PROGRESS IN" BIOLOGICAL INQUIRIES 23 



about 2 feet above low-water mark. Third, that the horizontal dis- 

 tribution in the vicinity of Milford was from the deep-water beds 2 

 miles offshore to areas in the harbor that are covered after the first 

 two hours' run of the flood tide. Fourth, that the greatest concentra- 

 tion of spat per square inch was found in a zone 10 to 12 inches 

 above low-water mark. Records of the rate of growth of the spat 

 under various conditions were made from July 18 to September 20. 



Environmental conditions.- — Six stations located in Milford Harbor 

 and the adjacent inshore waters of Long Island Sound were regularly 

 visited, and observations of general hydrographic conditions were 

 made. Water temperatures were unusually high, ranging from 20° 

 to 25° C. on the bottom from July 15 to August 20, and attained a 

 maximum ebb-tide temperature of 29° C. in the harbor on August 

 19. The salinity ranged from 25 in June to 26 and 27 during July 

 and the first part of August, a marked increase occurring the last two 

 weeks in August, when there was very little rainfall. The hydrogen- 

 ion concentration was determined by the prism-comparator method 

 using cresol red and brom-thymol blue as indicators. 



Commercial oyster culture. — The best and most general set of oys- 

 ters since 1914 was obtained in 1925 throughout the oyster-growing 

 region of Connecticut with the aid of unusally favorable weather and 

 water conditions. At the present time a set of commercial value in 

 these waters depends upon the early ripening and spawning of the 

 oysters on the inshore and offshore beds of Long Island Sound, as 

 these are the only ones large enough to produce a sufficient quantity 

 of spawn. In the past when the oyster industry succeeded in obtain- 

 ing a crop of oysters almost every year, large, natural beds were 

 situated in the harbors, bays, and river mouths, where conditions 

 were favorable for the production of large quantities of spawn. To- 

 day almost all of these valuable spawn-producing and shellfish-grow- 

 ing areas have been destroyed by excessive pollution and overfishing, 

 so that only the deep-water beds are left for the production of seed 

 oysters. 



When conditions existing on these deep-water beds in spring and 

 summer are such as would ordinarly exist in the harbors and estua- 

 ries, oyster culture is successful, but unfortunately this happens 

 rarely. The climatic and hydrographic records for the summer of 1925 

 reveal that precipitation, river discharge, air and water temperatures, 

 and salinity were unusual and produced the desired harborlike con- 

 ditions in the sound, which resulted in successful deep-water oyster 

 culture. The State of Connecticut recently passed an act creating a 

 State water commission with power to enforce the adoption of reason- 

 able and practical measures for controlling, reducing, and eliminating 

 pollution. No greater improvement could be made for maintaining 

 and increasing the oyster supply of Connecticut than the restoration 

 of its harbors and rivers. N 



CLAMS OF THE PACIFIC COAST 



During 1925 the clam investigations on the Pacific coast were con- 

 tinued by Dr. F. W. Weymouth, of Stanford University, and H. C. 

 McMillin, scientific assistant. Field work was carried on from April 

 to September, during which time two months were spent on the 

 Washington beds getting more exact spawning data and records of 



