PROGItESS IN BIOLOGICAIv IXQT'IltlES, 1929 1119 



the (liita foi- 11)10-11, it is found that tliis is an iiic-ivase of about 

 J 5 per cent for the New Jersey side and a decrease of about 50 per 

 cent for Delaware. The planted bottom under lease from the 

 States is 29.()00 and (),800 acres, respectively. 



Effect of pvlp-imll wastes on oysters in Sheltoti Bay. — In com- 

 pliance with numerous requests made by the oystermen of Shelton 

 Jiay, AVash., a study of the effect of sul])hite waste licpior dischari^ed 

 l)y the pulp mill has been undertaken. A temjxjrary laboratory has 

 been established in one of the floatin*; '" oyster houses " in Totten 

 Inlet near Olympia. The work, which was be^^un in November, 

 J029, is being carried on liy Dr. A. PI Hopkins and H. C. McMillin. 

 A complete report of these investigations will appear at a later date. 



CONTROL OF EXEIMIES 



Starf-sh. — An investigation for the c(mtrol and elimination of 

 .starfish on oyster beds in Long Island Sound, N. Y., where it is the 

 most serious natural enemy of the oyster, was carried out from June 

 to September by Miss Louise Palmer. The life history and growth 

 of the animal were studied, and a series of experiments was carried 

 out to ascertain the susceptibility of starfish of different ages to 

 various chemical substances. It has been found that starfish of Cold 

 Spring Harbor. Long Island, spawn the first and second weeks of 

 July and set on the grass and shells the first or second week of 

 August. The spawning temperature varies from 23.5° to 26° C. 

 (74° to 79° F.). 



The minute stars are very destructive to the newly set oysters, 

 and consequently are objects of special consideration for eradica- 

 tion. L^nfortunately, starfish are not very sensitive to environmen- 

 tal changes or the presence of toxic substances. It has been found, 

 however, that concentrations of copper sulphate from 20 to 150 parts 

 per million, while not affecting young oysters are very effective in 

 killing starfish. This effect is not dependent on temperature. The 

 study of the methods of controlling starfish will be continued, and 

 it is hoped that a practical solution of the problem will be found. 



The oyster drill. — A study of the biology of the oyster drill, car- 

 ried on at Beaufort, N. C, by Dr. Henry Federighi since 1926, has 

 been completed, and the report was submitted for publication. The 

 results of this investigation made possible the recommendation of 

 certain measures to control this destructive species, some of which 

 had already been mentioned in previous reports. A new method of 

 catching drills has been developed and successfully tested at Beau- 

 fort. It consists in using small concrete pillars, which are placed 

 on the infested oyster bottom. Because of the tendency of the drills 

 to creep upward, the animals gather on the pillars and are then 

 taken out and destroyed. Pillars of the size of 12 by 10 inches have 

 ■collected as many as 500 drills in 3 days. 



FRESH- WATER MUSSEL INVESTIGATIONS 



Mussel cultmre. — The new system of nuissel culture worked out 

 for the bureau by Dr. M. M. Ellis at the Fairport station during the 

 summer season, and at the University of Missouri under the super- 

 vision of the bureau cUu'ing the college' year, has made the advances 



