TWELFTH ANNUAL BLACK BRANT CENSUS IN CALIFORNIA 27 



the organism in the material, might indicate its presence; but for the 

 moment, it is assumed that his negative observations indicate relative 

 freedom from the disease. 



TABLE 2 



Report on presence of Labyrinthula in samples of Zostera marina collected in 



California and Oregon in 1942, examined by Dr. C. E. Renn 



of Harvard University, May 14, 1942 



Positive Samples 



Date 

 Sample Collected Collected by Collected 



Netarts Bay, Oregon S. G. Jewett 3/ 9/42 



Coos Bay, Oregon S. G. Jewett 3/10/42 



Yaquina Bay, Oregon S. G. Jewett 3/ 9/42 



Bodega Bay, California Bert Laws 2/10/42 



Limantour Bay, California R. J. Yates 3/11/42 



Morro Bay, California F. W. Hecker 2/10/42 



Mission Bay No. 2, California E. H. Glidden 2/16/42 



Negative Samples 



Nehalem Bay, Oregon S. G. Jewett 3/ 8/42 



Siletz Bay, Oregon S. G. Jewett 3/ 9/42 



Tillamook Bay, Oregon S. G. Jewett 3 /42 



South Humboldt Bay, California L. Werder 2/10/42 



Tomales Bay, California D. A. Simpson 3/ 8/42 



Point Mugu Lagoon, California R. E. Bedwell 2/16/42 



Mission Bay No. 1, California E. H. Glidden 2/16/42 



Summary 



In point of total numbers, the 1942 census of black brant in Cali- 

 fornia compared favorably with results of 11 previous censuses, even 

 though no count was obtained this year from Drake's Bay to include 

 in the total. In 1942, 64,703 brant were counted in six localities. A 

 year previous, 61,339 birds were recorded from the same areas, while 

 the ten year average from all localities, including Drake's Bay, prior 

 to 1942 was 57,344 Vant. 



Humboldt, our most important brant bay, showed better than 

 average numbers present this year with a slight decline over the pre- 

 vious season. The next to the smallest of 11 censuses was reported 

 from Bodega Bay in 1942. The Tomales total of 2,370 brant this 

 February was less than half of the previous 11-year average for this 

 locality, yet substantial improvement was evidenced over the all-time 

 low count of 1,540 brant in 1941. For the second successive year no 

 census was available from Drake's Bay. In 1942, Morro Bay yielded 

 a much larger than average total of 8,861 brant. This count has only 

 once been exceeded, in 1939 when 11,140 brant were reported, and is 

 substantially in excess of the average of 5,964 brant for the 10 former 

 Morro Bay censuses, even in spite of reports of continued eelgrass 

 depletion from the area. The unprecedentedly large numbers of brant 

 reported in 1942 from both Mission and San Diego bays, where respec- 

 tively 3,900 and 1,100 birds were censused, was one of the gratifying 

 features of this year's results. The brant have increased in this area 

 during the period that the censuses have been taken, from none in 1932 

 to the present high. 



