30 relejises at the inner-bay station (fig. 

 11). It is apparent that no single surface 

 circulation could have existed throughout 

 the summer and fall seasons to give such a 

 pattern of recoveries. On the June 7 (fig. 

 21 A) and August 10 (fig. 43 A) releases, 

 the direction of drift was to the northeast, 

 presumably resulting from prevailing south- 

 west winds at these times. Two days after 

 10 bottles were released on October 30 

 (fig. 68 A), moderate northeast winds caused 

 currents that carried all but 3 of the bot- 

 tles ashore to the southwest. 



The 27 recoveries from the 30 releases 

 at a mid-bay station show a greater disper- 

 sion than those recovered from the releases 

 at the inner-bay station (fig. 12). Subse- 

 quent to June 7, at which time 10 bottles 

 were released, the net wind vector was to 

 the north. The resulting water movement 

 accounts for the recovery of the 2 bottles 



found to the north of the release point 

 (fig. 23 B). The 7 bottles recovered at 

 least 49 days after release to the east and 

 southeast appear to have drifted in this 

 direction because of the net winds to the 

 southeast for the period of time they were 

 adrift (fig. 23 B). The 8 recoveries from 

 the 10 releases on August 10 were to the 

 east and southeast (fig. 45 B). The net 

 wind vector for the period of time these 

 bottles were drifting was to the east. The 

 10 bottles released on October 30 landed to 

 the northwest of their release point (fig. 

 69 C). Apparently these bottles were car- 

 ried with water moved by the winds that 

 blew the day of and the day after release. 



The 60 recoveries of 80 bottles re- 

 leased from ein outer-bay station substan- 

 tiate the theory that surface-current flow 

 was unstable during this study (fig. 13). 

 Recoveries from releases at this station 



41 MILES 



ABOVE PORT 



HURON 



STATUTE MILES 



Figure 11. — Location of 19 recoveries from 

 30 drift bottles released at an inner 

 Saginaw Bay station. Ten releases were 

 made on June 7, Aigust 10, and October 30, 

 1956. A triangle shows release point; 

 X's mark recovery points. 



Figure 12. — Location of 27 recoveries from 

 30 drift bottles released at a middle 

 Saginaw Bay station. Ten releases were 

 made on June 7, August 10, and October 30, 

 1956. A triangle shows release point; 

 X's mark recovery points. 



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