INVESTIGATION OF OYSTER SPAWNING, ETC., MILFORD, CONN. 477 



Table 12. — Approximate number of liters of water filtered by an average oy.iler in Milford Harbor 



[S= successful setting; F^faiiure in setting] 



In comparing the various years, we find that when spawning and setting were 

 successful, each oyster filtered from 200 to 500 hters of water more during the 4-month 



LITERS 

 3200 



AT NORMAL T£MP5. I3^^ 



1923 



1925 



1926 



1927 



1924 

 rEARS 

 Figure 29.— Approiimate tiuantity of water filtered monthly by an average oyster previous to the time of 

 spawning. The quantity (iltereJ dui'ing the years 1922 to 1927 is shown in comparison with the quantity 

 that would be filtered under normal water-temperature conditions 



period than it did during the years when spawning apparently was a failure. The 

 difference ifi total quantity of water filtered each year is shown clearly in Figure 29. 



