PEOGEESS IN BIOLOGICAL INQUIEIES, 192 9 1113 



by previous investigations to (lepcnd hir^'oly upon clinuitological and 

 hydrographic conditions in this region, it became evident that addi- 

 tional records and observations wouhl have to be made each year to 

 assist the industry in its oyster cultural operations and to increase 

 our knowledge and understanding of the controlling factors. For 

 this purpose, several cruises were made in cooperation with the State 

 Shellfish Commission of Connecticut and the Connecticut Oyster 

 Farms Co. to secure data as to the temperature and salinity of the 

 water, the abundance of adult oysters, and especially the quantity of 

 spawn which they had developed. The average air temperature dur- 

 ing the spring and early summer months was 4.3° F. above normal, 

 and could be correlated as in jn-evious similar years with the produc- 

 tion of a large quantity of eggs in the reproductive organs of the oys- 

 ter. The sunnner was exceptional, however, in tv^^o respects ; that is, the 

 discharge of fresh water from the rivers into Long Island Sound 

 was the lowest that it had been in several decades, and the spawning 

 and setting of oysters w'as over a month later than usual. Water 

 temperatures Avere favorable for oyster spawning the latter part of 

 July, Avhich is the usual time ; but this event did not take place until 

 nearly the middle of August, when the salinity was reduced by 

 heavy rains on August 11 and 12. The development and setting of 

 the oyster larvae Avas also greatly retarded and covered a period of 

 over 30 days, which is twice as long as any that had been recorded 

 previously. 



A cruise was made from Xew Haven Harbor to Black Rock Harbor 

 for the examination of shell plantings, which showed that a light 

 set had occurred on September 14 to 18 and that it w\as widely dis- 

 tributed OA'er both inshore and offshore beds. 



In April Dr. R. H. Luce, temporary assistant, made hydrographi- 

 cal observations in tidal rivers near Doboy Island, and collected and 

 examined the spat collectors (brush) which were planted there in 

 the summer of 1928. These observations have shown that oak brush 

 may be used as an excellent spat collector and that the catch of 

 oysters on the larger pieces of brush (3 to 6 centimeters, ll^ to 21/2 

 inches, in diameter) was decidedly better than on the smaller 

 branches and twngs. Of the brush planted in three diiferent locali- 

 ties in the Doboy Island region, one planting (Duplin River) w^as 

 very successful, one (North River) failed completely to catch oysters, 

 w^iile the third one (Doboy Island) caught but a small number of 

 spat. An analj'sis of h5'^drographical conditions show^s that the fail- 

 ure of plantings of 1928 in North River and Doboy Island can hardly 

 be attributed to any other factor than the unusual amount of fresh 

 water in this region from the middle of August through September. 

 The success of the Duplin River brush mav 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 did not affect it. 



In cooperation with the State Game, Fish, and Oyster Commis- 

 sion of Texas, Dr. A. E. Hopkins made, during the spring and 



