suitable for algal growth but lacking the necessary 

 substrata. 



The most promising results with a potential for 

 direct application in the production of quantities of 

 taw material for industry have come from the first 

 procedure. Growth of Hypnea musciformis and 

 GraciUiriafolifera in net-covered cages, floatingjust 

 15 cm under the surface, during the warmer months 

 of the year was very rapid, often doubling their 

 weight in 1 day. These plants, growing in a very 

 favorable environment and protected from grazers, 

 increased their weight from lOto lOOgin 10-14days. 

 The culture of Eialwnma isifonne and E. acantho- 

 chuliiiu. using some of these techniques, will be 

 emphasized during the next year. 



Methods to culture both benthic and planktonic 

 marine algae are being developed at the University 

 of Washington. The phycologists have demon- 

 strated that Iridaea cordalct, Gigartino exasperata. 

 dndAi^'dnlliii'lla teiu'ia vav. pacijka can be success- 

 fully transplanted to habitats in which they have not 

 previously grown, and have grown these three 

 species, plus Sarcodiotheca fitnaici, in laboratory 

 cultures. In a related effort, the investigators have 

 completed a study on extracellular, water-soluble 

 polysaccharides produced by various marine 

 diatoms and isolated in axenic culture the unicellular 

 red alga, Rhodosonis nuiriniis for subsequent 

 growth experiments. 



A multidisciplinary team at the University of 

 California at Santa Barbara is studying some of the 

 varied problems encountered by the seaweed indus- 

 try in the United States. Biologists and engineers are 

 studying the settlement and growth of spores, includ- 

 ing the effects of water motion on spore settlement 

 and on reproductive stages. Transplants of 

 Gelidiiim. Gnicilaria, and Maciocysiis are being 

 made for studies of growth and colloid production. 



As part of this program, economists are surveying 

 the present and future status of the U.S. seaweed 

 industry. An economic model is being developed for 

 the agar weed Gelidiiim. which considers growth, 

 loss, and reproduction rates; production problems: 

 and agar content. 



Future work will include an evaluation of harvest- 

 ing methods and packaging operations and the de- 

 \elopment of a '"breeding stock"" of rapidly growing 

 forms. 



Brown Algae 



One of the oldest programs in the United States in 

 seaweed management is the kelp research now being 



conducted at the Marine Laboratory of the Califor- 

 nia Institute of Technology. During their early at- 

 tempts of restoring the kelp beds off southern 

 California, the researchers simply transplanted adult 

 plants from an existing bed to an area where a new 

 bed was to be established or a disappearing bed 

 strengthened. The adult plant then released spores 

 \\ hich produced new plants. At the same time quick- 

 lime was spread over the bottom to kill the heavy 

 grazing sea urchins. Attempts were also made to 

 protect the young plants from grazing fish with net 

 covers. 



Recent work has been devoted to the development 

 of techniques for raising Macrocystis plants in mass 

 culture from liberated zoospores, through the 

 gametophyte to the embryonic sporophyte. The em- 

 bryonic sporophytes which develop on an artificial 

 substrate are scraped free and dispersed close to the 

 bottom in areas suitable for kelp growth. Preliminary 

 estimates indicate that about lO'* embryos must be 

 dispersed to yield one attached Macrocystis ']U\Qm\t 

 about 15 cm tall. 



The culture system now in use can produce 10^ to 

 10" embryos per cm- of culture substrate. Thus, the 

 low survival rates following dispersal do not prohibit 

 the use of this system for developing new kelp 

 stands. Out of five areas in which this technique 

 was attempted, youngM curacy stis developed in 

 three of them with hundreds to thousands of plants 

 resulting in two of the areas. 



MARINE PATHOLOGY 



Several institutions have directed research efforts 

 toward the diseases and parasites of seafood or- 

 ganisms, usually looking at several different kinds of 

 animals. Most of the animals examined are being 

 cultured, at least experimentally, in the United 

 States. Texas A&M University has established an 

 Aquatic Animal Medicine laboratory on its campus 

 and is working with a wide variety of finfish and 

 shellfish, looking for many types of bacteria, vi- 

 ruses, and other infectious agents. They have iden- 

 tified the microbial fiora of Gulf of Mexico and 

 pond-grown shrimp and developed new techniques 

 for detecting certain agents and diseases in finfish 

 and shellfish. 



Microbiologists at Georgetown University have 

 been examining several Chesapeake Bay organisms 

 for the bacterium, I'ihrio pciraliacituilyticiis. 

 responsible for many cases of food poisoning in 

 Japan and some recent cases in the United States. 



50 



