96 



U, S. BUEEAU OF FISHERIES 



April, 1929, most of the Duplin River brush planted in the summer 

 of 1928 from low "water to 18 inches above low water, was solidly 

 covered with 03'sters about 4 centimeters (l^/^ inches) loni?. The suc- 

 cess of the Duplin River brush ma^'^ be attributed to the fact that 

 this river is a " dead " river in that it ends in salt marsh and has no 

 supply of fresh water at its head, so that the freshet of August, 1928, 

 probably had but slight effect on this region. 



The catch of 03'sters on the larger pieces of brush was decidedly 

 better than on the smaller branches and twigs, but the counts of 

 oysters on the pieces of brush measuring from ly^ to 1% inches in 

 diameter have shown that within these limits no one size was better 

 (ium any other. Whether or not the density of packing of the brush 

 would increase the collecting capacity of the small branches and 

 twigs should be determined by further experiment. 



75 



^ 50 



o 



uJ 

 CD 



25 



^ ■ ' ' I ■ ' ' ' I ' 



15 30 45 60 



UNGTH MM 



Figure 21. — Length of oysters grown on brush, Duplin River, May, 1929 



75 



The observations at Duplin River also show clearly that oak brush 

 is far better than sassafras brush of the same size and position. 

 Examination of the whole line of brush failed to disclose a single 

 piece of sassafras brush with oysters caught upon it. 



Experiments with various types of collectors planted in the vicin- 

 ity of Doboy Island have demonstrated that the best results in 

 catching spat can be obtained with chicken-wire bags filled with 

 shells. A full description of this collector and the method of using 

 it is given in United States Fisheries Document 1076, by H. F. 

 Prytherch, 1930. Because of its low cost and ease of handling 

 antl transportation, the wire-bag collector must be regarded as far 

 superior to any kind of brush, although the latter type of collector 

 can be used in certain localities where there is a good supply of 

 brush and where it can be obtained at low price. 



SIZE OF OYSTERS AT TWO YEARS OF AGE 



An opportunity presented itself to examine oysters from brush 

 planted in the summer of 1927 on the south side of North River near 



