No monetary rewards were offered in 

 this study since remarks on returns of cards 

 released in Lake Michigan in 1954-55 clearly 

 indicated that finders were more interested 

 in learning when and where bottles were 

 released than in remuneration. Inquiry in 

 shore areas showed that once a bottle was 

 found word spread fast in the vicinity and 

 searching for them quickly became a loccil 

 pastime, merely for the satisfaction of 

 finding a bottle that had drifted from an 

 unknown point and for the feeling of parti- 

 cipating in a scientific study. Business 

 reply cards were used in this study so no 

 postage was required when they were mailed 

 in the United States. Where return of a 



STATUTE MILES 



Figure 4. — Drift bottles released at 42 stations in 

 Saginaw Bay and Lake Huron during 1956 and rela- 

 tive abundance of recoveries along the shoreline. 

 Triangles indicate stations where 30 bottles were 

 released, squares 40 bottles, X*s 80 bottles, zuid 

 circles 160 bottles. 



card was at the expense of the finder, as 

 viftien these cards were mailed in Canada, the 

 sender was returned the postage due him. A 

 letter was sent to the finder of every bot- 

 tle telling of the time, place, and purpose 

 of release. Any postcige due the finder, 

 was included with this letter. 



RELEASES AND RECOVERIES 



From June 5, 1956, until November 14, 

 1956, during nine cruises of the Fish and 

 Wildlife Service research vessel Cisco , 

 2,200 drift bottles were released at 27 dif- 

 ferent stations on Saginaw Bay and adjacent 

 areas of Lake Huron. In addi- 

 tion, on three synoptic sur- 

 veys of Saginaw Bay on June 7, 

 August 10, and October 30, 1956, 

 the Fish and Wildlife Service 

 research vessel Musky and a 

 Michigan Department of Conser- 

 vation patrol boat dropped an 

 additional 450 bottles at 15 

 different stations. Altogether, 

 2,650 bottles were released at 

 42 stations (fig. 4). In Sagi- 

 naw Bay the distance from any 

 one point to a release point 

 did not exceed 6 miles. Re- 

 leases were more widely spaced 

 in the adjacent waters of Lake 

 Huron. It was not the intent 

 of the investigation to make 

 an intensive study of Lake 

 Huron proper; rather we wished 

 to study Saginaw Bay and its 

 relation to the lake. 



It is common in drift- 

 bottle work to receive reply 

 cards from bottles recovered 

 months and even years Eifter 

 the date of release. The value 

 of a recovery in the determina- 

 tion of currents decreases the 

 longer the bottle is out in 

 excess of actual drifting time. 

 In areas where ice forms yearly, 

 the possible effects of the 

 spring ice breakup upon bottle 

 movements preclude sensible 

 analysis. To eliminate the 

 latter problem and to eliminate 

 other questionable records, 

 bottles recovered after Febru- 

 ary 28, 1957, were not used in 

 analysis. As of that date. 



