine littoral environments has received consider- 

 ably more attention than that of submerged areas. Information on the 

 biocoenoses of submerged habitats formerly came largely from the study 

 of material brought up by the dredge. Recent developments in under- 

 w^ater equipment, however, have made possible much more adequate 

 studies of the ocean bottom. During the past few years, the writer 

 (Aleem, 1951) has undertaken a study of the algal and phanerogamic 

 communities inhabiting the sublittoral region along the Egj'ptian Medi- 

 terranean coast. Material was collected mostly by diving, using a face 

 mask and respiration tube ; notes were recorded underwater on plexiglass 

 slates. A preliminary report on the ecology and distribution of the sea- 

 grass communities is presented in this paper. 



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