SOME DISTRIBUTION PATTERNS REPRESENTED BY THE 

 MARINE ALGAE OF NHATRANG BAY, VIETNAM ^ 



By E. Yale DawsOxN 



Allan Hancock Foundation, University of Southern California 



Los Angeles 7, California, U.S.A. 



It was close to a century ago that Martens, writing for the German 

 East Asiatic Expedition, summarized for the first and for the last time 

 up to the present, the marine algal flora of Indo-China. Twelve species 

 were listed! 



The Indo-China coast extending for over a thousand miles along 

 virtually the entire west side of the South China Sea has remained one 

 of the least known coasts of the world. Upon invitation of the Pacific 

 Science Board and with the support of the U. S. Office of Naval Re- 

 search," I was privileged to spend three months there during early 1953 

 in marine algal exploration in the vicinity of the Institut Oceanogra- 

 phique de Nhatrang, Viet-Nam. 



The vicinity of the Institut within a radius of five miles offers a 

 remarkable diversity of marine environments including mangrove la- 

 goons, mud flats, sand flats, rocky shores of both coral and intrusive 

 rock, calm lagoons, wave-dashed rocks and sea walls, surge-swept off- 

 shore rocks, and varied benthic habitats to depths of over 100 feet. 

 Sampling from each of these environments during the months of January 

 through March resulted in the collection of 224 species of marine plants 

 of which 2% were phanerogams, 8% Myxophyta, 22% Chlorophyta, 

 12% Paeophyta, and 56% Rhodophyta. Of tliese, only six species of 

 Rhodophyta occurred exclusively in depths of greater than three meters. 



Inasmuch as this investigation represented the first of its kind for 

 the South China Sea region, it was not possible to rely heavily upon 

 any particular work for aid in identifying the plants. Indeed, it was 

 necessary to search virtually the entire literature dealing with tropical 

 marine algae in an attempt to determine the specimens. 



This search pointed up sharply the great dearth of information 

 on the marine plants of the vast, tropical areas of the world. In the 

 tropical Indo-Pacific region, for instance, the only reasonably complete 

 marine floras are those of Weber van Bosse for Indonesia, Brgesen's 

 account of the algae of Mauritius, and Taylor's account of the rather 



' Contribution number 116 from the Allan Hancock Foundation. 



^ These studies were aided by a contract between the Office of Naval Research, Department 

 ■of the Navy and the National Academy of Sciences (NR 160 175). 



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