15 



Tlie saiuc i)r()l()iiLi;ili()n of llic l)i'fc(lin</ sfiisnn hi-yoiul its 

 i;su;il limits was ohsfrvi'd at sfViM-al (illicr points aloiiy- tlic coast 

 during'' the i)ast season. In Vermilion liay, where there were 

 heavy t'resliets durinji' tlie i)ast spring', the oystei's were breed- 

 inn- in llio latter ])art of' October and in the cai-ly part ol' Xo- 

 vendjer, while youiiii' oysters of a size such as would have Ix'en 

 normal for spat set in the spring were found oidy occasionally. 

 On the reefs in the open gulf near-by, whei-e the effects of the 

 licshets were not felt to any great extent, young oysters were 

 1 -resent whose si/.e showed plainly that they had settled at the 

 tinu' of the usual breeding season in the spring. 



TRANSFER OF SPAT. 



v 



A definite answer to the (piestion of how far an oyster em- 

 bryo nuiy travel during its active free-swimming state would be 

 of iuunense value to the oyster culturist, both as concerns the 

 recovery of beds depleted by freshets or other destructive agents 

 and also as affording a l)asis from which to calculate the j)roba- 

 bility of obtaining a set of spat on clutch exposed on liottmns 

 at a distance from any natural reefs. The principal factor that 

 detei-mines the disti'ibution of the fry is nndoubtedly the cur- 

 rents in the water, the activity of the endjryo itself never being 

 sufficient to offset even a comparatively weak current. Judging 

 from the time that oyster embryos, secured by artificial fcM-filiza- 

 tion of the eggs, are known to keep moving about actively, it is 

 safe to assume that under favorable conditions the embryos 

 might be carried for long distances from the point where the 

 (ggs were fertilized. 



The conditions that existed at Cameron during the past 

 season made it possible for one to give a definite statement that, 

 under conditions by no means especially favorable, oyster em- 

 bryos may be carried at least four miles. 



As was mentioned earlier in this report, it was shown con- 

 clusively that there were no living adult oysters yi the pass 

 above Leesburg during the latter part of June; so all the spat 

 for the new growth must have come from reefs in the lower part 

 of the pass. Tliese reefs are at least four miles from the one 

 nearest the lake at the head of the pass. The presence of spat 



