2f> CALIFORNIA FISH AND GAME 



the lagoon. At the time of the L942 census, however, eelgrass was 

 observed by Bedwell to be growing up through the silt, so thai normal 

 conditions may be reestablished, provided thai further Large deposits of 

 silt do not occur. Bedwell further advised thai a1 no time were eelgrass 

 stands a1 the extreme south end of the bay affected by the silt and thai 

 at the time of the census, there was sufficient eelgrass for the small num- 

 ber of birds found present. Samples of eelgrass collected by Bedwell 

 on February 16, 19-12, for Dr. Etenn, were found by the latter not to be 

 affected by Labyrinthula. 



Warden Glidden made observations of eelgrass conditions and col- 

 lected samples in Mission Bay on February 10, 1942, and again in mid- 

 March. He reported that the plant was plentiful in this bay where 

 larger growths of apparently healthy eelgrass were found than in pre- 

 vious years. Samples were taken from two localities in .Mission Bay 

 and examined by Dr. Renn who found Labyrinthula positively present 

 in one of them and not in the other. Since Labyrinthula was also 

 found in samples collected by Glidden in 1941, the disease has appar- 

 ently been present locally for at least several months with little or no 

 visible deleterious effect upon the plant's abundance. It will be inter- 

 esting to watch the future developments in this area to see if the disease 

 has so recently reached the locality as not yet to have caused depletion, 

 or whether some other factor is responsible, such as specialized local 

 conditions, or a less susceptible strain of eelgrass along the southern 

 part of the Pacific Coast. 



In the spring of 10-12. as in 1941, Glidden was unable to find any 

 eelgrass in San Diego Bay where the plant appears to have been com- 

 pletely killed out by some cause. In spite of this fact, the largest 

 number of brant reported in any of the 12 annual censuses was recorded 

 in 1942. In reporting this fact, Glidden commented thai he wondered 

 upon what the brant of San Diego Bay subsisted, lie stated that this 

 population and that of Mission Bay do not appear to exchange posi- 

 tions and that the birds of San Diego Bay seem to remain there for a 

 considerable time. The writer believes that the brant of San Diego 

 Bay may subsist to a large extent upon sea lettuce (Ulr<i lactuca), 

 great quantities of which plant he noted along the western shore of 

 San Diego Bay in October, 1942. 



In addition to examining for Labyrinthula samples of eelgrass 

 from the above mentioned California localities. Dr. "Renn was also able 

 to examine material from several localities in Oregon through the much 

 appreciated cooperation of S. G. Jewett, 1'. S. Fish and Wildlife Serv- 

 ice, Portland. Oregon. Jewell collected samples from the six Oregon 

 localities mentioned in the table below, which recapitulates Dr. Renn 's 

 reports on material from the Pacific Coast. 



The writer wishes to take this opportunity to express his sincere 

 appreciation of Dr. Renn's kindness in studying this material, and for 

 his permission to make the results known in this paper. His continued 

 interest in our Pacific Coast eelgrass problems is most valuable. In 

 the following table, Dr. Renn advises, "positive" simply means that 

 he found Labyrinthula definitely present in the samples, while "nega- 

 tive" means that he did not find it. It is quite possible that other 

 samples of eelgrass from localities whence Dr. Renn did not observe 



