THIRTY-SECOND BIENNIAL REPORT 



73 



Late in 1929 II. C. McMillin, one of the U. S. Bureau of Fisheries' 

 biologists engaged in oyster investigations in Washington and Oregon, 

 was able to give us some assistance while temporarily stationed ;*i 

 Stanford University. Paul Bonnot, one of our fisheries biologists, was 

 detailed to work under McMillin 's direction. During 1 !»:;() and most 

 of 1931 only occasional days were devoted to oyster work. This work 

 consisted of the inspection of seed oysters which were being imported 

 from Japan and of observing and advising in the experiments with 

 Japanese and native oysters at Elkhorn Slough on Monterey Bay. 



Our State law requires that permission be obtained from the 

 Division of Fish and Game to import marine plants or animals into 

 the State for the purpose of propagation or planting in State waters, 

 and that such plants or animals be inspected by the Division. There 

 is one exception to these provisions and that is oysters. The great 

 danger of introducing destructive oyster pests from Japan made it 

 advisable to inspect these oysters, even if we had no authority. It was 

 decided that we could compel the inspection of these shipments ;is 



Fig. 20. Oyster seed dike, Humboldt Bay, California. Photo by Paul Bonnot, 



June, 1932. 



they were sure to contain other forms than oysters for which inspection 

 could be required. 



From the beginning, the best of cooperation was had from the 

 importers of Japanese seed oysters who, impressed with the danger 

 of introducing foreign pests, have been only too glad to aid in the 

 inspection. Only Tomales and San Francisco bays have been infested 

 with exotic pests which were introduced with oysters shipped in past 

 years from the Atlantic coast. By a rigid inspection, it is hoped that 

 destructive pests can be kept out of the other bays. 



At first, several of the lots of incoming Japanese seed oysters 

 contained numerous exotic species but. none of the most destructive 

 Japanese oyster drills, a small mollusk which feeds on oysters. On 

 March 7, 1930, a shipment arrived which carried not only drills but 

 many of their egg cases. This lot was destroyed. Since that time the 

 growers in Japan have been much more careful to keep the seed off 

 the botton and free of the pests ; and in the shipments received in the 



